Reference Audio Amplifier without BjT's,jFET's and MOSFET's SpecialMadeForAudio wante

[tiefbassuebertr]

Most high end audio companies and authors for diy projects prefer the use of typical audio frequency (AF) transistors like 2SK389, 2SK170 and 2SJ74 for the input stages, BF469-BF471 for the VAS stages and 2SA1943/2SC5200 resp. 2SK1530/2SJ201 for the buffer stages.
About the URLs
http://www.diyaudio.com/forums/soli...l-mosfets-class-ab-overview-p-spice-urls.html
http://www.diyaudio.com/forums/solid-state/168851-transistor-data-sorting.html
http://www.diyaudio.com/forums/soli...istor-families-audio-power-output-stages.html
http://www.diyaudio.com/forums/soli...ver-stages-high-power-amplifier-overview.html
you will find some overviews about this kind of transistors.
I guess, in a short time all this types will be more and more obsolete.

Therefore I am looking to amplifier topologies suited for currently and in the near feature good available transistor types from the aera "recommend for Switching applications" but not from the area "recommend for audio applications".

A good known older example of such an amplifier was the allfet amps from the "Aleph" series, equipped with International Rectifier MOSFETs, also in the input differential amp.

After I have heard amps from the "Aleph" series, I wonder, why many complain, that typical audio transistors disappear from the market or are offered only as a copy of other manufacturers from India. Seen such typical audio transistors have really no reason to exist under these conditions.

On the other hand - until this day there are not much other comparable amplifier without semiconductors "Special Made For Audio" (except Class-D like UcD), particularly as commercial products and additional also as diy projects.

Appropriate topologies, mentioned here on diyaudio probably are the follow:

http://www.diyaudio.com/forums/solid-state/154388-its-cheap-its-n-its-dirty-its-circlomos.html
http://www.diyaudio.com/forums/solid-state/189599-my-little-cheap-circlophone.html
and the overview
http://www.diyaudio.com/forums/soli...e-ended-related-solid-state-output-stage.html

I am looking forward to find more such amp topologies in the near future.

 

[h_a]

No need for special topologies, all amps work also with 'normal' transistors as long as the requirements are met.

Audio transistors usually have 'only' particular linear hfe (BJT) or constant capacitances (Mosfet) which might in some cases lower distortion a bit.

Hannes

 

[jacco vermeulen]

the "Aleph" series

Back when the first commercial Aleph power amp came out, the O (or Null, whatever), it was regarded as somewhat of an oddity at first.
Not Class AB, not regular P-P Class A, but primarily single-ended, and with a constant power consumption figure that even die-hard Class A lovers found a tad over the top.
The Aleph was phrased as an amp for the sporadic aficionado, which still is valid today.

The typical "high-end" Japanese parts are/were aimed at main stream audio.
It's also pretty BJT components which are dissapearing, think A1349/C3381, think MAT02/03 and the likes.