El34 Grid Voltage

HIFI AMP Stereo Vacuum Tubes 500V Secondary Grid Voltage EL34 PSVANE Hifi Tube EL34PH. d = Diode Unit. Kt88 tube amp schematic. EL34 Datasheet - Vacuum Tube of Power Pentode - Philips ; EL34 is a glass envelope power pentode having a plate dissipation rating of 25 Watts with convection cooling. Skip to Search Skip to main content. Here is the latest on the screen grid resister problems with the XXX and now the JSX amps. Fixed biasing actually means a negative voltage externally applied to the grid which can be adjusted In 1965 I was 13 years old and hopelessly hooked on music and vacuum tube amplifiers. The only price we pay is a 20% reduction in amplification, so that (at least to me) is acceptable. You said: "G3 in an EL34 is better tied to the negative bias supply rather than ground. It can tolerate a higher plate voltage anyway. Product Description 100% Brand New and High Quality Electronic tube amplifier DIY adjustablenegative grid bias power supply board, single-ended and push-pull can be used. Because it has an extra grid in it for more power, they provided a unique distortion tone that became the very distinct Marshall sound!. Pentode and beam power tubes add an additional electrode between the screen grid and plate to reduce the occurrence of secondary emissions. This tube is truly a mouse that roared, as it can handle 12 watts on the plate at 300 volts, and 300 volts on the screen at 2 watts! The early Beatles music was. This will never be true due to non-linearities. In these calculations, 5% of the cathode current is assumed to be screen current. Looking at the plate current vs plate voltage curve with grid voltage plots, the EL34 is pretty linear at 440 to 480 VDC. Made by Mullard in the ‘60s, it was the stock tube in all the early Marshall and HIWATT amps. By turning this control, the bias and current through the. 2 DC (screen) dissipation 8 W Bulb temperature (surface hottest point) 250˚ C SED SVEL34 High Performance Audio Power Pentode Est. The bias voltage is 43 V @ 100 and 3. Due to increased demand, some orders may experience a slight delay. 07% which is an excellent measured result for most SE amps, and I the grid bias voltage ceases to control the Ia flow. 6mm, size 120 × 47mm. By applying a signal to the grid it causes a current to flow from the cathode to the plate. So, we apply a BIAS voltage to the grid. The wide frequency response of this tube offers excellent harmonics that work in a variety of genres ranging from the cleanest cleans to rich and aggressive breakup. 19 September 2014. Because this amp has the Hazen Grid Mod that activates only when EL34s are used, we ship the amp with top grade EL34/6CA7s that have been fully tested IN the amplifier. Tetrode: EL34-B. The Laney LA30BL 30W head comes loaded with a classic tube complement of three 12AX7 preamp tubes and two EL34 power-amp tubes. 6V6 and 6L6 are "low-ish Gm" when compared to EL34 and EL84. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. Place a guitar signal voltage on the control grid and the guitar signal will control the flow and the tube's output will be the amplified guitar signal. With a gold-plated molybdenum alloy grid and carbon-coated screen grid, the EL34 is the finest power tube of its type being manufactured today. You may also like 4 * RFT EL84/6BQ5 Vintage Power Pentode Audio Radio Valves Tubes Made in. With a more modern British-style sound thanks to EL34 power tubes, the 5150III EL34 head yields smooth contours, great sag and saturation than heads loaded with 6L6 tubes! Independent volume and gain control for. The above picture: 7027A RCA tall bottle in action with 5AS4 GE and 6201 Philips driver. The Laney PA60 is the same as the Supergroup and similar to some early Marshall amps, and a few other amps such as. The EL34 was introduced in 1949 by Phillips (parent company of Mullard), who owned the pentode patent at that time. In position 2, the heater voltage to power the meter on so you can test tube hot and cold on a possible closure between the electrodes. Carefully adjusting the bias voltage, the following waveform is seen. It is in fact the voltage gain of any tube where a grid causes anode voltage change without any current change. The EL34 being a pentode, the designer has a choice about the biasing of its screen grid: either to connect it to the B+ voltage to give conventional pentode operation (footnote 4), or to use the "Ultralinear" connection thought up by David Hafler and H. Legendary winged "C" selected from the original Svetlana production The Svetlana EL34 is very dependable and our recommended choice for combos. Without knowing exactly the ability of the power transformer to deliver that extra ampere without overheating - it is hard to say yes, go ahead. Assembly Manual • Schematic • Parts List • Tubes and Applications. Electronic Vacuum Tube. 0 w lload 32 25 % _ - mullard - may 1962 ' page d3 el9i output pentode design centre ratings , current plotted against control-grid voltage with screen-grid voltage as parameter may 1942 | mullard , control-grid voltage as parameter. The Telefunken Black Diamond Series EL34-TK Power Amp Vacuums Tubes has been designed to handle a slightly higher grid voltage than the traditional EL34. the KT88's. The JJ Electronic E34L adds more power to a standard EL34 due to its higher grid voltage rating. PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH SEPARATE ANODE AND SCREEN-GRID VOLTAGE SUPPLIES AND FIXED BIAS V"(b)=SOOV, Vg2(b)=400V @ ISSUE 2 EL34 256-13. All I can do is to assume it is the same. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34. This can lead to copious amounts of 'preamp overdrive'. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. (60% = 15 watts; 70% = 17. HIFI AMP Stereo Vacuum Tubes 500V Secondary Grid Voltage EL34 PSVANE Hifi Tube EL34PH. The pa21 has two gain stages, with the 6SN7s providing the input stage and the KT88's at the output stage. Ef86 transconductance. Here is a design for a valve based, stereo audio-amplifier, not using valves types which are expensive to procure because of their esteemed nature in performance and purity of sound for music reproduction, guitar amplifiers etc. 1 on pin 1. signal power output (not less than) total harmonic. This is known as the grid bias of your amp. Phase splitters are like religions, you belong to one or another and discussions between fans are often emotional. Both the Clean and Crunch channels feature independent three-band EQ, plus channel volume and preamp gain controls so guitarists can adjust the interplay between the preamp and power amp on each channel for an array of gain possibilities. With a slightly higher grid voltage (-13. 5 watts) Divide your desired wattage by your plate voltage from step 3. 6mm, size 120 × 47mm. The EL34, the CLASSIC British tone, loved by many. The transformer from ENIGMAoustics Lab provides 43% ultra linear tap to travel through a 100 ohms resistor to grid 2 of EL34, and the signal input at grid 1 is also. It suppresses the secondary emission where high energy electrons hitting the anode at high speed have. mu power triode preamp, this isn’t too much of an issue; the output swing is only a few volts, and the triode can be happily run at low plate voltage, leaving more of the available power supply volt-age to drop across the CCSs. