Hey guys, I bought this 1979 DR504 and the preamp cap is missing, looks like it calls for a 16-32 cap and as best I can tell and I’ve found ARS cap (Any good?) that might work.
Question is: Of the three wires that go to this cap does it matter which one goes to either of the + cap terminals other than the black wire which I assume is the negative.
Also if I go with the F&T 32-32 cap will this change the sound? Bear in mind I would like to restore this back to the original specs.
Thanks again for helping this newbie!
Sam
1979 Hiwatt Preamp Cap?
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- OldSchoolDave
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Re: 1979 Hiwatt Preamp Cap?
Sam,
By 1979, that cap was standardized on a 32+32. Either value will work, though. There won't be any tonal differences between them, as they're in the power filtering stage. There's a slight chance a 16+32 might have a bit of sag, but most folks can't seem to notice the difference in a Hiwatt.
ARS is fine, as are F&T - and JJ for that matter.
Persnickity folks might care if you switch the positives around. I don't know if the amp will notice the difference. Here's what an original 100 watter from 1977 looked like:
...and this is from a 1979 100 watter:
Hope this helps.
Dave
By 1979, that cap was standardized on a 32+32. Either value will work, though. There won't be any tonal differences between them, as they're in the power filtering stage. There's a slight chance a 16+32 might have a bit of sag, but most folks can't seem to notice the difference in a Hiwatt.
ARS is fine, as are F&T - and JJ for that matter.
Persnickity folks might care if you switch the positives around. I don't know if the amp will notice the difference. Here's what an original 100 watter from 1977 looked like:
...and this is from a 1979 100 watter:
Hope this helps.
Dave
Re: 1979 Hiwatt Preamp Cap?
The blue wire goes to the 32uF terminal and the red wire goes to the 16uF. The third wire (which may be gray, black or brown) goes to common.
--mark
--mark
Re: 1979 Hiwatt Preamp Cap?
Thansk guys for the help!
- OldSchoolDave
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- Joined: Wed Nov 14, 2007 9:24 pm
- Location: HP, NC USA
- