Single ended tube amp design pdf

The tube exhibits very good linearity at moderately high idle currents of around 30ma and at this level is dissipating roughly 10 watts. The objective of this project is to develop an output transformer for singleended tube amplifiers with. The two stage zero feedback rc coupled circuit uses parallel feed a. The result is an amp with amazing sound quality, super low noise, and can be used with headphones. The problem is as complexity increases the more likely you are to make an assembly mistake and troubleshooting a complex amp can be extremely difficult for a beginner.

It uses a single pentode as the driver a 12hg7 video amp tube, and a solidstate power supply with a microprocessor controller. This guide discusses all relevant aspects for an integrated pushpull vacuum tube amplifier design, including the power supply unit. This is a single ended triode amp that i built using the 8 transmitting pentode, connected as a triode. Single ended amplifier simply require much more care in design than pushpull designs. This page describes the tubelab sse simple singleended amplifier, and outlines its origins. Heres an amp project especially for firsttime builders featuring the 6bq5 tube.

Class a single ended amplifier to reduce distortion. Beside that, el34, el84, and 12ax7 vacuum tubes are used in many practical examples, to design the various parts of the circuits and to compute the values of the needed components. The project details the build of a singleended 6l6 harp amp. Spec said will be get 10w rms with 6l6 but actually never get 10w rms.

The pass labs aleph 5 amp is as quoted by shakey a 60 wpc class a single ended design, and not a push pull. The spec sheet shows almost 20w of class a1 output for a single tube, with a plate voltage of 400v and g2 voltage at 225v. Kt886550 compatible single ended amplifier 5th jan 2014 using fladance mp player 8w rms. To ptotect the amp,tube and machine are packed individually. Dec 24, 2018 14 videos play all kt88 single ended amplifier build 2018 blueglow electronics replacing coupling capacitors in vintage gear duration. The output on this amp is probably a little lower, but it certainly doesnt sound like it. Visit the links on the lower left to learn the detailed design methodology, and theory of operation. As rick spencer writes in its introduction, in order for this beloved hobby of ours to thrive and survive well into the future, we must always strive to make it interesting to newcomers. Jul 31, 2017 the other speaker design thats often teamed with an set amp is the single driver speaker thats close to 100db efficient, has no crossover, and has very easy impedance curves. If youre familiar with tube amplifiers, you know that the. The 6ck4 is an indirect heated triode originally intended for tv service as a vertical deflection amplifier. Having never built a singleended 300b amp, i figured the right thing to do would be to go overboard. One connection goes to the power supply, the other to the plate of the power tube or tubes.

According to the factory specs, the 6550 in singleended mode is capable of a fairly good power output. The use of a single tube in the output stage of the power amplifier is commonly referred to as a singleended design. This design has been optimized for low distortion and high efficiency with no negative feedback or any sort of servo correction circuitry. Jun 27, 2016 according to the factory specs, the 6550 in singleended mode is capable of a fairly good power output. Therefore comparison of the pass labs aleph 5 to single ended tube design can be made through shared circuit theory. The other speaker design thats often teamed with an set amp is the singledriver speaker thats close to 100db efficient, has no crossover, and has very easy impedance curves. Lower end does not resemble a tube amp so much, it is clear and. It is not a realistic schematic of its actual design.

Singleended pure class a 6sn7 300b tube amp hifi stereo amplifier diy kit 8w2. This amplifier design uses 6ck4s in the output stage. 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. With this in mind, rick spencer created this singleended design using. This is a fairly typical design that resembles entry level amps from the 1960s. The g symbol represents a galvanometer, a sensitive voltmeter movement.

Imagine a singleended amp, one with one power tube running in actual singleended class a, like a champ. Hifi stereo el34 vacuum tube amplifier class a singleended power amp diy kit. Singleended classa tube amplifier design and construction. Time tested, simple tube single ended stereo amp delivers that important first sweet watt that audiophiles love. Single ended el84 tube amp information, guitar amp. How to start a singleended design most audiophiles fall into two groups. Output audio transformer design the output transformer in a single ended tube amplifier is the device which matches the highoutput impedance of the tube to the low input impedance of the speaker load 4, 8 or 16 ohm. Instruction book for specimen single ended stereo tube amp 62718. Lt1567 a differential inputtosingleended output amplifier. Audio transformer is the primary part of a tube amplifier which generates an electromagnetic field. The phasesplitter is a very critical part of the pp amplifier, and its behaviour is of great importance for the performance of the amplifier. Output stage the major factor involving the design of this single ended output stage is matching an available output tube to an available output transformer ot, which can provide the proper impedance matching. Maybe you hear some unique distortion and harmonic flavor.