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. Page 1 of 3 1 2 3 (or 6L6GC/EL34/etc) uses 1k5 1W <- One watt! Lets find out. This is a single power amplifier using natural sounding and powerful 6L6GC tubes. A tetrode my be compared to a cascode connected pair of triodes: Since the upper cascode cathode current is equal to the lower plate current, these elements can be removed…The electrons flow as well in vacuum as they do in metal. I would have expected it to float up to near the anode voltage. If you are compulsive (like me), you get screen grid current by measuring the voltage drop across the screen grid resistor and then dividing that voltage by the value (resistance) of the screen grid resistor. PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH SEPARATE ANODE AND SCREEN-GRID VOLTAGE SUPPLIES AND FIXED BIAS V"(b)=SOOV, Vg2(b)=400V @ ISSUE 2 EL34 256-13. SUBSCRIPTS FOR MULTI-UNIT TUBES: b = Beam Power Unit. Find many great new & used options and get the best deals for EL34/300B Push-pull Tube Amp 4 Ways Negative Pressure Grid Adjustable Circuit at the best online prices at eBay! Free shipping for many products!. Since TubeDepot is in Memphis, TN, the home and main hub for FedEx and USPS, we get very good rates, so rest assured your heavy item will be shipped at the most affordable rates. 6V6 and 6L6 are "low-ish Gm" when compared to EL34 and EL84. Even worse, the effect only occurs on one side of the anode voltage swing (towards low Ea and high Ia) but not when the anode swings in the opposite direction (high Ea, low Ia). The 6L6 maxes out around 50-60W push-pull, while the EL34 can get as high as 70W, and some would claim 100W in push-pull. JJ Electronic E34L Factory Data Sheet: E34L Factory description: Gold plated control grid for improved fidelity. Now I'm putting it back to it's original 6550 specs and it isn't. http://www. If it is connected by either a wire or a resistor to the driving circuit, it is direct coupled and the high grid voltage is not a defect. Tube requires octal socket. This tube features a rugged construction leading to an incredibly reliable EL34 with astonishing tone. On all 6L6 types, the suppressor grid is connected internally to the cathode, Pin 8. Actually there are only two different test cases you can perform. And, as expected, the gm increased as the plate current increased. Electra Fidelity "EL34" for sale. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34. Untuk percobaan ini, saya masih memakai OPT dari Power Trafo dengan cara apa adanya. The idea is to modulate it by varying the negative polarity of the suppressor grid (g3). I am a bit EL34 fan and find a nice balance in that tube of SET-esque richness and modern linearity. The difference is in the range of 3-4 mA plate current. sciencewriter. 250 V Grid 1 Voltage. The KT77 is an interesting tube and is a drop-in substitute for the EL34. This model includes a footswitchable pre-amp Boost for an authentic classic rock and indie rhythm tone and articulately powerful blues leads. where I P is plate current, E G is control grid voltage, E P is plate voltage, E G2 is screen grid voltage (all voltages with respect to the cathode), µ is the amplification factor, and k G1 is a factor used to fit the equation to data. 5 volts) than the traditional EL34 vacuum tube. 5 volts) than the traditional EL34 vacuum tube. We set this voltage so the current to the plate is a tolerable IDLE current. pretty easily. Laney PA60 Screen Grid 3 Voltage Taming the grid 3 voltage to the EL34 valves. The Stealth 60i is designed to run the EL34 output tubes at a cathode (combined plate and screen grid) current of 100 mA per pair. The figure below shows the Marshall JMP50 Model 1987 grid bias supply circuit. Just like the idle of your car may need adjusting when a major change is done to the engine, new power tubes need their idle (the "bias") adjusted to make sure the amp sounds as good as possible. It tends to push vocals forward. Mullard produced this tube for nearly 15 years, and GT chose the classic XF2 dual getter version as the best e. The pentode equation differs from the triode equation in that the screen grid replaces the plate as a controlling element, and an arctangent term (from Scott. Indeed, we are getting our cake and eating it too. The Stealth 60i is designed to run the EL34 output tubes at a cathode (combined plate and screen grid) current of 100 mA per pair. Find many great new & used options and get the best deals for 4-Way Tube Amp Negative Grid Bias Power Supply Adjustable for EL34/300B PP or SE at the best online prices at eBay! Free shipping for many products!. On behalf of the Australian Government, the Australian Renewable Energy Agency (ARENA) has today announced $900,000 in funding to Victorian distribution business United Energy to trial delivering grid stability services through voltage-reduction demand response capabilities on their electricity distribution network. The Tube Center is dedicated to providing Ham radio, amateur radio operators, antique radio enthusiasts, audio professionals and hobbyists the ability to choose from an inventory of over 3. EL34-B belongs to tetrode tube compared to pentode tude of EL34A. Heater voltage Vf 6,3 (V) Heater current If 1,5 (A). Some amplifiers don't have a bias-adjusting control (pot) but instead use a fixed resistor to set the voltage. Classic circuit, AC 60V ~ 80V power supply, full bridge rectifier, secondary filtering, 200V filter electrolytic assembly, imports of domestic metal film resistors or high quality domestic. A failed biasing component that lets the grid assume the same voltage as the cathode will cause an output tube to act almost shorted. You will, as mentioned, need to sort out the bias for the EL34. Since voltage gain is directly proportional to transconductance, the EL34 would have about 2. Here is the latest on the screen grid resister problems with the XXX and now the JSX amps. In general, the grid resistor at the grid of the power tubes can be as high as 56K to 100K before any noticeable loss of high frequencies occurs. Quality high temperature alloys are used for the anodes resulting in a reliable and high performance valve. I didn't dime the volume but played them pretty loud and soft. A EL34 screen grid will over dissipate if you leave the 470 ohm in place. 6mm, size 120 × 47mm. Suppose we are using EL34 vacuum tubes, since the grid voltage peak of an EL34 vacuum tube is around 35V, which is much larger than 0. The E34L is a special low grid voltage version and is not always interchangeable. 