Retro Amp 50W Single Supply

[prasi]

1. Prasi 2 nos
2. Member (nareshn) thro PM 2 nos.
3. Bix 2 nos.
4. Indianajo 9 nos.
5. avtech23 2 nos.

7 PCBs remain.

 

[prasi]

Circuit with recent parts, if someone have models for original wellcome

thank you for the hard work overall feedback. I wonder if it will be stable with fast devices like mjexxxxx, although couldnt see ft spec in the original transistor datasheet.

 

[overall feedback]

Too fast is not the problem, we can always slow it down
Miller compensation for example.

 

[Bruce@bluff]

Split rail aaaargh you have ruined the friendship

 

[overall feedback]

Ah so, thanks for warning.
I hope it is acceptable now

 

[Bruce@bluff]

Perrrfect , just one small question how do you load the Cordell Models ? If you as add MJL21194 you could increase the voltage to 80-100v

 

[avtech]

I think you just drop the .txt file in the same place as the .asc file.

The .incl command in the schematic then directs the program to retrieve.

 

[overall feedback]

Also be aware that file name should be the same as in .incl directive.
You can find original file in archive I uploaded one page before.

 

[anti]

Split rail aaaargh you have ruined the friendship

Wow that was harsh ha ha ha! Usually such a firm sentiment would come from "no caps allowed in my amp" camp.

 

[prasi]

Al125 now good to go?

 

[anti]

IMHO not much would (could) change that would in any meaningful way affect the layout ... Only component value changes. But that could also mean transistor substitutions and thus different packages, so who knows.

 

[prasi]

Apex Retro Amp
1. Prasi 2 nos
2. Member (nareshn) thro PM 2 nos.
3. Bix 2 nos.
4. avtech23 2 nos.

16 PCBs remain.

 

[prasi]

Yes my friend, let's wait someone to help with the simulation, then i know a good friend ho can do the rest.

Your good friend has asked me to deliver this to you. It just something I made in 6 hrs straight.

regards
Prasi

 

[thimios]

Thanks!!!
I know that i have good friends..
Friends all over the world!

 

[Vrystaat]

Looking superbbbb Prasi !!

 

[prasi]

thanks fellows. Here is a revised one cap orientation corrected. Can some one take a look at my sch and confirm?

regards
Prasi

 

[Bix]

Wow Prasi, you’re a machine. Very generous with your time.

 

[anti]

2N5551 for T2 ... I'm not sure. I would put a BD139 there (and a small heatsink).

 

[prasi]

Wow Prasi, you’re a machine. Very generous with your time.

thanks man!

2N5551 for T2 ... I'm not sure. I would put a BD139 there (and a small heatsink).

Ok, Not a major problem. done...Small heatsink can even be a 1-1.5 mm al plate bent in u-shape. may be BF469/471 are better placed for T2 duty?

regards
prasi

 

[anti]

Hard to tell - these BF469 are 100mA parts. Perhaps a BF457/458? But these have lower hfe (!) Would have to measure each before install. A BD139 seems like a "universal fit", ha ha.

But yes, the small U-shape h-sink is what I had in mind when suggesting that.

A sidenote - with TO126 vas (probably useful if someone wants to build a "macho" version running on higher PSU rails), a TO92 BC639 would be pin-compatible (also bce) if somebody wants to build a scaled-down version...