Using typical operating parameters laid out in 1, the 6v6 power tube, operating in triode mode, has an ideal load impedance of 5k ohm. With the monopolar 24v power supply, we can expect an output power of about 6w into 8ohm loads. They are usually used for relatively small amplifiers, e. Higher powers are obtainable with either very large power valves, or by using multiple valves in parallel, but beyond about 15w it is usual to use. Often times all that is available is a data sheet, some simple design point information, and maybe some plate circuit characteristic curves if were lucky. We suggest that you only use tubes that yield good test results for the best amp performance. The spreadsheets generated for use with this book are specific to the manual. The input and output voltage connections are shown as single conductors. My design involves a fourstage preamplifier, which uses two dualtriode 12ax7 tubes. As can be seen, the design of the seamplifier is simple. This is a singleended triode amp that i built using the 8 transmitting pentode, connected as a triode. Full construction details are in the assembly manual.

The power amplifier involves three stages, two of which use a 12ax7, and the last of which runs through an el34 pentode tube. Singleended amplifiers normally operate in class a. Normally a weakness of tube amps, and even more so for singleended, the multivalve was a real surprise here. This is a testament to the james output transformer and the feedback loop controlling the. This design procedure and program works with either single ended or pushpull output stages. Summarjran amplifier circuit for pushpull operation of two. Its design has been optimized for single supply operation with a full set of specifications at 5v. The artist group avoids math, algorithms, and detailed procedures whenever possible, preferring to follow their instincts and subconscious whims. Whats so irresistible about a singleended triode set amp. This project is intended to be built as designed and not piece milled with other designs. The output transformer primary is not centertapped, having only two connections. There is an article in audioxpress magazine may, 2009 i put together on this, so i wont post all the details about the design and construction please buy the magazine. The use of a single tube in the output stage of the power amplifier is commonly referred to as a single ended design.

The cost of a tube amplifier mostly consists of the cost of an output transformer and tubes that is usually a factor limiting the sound quality. The advent of stereo in these years did not improve this situation. The project details the build of a single ended 6l6 harp amp. Seta single ended tube amplifier this is my first vacuum tube amplifier, original design by andrea ciuffoli. The major factor involving the design of this single ended output stage is matching an available output tube to an available output transformer ot, which can provide the proper impedance matching. Singleended and differential amplifiers chapter 8 operational amplifiers. In laymans terms, a single power tube does all the work. Building an amplifier is an important step in the experimental part of the project. In pursuit of great sound quality of the 300b amp, we have updated and improved the amplification, power, and feedback circuitry. The first tube power amplifiers were single ended circuits using a single tube driving the primary of a transformer. A good example of this is the data available for power amplifier tubes. I have said it before and ill likely say it again, you must have a tube manual to work with tubes. You can get a circuit board from them or you can build it point to point.

Imagine a single ended amp, one with one power tube running in actual single ended class a, like a champ. Singleended and differential amplifiers operational. Highquality singleended 8w amplifier using standard valves and the lundahl ll 1664 output transformer claus byrith 2002. The following design adds a triode to a zen singleended amplifier, so that the triode can impose its amplification factor upon the output signal.

Single ended tube based guitar amplifier digital commons their tubes, guitar amp makers, and especially their rockstar customers, 10k. Hoffman amplifiers tube amp forum, single ended el84. Keep always one hand, left hand is better, close to your back. I have met several musicians who not only fix their tube amplifiers, but modify them, without any deep knowledge of how tube amplifiers works, let alone such concepts as transconductance or perveance. Almost identical circuit to the 2w amp, except output tube is a single ended el84 6bq5. The lowest notes were deep, welldamped, and had excellent control without the slight tubbiness i normally associate with tube amplifiers. Single ended hi voltage, same as above, plus the need of a sufficient power triode. The origin of the power amplifier design came from the schematic below, which came from the 1959 rca receiving tube manual tech series rc19.

