HAL OPB amplifier

[OnAudio]

Heres one of the toys in the lab

 

[OnAudio]

some curves

 

[OnAudio]

more

 

[OnAudio]

PCB Volunteers needed

I hope now theres a toy for everyone

 

[OnAudio]

30k builders needed

This is another product of the formula . Data is required. Once you build the amplifier, simply post your findings in this thread. The formula indicates you will like it. Did you ? If you are looking for adventure and love to work with amps you are encouraged to join this thread, contribute by building the amplifier and posting your pictures and comments. Contribute to the state of the art

kind regards,

Harrison.

 

[drowranger]

confused...

Hi Harrison,

I'm confused of this amp.Is this a complementary feedback amp.?what is its classification?

regards,
joel

 

[OnAudio]

To simplify things, yes its a CFP, depending on how you look at it

 

[OnAudio]

Version 2

Heres version 2

I am thinking, part of R5 and part of R18 should be NTC thermistors , any ideas ?

 

[drowranger]

brilliant idea.

instead of muonting diodes on heatsink thermistor would do the job.besides of easy installation same function as the vbe and diodes.yeah we used that also in copier to maintain 180 degrees temp..it change value when temp. increase also.

regards,
joel

 

[OnAudio]

I have just found another thread dealing with that, hope PASS can tell us more

http://www.diyaudio.com/forums/solid-state/26043-thermistor-use-power-amp-bias-servo-circuit.html

 

[OnAudio]

draft

An externally hosted image should be here but it was not working when we last tested it.

 

[OnAudio]

Either one of Q4 and Q6 can be mounted on heatsink together with Q1 and Q8. Also included will be some minor mods to accomodate different tastes. Some like well done eggs while others prefer...

A large selection of opamps can be used.

 

[OnAudio]

Looking for constructors seeking fun and adventure.

 

[OnAudio]

This amplifier will require, two supply voltages.
1. A regulated +/-15VDC
2. An unregulated +/- 40VDC, it is preferred that the regulated supply come off its own transformer

 

[OnAudio]

The amp will sound as good as the selected opamp . I have not found a device yet that can do a better job than the TO3 MJ11032/33 in that position. C3 and C8 maybe increased to 22p.
R31,R32, D11 and D12 are optional.

 

[donpetru]

Good job but the fuse is somehow too big?! I'd say yes.
The rest is well known amplifier topology with multiple disadvantages, but can turn into a kind QSC amplifier with some small adjustments.

 

[OnAudio]

Thanks for your complements Don. What adjustments do you have in mind.
This amplifier may be more advanced....

 

[evette]

I,m In onsemi does make better sounding darlingtons than the ones listed. Evette

 

[OnAudio]

Thanks Evette, What darlingtons do you have in mind

 

[evette]

2n6287/2n6284 IMHO are great sounding devices, and are pretty easy to drive. Evette