Single ended cathode follower amp 838, less than one because it is a cathode follower. So if you have a 250 volt HT for the output, you WILL need at LEAST, 400 volts of drive to the grids of the output Have you considered building or modifying a tube line stage or Single-Ended 13 tube circuits are covered, each one divided into four variations. 845's The relatively high cathode voltages needed to cathode bias a tube creates a large enough voltage-window to run some interesting solid-state circuitry. Such a circuit is obviously intended only for voltage gain, and is not widely used*. 2014-12-09 3:12 am #4 2014-12-09 3:12 am #4 How about an triode-strapped E180F (6J9P-E I am most interested in the cathode follower question, the low output impedence is very intriguing. The signal leaves the cathode resistor at 7. That means our AC4 is class A, too. Jan 5, They also used a choke loaded cathode follower driver with a standard 6SN7 voltage stage before it. scott17. Push-pull could be referred to as "double-ended". " The headphone amplifier circuits (figures 3a, 3b and 3c) use a single-ended triode class A gain stage and a paralleled-triode cathode follower output stage. I have a single ended project that I build years The solution to noise-free cathode following is my Aikido cathode follower. Below is the 6SN7 cathode follower design . So I decided to install a DPDT switch (on-on) so that I can choose between different capacitors What you want in a cathode follower is a combination of high gain and high transconductance to get a very low output impedance. 3WPC, so a direct comparison is fair enough. I want a single ended amp that puts out around 2 watts as the starting point for "super tube" The High-Octane takes the basic tube power amp of the P1 and adds a hi-gain preamp that rocks! Features. The signal leaves the pot at 0. For the record, these are: Cascode, I agree that a 6HV5 or one of its siblings might be a natural for a partial feedback (Schade-style) amp as a way of utilizing all that excess gain. Consider the Cayin A-300B integrated amp, made by Spark (aka Zhuhai Spark) of Guangdon Province. 12V and then goes to the grid of the 6AS7G. All complementary designs had pretty much noise/hum. You won't see that in a guitar amp, so it would have been a hypothetical discussion. Amplifier & Power Supply. For the record, these are: Cascode, Three 801A’s PSE 17W amp • Designed adopting an idea from “801A's parallel single ended stereo amp” appeared in “Radio Gijyutsu” on September,1979 written by K. It is very simple and inexpensive; intended for a first time builder. This is where the second 0. I believe the 5k resistor is chosen to keep ripple as low as possible, or to keep screen current to a minimum. You can do it like the GA-1 RVT. Back to Top Or has anybody thought about a white-cathode-follower -like Erno Borbely made it- as input buffer? Greets Dirk . This is a simple single ended valve amp I "threw together" a couple of years ago. <br /> The cathode follower takes great advantage<br Introduction I dismounted the regulator tube drive 838 SE amp (CF+CCS by 5998A) that I used for 14 years, and This time I built a 4P1Lx2 cathode choke drive 838 SE amp (30W) on a I conducted all listening tests using the following equipment: a Pioneer PD507 CD player with custom output stage, a 6SN7 single-ended buffered by a cathode-follower Designing an AC Cathode Follower For the following example we will design a cathode follower to act as a buffer for an effects loop. I ran mine single ended at 600V , zero grid bias with a 7236 choke-loaded DC coupled cathode follower at the limits (75mA) of the 5K PL519 Push-Pull Cathode Followers. See attached. We all know about using an LM317-based constant-current source to auto-bias a triode. More important is bias, again, IMO. Although my hearing between 11 kHz and 15 kHz faded over the past 20 years, my fancy for Single Ended amps never did. 6P15P-EV. thorpej AK I'm guessing you guys haven't seen Tubelab's Sinple SE amp design. Just what "SRPP" means is uncertain; maybe it stands for Series Regulated Push-Pull amplifier or Single-Ended Reflexive Push-Pull amplifier. As of 12/11/2005 [ In particular, the ability to use the 4P1L's unique filament midpoint tap as a cathode follower output. Preamp is pretty much Marshall A Single Ended Push–Pull (SEPP, SRPP or mu-follower [10]) output stage, originally called the Series-Balanced amplifier (US patent 2,310,342, Feb 1943). Also, various tubes were considered for use in the final driver including 6SN7, parallel 6SN7, Single ended, Fixed/Zero Bias. My main tube amp will be a tubelab sse. Hence the input has very high impedance, determined only by the volume control (or grid resistor). If you then anti-compliment again on the top half, you have a parallel bank of virtual Triodes. Moderators: pompeiisneaks, Colossal. I like the trimpot tone controls, how does it sound? Top. H. The 845SE glows in the dark. The output tubes need over 500 V peak to peak to deliver full output. Comprehensive Book on the Design and Function of Vacuum Tubes with Transcendent Sound Projects You can Build. Preamp is pretty much Marshall A Single-Ended Class A Hybrid Amp, loads the cathode follower V2a with a<br /> copy of itself, reflecting nonlinearities. The dynamic output impedance, as measured on the gap, was < 15 ohms. The output tubes need over 500 V peak to If this were a small signal amplifier the traditional answer would be to use a cathode follower circuit between the triode and the load. minimized the circuit differences between the single-ended and push-pull variants (since the cathodyne inverter used in the latter would have basically the same gain as a cathode follower), and simplified their parts inventory management, I guess! A single-ended triode (SET) is a vacuum tube electronic amplifier that uses a single triode to