[pix] [finished] Germanium Preamp

[Whoops]

Amazing work! Congratulations.
And yes, please show us more stuff from your work.


It would be great to have an all germanium pre project,but with available and affordable components,
like a "germanium for everyone" type of project.

 

[Igor]

Yup!!!! VERSTARKUNG!!!!!!!!!!!!!
(Beavis????French FLY's?????)
LOOKS SWEET!!!
People, EXCELLENT work!
I very like BA-71's too...Actually, the only germanium is 404 transistor, but amplification
and sweet distortion comes from here. BA'71's used 2 kinds of TONLEITUNGSUBERTAGGER's
at the output, allways liked version with output trunny without any markings on it-
very sweet, "metallic" hi-mid coloration...

Impressed!!!

 

[Dorian]

Some news about your schematics ?
Very interested !

 

[hobiesound]

Some news about your schematics ?
Very interested !

Ditto!!!

 

[roginator]

woooow man great job ....

let me know when capsule arrive

 

[hitchhiker]

Not sure about why no schematic to see, but if this is what I think it is then it's the 6 transistor all germanium transistor circuit ba-71a and some or other ver of the ba-31.  The UTC inputs are a sweet input and also sound great on the input of any good design looking for 1:3.2 aprox. I found lower gain on the NTE replacements but nice smooth sound.

 

[hitchhiker]

http://www.geocities.com/pepperplace/BA71.html?1097956825668

The input transformer is 1:3.2

Output transformer 1:2.45

-30v power

 

[emrr]

Yep, Hitchhikers schematic is the BA-71A.  The 31/71 'B' and 'C' versions go to silicon PP output rather than germanium PPP output.

Here's my history piece:

http://www.groupdiy.com/index.php?topic=2867.msg180431#msg180431

 

[Stagefright13]

That is soooo cool. It's like a "German" anium preamp!

ehrfürchtig and Das is Gut. Sorry for my crappy German! My Dad is from germany and I only had 3 years of german in high school.

But real nice job done on that. Congrats!

 

[penquista]

hello,

this looks like a really nice project!
thanks for sharing those nice pics and the schematic.
i have almost all parts i need and hope to find some time to build some channels pretty soon.
does anybody have some infos about the haufe output transformer?
i have a lot of iron from old gear lying around and hope to find something usable for this design.


Christian

 

[3nity]

I'm doing a pcb layout for a Germanium preamp here....i found 2 transistors out of 3 locally....but still missing this...2N3391A.

Anyone here knows where can i find it?

Thanks.

 

[dissonantstring]

hey 3nity,
not sure about locally, but mouser carries them (both fairchild and Central Semi brands). http://mouser.com/Search/Refine.aspx?Keyword=2N3391A
regards,
grant

 

[Moby]

I'm doing a pcb layout for a Germanium preamp here....i found 2 transistors out of 3 locally....but still missing this...2N3391A.

Anyone here knows where can i find it?

Thanks.

Are you designing PCB based on the modified schematics or original one? Huh, I love the sound of BA's 

 

[3nity]

Is kubi using germanium transistors?
I'm after a germanium design!!

 

[Moby]

Yes, Q2 is ASY26  . The rest is silicon 

 

[3nity]

Alright....so wheres the original schematic...using ASY26??
i just checked the stock in my local supply and they got it surplus...

 

[Moby]

I think this is the link http://audio.kubarth.com/jensamp/

 

[Moby]

Kubi, are you sure that schemo posted on the site is 100% working?

 

[solderspongebob]

If it's of help for anyone, Cricklewood Electronics stock the ASY26: http://www.cricklewoodelectronics.co.uk/Cricklewood/product.php?productid=5840&cat=182&page=3, priced £4 each.

I'm thinking of building this - you reckon OEP's would be OK for this? Which ones would I need for the Input and Output?

 

[Moby]

Thanks for additional info Kubi. Also, did you evaluated the PCB board for this project or you ended with proto? It's possible that project is sensitive to layout arrangement (not sure) . Also, Is the schematics on your site 100%  correct?