Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Big chief on November 08, 2015, 09:12:41 am

Title: Guild amp
Post by: Big chief on November 08, 2015, 09:12:41 am

I am trying to repair an old guild amp have not been able to find any information please help
It has 50L6 power tubes when I rotate the bass pot is the only time I can get a gabled from amp
Any help
Thanks

Title: Re: Guild amp
Post by: HotBluePlates on November 08, 2015, 09:22:26 am

Is there any kind of model number on the amp?

Title: Re: Guild amp
Post by: Willabe on November 08, 2015, 10:22:45 am

Quote from: Big chief on November 08, 2015, 09:12:41 am

It has 50L6 power tubes.......

Does that amp have a power transformer (PT)? If not you need and isolation transformer to be safe.

I would NOT play or work on that amp before getting/using an iso PT.

Title: Re: Guild amp
Post by: HotBluePlates on November 08, 2015, 10:51:06 am

Also consider doing a search on this board for "Guild". There are user-drawn schematics for the 66-J, which is not your amp because it uses 6V6 output tubes.

However, in searching online for Guild amps, I saw 50L6 amps which appeared to have 2x 12A_7 tubes, a 6SN7 and a pair of 50L6 output tubes. So the preamp portion of that schematic might help you.

Repairing this amp will take some knowledge though; as Willabe said, the 50L6 tubes indicate a series-heater power transformer-less amp, which is a potential shock hazard even when working. You'll need an isolation transformer (though people stumble on these amps frequently where an iso transformer has already been added). You'll need to verify the heater-chain is good first, then check voltages throughout the amp, and visually inspect for loose connections.

Title: Re: Guild amp
Post by: plexi50 on November 08, 2015, 10:57:18 am

Pic's? Guild made some pretty cool looking amps. The Thunder Bird was one of them

Title: Re: Guild amp
Post by: uki on November 08, 2015, 06:17:27 pm

Some pics would help identify the amp.

Title: Re: Guild amp
Post by: Big chief on November 08, 2015, 08:16:54 pm

Wil take photos and place on line thanks for all your help
No markings on the chase any where

Title: Re: Guild amp
Post by: sluckey on November 08, 2015, 08:29:54 pm

How many tubes and what kind?

Title: Re: Guild amp
Post by: plexi50 on November 09, 2015, 09:33:00 pm

Looking forward to some pic's/

Title: Re: Guild amp
Post by: Big chief on November 11, 2015, 03:28:16 pm

I am trying to attach photos now

Title: Re: Guild amp
Post by: Sowndman on November 11, 2015, 09:37:01 pm

There appears to be a facebook page
https://www.facebook.com/Vintage-Guild-Tube-Amplifiers-346905715427993/?fref=nf (https://www.facebook.com/Vintage-Guild-Tube-Amplifiers-346905715427993/?fref=nf)

Title: Re: Guild amp
Post by: Steve_P on November 15, 2015, 07:03:06 pm

The early Guild Master 60 amps have a PT. Those are small amps with a flocked wire grill.

(http://i1159.photobucket.com/albums/p627/Steve_CPhillips/Masteramp/IMG_4159_zpsc1917fd8.jpg)

The big cabinet ones generally don't have PTs.



 I have one that has 6(!) 50L6s, and came with 2 Jensens, but it hasn't been enough of a priority to tackle. AAMOF, real life has killed my amp time.