Single ended el84 stereo amplifier with one 12au7 driver tubes are. Normally a weakness of tube amps, and even more so for single ended, the multivalve was a real surprise here. Where i build a singleended pentode amplifier steve. This circuit shows a circuit for converting a differential input to a singleended output. To ptotect the amp, tube and machine are packed individually. Welcome to the hoffman amplifiers forum may 07, 2020, 12. Get the best deals on vintage tube amplifiers amps when you shop the largest online selection at. One of the things that lure diyers to build set singleended triode amplifiers is their great sound, due in part to a fabulous first watt of undistorted power.

You can use el84s if you like but i prefer the russian 6p15. For a gain equal to one r1 r2 604w and v out v2 v1 the input referred differential voltage noise density is 9nvrthz and. The valve wizard single ended how to design valve guitar. A singleended guitar amp output stage is generally biased class a, in order to maximize the output power before distortion. Since a singleended amplifier usually can get around 20% of the max plate dissipation to go to the loudspeakers, i figured one could achieve approximately one watt from these little guys. This page describes the tubelab sse simple single ended amplifier, and outlines its origins. Singleended classa tube amplifier aug 10, 2007 2 this configuration serves two major functions. It was created by aleksandar kitic, who has said that the amp was really designed for the first time builder, to provide results even with salvaged parts or the cheapest.

The first tube power amplifiers were singleended circuits using a single tube driving the primary of a transformer. The following design adds a triode to a zen single ended amplifier, so that the triode can impose its amplification factor upon the output signal. Without having to analyze the actual transistor design of the amplifier, you can readily discern the whole circuits function. Apr 20, 20 single ended el84 stereo amplifier with one 12au7 driver tubes are. What i decided on was to build a singleended fender 5f2a princeton amp with the resistor and capacitor values from a 1957 gibson ga5 skylark amp.

With that in mind, the first thing to do when designing an amp like this is to choose an operating point for the output tube technically you start with the speaker, but i am assuming a standard 8ohm speaker. Lone wolf blues company single ended 6l6 circuitry. This amp circuit is derived from the classic single ended designs that began in the 1930s. A single ended guitar amp output stage is generally biased class a, in order to maximize the output power before distortion. After doing some research it seemed the perfect beginners project was the rh84 singleended amplifier. What i decided on was to build a single ended fender 5f2a princeton amp with the resistor and capacitor values from a 1957 gibson ga5 skylark amp. In this design the problem has been solved through the usage of. A combined input stage and driver drives the output valve, and a transformer matches. Beside that, el34, el84, and 12ax7 vacuum tubes are used in many practical examples, to design the various parts of the circuits and to.

The lt1006 is the first precision single supply operational amplifier. 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. One of the main problems encountered in modern vacuum tube design is a great lack of available information. A combined input stage and driver drives the output valve, and a transformer matches the valve and the speaker system. In looking for a tube amplifier to build for this course, i had very little experience working with tubes so i started looking at some of the original designs from fender and gibson. Sorry for the rapid swap 12au712ax7 both tubes were quite cold. From schematic to ordering parts to cab design, it is all here and explained in detail. How to start a single ended design most audiophiles fall into two groups. Singleended classa tube amplifier design and construction ben verellen, daniel nevistic, and max gorman m. An easily constructed highquality singleended 8w amplifier.

Hifi el34 vacuum tube power amplifier class a desk. You must put a coupling cap between the plate of the first tube and the gain pot. The design of this stage takes skill and care as explained in my earlier paper. Keep this in mind when choosing your first build, anyone can piece together a complex amp. How to build a tube amplifier rob robinettes car and tube. Kt88 single ended tube amplifier build 2018 part 11. Now imagine two output tubes, both running in true class a. The objective of this project is to develop an output transformer for single ended tube amplifiers with. Seta single ended tube amplifier audio design guide. Triode lab p10 output transformers specific designed and engineered for low watts refinement around 2a345300b6v6 tubes.