Aleph J Schematic

[Holger Barske]

Papa's schematic is god enough

Not sure if u lost an "o" somewhere out there

 

[Zen Mod]

Not sure if u lost an "o" somewhere out there

 

[Holger Barske]

Resistor added. Schematic:

 

[Holger Barske]

PCB:

 

[vdi_nenna]

Aleph J PCB? Here ya go.

HBarske,

You wouldn't happen to have a PDF of the trace or gerber file for pro board productions would you? I'd like to have some (4) made for me.

regards,

Vince

 

[Holger Barske]

No problem, I'll upload the pdf.

 

[vdi_nenna]

Thanks you, Sir!

 

[Holger Barske]

Here ya go. There are two pdfs in the zip file, one with normal drill size, one with minimum (0,3 mm) drill size:

www.hb001.de/alephjpcb.zip

 

[mpmarino]

Nice job Holger - that looks pretty tight

 

[Holger Barske]

Thanks. It's always the same with those boards: You are struggling a day or two, and you don't get it right; in the end, it makes "click" and everything falls apart into something very simple.

 

[Holger Barske]

Cleaned up a bit, we're slowly getting towards something useful:

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

Bottom layer pdf: http://www.hb001.de/aj_pcb3.pdf

 

[traw]

what about the film cap on in -?

Also, questions in general...
1 ) How come R27 now takes after the 1.5 + 3.32 versus in between R25 (1.5) & R26 (3.32) ?
2) I know AC gain could be measured, but is there a ballpark target that this setup gives? 1.2k - 1k

 

[Holger Barske]

what about the film cap on in -?

As said earlier, I omitted the input coupling cap for giving everyone the opportunity to tie a bulky paper-in-oil cap directly to the input jack

 

[vdi_nenna]

Holger,

Do you think it will be a problem when transfering the trace to the PCB with the input section so close togethger? Even at 150%, the traces are touching where they shouldn't.

I don't mean to sound critical or picky. I am grateful!


Thanks,

Vince

 

[Holger Barske]

Hi Vince,
don't get fooled by the screen display. It's a 600 dpi pdf with plenty of space between the traces and the pads. Just print it on a decent printer and you'll see.

 

[vdi_nenna]

QUOTE]don't get fooled by the screen display[/QUOTE]


Ok, thanks!

BTW- I just printed it on a HP 1200 Laser and there is plenty of room.

Thx.

 

[Holger Barske]

I should say that I consider the above version as far from being "final", so it might be a good idea to wait a little before you get started.

 

[traw]

The Vgds max at 25 volt. What does the 3 legged fuse see in Aleph J? Anything to worry about if using 26 volt or so supply?

 

[Zen Mod]

The Vgds max at 25 volt. What does the 3 legged fuse see in Aleph J? Anything to worry about if using 26 volt or so supply?

even 27 can be fine ;

more .............. poof!

 

[EUVL]

> even 27 can be fine ;

You probably have not been listening to Mr. Curl on the Blowtorch thread.

Whether the JFET will blow at 27V is one thing, whether it still operates properly is another.


Patrick