[nikongod]

I found this on a quick google images search for "12au7 starving student schematic" 
 

 
It can also be found HERE In the great Starving Student thread.
 

RE my statement about the kaidan amp. 
Quote:

Originally Posted by TestSubject /img/forum/go_quote.gif
 
Is there any pics out there for reference? Maybe you built one yourself?
 

 
There is a schematic in the first post. I read it, and theres more stuff going on in the "audio" section. You will also need to build a high voltage power supply VS just buying a power brick for the Starving Student which adds still more stuff. 
 
On that note, no, I have not built the kaidan amp myself. It seems like it could be nice, but is without a doubt a more involved build than a Starving Student.

 

[kchapdaily]

why must you build a power supply when its ok to just get a wallwart for the original? 

 

[nikongod]

I was referring to the kiadan amp. The 12au7 starving student runs on the same wall wart as the 19j6 version. 
 
On the note of the Kaidan amp I suppose you could buy a prebuilt 170V supply, a (whatever voltage) supply for the heaters, and then wire them together.
 
But at that point your at least $50 into the PS which takes you pretty far for DIY stuff. And people like the look of high voltage power transformers AND this gets you your choice of parts which IMO makes slight additional expense totally worth it. 

 

[kchapdaily]

i was actually trying to find some info on diy power supplies but i didnt come up with much.
 
the ones from amb are nice but they only output up to 36v.
could you point me in the direction of an affordable-ish diy power supply i could use for the starving student and other higher voltage tube amps?

 

[nikongod]

For the starving student its hard to get less expensive than the 48V brick supply everyone uses. MPJA.com sells a few power supplies that MAY be slightly better than the brick (linear regulated, ooh, aah) but for at least twice the price I dunno if Id do it. 
 
Once you get past ~50V just build the power supply for the amp. Many tube amp schematics are paired with suggested power supply designs. 

 

[kchapdaily]

the only reason i ask is because i ordered the cisco wall wart for the starving student june 29th and its not scheduled to arrive until august 2nd kind of a bummer because thats the last thing i need. i could finish building it tomorrow but theres no way to test it out until the power supply arrives. would it be possible to hook up 5 9 volts and 2 AA batteries to get all 48 volts?

 

[nikongod]

I dont think a stack of 9V batteries will supply adequate current (~300mA). Just wait it out. 

 

[kchapdaily]

good call. i added up the voltage but forgot about the current.

 

[TestSubject]

Well here is half of it... How does it look? This is my first time attempting anything like that.
Green line are grounds. Thanks for having a look.

 

[TestSubject]

Quote:

I found this on a quick google images search for "12au7 starving student schematic" 

 
Any difference in the parts list?

 

[digger945]

One link for the 12au7 amp...
http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/
 
 
....I think there is more than one version of this amp.
 

 

[TestSubject]

Thanks for sharing ! Looks great
 
Wonder how it compares to the SSMH, and its to bad it's a mono amp any alternatives?

also found this, it's small enough to fit into an altoids! i thought i would share: Link
 
REDIT: Not a mono amp sorry. This mislead me:
 

 

[pabbi1]

Bah, build it balanced...
 

 

[digger945]

 
Quote:

Thanks for sharing ! Looks great
 
Wonder how it compares to the SSMH, and its to bad it's a mono amp any alternatives?
 

 
 
 
 
 
 
 
 
 

also found this, it's small enough to fit into an altoids! i thought i would share: Link
 
REDIT: Not a mono amp sorry. This mislead me:
 

 
I think that you may have a small misunderstanding about what you are seeing in the schematic. The amp that I posted a link to, as well as the amp you posted above, are schematics for a single channel(one channel). You must multiply this schematic by 2 for a stereo amp. The 12AU7, like many tubes(but not all), is a dual triode tube, having inside it's glass shell 2 independent triodes(devices), so that each triode can be used for just 1 channel(left or right), and so you only need 1 tube for a stereo amp, using this particular type of amp topology. Comprendre?
 
 
 
 
 
 
 
 
 
 



 
 

 

[TestSubject]

So:
 
1) The 12AU7 tubes can handle 2 channel per tube
2) The amp from the link you gave me only uses one of those channel so two tubes (plus the reciprocal of the circuit) would be needed in order to output stereo
3) The SSHM must be the same because it uses 2 tubes.
 
Thanks for the help you are supplying.