Diy 12sl7 srpp pushpull kt88 tube amp diyaudioprojects. The output of this small amplifier in which a 6v6gt output pentode is connected as triode is about 4. An inexpensive, easy to build diy valvetube tester for quite some time i have been looking at developing a design for a diy valvetube tester that is easy to build and uses readily available, low cost parts. All menu of my experiment valve amplifiers and solid state of this site. I think it can vary by the amp design, but for my line magnetic, the el34s sounded like what id always pictured a tube amp sounding like, where as the kt88 s had a little more of the force and slam of solid state. The orange vt valve tester will become an essential piece of kit for the professional guitar amp technicians workbench. The vt is going to make life a lot easier from now on.
They are usually used for relatively small amplifiers, e. Valve technology is now redundant and there is no point discussing valve amp designs that fall short of achieving the highest performance for replicating music. Octal valve retainer kt88 6550 valves sockets this is an octal tube retainer for kt886550 types. Searching on the internet, i could find what i can only call gimmick designer amps and second hand guitar heads. The wd kt88 amplifier, in both forms is excellent, but i would spend the extra on the xl version. A tube amplifier chassis contains lethal high voltage even when unpluggedsometimes over 700 volts ac and 500 volts dc. Im so blown away with the tone quality of my 4x kt88 reeves 225 running guitars, that i thought it would be quite cool to do a 2x kt88 version to make it just a smidge safer on the ears. Oct 14, 2016 the kt88 is one of the few classic audio output valves. Create innovative programs and fun games on your tiny yet powerful raspberry pi.
By way of legendary amp engineer ed jahns, fender would produce the most powerful production tube amp ever made, the fender 400 ps. Few people working in transformer winding companies have a knowledge of electronics or valve amps. See more ideas about valve amplifier, electronic schematics and vacuum tube. Tube bias calculator rob robinettes car and tube amp. Glassware tube audio design software including free curves software. Icon audio stereo 25 mkii integrated amp based on st40 mkiiim icon audio created the handmade stereo 25 mkii integrated tube amplifier with the goal of making it the easiesttouse, lowestmaintenance, and most powerful highend. Testing and measurements monoblock kt88 pushpull tube amp kit. Kt88 s sovtek vs valve art audiogon discussion forum. This text attempts to explain how the design decisions were made and describe the design. With highly sensitive speakers like this hum is pretty much a show stopper for me. Never touch the amplifier chassis with one hand while probing with the other hand because a lethal shock can run between your arms. Transformer winding is an extension of the fitting and turning industry. As musical tastes transformed from big band to swing to jump.
Allen wright design class a kt88 tube amp, built by. The kt88 is one of the few classic audio output valves. My amp came in el34 and kt88 versions, and i picked the former. Specifically designed for audio amplification, the kt88 has similar ratings to the american 6550 which was designed for use as a servo. The slides are pretty heavy on engineering design terms, but give a good feel for what it takes to construct and tune an audio amplifier using vacuum tube. The kt88 is a beam tetrode k inkless t etrode hence kt vacuum tube for audio amplification. Kt88 tube power amplifier class a single ended valve triode amplifier has not same tone with push psu amplifier. This power could be considered low for a pair of kt88 but i want low feedback, low distortion and good damping factor. Pp2012 kt88 hiend push pull amplifier audio design guide. But i need more information about valves and what valveparts i should look for when it comes to sub bass. A pair of pushpull class a, ultra linear mono block tube amplifiers that can be used with several different vacuum tubes including kt77 6l6gc kt88 with a 12sl7 driver and 6no30 tubes. Kt88 distortion at 30w with 10db feedback and vin0. Kt88 valve amplifier project 3d cad model library grabcad.
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. A perfectly balanced pushpull stage will cancel all even harmonic distortion and sum odd harmonic distortion generated within the power stage. Debuting in 1969, the 400 ps was a behemoth conservatively rated at 435 watts rms. May 20, 2010 this 7 page chapter on valve amps is centred on understanding the operation of the williamson ultra linear 100 watt valve amp. Theres an air of magic surrounding a valve amp thats had its valves on for a couple of hours it just sounds incredible. However, guitar amps rarely use matched valves and usually have a lessthanperfect phase inverter. This amplifier was featured on the february 2004 issue of the highfidelity audio. High quality low distortion stereo 400w valve amplifier. Group a consists of kt77, 6ca7, el34, 6l6gc and similar variants.
