diyAB Amp - The "Honey Badger"

Member Keentoken also has a point about the current mirrors.

Replacing Q 5/6 would be simple , only the pair would be back-back instead of face-face. This improved current balance would indeed reflect on the sonics .. even if only by a small amount. This is explained in Hugh Dean's AKSA threads.

This is wrong information. Q5/6 are installed facing the same way on the board. Also KSA992 are ECB layout and BC560 CBE layout so it is not as simple to mirror them around as one has Collector center pin and other has a base center pin.
 
That's a great find! They are probably even better, as you can see in the Fairchild BC560 datasheet there is a droop at 1V/50uS, but not for the japanese part. Only drawback is the lower Hfe. I will have to try these in my Kmultipliers whenever I have the chance.

Unfortunately the NPN part, KSC1815 doesn't show Vcesat comparable to the BC550. Possibly, the BC327-40 and KSC1015 are the ultimate BJT pair for low-Vce linearity. If Ft match is desired, BC550/KSC1015 both should still work great. However I want to test this to make sure.
 
Can you see if this is correct?
327568d1359746574-diyab-amp-honey-badger-honeybadger.gif

R7+R8 constrained the dial to block overcurrent settings (did I do it right?)
R29+R30 constrained the dial to block overcurrent settings (did I do it right?)
R27 changed per information in this thread (and from there I just guessed)
Q5,Q6 changed per information in this thread (does it affect Q3, Q4?)
Q14,Q15 changed to avoid severe mismatch (onsemi's low HFE new China fab NPN)
Q16,Q17,Q19,Q20 per information in this thread, 50,50v rails, 8 ohm speaker
Marked all higher current resistors
C4, changed to a reasonable value for higher resolution bass with non-ringing treble
D3 indecipherable, "different compensation options" indecipherable and therefore these need checked out too.
 

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Not sure if its the right place,
but i wanted to give this amp a try. However, my PSU is at +-85v on load.. Would maybe be a bit too much when running this on 4r speakers? How would the amp handle it, do i need to change something, maybe add a pair or two of output transistors?

For +/- 85Vdc you should have six pairs of plastic output devices for driving four ohm speakers. +/-60Vdc really is the max for the Honey Badger.
 
Sorry if I missed it, but what does R9, R10, and R14 do in the LTP CCS do?

1. Help us All out. Leave out R9, R10 and R14 then report to us how the circuit you built responds to the upgrades.

2. Earl Muntz circuit improvement methods are a well established design process.

3. Plant the circuit in question in to Spice and give it a run or two and report to
us how the circuit responds. " What if " questions are ideal for Spice examination
and you would be Helping your self and others.
 
1. Help us All out. Leave out R9, R10 and R14 then report to us how the circuit you built responds to the upgrades.

2. Earl Muntz circuit improvement methods are a well established design process.

3. Plant the circuit in question in to Spice and give it a run or two and report to
us how the circuit responds. " What if " questions are ideal for Spice examination
and you would be Helping your self and others.

I'm simulating a similar amp, using the BC550 pair for the CCS, KSC1845 for the diff pair, and a simpler two transistor current mirror. R14 at 2.2K does lower overall distortion, but I'm not sure why. R9 makes it worse, and R10 doesn't do much that I can see. I assumed there was a real world application for them that would not be easy to see in a sim.
 
It fascinates me that the opamp internals mirror the typical Class AB Amplifier; and there are some fantastic audio opamps now; NE5532 and OPA2134's I favor. I saw a great "tube" video where a person had, I think, three silicons which was putting out some decent volume with minimal parts. And the "Long Tailed Pair" Tube Amp Front-End (12ax7 Phase Inversion) always finds it way into the solid state world by necessity. The concept is the same, just bigger and different parts. It's all the same. We enslave electrons to dance at frequencies that we can see with our ears.