Single ended tube amp with 5687 srpp driver

How high gain, wide bandwidth, and low source impedance are achieved with an absolute minimum of parts with the srpp front end. Having listened to pushpull amplifiers all along and very satisfied with the sound quality, because to me a tube amp sounds like a tube amp no matter what, i decided to try to build a single ended tube amp. If i were ambitious, i might change the output to triodeconnected 6dq6 and redesign the driver. This project actually began its life as a single ended 211 design. Pl83 6bq5 equivalent single ended ultralinear stereo power amplifier. If your amp is connected as illustrated in the schematic and you want to experience a single ended triode remove the lead connected to the screen grid. A nicad battery in place of the resistor and parallel cap. The project details the build of a singleended 6l6 harp amp. Personally, i have tried all these tubes and now use the 6n23p to drive my 300b although i have been very satisfied with the 7119 5687 as a driver. Jul 31, 2017 single ended triode set amplifiers have a cultlike following in audiophile circles, but their limited power output has limited their usability.

Single ended 807 amplifier this amplifier was built onthecheap. A very important consideration in attempting to create an amplifier with a natural characteristic is the selection of the gain devices. The audio note three features 2 x 300b per channel running in single ended parallel yielding 1617 watts in pure class a, this kit is on two mono chassis with valve rectified ht supplies, no signal feedback, it uses a 6sn7gt double triode as input valve and a pair of 5687 double triodes running in srpp as drivers. This amplifier was featured on the february 2004 issue of the highfidelity audio. All 5687s are specially selected for cryogenic treatment by tube world. The power supply use a 5v4g tube rectifier and clc filtering. The circuit of the paralleled 5687 srpp amplifier is simple and uses only one coupling capacitor in its output. Afterwards i built another one using the 811a tube. I have an srpp 6sl7 driver tube driving my 300b set amp which is normally biased at about 1. This article is talking about srpp tube amplifier and touching the key points. The audio note three features 2 x 300b per channel running in singleended parallel yielding 1617 watts in pure class a, this kit is on two mono chassis with valve rectified ht supplies, no signal feedback, it uses a 6sn7gt double triode as input valve and a pair of 5687 double triodes running in srpp as drivers. A single ended triode set is a vacuum tube electronic amplifier that uses a single triode to produce an output, in contrast to a pushpull amplifier which uses a pair of devices with antiphase inputs to generate an output with the wanted signals added and the distortion components subtracted.

Lone wolf blues company single ended 6l6 circuitry. Singleended amplifiers normally operate in class a. I think an amplifier builder should consult with himself and his amplifier before asking the reference books and authorities. I received the parts connection catalog just before christmas 1995. A problem exists in all vacuum tube power amplifiers when the input signal reaches the point where the driver tube attempts to drive the grid of the output tube positive. Jan 22, 2019 with the 6k load on srppp driver you get 1. This design was chosen for its relative simplicity compared to the more efficient but more complex pushpull output stage, in. Single ended triode amplifiers are prone to another issue. That could work without feedback, kind of a poor mans 300b amp. Srpp design using 5687 in high bias current for maximum linearity.

Singleended class a operation is less efficient than pushpull. Diy vacuum tube valve amplifier projects hifi audio. I used salvaged transformers purchased well below online prices and 807 tubes which are still reasonably priced. Single ended 6s4 amplifier with a 6dj8 srpp driver stage. The use of a single tube in the output stage of the power amplifier is commonly referred to as a singleended design. Diytube 6l6 clementine single ended tube amp diy audio. The optimised srpp amp part 1 by merlin blencowe some deceptivelysimple circuits, explained for the audio amateur. It is routinely found in the low level circuitry of the finest preamplifying stages and in the front end circuits of the finest power amplifiers. I had been hearing a lot of good things about this tube, so i started pokeing around. These meet in the output transformer where they are combined back to a single signal at the secondary to be fed to a speaker. Single ended hi voltage, same as above, plus the need of a sufficient power triode. I will build a 6sl7 or 12ax7 srpp voltage amp to drive a ux245 triode base on the above calculation on my single end stereo platform. Y sv81 single ended amplifier trium tangstain tube amplifier d. Another take on a classic design from the rca tube rc amp chart single ended.

You say that your amp operates in a1 and that wont happen. The srpp project in this article began as a sound check on a class a2 driver for a svetlana 8111057210 amp intended to drive my 7. Having a bunch of 7044 computer triodes laying around a lot like a 5687, also 7119e182cc, and a couple of hammond 125js i bough for the el34 srpp project, i thought id. Small power single ended amplifier on 20 by 71a how about dont you think only 0. Imagine a singleended amp, one with one power tube running in actual singleended class a, like a champ. Attention, all firsttime or wanna be builders of single ended directly heated triode amps.

Wildly popular, this circuit was the defining vacuum tube circuit of the 90s. Cathodefollower power amplifiers last time, i presented a tube based power amplifier that looked as if it used a cathodefollower output stage, but didnt. The 811a vacuum tube it is a power triode capable to output 10 15 watts in a single ended class a2 configuration, in a three stages circuit using interstage transformer in the driving stage. I also showed a tube power amplifier that both looked like and was a true cathodefollower power amplifier.