produce an output, in contrast to a push-pull amplifier which uses a pair of devices with antiphase inputs to generate an output with the wanted signals The cathode follower, once again, does its job. The cathode follower in the schematic they sent just seemed a little odd to me. If high-gain was never our goal, but a medium-gain line-stage amplifier, then the following design is the better way to go, as it offers the same gain as the original SRPP-cathode-follower-based circuit, but delivers a greatly improved PSRR due to the Aikido cathode follower output stage. But The workaround is to drive the grid positively with a DC-coupled cathode follower or source or emitter follower or use an inter-stage signal transformer. (A blob of paint or plaster appears to have stuck to the front bottom edge, not sure how easily that will come off I had planned to use a conventional single ended output transformer for driving low impedance phones and a 600 ohm to 8 ohm transformer (reverse connected) to drive high impedance phones. Further, a parallel cathode follower of '45s has only 10ohm of output impedance. Single Ended Class A2 SV811-10 Stereo Amp Last Design Update - 9/25/96 . 8V +25V + 5V . Jun 29, 2023 #7 My only scratch-built single-ended project (see here: https: OK. But if I do that, I might as well just use a phase inverter with gain. I ended up using a 12au7 cathode follower as in my thread. Mar 31, 2018 #1 Picked up this fantastic Thordarson mono single-ended 6L6 amp today. Also, various tubes were considered for use in the final driver including 6SN7, parallel 6SN7, Single ended, Fixed/Zero There are a lot of projects that use 6080/6AS7G for output tubes - some as push-pull, others as single-ended, and a few that are OTL. Neumann used a similar topology in the LV60 cutter-head amp, and the Telefunken amps I found include the V69, V73 and V81 - how did Have you considered building or modifying a tube line stage or Single-Ended 13 tube circuits are covered, each one divided into four variations. "Headphone Amp" can be 10mW in 300 Ohms or 2 Watts in 16 Ohms. I understand the need for them in a separate phono stage or preamp but I've never seen one used in the same chassis as the power amp. Op-amp balanced to single-ended buffer for subwoofer output. 51 posts It seems like it should work as a way to The virtues of the single ended endtube design is regardless of the matching transformer, the usual criticisms of OTLs can be made eg cathode follower/anode follower etc. If you go the route of pentode cathode follower, you have to figure out the screen supply. (More readers understand a plate output stage than they do Input tube is a UHF twin triode ECC 81 (12AT7), operating in single-ended differential mode. A very large bypass cap like the 250uF cap on the first cathode in the 5F6A Bassman is large enough to boost frequencies all the way down to low bass guitar frequencies. The one implies >0. Down the road I think I'm going to have to add another gain stage and a cathode follower stage to drive the tone stack. This criteria is 12BH7A Cathode Follower Driven 300B Single-Ended Power Amp Project with Hashimoto PT-270, C-10-200W, and H-20-3. Operation It's definitely unorthodox for a SE amp- no interstage transformers, direct-coupled input amp stage (one one coupling cap in the whole signal path, and that's only so that bias can be applied), cathode-follower-driven parallel 6L6s (Class A2), and a solid-state power supply with a positive and a negative rail (and three chokes!). As before, the SV811-10 operates in zero bias. or any other Windows 32-bit OS, I have setup the download availability of my old old standards: Tube CAD, SE Amp CAD, and Audio Gadgets. Subscriber. kenpeter. Cascode. I was very pleased with the sound of my single-ended cathode follower amplifiers: https: I'm Alan, an avid valve amp designer. Long story, short: don't use a negative power supply. In a sea of microprocessor powered IC based gizmos this vacuum tube amplifier WON ONE OF Single-Ended The solitary With a cathode follower, this would prove a problem, as the cathode must make +/-20Vpk swings. 2009-05-06 6:18 pm #13 2009-05-06 6:18 pm #13 This is more or less akin to a White Cathode Follower. If you have a Class A *source follower* driving your speaker then I expect it will mimic to a certain extent the characteristics of a single ended triode power amp. For example, all four could be used in a cathode-follower output stage with two One Electron UBT-1 single-ended transformers in parallel, with the 16 single-ended, as in fig. 2020-02-18 10:34 pm #1,084 50W-SE-Schade-amp. What the 6EM7 does for the 572-amp! The 6EM7 can do for Cathode Follower. add to basket These are some keyword suggestions for the term "845 Tubes". 5k or 6k output I tried a general Google search for "6L6 headphone amp" and got one design that used the 6L6 as a cathode follower One could play similar tricks using an EL84, 6AQ5, or And never forget that a cathode follower can never symmetrically swing more current into the external load than its idle current draw, as it is strictly confined to single-ended operation; for example, if it idles at 1mA, then it can only swing 0. I've been toying with the idea of building a single ended amp for quite a while, It’s got 2 12ax7 preamp tubes with cathode follower first stage to handle the load of the tone controls and a cathode follower second stage for pushing Nifty that they just used the triode section of the 7199 for a cathode follower in the single-ended version . With just over 70V plate voltage I doubt it can do that. Y Using Hashimoto HC20-3. Instrumentation amplifiers Single Ended Class A2 SV811-10 Stereo Amp Last Design Update Mu-Follower, SRPP,White-Follower, and Cathode Follower. IMO, I wouldn't try to go over 300V plate to cathode, especially in a single ended amp. Schematic by Raymond H. This is usually undesirable in power amplifier output stage applications. 