Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ganzonimx on February 27, 2013, 01:47:53 pm

Title: one channel AB764
Post by: ganzonimx on February 27, 2013, 01:47:53 pm

Hello folks

its a long time I last visited this forum and I did a lot of turns in my life, but now I'm back with a amp on my bench. I have to convert a messed up circuit to a one channel AB764. I just want to assure I don't do anything wrong if I connect the 0.1 uf cap from the second stage direct to the PI, dropping out the 220k mixing resistor and the 0.001 cap.

EDITt: I just realized that I have only tree 0.1 caps and I need them for the PI and between the PI and the power tubes. I could take a 0,022 cap from the second stage to the PI I have left over - I think that should also do the job without any major changes to the sound... pleas correct me if I'm wrong...

Thanks Chris

Title: Re: one channel AB764
Post by: sluckey on February 27, 2013, 02:46:41 pm

Take out the .1µF from the second stage and remove the 220K mixing resistor.

Then connect the plate of the second stage to the .001µF in the PI circuit.

Title: Re: one channel AB764
Post by: ganzonimx on February 27, 2013, 03:28:04 pm

Thank you Steve

I thought so...  I see if I find a 0.001, if not,  I'll use a 0.0047 I have laying around ...

Chris

Title: Re: one channel AB764
Post by: Geezer on February 27, 2013, 04:30:22 pm

Quote from: ganzonimx on February 27, 2013, 01:47:53 pm

Hello folks

its a long time I last visited this forum and I did a lot of turns in my life, but now I'm back with a amp on my bench.

Thanks Chris

Hey Doc, good to hear from you.

I hope those turns were good ones for you.

Welcome back.....

G

Title: Re: one channel AB764
Post by: ganzonimx on February 27, 2013, 06:05:40 pm

Hy Geezer!

yea I had a good time and finally I ended up in Tulum on the Caribbean coast... I definitely needed soma climate change   :thumbsup:!