Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: British1011 on September 28, 2020, 07:34:02 am

Title: 79 deluxe reverb bias cap question
Post by: British1011 on September 28, 2020, 07:34:02 am: I have a 79 deluxe reverb with a 70uf 50v bias cap. I am having a hard time finding a replacement can I use a 50uf or 100uf instead or is that to far off. The chassis wasn't stamped but from what I can tell it's the a1172 schematic.
Title: Re: 79 deluxe reverb bias cap question
Post by: sluckey on September 28, 2020, 07:40:22 am: I would use a 100µF @ 100V. A 50v rating such as the original is not high enough these days. This cap is available right here for only $2.34...

(https://hoffmanamps.com/MyStore/catalog/images/Img_7933.jpg)
Title: Re: 79 deluxe reverb bias cap question
Post by: British1011 on September 30, 2020, 07:44:22 am: Thank you for the reply.
Title: Re: 79 deluxe reverb bias cap question
Post by: Latole on September 30, 2020, 08:23:29 am: On Fender amp ( american made or desing )I use only American or Germany filter caps

F & T or Sprague
Title: Re: 79 deluxe reverb bias cap question
Post by: finkaudio on September 30, 2020, 03:57:50 pm: ....nothing wrong with Nichicon capacitors. Use them all the time and never had a problem. F&T are OK on high voltage, but Nichicon makes great sounding capacitors.

So why only German or American caps?

ATB KH
Title: Re: 79 deluxe reverb bias cap question
Post by: mresistor on September 30, 2020, 07:20:08 pm: Quote from: finkaudio on September 30, 2020, 03:57:50 pm
....nothing wrong with Nichicon capacitors. Use them all the time and never had a problem. F&T are OK on high voltage, but Nichicon makes great sounding capacitors.

So why only German or American caps?

ATB KH

Probably because they are what the customer expects, however that nichicon bias cap would be totally acceptable imo
Title: Re: 79 deluxe reverb bias cap question
Post by: Latole on October 01, 2020, 03:19:30 am: Because I don't like to put Japan or chineese parts on American, Canadian or European (Marshall, Wem, Vox..) amps if American or European parts are easy available.

I try to keep these amps as original as possible and Sprague and F & T better represent this authenticity.

Nichicon caps, in my opinion, do not go with the story that these amps represent.

This is not about (my ) customers who, most of the time, know nothing.
Title: Re: 79 deluxe reverb bias cap question
Post by: pdf64 on October 01, 2020, 03:30:13 am: Basing purchasing decisions on product branding seems somewhat simplistic?
If no other product info available then that’s what you’re stuck with, but generally, manufacturers provide spec and characteristic documentation for each of their product lines.
Some ecap lines may have an operational life of 1000 hours, others 20000 hours. Lumping them together just because they happen to be made by the same manufacturer doesn’t seem a valid approach.
Title: Re: 79 deluxe reverb bias cap question
Post by: Latole on October 01, 2020, 03:38:05 am: Quote from: pdf64 on October 01, 2020, 03:30:13 am
Basing purchasing decisions on product branding seems somewhat simplistic?

No, Sprague and F & T are very good products.

To say that you may not know Sprague and F& T caps ???

I use Nichicon or other brand on amps witch come with or low cost amp made in China or Korea to name a few. Not on vintage amp
Title: Re: 79 deluxe reverb bias cap question
Post by: mresistor on October 01, 2020, 08:54:07 am: Sprague 22uf 500v - $14

F&T 20uf 500V - $4

Vintage fender amps aren't going to notice the difference, but I guarantee their owners will.
Title: Re: 79 deluxe reverb bias cap question
Post by: British1011 on October 02, 2020, 08:24:36 am: I prefer f&t. I've had good luck with them, they sound great, and they look good. Not that I personally care for how things look but a lot of customers do. However this is my buddy's amp I'm working on and he doesn't care about cost and requested all sprague.