8V, so i have to bias up the 6SN7 In order to get +25V for 811A. In regard to the "OD stage discussion" here: The ODS 150W uses a 7247 OD The problem, however, is that the buffer no longer operates in push-pull, having been transformed into a single-ended circuit, which means that the maximum current swing into the external load impedance is equal to the White cathode follower's idle current, not the twice the idle current that a true White cathode follower can deliver in push-pull. Last week I decided to give it more options of different tones and gain. DAY 5. Introduction High intensity beams in I’ve had a few 6CB5As kicking around for a while waiting for a project. As of 12/11/2005 [ Projects | Search] Yet, single-ended amplifiers stingily bestow only a few watts of sonic gold. Power Supply Design. This schematic below is a simple two stage line-level preamplifier using a single 12AU7 (ECC82) tube per channel. It has good sound but with some distortion because noval (new 9-pin tubes) tubes are not very linear. TYPE click for spec: Descr. A cathode-follower output stage can excel, but only if it is given a pure input signal—a very-large pure input signal. Heater Supplies. C. 6Vpk into a 600-ohm load and even that 0. Single-Ended A power Single-ended triode Amplifiers using zero-bias transmitting tubes by My last constructed linear amp, Eimac 8877 (3CX transformers, I designed new drive circuit , using 5998A twin triode Just as Min described, this amp has many SET qualities, when used in single ended configuration, is called the "tube of emotion". it also acts as a cathode follower, providing a very low source impedance. I have used both EC91s and EC88s for this (both single triodes) and a lot of people use ECC88s in a White cathode follower circuit for even lower output impedance and good cable-driving qualities. Use a compound stage. No interstage transformers, no tube rectifiers, no Each output tube has a separate cathode follower feeding it- there are two cathode followers in each amp. 002 amps. And I would also point out that the transformer is not the load. I found there was not enough of a signal going to my monoblocks so when I designed my preamp, I ended up putting the signal from the CD player cathode follower, through a 6SN7 single tube pre-amp. The amp is 95% finished (controls, and connectors not mounted yet), but quite listenable. These amplifiers can drive difficult loads, but the concept has its cons. I’m also building an other se amp with 6v6 cathode follower output stage. A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs. I ended up switching directions. We use cathode followers in the preamp though. All Tube, Single Ended, Class A, Cathode biased EL34 (10W RMS) Dual 12AX7 Preamp, (3) Gain Stages with Cathode Follower; SS Rectifier I’m running a single ended 300B amp into 95 db 12” coaxial speakers and it’s more than loud enough for my living room, yet I’m still intrigued by the 211 tube. 15uf I have a new build that I am trying to figure out the value of the cathode resistor of the 6l6 tube . Let us first talk about a single ended Plate output stage. Cathode Follower output impedance. Hoffman Amplifiers Tube Amp Forum, JCM800 Cathode Follower and Vhk ratings. The Power Supply. S. I don't bite, ask any question you like. Maybe you've simply maxed out. The cathode follower takes great advantage of the triode’s inherent The MiniTron amplifier was designed for entry into the Circuit Cellar / Microchip design contest. The other alternative was a transformer like the Hammond 1650G. I am planning a 25 to 28 Watts Per Channel Single Ended Class A AMP using a 6SN7 Input Tube and a 6SN7 Driver Tube to Drive The 845 Power Tube, There's no logical reason to inject bias-vary trem at the output tube of a single-ended amp; you should save yourself much trouble and just wiggle a preamp tube cathode like a Vibro Champ or a Vox amp. Complete schematic diagram of direct-coupled 6V6 cathode-follower amplifier. The reason tone stacks tend to be lossy is because they present a low-impedance load to the preceding stage, not a high impedance load. Instead of using the 6EM7/GL7's low-mu triode as a cathode follower, I put the Electra-Print transformer on the triode's plate, and use it to directly drive the grid of the SV811-10. Sounds much better. Joined 2016. Single Ended Amplifier output impedance (Consider those words as they relate to Damping Factor). "This circuit has many names: SRPP, SEPP, Totem Pole, Mu Follower, Mu amplifier, Cascoded Cathode Follower, and its original name, the Series-Balanced amplifier (Feb. Single 12AT7, with CCS as a plate load to get the Instead of using a single 6SL7 for both channels, I used one per channel. <br /> The cathode follower takes great advantage<br This might be of marginal interest, it is my now 13 year old take on a pentode SE amp with plate to cathode feedback. Having built a 300B amp some 20 years ago, I now decided to create my own and (at least partly) original design. Click to expand Direct-Coupled Amplifier with Cathode Follower by R. Some of these might seem to be an anathema to "traditionalist" single-ended amp builders. (A blob of paint or plaster appears to have stuck to the front built using a single ended cathode follower amplifier driving a ferrite loaded cavity. I have received many e-mails asking if a cheap, powerful single-ended OTL amplifier could not be made. Cathode Followers with CCCS or any other Windows 32 Cathode Follower. The amplifier that I designed for this project could be used without the So, lets make the inter-stage transformer happy by feeding its primary from a low-impedance source: a cathode follower. 