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DIY Stompboxes => Building your own stompbox => Topic started by: Arn C. on February 19, 2007, 03:25:20 PM

Title: OT: Amp related?
Post by: Arn C. on February 19, 2007, 03:25:20 PM
Howdy All !!!

I am replacing caps on an old Dukane tube amp(power).    There are some electrolytics that are .25uf 600v.  Can I use non electrolytics to replace these caps?

Thanks!
Arn C.
Title: Re: OT: Amp related?
Post by: bancika on February 19, 2007, 03:49:31 PM
sure thing
Title: Re: OT: Amp related?
Post by: John Lyons on February 19, 2007, 03:53:18 PM
Are you sure they are .25uf? Seems like an odd value. Are they physically large caps. How big are they. Maybe they are 25uf?
Where are they in the amp. connected to what?

John

Title: Re: OT: Amp related?
Post by: Arn C. on February 19, 2007, 04:04:26 PM
Yes they are .25 uf 600v  paper caps.   3 of them are connected to the preamp tube sockets (12axa7) and one across the power tube socket.

Peace!
Arn C.
Title: Re: OT: Amp related?
Post by: John Lyons on February 19, 2007, 04:29:33 PM
Ok, seems right, just odd that they are lytic caps for such a small value.
.22 polyester/film caps will be fine there.

I have a few .22uf 400v caps lying around, not sure the voltage will make a difference in that circuit. Depends where I guess.
If you think you can use them let me know.

John



Title: Re: OT: Amp related?
Post by: snoof on February 19, 2007, 04:57:33 PM
the preamp tubes won't run over 300V, but the power tubes prolly will...  the 600V might be needed there.
Title: Re: OT: Amp related?
Post by: markm on February 19, 2007, 06:27:12 PM
Quote from: Basicaudio on February 19, 2007, 03:53:18 PM
Are you sure they are .25uf? Seems like an odd value. Are they physically large caps. How big are they. Maybe they are 25uf?

Sounds like the paper/foil old-school-type caps.
Title: Re: OT: Amp related?
Post by: Arn C. on February 20, 2007, 08:16:54 AM
Thanks for all the help!

Peace!
Arn C.