TUBE preamp based on 12ay7 tube

Hi Guys!I need help for PSU for my tube preamp!
I bought finished universal PCB of tube preamp, and use Jakobs G7 mic tube PSU which is around 160V!My preamp works very well!
But I read that is the 200V is start point for B+ for tube preamps!
What i need to do!?
Increase power transformer?Put larger elkos there?Im still very inexperienced....
 

You have to find out what are your preamp's requirements for voltage and current. Ask seller or at support thread if there is any. If design is "usual" something like 250V/20mA should be ok. I don't know if G7's psu is what you need in terms of current and voltage. Tubes won't notice quite a bit lower voltage if they have enough current.
Check G9 psu, it is very flexible. Instead of using back to back transformer order one with proper secondaries, recalculate R35,R36 so it will work without the load. Maybe change phantom part for something else like Bo Hansen API PSU if you go with custom transformer. All this is well covered in this thread, see reply #14 and others:
http://www.groupdiy.com/index.php?topic=52985.0

Thanks a lot My3gger!I just looking the Gyraf G9 PSU!
With G7 PSU i have 160B+ and 6.3V for heater and preamp works very well...

But will try G9 PSU...

It would help if you could post the schematic of your tube preamp.

Cheers

Ian

Here it is!
Drawn by hand, its not perfect picture but all components are recognizable....

And forget to tell it,its a stereo tube premap!

Thanks for the schematic. It doe not say what the tube type is but looking at the plate and cathode resistor values I would guess it is a 12AX7. Your HT current consumption is therefore only a few mA.

I am not sure if raising the HT voltage will improve this preamp. The first thing I notice is it appears to have 1Meg grid stoppers in series with each grid. This is likely to mean the high frequency response is 3dB down at about 1600Hz which is not a lot of good unless this is intended to be a bass guitar preamp. Also the 1Meg in series with each input will inject a significant amount of noise into the input. It also has 47K series resistor at the output feeding an preset pot of unknown value.

Perhaps a description of what you intend it to do would help.

Cheers

Ian

Edit:  LOL just realised the subject line says the tube is a 12AY7. Comments still apply though.

It got me too, ECC83 It looks like two high impedance outputs, this won't work into usual 10-20k solid state inputs and probably won't drive transformer either.
Ian, wouldn't be your Mu Follower/SRPP board much better? Cost of pcbs and material is so low that he could just replace existing preamp.

Thanks a lot Ian!

So what i need to change to make this schematics work for Tube preamp for condenser mics like G7(vocals)!?

Im a inexperienced with thing  like this....

I planing use input and output transformersfor this (OEP or Lundahl)!

iprovlek said:

Thanks a lot Ian!

So what i need to change to make this schematics work for Tube preamp for condenser mics like G7(vocals)!?

Im a inexperienced with thing  like this....

I planing use input and output transformersfor this (OEP or Lundahl)!

Click to expand...

Basically you need to change just about everything. Rather than suggest a particular design I think you would learn more if you looked at other threads on this board to do with mic preamps. In particular I would recommend New York Dave's One Bottle Preamp which uses a 12AV7.

http://www.groupdiy.com/index.php?topic=6711.msg78682#msg78682

Cheers

Ian