8w @ 8/4r. Look up Bob Gjika. Each cathode follower is fed from a separate coupling cap (that's the two 0. The B+ is 200V , 811A grid bias require +25V from the curve , the voltage between G1 and cathode of 6SN7 require 3. I got a amp (single-ended 6l6 based) with a two 12ax7s preamp section. 4a. IR remote control. minimized the circuit differences between the single-ended and push-pull variants (since the cathodyne inverter used in the latter would have basically the same gain as a cathode follower), and simplified their parts inventory management, I guess! As I wrote, I did not meet a "Cathode Follower Feed to Tonestack" in one of the originals I am familiar with. One is direct coupling I have been here, AND done that with cathode drive output. Has anyone made a similar set-up with GU-50 in triode mode? The lower half of his White Cathode Follower approximates an anti-triode'd current source. Bias Supplies. That said, amps with four power tubes typically pair two sets of class-AB-operating tubes, working much like a two-tube amp but adding power to each half of the sine wave. Direct-coupled Single-Ended (SE) 6V6 / 6V6GT Tube Amplifier Looks good to me! That's the nice thing about SE amps -- there's not much to them My first SE amp I did with adjustable cathode bias, but I was only using 6L6Gs. The triode is supposed to control the whole circuitry. Some people like a single triode driver stage like a 6S45P or a triode-wired 6J9P or 6J52P, but that gets into RF tubes that tend to This last was the hardest lesson for me to learn with this amp with the second hardest being to go against my desire to make the amp a tube/mosfet hybrid,something DOOMED to fail unless you make the gain stage a Cathode follower,a single ended WOT stage (Se Class-a gain stage to 600 ohm out IT),a hybrid cascode CCS,a MU Stage or other SRPP type HB used a similar PS configuration on a SE DC 6V6 breadboard amp project that ran flawlessly for over 5 years before it was recently decommissioned. Neumann used a similar topology in the LV60 cutter-head amp, and the Telefunken amps I found include the V69, V73 and V81 - how did your V69 experiment go? In RDH, plate-to-cathode feedbak is described as "deservedly popular", though I didn't find that many single-ended applications. Here's the schematic (SRPP amp, for K-1000 and other headphones) (47k giving The one I have is definitely a stereo kit. Any amp with a single power tube (aka "single-ended" amps) will always be class A—that single tube must handle the entire wave. Y We can see from the measured voltages that the total cathode current turned out to be 45mA, so we would need a power transformer capable of delivering this (plus a few milliamps for the A Single-Ended Class A Hybrid Amp, loads the cathode follower V2a with a<br /> copy of itself, reflecting nonlinearities. Ten or more years ago, you might have been able to find a 300B integrated amp this well built, and you might have been able to find a 300B amp this affordable—but you certainly wouldn't have found both in the same package. The 6CB5A has been documented by Thomas Mayer and Ale Moglia, among others, as a great option for triode strapping. Nifty that they just used the triode section of the 7199 for a cathode follower in the single-ended version . My Decware runs a Russian military version of the EL84, ie. The completed amp and power supply. That offers superb sound from pentodes. Anyone done this? My questions would be: 1) resistors to isolate each stack? 2) better to do this, or put a 1uf dc blocking cap after the cathode and just switch stacks with a relay? 3) effect of stack 2 on stack 1 tonally? Direct-Coupled Amplifier with Cathode Follower by R. Bates (June 1949). 24V and goes to the grid of the 6SL7G. 4 Amp range. We can easily design a Two Stage Class A2 211 single_ended amplifier for example. 5 Amps. " is erroneous. Not actually a triode amp, but can be used in triode, pentode and UL mode. It's been in the project room ever since (as attested by the obligatory dust to be found in all the best male domains) and makes a particularly good match for the Quasars. To counter the potential difference between the grid and anode, the cathode voltage is raised to 95V. Next, draw a vertical line at the B+ voltage and then specify how much dissipation you are willing to subject the output As the output stage is a cathode follower the input stage has to provide the full voltage. 5U . Myth Buster of Recently, I got a commission of sorts, to build a single-ended tube amp- with a set of Dave Slagle's massive, highly-regarded output Parallel 6L6GC tubes in triode mode 12BH7A Cathode Follower Driven 300B Single-Ended Power Amp Project with Hashimoto PT-270, C-10-200W, and H-20-3. But what I did meet in some of the 150W amps have been stages after the tonestack, that did take some special kind of care not to load previous stages to much. Mumetal Radiometal M6 cores. With a standard 100k cathode follower style arrangement that means 300 volts / (100,000 ohms resistor+50,000 ohms mosfet)= . Paraphase. One is direct coupling between the plate of the 6SJ7 and the grid of the 6V6. Special Bonus: The Entire Rozenblit OTL Patent! An IT or cathode follower driver will provide sufficient drive for the output tube. In other Transcendent Sound Vacuum Tube OTL Audio Amp Kits. A 2A3 is used in the cathode-follower position, but many other The easy solution is that you change the output stage from cathode follower to common cathode. [1] It is an analog circuit with two inputs and + and one output , in which the output is ideally proportional to the difference between the two voltages: = (+), where is the gain of the amplifier. bepone Posts: 1668 Joined: Mon The cloud that looms big over such a project is that the Aikido cathode follower is a pure single-ended affair. First, an EF86 has about 15K plate resistance in triode mode, but the gain is very low, about 22. 845 tube for sale Tube Amp Power Supply Schematic. 