5AR4 / GZ34. An extremely faithful reissue of the XF2 Mullard EL34 from the 1960’s. Heater-cathode type used as af power amplifier and modulator and as rf power amplifier and oscillator. The max voltage rating of the capacitor used for the lag-lead compensator is important. If they are biased incorrectly or if there is a fault in one of the biasing components, it can cause a number of power supply and output section problems. The other possibility is that you could lower the 1K screen resistors to 470ohm (since the screens are a little less fragile, and less prone to drawing high currents), but the 1K's are quite useful to leave in place, since provided you have enough range on your bias pot for EL34's as well as 6550's, the 150K grid stoppers will still work with. The JJ Electronic E34L adds more power to a standard EL34 due to its higher grid voltage rating. With three EL34 output tubes and an idle current of about 160mA, we can expect about. the mu quoted on the datasheet when operating in triode mode. Realize when you adjust the bias screw your not adjusting the actual voltage you read at the test point you are adjusting a voltage applied to the control grid of the tube that causes the test point voltage to change. Find many great new & used options and get the best deals for 4-Way Tube Amp Negative Grid Bias Power Supply Adjustable for EL34/300B PP or SE at the best online prices at eBay! Free shipping for many products!. The amplifier is directly coupled to a cathode follower which is required to drive the 47 k ohm grid resistors of the output tubes. Laney PA60 Screen Grid 3 Voltage Taming the grid 3 voltage to the EL34 valves. 2 DC (screen) dissipation 8 W Bulb temperature (surface hottest point) 250˚ C SED SVEL34 High Performance Audio Power Pentode Est. 100 watts with two KT88 is also push-pull. Specifically designed for audio amplification, the KT88 has similar ratings to the American 6550 which was designed for use as a servo amplifier. The 6CA7 is the US designation for the EL34 and is complete interchangeable. In contrast to the 6L6 beam tetrode, the EL34 is a true pentode vacuum tube. This amplifier was originally featured on the February 2003 Issue of the "High-Fidelity Audio: Radio Technology" by Mr. The EL34 was introduced in 1949 by Phillips (parent company of Mullard), who owned the pentode patent at that time. (d) The power output is calculated as though you are generating a pure sine wave. Great tone and very rugged. THE NATIONAL GRID. EL34 being the European hi fi tube, specifically made for music. The clear and harmonic open top end allows for great clean tone and at the same time the TAD EL34B-STR offers incredibly powerful mids and equally powerful bass. EL34 PP @ 375 plate, pentode mode, 3K5 OT Cathode bias app. Winged C EL34 price from reliable sources are actually pretty close to that of the RFT/Siemens EL34. 100 watts with two KT88 is also push-pull. One key point is that the EL34 output tube is being used as a triode, not a pentode. 2 DC (screen) dissipation 8 W Bulb temperature (surface hottest point) 250˚ C SED SVEL34 High Performance Audio Power Pentode Est. The EL34 version captures all of the midrange liquidity that it is famous for. Re: Amp biasing question -- Bogner EL34 Shiva Guys, at the risk of stating the obvious, there is no magic current (milliamps) for a specific tube type. Certain assumptions may be made as long as the power output of an amp is known: A 50 watt amp with two 6L6 or EL34 tubes, or a 100 watt amp with four 6L6 or EL34s, is a push-pull amp. In the case of an EL34 the grid 3 is connected to pin 1. Of course we know that modern tubes are not as rugged as vintage tubes were, so they don't tolerate higher voltage/ current as well. 243 data points taken by the tester and used to produce this chart in open office. :) A EL34 is also a very popular power tube for many amplifiers. JJ Electronic E34L Factory Data Sheet: E34L Factory description: Gold plated control grid for improved fidelity. By applying a signal to the grid it causes a current to flow from the cathode to the plate. ‘Properly’ biased Marshall cannot achieve ‘extra’ output power, but the tone will definitely improve. Filament voltage *5. airtime Super. 2 Vrms input to the EL34 grid so anyone may try all this without adding yet another input tube V1. 5 vs -10 to -13. Adjust RV1 for MAXIMUM negative voltage reading. You will, as mentioned, need to sort out the bias for the EL34. Premium high-voltage power pentode. [Features] - Comes with 6L6GC power tubes, but also supports wide range of power tubes, such as KT88, KT90, KT66, EL34, etc. What is Class A and how does it differ from Class AB? The following is extracted from an Article - Class 'A' Exposed and Explained - written in 2005 by MESA Founder, Randall Smith. Many amps which use "fixed" (negative grid) bias have provisions for adjusting the negative grid voltage upward or downward. 5 volts) than the traditional EL34 vacuum tube. The bias for 250-volt, push-pull operation is -15 volts. It is intended for ultra linear audio frequency power amplification service. Laney PA60 Screen Grid 3 Voltage Taming the grid 3 voltage to the EL34 valves. Less plate current means higher negative bias to grid, it can be have more ability to suppress the unstable status, also if supply voltage Vsg of screen grid too high will causung this problems, El34. Why Should I Match My Tubes? the power tube conducts a certain amount of plate current depending on the amount of plate voltage and control grid voltage we apply to it. This is a simple tube tester which is based on a schematic published in the middle 50's in a Polish radio amateur magazine. Svetlana EL34/6CA7 High Performance Audio Power Pentode Typical Operation AF Power Amplifier, Class Al (single tube) Plate Voltage Grid 2 reen Oltage ntrol Voltage* rid I Peak AF Grid 1 Control Voltage ero Signa Plate Current Maximum Signal late urrent ero ignal Grid 2 Screen urrent avg Transconductance nominal) Load esistance. Since voltage gain is directly proportional to transconductance, the EL34 would have about 2. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. These models were designed for 6550s, and can also accept KT88s or EL34s. At normal listening levels of 1W, THD can be expected to be 0. The EL34 is biased at 65mA and 300V, with a grid voltage of about -25V, by the IXCP10M45S and the 383 ohm cathode resistor. Best el84 tubes for metal. EL34 output tubes may be substituted with the following: KT77, 6550 KT66 KT88 6L6s, 7027 and with a socket adapter, 807. EL34 Tube Overheats by scuba100 on Wed Jun 27, 2012 11:08 am I have a modified ST70 with solid state rectifier and on two occasions I have had a single EL34 tube get red hot and the bias voltage to spike. Speakers are 80's Infinity RS6. 0 w lload 32 25 % _ - mullard - may 1962 ' page d3 el9i output pentode design centre ratings , current plotted against control-grid voltage with screen-grid voltage as parameter may 1942 | mullard , control-grid voltage as parameter. many 300B SE does't get "real 300B tone's" even power does't reach 8W rms and frequency response are narrow. Just like the idle of your car may need adjusting when a major change is done to the engine, new power tubes need their idle (the "bias") adjusted to make sure the amp sounds as good as possible. 5 vs -10 to -13. Another component, called a control grid, is placed between the anode and the cathode, and it looks like a mesh or screen. Still used in many amps that Marshall produces today, the EL34 is a Marshall favourite, when creating the first Marshall amplifiers these were used in the place of the 6L6. Increasing or decreasing that voltage by a small amount will affect the amount of current drawn by the anode. To be more exact, the potential difference between the cathode and the grid controls the dynamic resistance of the plate-cathode circuit. ) R1-R3 = Low: Early distortion, wid. It has an international octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of audio amplification circuits and was designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. 