100W Ultimate Fidelity Amplifier

[still4given]

Thanks guys,

I have a 5k trimmer in the offset and 500 trimmer with 680R resistor in the vbe. I didn't realize they even make a 4.7k trimmer. If it is important I can order some. I have the boards ready except I am waiting for some 0.68R 2
3W resistors. As soon those arrive I will be testing. Thanks for the help.

Blessings, Terry

 

[AndrewT]

pots and trimmer generally come in E3 values, 10, 22, 47 (or 50) and all the decade multiples
a
The tolerance is usually +-10%
so a 4k7 could be from 4k23 to 5k17, whereas a 5k could be from 4k5 to 5k5.
Note the big overlap.

 

[still4given]

I guess the question is whether or not the 300R difference across the circuit makes a difference.

 

[AndrewT]

The 10% tolerance is bigger than the difference !

 

[still4given]

That was not the question. I'm asking either Mile or someone who built the A33 if the circuit works properly with a 5k trimmer or if there are other changes needed if the 5k trimmer is used.

 

[AndrewT]

That is the question you should be asking yourself.

If the tolerance is bigger than the difference, then in what circumstances could the difference in absolute value affect operation?
I would answer: "none".

They are effectively the same.
Use either a 4k7 pot, or a 5k pot, they are equivalent.

 

[olafk]

That was not the question. I'm asking either Mile or someone who built the A33 if the circuit works properly with a 5k trimmer or if there are other changes needed if the 5k trimmer is used.

It works perfect.

regards Olaf

 

[RSK]

Electrocompaniet give me idea for this inverting amp.

Any PCB done for this amp?
What is the +HV voltage?
Bias setting?

 

[cook77]

I finished my second A33 amp. Both tested +/-40V, single pair of output transistors.
I'll place them in an old audio amplifier housing.
The sound is very good for my taste.
Thanks Mr. Mile for amplifier schematic , Mr.Alex for PCB design

 

[sonal kunal]

Tested Apex AX9 today with OPA2604 opamp and its . I like the sound on my PC monitor speaker currently I'm playing it with Apex NX-14.

 

[apexaudio]

Any PCB done for this amp?
What is the +HV voltage?
Bias setting?

This amp isn't tested and there is no pcb for it,
Regards

 

[apexaudio]

I finished my second A33 amp. Both tested +/-40V, single pair of output transistors.
I'll place them in an old audio amplifier housing.
The sound is very good for my taste.
Thanks Mr. Mile for amplifier schematic , Mr.Alex for PCB design

Nice work, can you post picture of housing amplifier?
Regards

 

[apexaudio]

Tested Apex AX9 today with OPA2604 opamp and its . I like the sound on my PC monitor speaker currently I'm playing it with Apex NX-14.

Nice work, can you compare AX9 with NX14?
Regards

 

[cook77]

Nice work, can you post picture of housing amplifier?
Regards

I will.
Looking for a large enough, simple, vintage housing. I'm thinking of dual mono with 2 traf of 180watt each. I have the traf, and I think 180 watt traf for each channel is more than enough for what I need. (46V +/-)
90% of listening time is under 1watt for me, the rest is
Regards, Laur

 

[vargasmongo3435]

Hello guys

I have an idea because I always have the problem where I can place the power supply board on the case, so I place a capacitor bank and RL on the PCB to see how it looks


those caps are 22,000uF 63V so far I like the idea what you guys think ?

Regards
Juan

 

[wiljj78]

Stereo protect for A17,
Regards

What's the max. AC Supply of this protect.

 

[apexaudio]

What's the max. AC Supply of this protect.

40vac

 

[wiljj78]

40vac

Thanks... i'll try this one.

Regards,

 

[44250]

maybe you should do 2N5551 in Darlinton with BD139 or even better MJE340 to get more hfe and to drive that relay with stronger/more powerfull transistor. usually relay coil uses about 20-40mA but that one can take 100mA,so BD or MJE would be a good choice to drive it...

 

[wiljj78]

Why not....thanks.