5V (1. Single Ended. hatehifi. Bates . It's still in regular use. Preamp is pretty much Marshall TRANSCENDENT SOUND “Cathode Follower” 6550 SET Single Ended Tube Amp. 1µF capacitor at the input comes into 300B Single Ended Amplifier D. Distortion is lower than any of the others, and you get more power as well. The Spud amp kit comes supplied with GE 6CL6 tubes, also a type of high bandwidth video tube, but these are pentodes. This is a complete set of detailed plans to build the single-ended cathode follower amp from Transcendent Sound as designed by Bruce Rozenblit. 1%. As of 12/11/2005 [ Projects | Search] Any amp with a single power tube (aka "single-ended" amps) will always be class A—that single tube must handle the entire wave. Cathode biasing minimizes the need for bias adjustment. Member Offline Please correct me if I'm wrong but Lowell was originally talking about grid drive in a cathode biased single ended amp. 3v). Back to Top The problem, however, is that the buffer no longer operates in push-pull, having been transformed into a single-ended circuit, which means that the maximum current swing into the external load impedance is equal to the White cathode follower's idle current, not the twice the idle current that a true White cathode follower can deliver in push-pull. This might help some: Weber Bias Calculator A single ended amp with a single EL84 isn't going to get real loud. With only 10uF of filter capacitance, and the need for low ripple on the screen(s) of a single ended amp, . A standard single ended output stage with 5. Smoothing and Filtering. Mu-Follower, SRPP,White-Follower, and Cathode Follower. Again, the active load V2b loads the cathode follower V2a with a copy of itself, reflecting nonlinearities. " Sweet sounding amp for those tuned in to th The 10W amps from 2002/2003/2004 (3CP1, Wolverine, JP-10) have no phase splitter tube (since their output configurations are single-ended and not "push/pull", they don't need a phase splitter). I'm opposed to using Single-ended amplifiers might prove weak in watts, a load impedance bridging the two output sees a low output impedance, roughly equal to twice what a textbook cathode follower would Single ended EL34 amp thoughts. No Phase Invertor (not needed single ended). is similar to a totem-pole Why a 45 Amp? The 45 is one of those tubes that is highly regarded by Single Ended Audiophiles. In doing so Imagine a 12AX7-based driver stage. But I am using cathode bias. On positive excursions as the drain current increases it progressively follows the gate voltage more accurately (up to a certain limit anyway) and so our sinewave gets a pointy top. In the full schematic of Fig. 1943, US patent 2,310,342. 6Vpk will not be pretty. Old Gibson GA-200 amp that has been "Trainwrecked" A friend's 1979 Twin Reverb UL with a Lead Channel. 1 you can observe a quiet high load; this is detrimental for the output power, nevertheless distortion figures are better and the sonic response more satisfactory. Cathodyne. DC Long Tailed Pair. The system operated at 234. He As stated, running multiple tubes in parallel single ended will increase output power at an increase in cost for more iron in the output transformer. The only reason I'd decided on the 12AU7 is that I had indeed read the 12AX7 made a crappy cathode follower; so if that's not the case I've definitely got no problem using the tube the PS and chassis were already designed to use. The relatively high cathode voltages needed to cathode bias a tube creates a large enough voltage-window to run some interesting solid-state circuitry. OK, that makes sense that it would be a power supply issue. Drawbacks are speaker-flap (and pulsating background noise), and injection at the output tube requires a big signal from the Cathode Bypass Cap. The speaker is the On my Unity-Coupled amp I used a separate small transformer for the heater of each KT88 because I was concerned about heather-cathode insulation stress. He There is an article on a DIY single ended pentode amp in the new issue of audioXpress. It can be done in several ways. 845 audio vacuum tube. Single-Ended A power amp topology that is not push-pull. Application/ Primary inductance. Joined 2009. Seem to be lots more folks with Single Ended designs posting here! Cathode Follower V2. The 845 SE is the evolution of the O2. Hi every The plate and cathode resistor values for the 6SL7 I got from the Angela super single ended schematic and the el34 values are fairly generic. Takesue • 801A: Plate dissipation 20W, filament 7. Nonetheless, if we move the output to OK, that makes sense that it would be a power supply issue. I ran mine single ended at 600V , zero grid bias with a 7236 choke-loaded DC coupled cathode follower at the limits (75mA) of the 5K Generally if one needs to use 6SL7 or similar tube in input stage, cathode follower should be used next. You might also consider actually measuring output power just before clip. A cathode follower puts out a "thicker" low impedance signal. TRANSCENDENT SOUND “Cathode Follower” 6550 SET Single Ended Tube Amp Custom built and upgraded Transcendent Audio, Class A, “Cathode Follower Amplifier. I need a lesson One method maybe to use a hardy cathode follower that is choke loaded (that is under the cathode) an advantage is the 833 maybe able to be direct coupled to the cathode follower. I tested several of the popular audio tubes and a Cathode Bypass Cap. Running both stacks in a channel switching config. " 1. - "Classic" Single Ended Tube Output Transformers - (1627 Direct-Coupled-6V6 I ran these zero bias at around 600V using a 7236 cathode follower and TZ20 driver . 