Single ended class a 6v6 6j5 valve vacuum tube amplifier circuit. Specifically designed for audio amplification, the kt88 has similar ratings to the american 6550 which was designed for use as a servo amplifier. The amps will also work with el34, 6550, kt88, or kt90 tubes. Ever wonder what goes into the design of a vacuum tube audio amplifier. The minimum for acceptable kt88s in a good power amp in my pompous opinion is the jj tesla, a little more laidback than the svetlana, but i reckon the svetlana will suit the character of the power 3s better. Oddblocks classa pushpull kt88 tube amplifier 12sl7. With the kit supplied jan philips 5751 drivers and genalex gold lion kt88 output tubes the sound was superb. It is one of the largest tubes in its class and can handle significantly higher plate voltages than similar tubes, up to 800 volts. For a 2x kt88 guitar amp, you would have spectacular rich cleans, and some rather chest pounding power wide open, with the right speakers, in the right circuit. Professionally built from allens schematic by local amp builder and classicsound. Tube rectifier in doubleend amp power supply sag sustain.
For many years the kt66 valve has been regarded by many as the hallmark of a highquality amplifier whether home made or commercially manufactured. The mainstay of high power valves for valve amps over the past 50 years, most high end hifi and guitar manufactures have built, or have an amp capable of running the kt88 ampeg, audio research, beard, carey, conrad johnson, mcintosh, marshall, rouge audio, sonic frontiers, mesa boogie etc. Kt88 distortion and frequency at 25w with 16db of feedback vin1vrms. With this valve it is therefore possible to build amplifiers having higher power outputs suitable for publicaddress equipment and highquality sound reproduction in general. General view of the 8850 amplifier with left its complementary pre amplifier. The valve wizard single ended how to design valve guitar.
Not changing it will both shorten the life of the tube probably dramatically and also not allow the kt88 to be run close to their design ratings. High chrome finish gives a very snug fit to kt886550 which is. For years i have been using a valve tester that i had developed in the past. The world design kt88 kit amplifier developed 26 watts into 8 ohms and 33 watts into 4 ohms, so its untapped secondary is load matched to a low load, as it needs to be to suit modern loudspeakers, most of which have 4 ohm bass. The humble valve amp pretty much defined the sound of guitar music from the 50s onwards. This page describes a low power single ended audio amplifier. Icon audio stereo 25 mkii integrated amp kt88 demo. Designed and manufactured by our own great british company the gecmo valve co, she is one of the best. This will be enough to bias the valve almost to cutoff, and we dont really need more than that. The subject amplifier is a medium power monoblock design, based on triode connected kt88. Looking at the ax84 website, they have a schematic that would work for an el84, 6l6 or kt88.
It was absolutely, systematically and thoroughly pulverised sonically by my 211 parallel single endedbased amps. I was asked by kegger on the ak tube amp audio forum if i was interested in designing a pcb based amp on the 6l6 output tube family. Studio 10 kt88 is driven by the monumental kt88 power amp valve and an ecc83 in the preamp stage. The difference is in both the bias voltages and maximum power dissipations. Design and construction of a pair of pushpull classa, ultralinear mono block tube amplifiers that can be used with several different power vacuum tubes including pp tube amp kt88 pp tube amp see more. Using only a pair of kt88 i have got 25w in triode connection and 3540w using the ultra linear configuration. These amps give the warmest and truest guitar tone that players around the world still love today. The amplifier stage is based on the compact hifi power amplifier by melvin leibowitz.
Gio writes in to tell us about his latest vacuum tubebased audio amplifier design, the 5751 srpp pushpull tube amp. Most valve amp manufacturers have a basic academic understanding of output trannys, but often. Our el34 valves and kt88 valves will tolerate much higher voltage, so we have a big safety margin, and we can give 2 years guarantee for our el34 and kt88 valves in our amplifiers. This 7 page chapter on valve amps is centred on understanding the operation of the williamson ultra linear 100 watt valve amp. Kt88 valve amplifier project likes 3d cad model library. We have set new goal to implement the newest true balanced circuit topology from input stage, driving. The new kt88 is a pentode with a higher anodeplusscreen dissipation of 40 watts, and a higher mutual conductance of 11 mav. The following pages of this chapter will describe how a williamson ul class ab ab1 amplifier works and how valve amps can be serviced and maintained to give the best performanse.
Using only a pair of kt88 i have got 25w in triode connection and 3540w using the. Gotta replace power tubes in my cary monoblocks any. Well, radio building master greg charvat has you covered with his latest presentation, design your own vacuum tube audio amplifier. Kt88s can be put in the 1959hw with some modifications to the bias circuit, yes. See more ideas about valve amplifier, tube and vacuum tube. Apr 17, 2016 this 2 x kt88 amplifier is for sale by ebay member ukmarshph1qriwi you will not find another like it. Classa ultralinear 12sl7 srpp kt88 sipp tube amplifier. The valve wizard pushpull how to design valve guitar.