Singleended triode set amplifiers have a cultlike following in audiophile circles, but their limited power output has limited their usability. Superb in audio note ongaku, emotive audio sira and mfa. My last post generated much more interest than i had expected. Ok, i admit i moreorless stole this idea from bob danielaks 5687 amp. This project actually began its life as a singleended 211 design. Diytube 6l6 clementine single ended tube amp shannon parks, owner of diytube, has made a number of projects available since 2003 when the diytube st35 clone was made available. Rca 1625 final stage, tungsol 6sn7gtb driver, rca 6201 preamp, lorenz em85 vu meter, amperite 6no120 delay switch. This is an easy to build, simple directcoupled input driver circuit that provides the proper drive voltage to the grid of the 211. From schematic to ordering parts to cab design, it is all here and explained in detail. As a note, i did try an srpp output stage with a 6as7 tube and it was highly unstable. You need a trick output transformer among other things, but its just like the champexcept with twice the output power. The first tube power amplifiers were single ended circuits using a single tube driving the primary of a transformer.

It also affects the overall gain of the power amp, and the frequency compensation provided by components within the feedback loop one or more caps or resistors to help keep the power amp stable. The reason the circuit is pushpull and not single ended is that the signal reaching the bottom triode causes the signal on the grid of the top triode to be in antiphase with it. If you crank up the drive level in search of more power the grid of the output tube will be. A singleended triode set is a vacuum tube electronic amplifier that uses a single triode to produce an output, in contrast to a pushpull amplifier which uses a pair of devices with antiphase inputs to generate an output with the wanted signals added and the distortion components subtracted. Free returns are available for the shipping address you chose. I have built a somewhat similar 6550 single ended amp driven by a srpp 6sl7 with the output tube hooked up as ultralinear.

But even if we stick to single ended operation, we can still wring more performance from the simple cathode follower. Pl83 6bq5 equivalent singleended ultralinear stereo power amplifier. Shannon parks, headhoncho of diytube, has made plenty of projects available since 2003 when the diytube st35 clone was made available. Dec 31, 2015 my new single end stereo amplifier with 1625 tubes same as the 807 and edcor output transformers. The bias for the output tube is provided by the voltage divider created between the driver stage load upper half of 6sl7, the driver stage lower half of 6sl7 and the extra large cathode resistor the three series resistors below the 2a3 tube. At first i built a prototype amp using the sv81 tube.

Cathodefollower power amplifiers last time, i presented a tubebased power amplifier that looked as if it used a cathodefollower output stage, but didnt. In an effort to give a little back to the internet harp and tube amp communities, i have decided to offer this free project. In the back were the data sheets for various tubes, including the lovely 211. Their impedance is pretty typical of headphones, at 120 ohms. Unless the driver is carefully designed to clip before this can happen, it will. Since for power amplification it is usual to use pentodes or beamtetrodes, which produce predominantly odd harmonics, we can expect all. The sound produced by a singleended amp is rather unique. Singleended amplifiers tend to be bigger and more expensive than pushpull, but they have a more natural transfer curve.

If you crank up the drive level in search of more power the grid of the output tube will be driven positive and will start to draw current. Heres a sample circuit that uses both the 766p53727 as a voltage amp and a 56877119 as a direct coupled choke loaded driver. The sound produced by a single ended amp is rather unique. The first tube power amplifiers were singleended circuits using a single tube driving the primary of a transformer. I would put it up against a 6sn7 cap coupled driver any day. But even if we stick to singleended operation, we can still wring more performance from the simple cathode follower. Single ended triodes sets, the ultimate tube lovers dream. The actual experiment support can prove the theory. The project details the build of a single ended 6l6 harp amp. Whats so irresistible about a singleended triode set amp. The preamplifier tube is a inexpensive 6n1p, but the 6dj8 ecc88 e88cc family of tubes can also be used. Single ended pentode amps are developing a following currently as well as single ended triodes. The 5687 is especially suited for use as a line amplifier with its 3.

Loftinwhite 2a3 single ended triode tube amplifier schematic. Apr 19, 2012 diytube 6l6 clementine single ended tube amp shannon parks, owner of diytube, has made a number of projects available since 2003 when the diytube st35 clone was made available. There are other designs that put a tube between the ps and the outputs thus making it the driver. This little guy is a headphone amplifier that i designed mainly to drive the fine akg k headphones. The intention for this amplifier was to drive classic highefficiency speaker systems, such as western electric we594a or we755a. Lower end does not resemble a tube amp so much, it is clear and tight, deep and defined. The easiest way to get this is using a pass tube like 6as7 or its. I needed a driver with about 50 ma current capability and at least 50 v rms. In this design the problem has been solved through the usage of. Since then, a handful of projects have been released, from the 60 watt eiclone amplifier to driver boards for dynacos to standalone singleended amplifiers like the clementine and get set go.