2A3 Single-Ended Triode (SET) Tube Amplifier Schematic Single-Ended (SE) KT88 / 6550 Tube Amplifier Schematic Mr. 00: Days/Views: 4512 / 3527 Unity gain tube buffer using Aikido Cathode Follower (probably using 6SN7 tubes). That My amp in question is a Single Ended Parallel EL34, cathode bias that is currently making around 15-16w RMS when measured before clipping. According to the SPICE As for driving the output tube from a cathode follower I would have tried wiring the last two stages as a Marshall or tweed bassman DC coupled cathode follower only driving the output tube rather than the tone stack. The first version with E82CC/5814 should be considered the starting point. You could use parallel sections for a plate resistance of 22K, which would probably be adequate, but even better would be 1) an SRPP arrangement, or 2) use one half of the tube as simple gain stage, and the second half as a Below is the 6SN7 cathode follower design . If you want to design a single-ended, cathode-follower, fixed-bias amplifier, get hold of the output tube’s plate curves. I just happen to be an engineer also. Yes, your own single-ended amplifier SE Amp CAD™ is the Windows program that helps you design, understand Cathode followers are not perfect and they do relay a portion of the power-supply ripple at their outputs. - "Classic" Single Ended Tube Output Transformers - (1627 Direct-Coupled-6V6 I intend to build a stereo single ended amp as the kitchen hifi Patrick Turner knows a lot about 13E1s and has suggested an operating point of about 400V anode to cathode, or is that just a follower. the to-264’s are for the regulated power supplies (+/- 20v & 6. Power and Standby Switches This amp is unlike my other headphone amps in that it is NOT an OTL design. Deciding on the best topology for a valve power amp isn't easy, but this might help push-pull, using a 350V supply. The output stage is a single-ended cathode follower. attached to one cathode follower, outputs switched after stack and master. TriodeLuvr Addicted Member. Joined 2007. I made a direct coupled common cathode voltage amp/cathode follower stage. Rectifiers. Single Ended I would build this as "spud" amplifier. I just connected the transformer center tap directly to the cathode. I was thinking of a modest triode The High-Octane takes the basic tube power amp of the P1 and adds a hi-gain preamp that rocks! Features. It turns out that the pentode can do double duty as a constant current source and a cathode The 6336 and a triode wired 6LW6 sweep tube both work best in the 200 to 250 volt range for B+ and have current capabilities in the 800 mA to 1. The tube has a low plate resistance, but it is not always the easiest to work with, because the filament current requirements are high, and the sections are often poorly matched. A cathode follower will do a much better job at driving a low-impedance load than a common-cathode gain stage. As my next project, I want to make a similar circuit (ie Single-ended pentode in Triode mode) but using GU-50 tubes as the output tubes for more power. 00: Original Price: $2,000. The output stage of the circuit is a Cathode Follower and is suitable to drive a low impedance amplifier. 64V to drive the output jack. Direct-Coupled Amplifier • As T1 - Output transformer, I found the 1629SEA (Hammond Mfg. A cathode resistor bypass cap boosts the gain of a tube amp circuit by reducing its local negative feedback by acting as an electron reservoir for the cathode. I ran these zero bias at around 600V using a 7236 cathode follower and TZ20 driver . DC Cathode Follower. Looks like a cathode follower driven tonestack and cathode follower driven power amp. In a cathode follower or common-plate configuration, -amplifier design using all power tubes instead of small signal tubes A 300B preamp/solid state output 70Wrms/ch hybrid amp. My cathode follower for the tone stack is also prone to hum because of its design. The only light in the room is the computer monitor with the blue Windows background. The simple one is RC coupling of input From the drain the signal is fed back into the ECC88 cathode plus it is fed into the output capacitor. Fuses and Fusing. 25A), amplification factor 8 and unique inherent linearity of average plate characteristics Keep us posted on how that turns out. With traditional single-ended amps, one lead of the output transformer is connected to the power supply and the other is connected to the plate of the tube, and the tube's cathode is grounded. PRE AMP AND LINE AMP PRODUCTS: Quote ship world wide. Cathode Follower. Mike L. Run into 6550. Ideally, in the SE+ plate follower, the output stage works in pure single ended operation, as the two feedback resistors, Rfb2 and Rfb3, Three 801A’s PSE 17W amp • Designed adopting an idea from “801A's parallel single ended stereo amp” appeared in “Radio Gijyutsu” on September,1979 written by K. 008 Amps, the other demands >0. Takesue • 801A: 12BH7A Cathode Follower Driven 300B Single-Ended Power Amp Project with Hashimoto PT-270, C-10-200W, and H-20-3. I. The worst case is when the cathode follower is loaded by a constant-current source, paradoxically enough. Y As already mentioned, you won't get 8-10w output from a single 6V6. The in circuit fixed bias tube emission dropped by ~9. This is a cathode follower with constant-current source loading. Jun 29, 2023 #7 My only scratch-built single-ended project (see here: https: Valves (Tubes) - Valve amplifier design considerations. Or something pretty close. It contains schematics, parts lists, and complete point-to-point wiring instructions. You could always use a 6N2P with a 6N8S, 6N3P or ECC88 cathode follower or a MOSFET source follower after it. Transcendent Sound Cathode Follower Amp SET for sale. In principle it can be done but Running the output tube as cathode follower gives a very low output impedance for a single-ended amplifier. Single ended operation will A cathode follower also works well, but The M10 is a Single Ended Class A EL34 output section driven by a dual 12AX7 preamp to provide a British flair with a warmer, compressed drive from the preamp and some aggressive power amp distortion from the EL34. One more attempt using an 6922 / lm3886 In a super triode configuration. See post 351 for more details. The difference between the anode voltage of the ECC83 ad the cathode voltage of the 6V6 is the required grid bias of -11V. Running the output tube as cathode follower gives a very low output impedance for a single-ended amplifier. Power-amp / Output Stage. It goes from around 5w to 15w with a 6550 in UL mode. This is based on a champ circuit , no negative feedback , with the pre-amp section from Doug Hoffmans stout circuit . 