Class A, 4 Watt, No Feedback, Simple Circuit, Great Sound

[cumbb]

The circuit in #3 has the much much higher sonic potential than the circuit in #4!
Bonus: you could build #3 quickly without pcb.
I suggest: do not use any TO-3P-transistors! Many TO-220-types will do this job.
I am sure, you will find some TO-126-types to do the endjob;-) It will sound much much better than every TO-3P;-)

 

[Charm]

How does it sound compared to the JLH circuitry?

 

[sumeshak]

The circuit in #3 has the much much higher sonic potential than the circuit in #4!
Bonus: you could build #3 quickly without pcb.
I suggest: do not use any TO-3P-transistors! Many TO-220-types will do this job.
I am sure, you will find some TO-126-types to do the endjob;-) It will sound much much better than every TO-3P;-)

HI,
What could be the reason...?
Less Cob value? or Higher Ft?
Regards,
Sumesh

 

[widea]

The circuit in #3 has the much much higher sonic potential than the circuit in #4!
Bonus: you could build #3 quickly without pcb.
I suggest: do not use any TO-3P-transistors! Many TO-220-types will do this job.
I am sure, you will find some TO-126-types to do the endjob;-) It will sound much much better than every TO-3P;-)

In LTspice I cannot get it to work (yet)... Must be doing something wrong but I cannot find the problem.

 

[Michael C]

Looking 4ward to building this babby.4watts awsome.have a question as olddiy stated we can delete q1 and q2. Use q3 as input. Can olddiy clarify how to do that. Thanks.

 

[OldDIY]

delete q1 and q2

See #4

 

[lmkopqqaa]

谢谢楼主，该放大器声音很好 ！

 

[lmkopqqaa]

 

[lmkopqqaa]

Hi Sumesh,
Personally， I think it sounds better than Pass aca, in addition, I made some changes and improved the power supply up to 24 voltage. The circuit diagram is already uploaded to the forum.
Appteciate the good circuit diagram from lineup!
Kind regards,
Mong

 

[sumeshak]

Thank you Mr. Mong,
I am also planning to build his amplifier.
Best Regards,
Sumesh

 

[lmkopqqaa]

optocoupler constant current。

 

[EUVL]

2SC2837, 2SK2586, 2SJ555 are all obsolete for a long time.
Are you using Chinese made equivalents, or "refurbished" devices "removed from equipment" ?


Patrick

 

[lmkopqqaa]

K1058 J162，ECX10N20 ECX10P20 。

 

[EUVL]

So which schematics from you refers to the laterals ?

 

[lmkopqqaa]

Because I borrowed some of the circuits from Pass and didn't get his permission, I deliberately typed them.
Dear Mr. Pass

 

[lineup]

Lineup,

A very nice circuit. Elegant driver. Do you think you could almost double efficiency with an inductor in place of the CCS?

You have added something very worthwhile and good sounding to DIYaudio! Congratulations!

Hugh

Thanks AKSA 🙂

 

[lineup]

Here I repost the original circuit.

 

[Mark'51]

The @lineup schematic /\ is correct, the one shown in #271 is wrong. The "U7" emitter and collector connections need to be reversed, running a transistor with its emitter and collector swapped won't work too well. I presume that's why he re-posted his schematic (?).

 

[lineup]

Well spotted @Mark'51
I did not even see that wrong schematic.
I just posted my correct schema anyway.

 

[lineup]

This amplifier is perfect for speakers that have high sensitivity.
Say SPL more than 90dB or even 95dB.
Then 4 Watt is more than what is needed.