hybrid output

[IceFyre13th]

Nice work, thanks for the schematic

 

[jfetter]

Jfetter, very interesting. Thanks for sharing your thoughts. I am a bit surprised the circuit shown would be patentable as it appeared (substantially) in 1966:

http://www.spontaflex.free-online.co.uk/pentonlector/circuit.jpg

I have built some variations of this amp using both si and ge outputs, Stancor TA-50 autoformer, and 15CW5 tube at about 20 volt supply. Some results were very pleasing but not measured. An efficient speaker is required. Simple and sweet.

Terry

Somehow I had missed this link, Sir Douglas Hall I believe would be the greatest hybrid designer ever.

He must have specialized in pentode hybrids.


more here
The Spontaflex Reflex Web Page

so i'll put up something about it after my experiments.
Will try the ef86 and a few others.

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[jfetter]

Another example using device characteristics to self stabilize operating point.

Did you build this? if so any measurements or comments ?

 

[jfetter]

Have the class-d setup for high power real time analyzing. Threw together a pad/filter box with overload protect to the sound card UR22.

I reduced the gain of power module to 4 so that the hybrid pre can really sing loud.

Now moving back to the 12AU7/fet pre.

pic of some testing, plots. Note these are at low power , the UR22 cannot really output high line levels.

.

Finally got a chance to sketch up my D test filter / Isolator for interface to analyzer. It requires a balanced line-in. Usually not a problem on pro-audio a2d boxes. You can pad the transformer input for hi-voltage input. I simply use two taps.

Note the input is on the 'output' side of transformer. It has a little more ripple than the AES but a lot more simple and cheap. Totally passive too.

Merry Christmas !

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[jfetter]

Two years now of testing and comparing to other topoligies. This is the best sounding amplifier, at least I've ever heard. I sort of got the hybrid bug at a store in New Orleans upon hearing Rogues original Sphinx amp. It inspired this design.


Here is original schematic again. It really likes blues and zydeco. Makes mp3 sound lossless. The huge fets are for their gate characteristics not for current.
Cheap too using D class TPA311x module.
Its driving two KEF Uni-Q in parallel. I like listening hi-fi mode. (mono)


For total instrument use I would add a scoop in tone circuit and increase gain somewhat. Not sure why this thread is moved to live music.

Cheers

 

[djgibson51]

Good thread. Thanks for sharing.