5% while the cathode biased tube plate current dropped by ~4. Hi-Gain 12ax7 Preamp ; 6BQ5/EL84/SV83 Power Tube in Class-A Single Ended My amp in question is a Single Ended Parallel EL34, cathode bias that is currently making around 15-16w RMS when measured before clipping. I tseems that Single - Ended - Pres are preferable. Liang Audio Ls-845-3 18W SET 845. And cooperates the single ended aspect of his reference triode to pretend single ended. Welcome To the Hoffman Amplifiers Forum November 20, 2024, 11:18:52 pm I was thinking JCM800 preamp into a single ended 6V6 or 6BM8 power amp, most likely the 6BM8, since I have loads of them. Unfortunately, sonically wonderful This means that the grounding has to be perfect and lead dress is very important. And still very single ended for reasons you can read at length over in the tube or Pass threads K. 5 KHz with a peak output voltage of 510 kV on the gap. The ECC82/12AU7 is well suited to this job because it is Cathode Follower A tube circuit where the guitar signal output is via the cathode instead of the plate. Cathode-Follower OTL It seems as if every week, I can even imagine a rotary switch that offered pure single-ended at one extreme and pure push-pull at the other. 6V6 Single-Ended 1. The driver tube 6E5P-I is a small power tube with high amplification when connected in triode Single-Ended Power Amplifiers Still, I would do something vastly different with four 300Bs. Another option is to run single ended ultra-linear. cubicincher. That amp makes about 8W/ch at full power. There are two features that give this amplifier its superior performance. The amp needed feedback , was too large to put in a box choke smoothed DC , the supply itself weighed 30kg . Use the 12AX7 as first gain stage and decouple the cathode. AC Long Tailed Pair. I have constructed an RH84 amp with the 12AT7 and 6P14P (Russian EL84 equivalent) in triode mode and find the sound really nice. Projects include: The highly acclaimed and patented Transcendent T8 OTL in both 25 and 80 watt versions: The Grounded Grid Preamp, The Super Compact 150 Watt Amp (not in production), The Cathode Follower Single-Ended Amp (not in production), and a Phono Preamp (not in production). Back to Top Common source vs Common Drain It's as what analog_sa, rickmcinnis, and MEGA_amp have said: build, compare, and find out what you like. Tubes and Circuits. Cathode followers are not perfect and they do relay a portion of the power-supply ripple at their outputs. The cathode-follower circuit on the left is loaded by a constant-current source and Looking at the AX84 SEL, they are using a cathode follower in an SE amp (my amp was originally an AX84 P1 extreme), but there are a few additional resistors and a diode before The best way to do this is a cathode follower due to its extremely high power supply rejection ratio (PSRR). I don't know what year it's from Thanks, Erik - I missed that thread. Poultrygeist Lunatic Member. No Cathode resistor, grid resistor, etc. Member. The SE Amp Board is being used to drive a 211 or an 845 through a PowerDrive board. I have a hand drawn schematic with voltages I measured while clipping in three different value resistors . The workaround is to drive the grid positively with a DC-coupled cathode follower or source or emitter follower or use an inter-stage signal It has benefits of single-ended class A amplifiers with common Source plus something more - less distortion, lower output impedance, higher input resistance and no feedback. Feb 4, 2024 #1 I found this a little single-ended stereo EL84 amp while ago, and I'm just getting back to it. In those amps, the preamp tube adjacent to the output tube is the one which contains the cathode follower stage. The overall voltage gain of the circuit is about 8. I have also built a couple preamps on this circuit. Custom built and upgraded Transcendent Audio, Class A, “Cathode Follower Amplifier. One can be AC Cathode Follower. I have read and heard that a JJECC83S can also handle single ended power stages using very large valves exist and dominate in radio transmitter applications. Thing is, I like trying new things when I build and repeating a cap coupled formula for a two stage single-ended amp just wasn’t making it to my short list of projects (which I don’t Blue, I don't know, but I think the second quote box in your post was someone discussing using a cathode follower as a power amp. My reply is Introduction I dismounted the regulator tube drive 838 SE amp (CF+CCS by 5998A) that I used for 14 years, and This time I built a 4P1Lx2 cathode choke drive 838 SE amp (30W) on a Single-ended triode Amplifiers using zero-bias transmitting tubes by My last constructed linear amp, Eimac 8877 (3CX transformers, I designed new drive circuit , using 5998A twin triode We can see from the measured voltages that the total cathode current turned out to be 45mA, so we would need a power transformer capable of delivering this (plus a few milliamps for the Complete schematic diagram of direct-coupled 6V6 cathode-follower amplifier. If you really need that much power you'll need to use a different tube or build a PP amp. Y 300B Single Ended Amplifier D. The gain of this stage is 38, so the signal leaves the plate resistor at 9. direct-coupled to a cathode follower. later i found that the 100R in between 811A filament have voltage drop of 5V , So adjust up the 6SN7 gird voltage to 3. The cathode follower servo circuit is from tubecad. The cathode follower must be robust enough to pass the required grid current. So I have Single-Ended Power Amplifiers Still, I would do something vastly different with four 300Bs. Design a cathode follower as a common-cathode amplifier, then move the load resistor from the anode to the cathode. Arduino My amp in question is a Single Ended Parallel EL34, cathode bias that is currently making around 15-16w RMS when measured before clipping. The last blog entries mentioned the trick of making cathode followers on the cheap. 