Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Blind Lemon on April 15, 2012, 08:58:08 am

Title: AC30TB Vib/Trem help
Post by: Blind Lemon on April 15, 2012, 08:58:08 am

Hey guys, I've been helping a gentlemen out who got in over his head with an AC30TB build. I've got everything straightened out except the Vib-Trem. It will not sustain, when it is turned on or off (not sure which) it will warble and fade out. Something is not set up right and I have no experience with this. He built it on Webers layout.

The rest of the amp sounds fine.

BL

Title: Re: AC30TB Vib/Trem help
Post by: sluckey on April 15, 2012, 09:00:56 am

Hey

Title: Re: AC30TB Vib/Trem help
Post by: Blind Lemon on April 15, 2012, 09:06:07 am

Hey Steve how you doin'.

Title: Re: AC30TB Vib/Trem help
Post by: Blind Lemon on April 15, 2012, 10:57:09 am

Ok I got it, there was an AT7 where there should have been an AU7. Works like a champ.

BL

Title: Re: AC30TB Vib/Trem help
Post by: Blind Lemon on April 15, 2012, 11:20:40 am

I've got to work at getting better speed range out of it though, slow end needs to be slower.

BL

Title: Re: AC30TB Vib/Trem help
Post by: sluckey on April 15, 2012, 11:54:58 am

C29, C30, and C31 have a lot to do with frequency. Larger value = slower. Try changing C30 to 0.047µF.

Title: Re: AC30TB Vib/Trem help
Post by: Blind Lemon on April 15, 2012, 02:28:49 pm

Splitting the difference with a .022 worked about right. Thanks

BL