2 power, heater power, and air flow may be removed s imu1taneous1y. EL34 excels at reproducing horns and female vocals, with silky smooth texture. Lead connection is via 10 bottom mounted lugs. Here each KT88 is wired as a triode by having the screen grid connected to the plate via a current-limiting resistor. It is intended for ultra linear audio frequency power amplification service. Mullard gives 800V anode 400V screen-39V grid Power (push/pull pair) 100W. It tends to push vocals forward. Designed to handle a slightly higher grid voltage than a traditional EL34 Great for guitar amplifiers and hi-fi equipment Smaller in diameter and taller than a 6L6, and capable of a higher plate voltage Commonly used in pairs in a Class-AB1 push-pull configuration Each tube is meticulously measured for all critical parameters of performance. The "trans" in transconductance describes a change in conductance. HIFI Valve Electronic Vacuum Tube Amplifier Current 2. 5 watts is 70%. The control grid is placed between the cathode and plate and is given a negative voltage to repel electrons and restrict their flow to the plate. G1 Bias Negative voltage to achieve a 50 mA cathode current at a given screen voltage GM Transconductance at 50 mA cathode current in micromhos. Re: Voltage recomendaions for EL34 RFT's Post by Jerry G » Sun Jul 27, 2014 4:02 pm I remember looking at the reference information when I bought these and according to the performance chart (if that is what you call them) it should be capable of much higher plate voltages. at full rated power (+/- 1 db max. 19 September 2014. The difference though is that the 6L6's 5th element is a beam-forming plate (that focuses the eletrons flowing through the tube, kinda steers them) and the EL34 has a suppressor grid (which attracts stray electrons that missed the cathode). The complete schematic to implement the separated grid voltage could be found here. Grid resistors will limit the screen current (and cut the power somewhat). Slightly higher grid voltage (-13. Fig 8A, EL34 pentode, small signal amp stage, use and properties. The 6CA7 is technically a different tube and has a bit more of an American tone as well as being much fatter. I just wanted to address, if you pull all the tubes (assuming your filter caps are rated to take a jump in voltage) is the hum still there?. It doesn't work with cheap phony imitations which are made by the same companies as the better ones that can often be recognized by their impressive vacuum envelopes. SUBSCRIPTS FOR MULTI-UNIT TUBES: b = Beam Power Unit. So, we apply a BIAS voltage to the grid. EL34 Vacuum Tubes at Europe's largest retailer of musical instruments - fast delivery, 30-Day Money-Back Guarantee and 3-year Thomann warranty Thomann uses cookies to give you the best shopping experience. Comparison to EL34. With the proposed cathode current. Modulation is not affected by variation of excitation voltage. The NOS Winged C (SED) EL34/6CA7 tubes are an exceptional upgrade for our Triple Crown TC-100 or TC-50, or any of our amps with EL34 Bias Switches. Asking 20 dollars per tube or best offer. This calculator is for a single tube. 0 w lload 32 25 % _ - mullard - may 1962 ' page d3 el9i output pentode design centre ratings , current plotted against control-grid voltage with screen-grid voltage as parameter may 1942 | mullard , control-grid voltage as parameter. Eurotubes Power Tube Descriptions. Kurt Prange. First I checked the grid AC voltage @ bias == 0. So most tubes are built for an operating range with a negative grid bias of several volts. This tube is a pentode of the power amplifier type. The 6550 version sounds more like the traditional sound of an EL509 push-pull OTL. Due to increased demand, some orders may experience a slight delay. The Laney LA30BL 30W head comes loaded with a classic tube complement of three 12AX7 preamp tubes and two EL34 power-amp tubes. The opposite was true of screen voltage, the lower the voltage the lower the distortion. (d) The power output is calculated as though you are generating a pure sine wave. Suppressor grid characteristics of EL34? Re "Tone Lizard" article (warning Amp Content) Showing 1-3 of 3 messages. This amplifier was originally featured on the February 2003 Issue of the "High-Fidelity Audio: Radio Technology" by Mr. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34 This allows the E34L to offer more headroom (later breakup) than the traditional EL34. negative gate voltage regulator tube, adjust the tube current. Electrical Grid. Each output tube type can take a hugely different applied negative voltage applied to the tube to achieve the proper bias current. Ultra Linear (Grid) 43% A Pin 15 Ultra Linear (Grid) 20% A Pin 14 Centre Tap (Ht) Pin 13 Ultra Linear (Grid) 20% B Pin 12 Ultra Linear (Grid) 43% B Pin 11 Anode B Pin 10 Output common Pin 17 Output 3 to 4 ohms Pin 18 Output 7 to 8 ohms Pin 19 Output 15 to 16 ohms Pin 20. Because it has an extra grid in it for more power, they provided a unique distortion tone that became the very distinct Marshall sound!. The supply voltage is around 500V-DC, the EL34 spec. Another design constraint is managing the conductance of the LO tank circuit over the tuning range. So if you've got a socket properly connected for metal 6L6s (which IMO any 6L6 socket should be), if you put an EL34 in, the suppressor grid will be grounded. The sound is well balanced with tight bass response and great mids. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. The "trans" in transconductance describes a change in conductance. You may also like 4 * RFT EL84/6BQ5 Vintage Power Pentode Audio Radio Valves Tubes Made in. The EL34 version captures all of the midrange liquidity that it is famous for. I had to come up with some sort of alias and EL34 is what I came up with. 5 Million Vacuum Tubes on hand under one roof. Indeed pin 1 is not even present on any 6L6 tubes that I have seen, it is simply not there, instead there is a hole in the base where the pin might have gone. The E34L is a special low grid voltage version and is not always interchangeable. airtime Super. Svetlana EL34/6CA7 High Performance Audio Power Pentode PLATE CURRENT (MILLIAMPS) GRID VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0-60 -50 -40 -30 -20 -10 0 Svetlana EL34 Plate Voltage = 250 Screen Voltage 400 300 250 PLATE CURRENT (MILLIAMPS) PLATE VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 Svetlana EL34. When I got the amp the conversion was halfass complete. USD $ 119. JJ Electronic E34L Factory Data Sheet: E34L Factory description: Gold plated control grid for improved fidelity. Quality high temperature alloys are used for the anodes resulting in a reliable and high performance valve. The EL34 (the KT77) power pentode was introduced by Mullard in 1953 — unlike the 6L6, the EL34 has its