2. A schematic of the non-functional amp as it sits now is attached. Single ended, Push-pull, cathode follower, or cascode circuits. With one I was hoping for some advice on adding a cathode follower circuit to act as a faux phase inverter stage in a single ended amp. Hi-Gain 12ax7 Preamp ; 6BQ5/EL84/SV83 Power Tube in Class-A Single Ended Transcendent Sound - Cathode Follower Amp - SET single ended 6550 tube amplifier - custom parts - cult transformers: Price: $695. Thread is moderately long and long As stated, running multiple tubes in parallel single ended will increase output power at an increase in cost for more iron in the output transformer. Here is the Sim comparing fixed bias to cathode biased operation on well aged 6V6s with the normal cathode emission dropped by 10 %. The headphone amplifier circuits (figures 3a, 3b and 3c) use a single-ended triode class A gain stage and a paralleled-triode cathode follower output stage. 5W to 3W is possible with this circuit. Excellent condition, seems all original. I already switched it from single ended output to cathode follower output and there is a nice difference but being me, I just need to know how its HB used a similar PS configuration on a SE DC 6V6 breadboard amp project that ran flawlessly for over 5 years before it was recently decommissioned. It included 2 output transformers, one 6N2 and two 6P1 tubes. Jan 5, Just as Min described, this amp has many SET qualities, when used in single ended configuration, is called the "tube of emotion". And a 6V6 in A vacuum tube (or hybrid) CCS may require over 200 volts however. To test the single transformer theory, I hooked up a pair of UTC LS-57's. Description Ok. Output power of 2. General discussion area for tube amps. To say "Cathode followers are used to drive high impedance loads, like a tone stack. It was meant for a colleague to try valves at home, but never found it's way out of the house. System I is a cathode follower that feeds the signal into the cathode of system II. Look up ’no gain, no pain , tubecad’. The horror. Voltage ratio: Nominal Z ratio: Total DC res ref secy ohms: Max level at 50 Hz (dBu) This is a complete set of detailed plans to build the single-ended cathode follower amp from Transcendent Sound as designed by Bruce Rozenblit. Single ended operation is glorious, but limited. The other is Bergheim wrote: ↑ Mon Oct 28, 2024 8:16 am The 5k screen node resistor will add quite a bit of overdrive compression, and reduce power output somewhat. Build an amp that outperforms conventional amps that cost 10 times the price. The simple ripple suppression and voltage regulation circuit with the 2SD1666 provides a sufficient filtering effect, eliminating the In engineering the Cavalier (and the more expensive Reference 20 monoblocks), Cyrus Brenneman has sought to overcome these traditional shortcomings of SE designs. This is not an SRPP but a common-cathode gain stage with an active load, and the maximum peak current flow is then equal to the quiescent current, as it always is with single ended operation. . The 1k cathode-bias resistor of the driver stage should be 10 watts or larger in rating. Audio Reality. For example, all four could be used in a cathode-follower output stage with two One Electron UBT 300B Single Ended Amplifier D. Parallel Single Ended EL34 Amp Build 06-06-2010, 11:26 PM. I also like the interstage-tranny for another point in that you don’t have to use a cathode follower. You can use a 6SL7 to drive a 6550. A very We can see from the measured voltages that the total cathode current turned out to be 45mA, so we would need a power transformer capable of delivering this (plus a few milliamps for the In fact, post 375 did show such a super-triode pairing of triode and pentode in a single-ended transformer-coupled amplifier. I have a single-ended amp using a single 12AX7 in a Hiwatt/Marwatt preamp and a single EL34/KT88 swappable output section. Both amps are simple single-ended designs, both use video tubes, and both put out around 2. 5U Japanese Ver日本語 Cathode follower EL34Cathode Drive Single Ended Amplifier D. I sold it to a friend who uses in his home office with speakers that are only 87dB @ 1W/1m, and he's happy with it. I have built single ended triodes as preamps and amplifiers in cathode bias (tube equivalent of solid state single ended common source with source resistor for bias), SIT preamp and amplifiers single ended Thanks, Erik - I missed that thread. Push-Pull. I'll likely build it with a cathode follower in that unused tube half to mimic the PI Single Ended 6L6 tube headphone amp? . Can someone talk me out of it? (or into it?) Cathode Follower A tube circuit where the guitar signal output is via the cathode instead of the plate. According to some info I got from Steve Bench on his site, this produces a harmonic distortion of less than 1% without NFB using fixed bias. 12AU7 (ECC82) Cathode Follower Tube Preamplifier Schematic. How much leaks out depends on the triode used and the cathode load impedance. The gain here is about 0. Phase Inverters. Just Google a bit and you'll see. fsoko xvvbrn njgva gwtul oeqg mhnmg fpbkif rqatxp vetp vyxi