Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: punkykatt on January 15, 2024, 02:05:30 pm

Title: Need treble pot value
Post by: punkykatt on January 15, 2024, 02:05:30 pm

By any chance would anyone here have access to a Blackstar HT Stage 60 MKII schematic? All I need is the treble pot (in the overdrive  tone stack VR 10) ohm value so I can order one.  Thank you in advance for any help.

Title: Re: Need treble pot value
Post by: tubeswell on January 15, 2024, 11:11:38 pm

If it’s a standard Fender blackface amp type TB or TMB tone stack, then 250kA would be a safe guess.

Title: Re: Need treble pot value
Post by: Latole on January 16, 2024, 03:15:00 am

Quote from: tubeswell on January 15, 2024, 11:11:38 pm

If it’s a standard Fender blackface amp type TB or TMB tone stack, then 250kA would be a safe guess.

You are right .

Title: Re: Need treble pot value
Post by: punkykatt on January 16, 2024, 06:14:10 am

Thanks guys, it is a TMB stack and I did see a 250kA online. Don`t know why Blackstar is so stingy with their schematics. :dontknow:

Title: Re: Need treble pot value
Post by: shooter on January 16, 2024, 07:26:19 am

only blackstar schematic I found on the hardened drive is a reverse engineered from a familiar face  :laugh:

Title: Re: Need treble pot value
Post by: punkykatt on January 16, 2024, 02:38:04 pm

Well I`m glad I tore the amp apart before I ordered what thought was the correct pot. Evidence showed this treble pot took a  hard hit on the end of the shaft, so I removed the pot from the PCB and took it apart. While  apart I measured the carbon trace = 50k ohms. Further inspection showed the contacts and and wiper were bent not making contact. With a dental pick I bent the contacts and wiper up to make good connection, put back together works like new.  :icon_biggrin:  Rock On! :guitar1