By trying out several different sets of operating conditions in the computer i could eliminate hundreds of possibilities without playing with electricity. The valve amp hospital vintage amp repairs a gec kt88 batch date 7307 1973july. If you have not been trained to work with high voltage then have an amp technician service your amp. From andrew champ cba 200200 stereo 8 x kt88 amp august 2011 i wanted to replace a 400 watt valve amp that i had custombuilt back in the early seventies but hadnt owned for many years. Hifi world world favorite component features simple bias circuit, alltriode front end, tube rolling options. I set the amplifier using vacuum tubes of different types in the same circuit this time. Tube bias calculator rob robinettes car and tube amp website. To get the best sonic result there are no electrolytic capacitors on the signal path and in the anodic power supply. When building high power valve amplifiers, using multiple kt88 output valves in push pull is preferable to using 2 very large valves, as an ht power supply requirement of 560v is very easy to achieve and output valve failure will not cause the amplifier to shut down, as at least 2 valves would have to fail in each half of the push pull output. C, remodelled the tt21 transmitting tube, naming it kt88. With an anode to anode load of 4,000 ohms and 550 volts on the anode a pair run in ultra linear ab1 will deliver 100 watts at 3. Valve amp manufacturers purchase trannys from transformer winding companies. Assembly manual schematic parts list tubes and applications design simulations. After balancing the bias i hooked up the amps to a pair of back loaded horns with fostex fe206e drivers 96 db 1 w and checked for hum.
The response is very smooth, there is plenty of detail and that wonderful warm tube sound. There are a lot of testimonial forms for the el34 valve amplifier, which is an older and more established model. Im interested in letting someone build a kt88 pre amp just for this purpose. Design and construction of a pair of pushpull classa, ultralinear mono block tube amplifiers that can be used with several different power vacuum tubes including el34, kt77, 6l6gc, 6550, kt88, kt90. This is a set of 6 matched kt88 jj tesla specially selected for the ampeg svt. The poddwatt is a small classa stereo vacuum tube amplifier that will provide about 5 to 7 watts of high quality sound. Mike clementtech for tony iommi, david gilmour band, motorhead, iron maiden, jeff beck band. The kt88 audio tube is considered to be one of the best sounding power tubes for hifi tube audio amplifiers. I dont own any valve arts but something tells me they are chinese valves. The current tubes are golden aero kt99s, rare and probably unobtainable at this point. Bad anyway,but this web site is not english program site. In general, the kt88 tube has a magical midrange similar to the smaller el34 tube, but with low and high end extremes that reach much further.
El346550kt88 single ended amplifier on 28th mar 2018. Kt88 s can be put in the 1959hw with some modifications to the bias circuit, yes. Class ab1, 12 x 6550 per channel, very basic details. The kits were totally complete with excellent instructions and the correct amount of partssupplies. Im very satisfied with my ab1 jolida p with vintage siemens tubes in it its really a heavenly amp to drive my ar3as. With a total anodeplusscreen dissipation of 28 watts, when operated with cathode bias, its power output, in pushpull. Design and construction of a pair of pushpull classa, ultralinear mono block tube amplifiers that can be used with several different power vacuum tubes including pp tube amp 12sl7 srpp kt88 pushpull tube amp schematic see more.
Group b consists of kt88, kt90, 6550 and their variants. For design purposes i found that potential power tubes pretty much fell into two groups. But the design centre value should be about 400 volts or less. The kt88 fits a standard eightpin octal socket and has similar pinout and applications as the 6l6 and el34. Front lcd is controlled by a micro controller which can be software upgraded at later time to. Final connections kt88 tube amp kit tube, audio, amp. Benefitting from the extra headroom of the kt88, the studio 10 kt88 is the pinnacle of dynamic modern cleans and tight highgain overdrives. The amps are cary audio slm70 monoblocks made in 1991, each amp using four power tubes. The figures given are for single ended use, but the valve is almost invariably used in push pull pairs. Listening impressions odd block kt88 tube amp kits.
Anyone know off hand what the power requirements are or where i would find the information. After many years designing single ended amplifiers i have decided to start a. Even if the phase inverter is perfectly balanced it will inevitably go out of balance when the power. Its quite nice looking, especially if you like wood. Kt88 distortion and frequency at 35w with 16db of feedback vin1.
930 1529 284 431 1218 377 458 711 1188 1482 990 616 1207 485 1022 1197 337 1183 1139 974 364 535 733 1307 438 499 1404 1285 1195 945 530 773 838 169 1018 1442 271 951