suppressor grid connection brought out to a separate pin (pin 1) as shown Figure 3. Transconductance is a measure of the gain, the current at the plate (Ip) over the voltage at grid 1 (Vg1). (d) The power output is calculated as though you are generating a pure sine wave. signal power output (not less than) total harmonic. That means the latter may be more susceptible to oscillating, and so bigger grid stopper should be seen as "normal". As previously mentioned, the phase angle between the voltage produced by the generator and the voltage produced by the grid must be zero. Click here to download and read the full article (with illustrations & examples). High transconductance (Gm) tubes, like the EL34 and EL84, will have bigger changes of plate current with a given grid voltage input than lower-Gm tubes. By turning the output control, a voltage from zero up to one half of the low B+ supply voltage can be selected. In the 1950s, the push toward greater power and higher efficiency, coupled with the availability of new power tubes such as the EL34, KT88, and 6550, ousted filamentary triode designs from mass market applications. That means the latter may be more susceptible to oscillating, and so bigger grid stopper should be seen as "normal". Octal power tube (Max Plate Watts = 25W) Sensational new high-gain EL34 tube with a very dynamic tone. Characteristics Svetlana Outline drawing T SVETLANA TECHNICAL DATA EL34/6CA7 High Performance Audio Power Pentode he Svetlana™ EL34 is a glass envelope power pentode having a plate dissipation rating of 25 Watts with convection cooling. The Reproducing Classic Power Amplifier EL34PH of the top vacuum tube brand PSVANE perfectly reproduces PHILIPS iron pedestal EL34of 50s. 6l6 tube amp. Screen R's: Fender ran the screens at almost the same voltage as the Plates (for maximum power). On an EL34 the suppressor grid is tied to pin 1 and since the suppressor grid must be grounded it must be physically wired to ground on the tube socket by tying pin 1 to pin 8. With KT77s in place of EL34s, the grid bias voltage is -32. The two types perform similarly under identical conditions, but the EL34 has much higher voltage ratings. Suppressor grid characteristics of EL34? Re "Tone Lizard" article (warning Amp Content) Showing 1-3 of 3 messages. EL34 is a beautiful tube for audio service, and much improved over the 1625s used in the DX100. el9i output pentode , 1. The screen grid is part of a tetrode or pentode (in our case) tube. Making the grids LESS negative will cause MORE current to flow through the tubes. HiFi Audio Stereo Vacuum Tubes Mini Size PSVANE 300B-N For 300B Tube Amplifier. How to Bias a Tube Amplifier. Here is the latest on the screen grid resister problems with the XXX and now the JSX amps. Re: EL34 vs. Untuk percobaan ini, saya masih memakai OPT dari Power Trafo dengan cara apa adanya. 5K seen on the grids of 6L6 tubes in most Fenders, and the 5. http://www. It tends to push vocals forward. Ultra Linear (Grid) 43% A Pin 15 Ultra Linear (Grid) 20% A Pin 14 Centre Tap (Ht) Pin 13 Ultra Linear (Grid) 20% B Pin 12 Ultra Linear (Grid) 43% B Pin 11 Anode B Pin 10 Output common Pin 17 Output 3 to 4 ohms Pin 18 Output 7 to 8 ohms Pin 19 Output 15 to 16 ohms Pin 20. The elegant Studio 10 EL34 is a low gain, classic British crunch amp with an EL34 in the power amplifier and an ECC83 in the preamp stage, resulting in a flawlessly boutique, sultry crunch. HIFI AMP Stereo Vacuum Tubes 500V Secondary Grid Voltage EL34 PSVANE Hifi Tube EL34PH. The E34L has a slightly higher grid voltage rating (-13. The E34L is a special low grid voltage version and is not always interchangeable. EL34 Triode Connection Non-NFB Push-Pull with Hashimoto Transformers - Project #1. FIXED-BIAS – A way to achieve bias in a vacuum tube in which a fixed amount of negative voltage is placed on the grid of a tube. By Rob Robinette. Once you have decided to change your el34 for the kt77, the next step is to bias the latter. Design based on the original '60s Mullard EL34 tube Quartet of EL34-M tubes rated from power range 1-10 Each quartet is matched and biased to a specific output level (R2, R7, etc. Pickup preferred or buyer pays shipping. Modern EL34's have questionable reliability at such high voltages, so it would be wise to restrict ourselves to an HT of less than 500V. The TELEFUNKEN EL34-TK has been designed to handle a slightly higher grid voltage than the traditional El-34. The DX100 displays CATHODE current, which is the sum of the control grid current (negligible), the screen grid current (15 to 20 mA for two tubes) and the plate current. All readings have been verified. 6L6 being a home version of military (5881) amplifier tube. With a plate voltage of 470 V, the plate dissipation for each EL34 is close to 22 W. The E34L is a special low grid voltage version and is not always interchangeable. Turn off your ST-70 and replace the pulled rectifier tube. Designed for push-pull tube output circuits. This makes it possible to tie the suppressor grid to a voltage other than that of the cathode, perhaps the raw bias supply as used in some Traynor amps. In case of 6L6 there IS no grid 3, it is a beam tetrode. 4) EL34's are 25 watts max and you want to set the bias to be between 60% and 70% maximum dissipation watts. Assembly Manual • Schematic • Parts List • Tubes and Applications. Output Pentode suitable for use in power amplification Quick reference data • Anode current Ia=100mA • Transcoductance S=12,5mA/V • Amplification µg2g1=11 • Output power, Class B WO=100W Heating Heating is indirect by AC or DC, with parallel supply. In general, the grid resistor at the grid of the power tubes can be as high as 56K to 100K before any noticeable loss of high frequencies occurs. This increase gives the tube more headroom and a tighter response on the low end. At the time this manual was written, the Tubelab SPP has only been tested as a stand alone push pull amplifier. Incredible Service. EL34 is a beautiful tube for audio service, and much improved over the 1625s used in the DX100. The low cost of the EL34 is a considerable upfront saving. RCAs about the only 6v6 I can use without red plating. A statistical extrapolation from 31 years of magnetic field measurements is made by identifying 84 geomagnetic storms with the Kp and Dst indices. Design based on the original '60s Mullard EL34 tube Quartet of EL34-M tubes rated from power range 1-10 Each quartet is matched and biased to a specific output level (R2, R7, etc. It's not redundant. Eurotubes Power Tube Descriptions. el9i output pentode , 1. HIFI AMP Stereo Vacuum Tubes 500V Secondary Grid Voltage EL34 PSVANE Hifi Tube EL34PH. Because the EL34 grid number-2 sees a filtered DC voltage, the EL34 behaves as if the plate also saw a filtered B+ voltage. A simple PP amp with EL34 is capable of 30W per channel… but there is a huge difference in sound. A real three grid pentode, no beam pentode like 6L6 or KT66. 6 and the 6550, which are beam tetrode tubes. Keroes in 1951. If the grid is made less negative, the number of electrons passing through the grid increases. Can you share where you find 6S4 for $10? Last time I look, a matched quad would set me back about $90 US. Want a different sound, use different tubes. WBT-0703 Nextgen speaker connectors. 