Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: GuitarPilot65 on May 13, 2025, 12:28:12 pm

Title: Parts not in Doug's catalog
Post by: GuitarPilot65 on May 13, 2025, 12:28:12 pm
Please provide recommendation for where to purchase:
Title: Re: Parts not in Doug's catalog
Post by: tubeswell on May 13, 2025, 02:50:56 pm
Mouser
Title: Re: Parts not in Doug's catalog
Post by: Willabe on May 13, 2025, 05:07:14 pm
.... 2-watt/1-ohm resisters for Fender bias test points.

1/2w is plenty, you don't need 2w. It's only 1 ohm and very little current is going through.
Title: Re: Parts not in Doug's catalog
Post by: EL34 on May 14, 2025, 06:31:12 am
1/2 watt 1 ohm is watt is used for bias and I stock those here
Resistors-3 (https://hoffmanamps.com/MyStore/catalog/Resistors.htm)

I stock 47p/500v caps also here
Capacitors-4 (https://hoffmanamps.com/MyStore/catalog/Capacitors.htm)

Why do you think you need 2 watt and 1000 volts
Title: Re: Parts not in Doug's catalog
Post by: HotBluePlates on May 18, 2025, 10:41:33 am
I stock 47p/500v caps also here
Capacitors-4 (https://hoffmanamps.com/MyStore/catalog/Capacitors.htm)

Why do you think you need ... 1000 volts

On other forums, builders have noted so many recurring problems with "500v silver mica" caps leaking DC even when brand-new, even when applied voltage is well below 500v, that they have switched to using 1kV mica caps for pF values in things like Fender amps.

I have no idea whether this is like JJ octal tubes from 10-15 years ago (which had the too-skinny pins that would lose contact with Pin 5 and go into meltdown), and is a problem that has since been resolved.  But those builders were burned enough times by having to troubleshoot new builds & replace the same 500v silver mica caps that they use only 1kV micas or simply skip to ceramic caps.
Title: Re: Parts not in Doug's catalog
Post by: EL34 on May 18, 2025, 12:17:33 pm
Well, I have ceramic 500p 1kv caps on the page above also
FYI, Been selling those same caps for 25+ years
This is the first time I have heard of anyone having an issue with the caps I sell