100W Ultimate Fidelity Amplifier

[ammel68]

T1 and T2 like to be grade C

C-grade is much harder to find. Suppliers like Mouser only carry the B-grade.

 

[still4given]

This should probably be in the VSSA thread. It is not Apex. Or, like you said, a thread of its own.

 

[Jay]

Hi X,

Certainly inspired by the last VSSA amp I built.

Check out Borys' HEXFET and BJT version of the VSSA:
http://www.diyaudio.com/forums/solid-state/237219-fet-hex-explendit-amplifier.html

In the VSSA world, Borys seemed to prefer the HEXFET version due to unique bass quality of the HEXFET (just like you).

The BJT topology is (such as used in Borys' BG1-BJT) imo has a very interesting quality too.

 

[xrk971]

Thanks for pointing that out Jay - it looks similar indeed with Borys using an extra 4 actives to get the CCS for each rail and he has a MOSFET for the temperature compensator. I was frankly surprised at how well this thing models with a basic resistor for a current source. I guess I could get fancy and maybe try the 2SK170 CCS pointed out in the new Jason K CCS thread. Those have measured noise in the the 10E-22 amps^2/sqrt(Hz) current noise for a 100uA CCS current.

Although 1st cut would be to just build the very easy to make 7 active parts version. So simple, point-to-point could probably work well.

This should probably be in the VSSA thread. It is not Apex. Or, like you said, a thread of its own.

@Still4given: you are right - I will move this out to another thread.

 

[Hadighorbani]

best APEX amp in class AB with power more than 130 watt 4 ohm

 

[kees52]

I tried 220R (the usual and customary value here) and it rings like crazy...

C grade then if you have it - my model was for B grade and seems ok.

IRFP has big capacitance, that is why the driver needs low impedance, to drive proplerly.

Nice design, but BC is oldfashion there are better ones less noice all I think in this kind of amp it is not a issieu. My circlotron do have bigger distortion figures but go as high as yours in frequenty, I limit that to 100 Khz on input.

regards

 

[xrk971]

best APEX amp in class AB with power more than 130 watt 4 ohm

Which Apex amp is this?

 

[xrk971]

This should probably be in the VSSA thread. It is not Apex. Or, like you said, a thread of its own.

Ok, new thread started here:

http://www.diyaudio.com/forums/solid-state/294834-cfh7-amp.html

 

[xrk971]

Look at these beauties (from an old Dell Pentium CPU). Perfect for FH9 or CFH7.

 

[ammel68]

Nice sinks. Did you remove them from an old computer or purchase them?

Thanks...

 

[xrk971]

Bought used on eBay for $4ea.

 

[ammel68]

Is this the same?
Dell Dimension 2400 3000 4600 8300 Tower CPU Heatsink - 5R180

 

[xrk971]

I actually got on Amazon for $4. Same one though. 9y692 part no heatsink.

 

[Hadighorbani]

Which Apex amp is this?

i ask you😉
you say me which one is best amp in APEX design ?

 

[Bangla H]

Hallo Amigos.
Any news around a buildet/testet FH11/12- files/pics to share here?
The sonal compact pcb, i like, is very comfortable to fix on 75mm high heat sink.

Cheers Bangla.

 

[xrk971]

I think at least 3 people have made the FH11 (Andrewlebon, still4given, and someone else?)

Not sure if FH12 has been made yet?

 

[xrk971]

i ask you😉
you say me which one is best amp in APEX design ?

Personally, my favorite is the FH9HV. I have not made the FH11/12 but it would sound similar and have more dynamic reserve. They have a very good musical quality that derives from the FX8's front end topology and use of VAS to drive the output MOSFETs directly. Very natural, clear and excellent bass authority. More so than the lateral FET FX8.

 

[thiagomogi]

i ask you😉
you say me which one is best amp in APEX design ?

A33

 

[Bangla H]

Hi X.

I think at least 3 people have made the FH11 (Andrewlebon, still4given, and someone else?)

Not sure if FH12 has been made yet?

must read again and find clarify- not sure FH9 or single OP VHEX- i will find out.

Cheers.

 

[thimios]

Personally, my favorite is the FH9HV. I have not made the FH11/12 but it would sound similar and have more dynamic reserve. They have a very good musical quality that derives from the FX8's front end topology and use of VAS to drive the output MOSFETs directly. Very natural, clear and excellent bass authority. More so than the lateral FET FX8.

Post please,where we can find shematic and pcb,this is a long thread