1 (control) voltage -100 V DC cathode current 150 mA Plate dissipation 25 W Grid no. The most popular tube families found in Scott gear are: 7591, EL84, and EL34's. Using the same two Mullard EL34 tubes from above, let's see how they did at 265v. Our observation: This tube has about 20% more head room than the standard EL34 and it also has a deeper, tighter. We know bringing power back home means going out to sea. First I checked the grid AC voltage @ bias == 0. a high supply voltage of 450V (at maximum power output), and a quiescent current of 45mA per EL34 pentode tube. So if you've got a socket properly connected for metal 6L6s (which IMO any 6L6 socket should be), if you put an EL34 in, the suppressor grid will be grounded. It is intended for audio frequency power amplification service in either pentode, ultralinear or triode connection and single or push-pull/parallel applications. Special grid windings give a unique sound for both guitar and hifi; Perfect power tube for Dynaco ST-70 or vintage Marshalls, Hiwatt or other British Amps; 6CA7 equivalent. With the proposed cathode current. All tubes come with a 90 day warranty. The 6CW5 was developed for low voltage use in line powered television sets and radios. My amp is a class AB push-pull type which takes either 6L6 or EL34 tubes. But KT77 is already pretty sweet. The GTEL34M is an exact replica of perhaps the most famous power tube of all time, the EL34. This calculator is for a single tube. Buy Telefunken KT88-TK Black Diamond Series Vacuum Tubes (Matched Pair) featuring Beam-Power Tetrode Output Tubes, Ideal for Guitar & Power Amplifiers, High Power & Low Distortion, Handles Plate Voltage up to 800V, Signature KT88 Midrange, Expanded Low & High Frequencies. Controling (or modulating) the current flow in the device by varying the control grid voltage is the mechanism through which gain is achieved. I HATE jj power tubes and to me they are tone suckers and unreliable BUT I took there advice and picked up a quad of el34l's from doug and they are popping and making weird noises. The 6L6G and 6L6GB are rated 360V max and 19W max plate dissipation. The JJ Electronic E34L adds more power to a standard EL34 due to its higher grid voltage rating. 470 ohm screen grid resistors and a power supply dropping resistor got toasty. Characteristics Svetlana Outline drawing T SVETLANA TECHNICAL DATA EL34/6CA7 High Performance Audio Power Pentode he Svetlana™ EL34 is a glass envelope power pentode having a plate dissipation rating of 25 Watts with convection cooling. The cathode of the input stage is coupled to the cathode of the 45 via the 680 cathode resistor of the 76, directly to the cathode of the 45. 6K seen on the grids of EL34 tubes in most Marshalls. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34. Without knowing exactly the ability of the power transformer to deliver that extra ampere without overheating - it is hard to say yes, go ahead. like 6V6, 6L6, EL34, EL84, 12AX7 etc. A statistical extrapolation from 31 years of magnetic field measurements is made by identifying 84 geomagnetic storms with the Kp and Dst indices. The power output is rarely more than 27% of power input because the Ea minimum swing is restricted by the onset of grid current. Calculating Cathode Bias Resistor. Mar 28, 2013 · 6L6 and EL34, both popular power valves for guitar amps, but what is the sonic difference between the two?. Svetlana EL34/6CA7 Vacuum Tube; The Svetlana™ EL34 is a glass envelope power pentode having a plate dissipation rating of 25 Watts with convection cooling. The JJ EL34 is a great replacement for guit. It is intended for ultra linear audio frequency power amplification service. SEARS NOVEMBER26, 2000 explains and demonstrates that the THD dip is due to reversal of the relative phase of the signal current in the active load to that delivered to the subsequent grid leak. The other possibility is that you could lower the 1K screen resistors to 470ohm (since the screens are a little less fragile, and less prone to drawing high currents), but the 1K's are quite useful to leave in place, since provided you have enough range on your bias pot for EL34's as well as 6550's, the 150K grid stoppers will still work with. With a gold-plated molybdenum alloy grid and carbon-coated screen grid, the EL34 is the finest power tube of its type being manufactured today. 4 and listen. The EL34-B is thus run conservatively. mains operated equipment. This tube is truly a mouse that roared, as it can handle 12 watts on the plate at 300 volts, and 300 volts on the screen at 2 watts! The early Beatles music was. When the Amp is fully cranked, the Plate voltage drops, and now the screens are conducting current, since they are now more positive than the plates, not good. I'm going to keep reading to see what they mean about the grid going positive. High transconductance (Gm) tubes, like the EL34 and EL84, will have bigger changes of plate current with a given grid voltage input than lower-Gm tubes. this time put 51V zenner into screen grid and connected SG Tap. In cathode bias a small value resistor is placed between the cathode and the ground so it develops negative voltage on the cathode thus achieving bias. The plate and screen grid operate at different voltages, so only pentode mode can be used. (*)These specifications are provided 'as-is', with no warranty of any kind. Shop for the Groove Tubes GT-EL34-H High Duet Matched Power Tubes and receive free shipping on your order and the guaranteed lowest price. Then measure the voltage drop across your new screen grid resistors and calculate your screen current. Free shipping is limited to the contiguous 48 states. Frequency response 30 Hz. Incidentally, although the El34 data sheet claims the maximum quiescent anode voltage is 800V, this applied to current production in the 1960's. Turn off your ST-70 and replace the pulled rectifier tube. 0V Nominal filament current 1. Having selected our operating point at 85V, we know anode, and hence, cathode current. Beam power tetrodes achieve the same effect by beam-focusing plates and careful alignments of both the. The distortion was entirely 2nd harmonic. The Laney LA30BL 30W head comes loaded with a classic tube complement of three 12AX7 preamp tubes and two EL34 power-amp tubes. Amp DIY • 6550 • Gear • Amps • 6L6 • 6V6 • August 2015 • EL34 • EL84 • Tube Combo • Tube Head • Ampeg • Fender • Marshall • Vox Power Trip: A Guide to Power Tubes and Their Signature Sounds. Legendary winged "C" selected from the original Svetlana production The Svetlana EL34 is very dependable and our recommended choice for combos. I HATE jj power tubes and to me they are tone suckers and unreliable BUT I took there advice and picked up a quad of el34l's from doug and they are popping and making weird noises. I first used EL34 as my gaming name when playing Quake 3 at LAN parties and on the internet. 