The Pioneer Super Linear Circuit

Every now and then, we do something totally different, for fun but also for bench-marking.

This is almost 180° to what we normally do.
No FETs, no NOS parts, no 0.3% matching (although hfe matching does improve performance significantly).
All parts are in active production; you can get them from Digikey or Mouser for very little money.

It is Class A, has no global feedback, can deliver +/-10V into 30R before clipping.
It delivers 1Vrms into 30R at an amazing -97dB THD, and has a -3dB bandwidth of 2MHz.

You can read about it here :
http://xen-audio.com/documents/SLHPA/SLHPA Description Public 171005.pdf


Patrick

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Some more measurements
(Green is input, cyan is output.)


Patrick

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Thanks for sharing such a cool design Patrick.
The choice and use of mostly SMD devices just plain sucks and will unfortunately be a major deterrent to many who may want to try this super-duper Pioneer Japo design.

Keep up the great work and Merry Christmas.:xmastree:
 
Many people said that before, until they tried.
Now they are all hooked on SMD.

You can of course build the same thing with TO92 devices.
Here is such an example built by another DIYer.
The problem is, he has plenty of matched 2SA970 / 2SC2240 on hand.
You will only find their SOT23 equivalent (2SA1312 / 2SC3324) in active production now.

So for me, performance comes first.
I have no problems with SMD.
And they are also pin-compatible with the likes of BC807/817, which is a big advantage.


Patrick

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Very cool, and impressive performance!

I was once a SMD sceptic, now I'm a believer :) For me, stuffing a SMD board takes about half the time it would with through holes, and error correction is also easier.

If you make PCBs available at some point, I'm certainly in!
 
I was also surprised by the performance, and that it did not receive more attention all these years.

> If you make PCBs available at some point, I'm certainly in!

Too early.

The protos will have to sit on a proper test platform with cross feed and protection boards, etc.
Then they will go through some independent auditions.
When all these are finished and we are happy with the final outcome, we'll think about a public offer.

At least 4~6 weeks more.


Patrick
 
Amazing proyect!
I have always been very interested in all the development of amplifiers by the Japanese manufacturers in the 80s.

The links of reference are very interesting, I have no found more information about this circuit that only the Andrea Ciuffolli (simple) implementation.

Off-topic: Do you try something with the Hyperbolic Circuit Amplifier by Yamaha?
Do you have any reference about this?

Regards
 
> I think thermal coupling is with THT components possible (BC550C/60C, SANKEN; SK482 heatsink).

I know that, but 2SA970 / 2SC2240 are no longer active parts.
And BC550/560 do not have a comparable (low) noise spec.

As already stated in the PDF document, the thermal coupling as implemented has been proven successful.


Patrick