5 vs -10 to -13. Fig 8B, EL34 triode, small signal amp stage, use and properties. But you an change from EL34 ,6L6, KT66, 6550,etc. This calculator is for a single tube. Keroes in 1951. Carefully adjusting the bias voltage, the following waveform is seen. By simply changing the power mode, 6V6, 6L6/EL34 and most of the KT series tubes can be used. Output Pentode suitable for use in power amplification Quick reference data • Anode current Ia=100mA • Transcoductance S=12,5mA/V • Amplification µg2g1=11 • Output power, Class B WO=100W Heating Heating is indirect by AC or DC, with parallel supply. The MESA EL34 STR 450 is a Genuine "A" quality NOS (New Old Stock) German made Siemens EL34 - This is a legendary European EL34 known for its unsurpassed "bell-tone" clarity and touch sensitive sustain & articulation - Premium German engineering provides unsurpassed structural quality that makes this one of the most consistent and reliable EL34s you can buy. The idea is to modulate it by varying the negative polarity of the suppressor grid (g3). I had to come up with some sort of alias and EL34 is what I came up with. Octal power tube (Max Plate Watts = 25W) Sensational new high-gain EL34 tube with a very dynamic tone. Also the screen grid is held at the voltage specified. Some amplifiers don't have a bias-adjusting control (pot) but instead use a fixed resistor to set the voltage. 6K seen on the grids of EL34 tubes in most Marshalls. The Tube Center is dedicated to providing Ham radio, amateur radio operators, antique radio enthusiasts, audio professionals and hobbyists the ability to choose from an inventory of over 3. Therefore, the ripple voltage arriving at the grid will be reduced as well by the voltage divider, and will be around 0. Svetlana EL34/6CA7 Vacuum Tube; The Svetlana™ EL34 is a glass envelope power pentode having a plate dissipation rating of 25 Watts with convection cooling. 5k ala standard El34 grids (although Hiwatts have 22k as well). OK, so now the amp makes 25Watts at 0. The E34L is a special low grid voltage version and is not always interchangeable. My tube manual didn't give this data for a 6CA7, the US equivalent of the EL34. The wide frequency response of this tube offers excellent harmonics that work in a variety of genres ranging from the cleanest cleans to rich and aggressive breakup. Product Description 100% Brand New and High Quality Electronic tube amplifier DIY adjustablenegative grid bias power supply board, single-ended and push-pull can be used. Or does that not work and I have to buy an adapter for some reason I can't think of?. It has an international octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of audio amplification circuits and was designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. Beam power tetrodes achieve the same effect by beam-focusing plates and careful alignments of both the. Back to First Preamp Stage. All tubes come with a 90 day warranty. Electronic Vacuum Tube. Vacuum tubes wear out due to heat and high temperature. The DX100 displays CATHODE current, which is the sum of the control grid current (negligible), the screen grid current (15 to 20 mA for two tubes) and the plate current. B&K model 747 tube tester for EL34. About National Grid. A EL34 would use a 1 k ohm in most cases. If you have not been trained to work with high voltage then have an amp technician adjust the amp's bias. The KT77 avoids this. And note that the option of running into positive grid voltage is an easy one to opt for in this topology, as the cathode is driven, not the grid; the grid, being grounded, can draw as little or as much current as it needs without tumbling the input tube. OUTPUT PENTODE Output pentode rated for 25W anode dissipation, intended for use in a. A wide range of Preselected Amp Tube Sets Marshall, Fender, Vox and Many more. This increase gives the tube more headroom and a tighter response on the low end. Specifically designed for audio amplification, the KT88 has similar ratings to the American 6550 which was designed for use as a servo amplifier. It is intended for ultra linear audio frequency power amplification service. The two types perform similarly under identical conditions, but the EL34 has much higher voltage ratings. Member: Joined: Jan Thu 01, 1970 1:00 am Posts: 307. 5 volts) than the traditional EL34 vacuum tube. I have a question concerning the correct operating point of the EL34 output stage. Tieing The (EL34) Suppressor Grid to Negative Bias. Vacuum tubes wear out due to heat and high temperature. 5K seen on the grids of 6L6 tubes in most Fenders, and the 5. El84 tubes vs 6l6. Modulation is not. RCAs about the only 6v6 I can use without red plating. You can substitute EL34's for the KT88's, and switch the toggle on the side to give the proper bias voltage for the EL34's vs. Regards Tom _____. This is negative, otherwise the tube will guide. At National Grid, we do amazing work — like updating our infrastructure so we can deliver renewable energy efficiently. 5 watts) Divide your desired wattage by your plate voltage from step 3. This will be enough to bias the valve almost to cut-off, and we don't really need more than that! The triode mu of some popular valves are: EL34 = 10 EL84 = 20 KT66 = 7. EL34 Vacuum Tubes at Europe's largest retailer of musical instruments - fast delivery, 30-Day Money-Back Guarantee and 3-year Thomann warranty Thomann uses cookies to give you the best shopping experience. The G3 will not follow the lowest impedance path to prevent excedentary emission to bounce I to the screen, so I wonder why you doing so?. Tube Amp Doctor - EL34-SVT Premium - Power Tubes Australia. It's not redundant. Shuguang 6J1. Svetlana EL34/6CA7 High Performance Audio Power Pentode PLATE CURRENT (MILLIAMPS) GRID VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0-60 -50 -40 -30 -20 -10 0 Svetlana EL34 Plate Voltage = 250 Screen Voltage 400 300 250 PLATE CURRENT (MILLIAMPS) PLATE VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 Svetlana EL34. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34. Electronic Vacuum Tube. In most amplifiers they will be fed via resistors, the power supplies will sag and the transformer will have losses. el9i output pentode , 1. A tetrode my be compared to a cascode connected pair of triodes: Since the upper cascode cathode current is equal to the lower plate current, these elements can be removed…The electrons flow as well in vacuum as they do in metal. Red plating only occurs in one group of amplifier valves. 5 watts) Divide your desired wattage by your plate voltage from step 3. Making the grids LESS negative will cause MORE current to flow through the tubes. The EL34 is a pentode, whereas KT66, KT77, KT88, 6L6 and 6550 are beam tetrodes which work on a slightly different principal to a pentode. Asking 20 dollars per tube or best offer. Indeed pin 1 is not even present on any 6L6 tubes that I have seen, it is simply not there, instead there is a hole in the base where the pin might have gone. I would have expected it to float up to near the anode voltage. Another consideration is that a 6L6 frequently has a 470 ohm screen grid resistor. The EL34 and it's "Americanized" version, the 6CA7, are among the most popular and sought out vintage tubes today. 1912 TM SED ST. • Special grid windings give a unique sound for both guitar and hifi • Perfect power tube for Dynaco ST-70 or vintage Marshalls, Hiwatt or other British Amps. uses a quad of EL34's, with tube rectification, but produces more power. As with many of the Eastern European tubes, mechanical noise is an issue if used in high power combo style amps. http://www. EL34 (as well as some. The instant response and feedback you get when playing, create a direct connection between your fingers and the speaker. 5AR4 / GZ34. A standard EL34 can’t be plugged in because the input grid would be shorted to the suppressor grid via pin one. Hoping to hear from experts here. More and more amp models will be placed online over the next few days. EL34 being the European hi fi tube, specifically made for music. 2 power, heater power, and air flow may be removed s imu1taneous1y. A wide range of Preselected Amp Tube Sets Marshall, Fender, Vox and Many more. the mu quoted on the datasheet when operating in triode mode. 5k ala standard El34 grids (although Hiwatts have 22k as well). An authentic remake of the British Mullard EL34. The only caveats are to ensure that your power transformer can supply an extra 500ma of heater current per tube and that the range of bias voltage adjustment is correct. 5; Start the 0. But KT77 is already pretty sweet. To estimate where the load line impacts the zero grid voltage curve (marked in red) we can multiply the plate current by 450V / 360V raised to the power of 1. Aeolos Ultima. If not what kind of EL34 would be a good match for this circuit?. the KT88’s. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. There is a pretty good chance that when the tube shorted, it burned out the screen grid resistor, or the cause of the tube failure was not actually a short, but an interruption of its bias supply (this is generally preceded by a hum which gets progressively louder, the tube's plate structure glowing bright red and then the fuse (hopefully. -sheet says for a PP-Class B-Amplifier the negative grid voltage has to be -36V. The screen grid is part of a tetrode or pentode (in our case) tube. El84 tubes vs 6l6. Turn off your ST-70 and replace the pulled rectifier tube. All I can do is to assume it is the same. Tube Amp Doctor - EL34-SVT Premium - Power Tubes Australia. 1 Khz) minimum. This increase gives the tube more headroom and a tighter response on the low end. The only difference is that the negative grid voltage is often changed when switching tube types for proper bias. Back in 1904, British scientist John Ambrose Fleming first showed his device to convert an alternating current signal into direct current. Note: Worthy of note is the KT88, which GEC (MO Valve Co. Making the grids LESS negative will cause MORE current to flow through the tubes. [Features] - Comes with 6L6GC power tubes, but also supports wide range of power tubes, such as KT88, KT90, KT66, EL34, etc. You cannot reach 100% test coverage with this tester. 5AR4 / GZ34. If the grid is made less negative, the number of electrons passing through the grid increases. (Well, set to any voltage somewhat BELOW that produced by the rectifier and filter anyway). 250 V Grid 1 Voltage. 5 vs -10 to -13. Suppose I load the EL34 plate with 500 volts DC and a current of 150 ma with 0 volts suppressor, does anyone have any idea what negative voltage in g3 is needed to reduce the anode current by half, needed for screen AM modulation ?. Hence running in AB but bias closer towards A. The EL34 was introduced in 1949 by Phillips (parent company of Mullard), who owned the pentode patent at that time. The idea is to modulate it by varying the negative polarity of the suppressor grid (g3). EL34 output tubes may be substituted with the following: KT77, 6550 KT66 KT88 6L6s, 7027 and with a socket adapter, 807. 2 in 1 Tube amp bias tool Current and Plate Voltage test probe 6l6 el34 kt88 tool Current and Plate Voltage test probe 6l6 el34 kt88 on most octal power tubes Jul 13, 2014 · Know Your Amp: Different Kinds of Tubes The KT77 is often described as a pentode because it shares the same pin configuration and bias as the EL34, but that’s How to. EL34 Vacuum Tubes at Europe's largest retailer of musical instruments - fast delivery, 30-Day Money-Back Guarantee and 3-year Thomann warranty Thomann uses cookies to give you the best shopping experience. get about 6W from an EL34 in triode. 5K seen on the grids of 6L6 tubes in most Fenders, and the 5. HiFi Audio Stereo Vacuum Tubes Mini Size PSVANE 300B-N For 300B Tube Amplifier. EL34 Page 1 of 9 EL34 is A. In common with all 'E' prefix tubes, using the Mullard–Philips tube designation, the EL34 has a heater voltage of 6. Because this amp has the Hazen Grid Mod that activates only when EL34s are used, we ship the amp with top grade EL34/6CA7s that have been fully tested IN the amplifier. 6l6 tube amp. Audio tubes for guitar amplifiers and audiophile equipment. Asking 20 dollars per tube or best offer. This causes the. The 6CW5/EL86. A typical characteristic of regulators is the ability to set an output voltage, independent of the rectifier and filter voltage. The EL34 is a thermionic valve or vacuum tube of the power pentode type. Indeed, we are getting our cake and eating it too. The Laney PA60 is the same as the Supergroup and similar to some early Marshall amps, and a few other amps such as. None of these valves are interchangeable in circuits unless the circuit is specifically designed to accept these different valves, which all have different filament/plate/grid voltages. However when the suppressor grid of the EL34 is modified with the cap there is a huge difference in the presentation of the amplifier for the better, despite the fact that typical measurements show no substantial change has occurred. A statistical extrapolation from 31 years of magnetic field measurements is made by identifying 84 geomagnetic storms with the Kp and Dst indices. The Laney LA30BL 30W head comes loaded with a classic tube complement of three 12AX7 preamp tubes and two EL34 power-amp tubes. A nicely defined bass note becomes not only nicely defined and precise, but a loud, fast, and almost brutal attack!. Offering a tight low end and smooth mids, it will bring new life to guitar and hi-fi amplifiers while retaining the historic tone TELEFUNKEN tubes have always been know for. You can think of a vacuum tube circuit as a high voltage, low current circuit, and a transistor circuit as low voltage, and more of a current driven circ. Thus the cathode voltage excursions are smaller than control grid excursions if it were purely grid modulation. OK, so now the amp makes 25Watts at 0. Its function is to create a lower voltage region between the screen grid and the anode. In most amplifiers they will be fed via resistors, the power supplies will sag and the transformer will have losses. Special grid windings give a unique sound for both guitar and hifi; Perfect power tube for Dynaco ST-70 or vintage Marshalls, Hiwatt or other British Amps; 6CA7 equivalent. El84 tubes vs 6l6. The G3 will not follow the lowest impedance path to prevent excedentary emission to bounce I to the screen, so I wonder why you doing so?. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34. In common with all 'E' prefix tubes, using the Mullard–Philips tube designation, the EL34 has a heater voltage of 6.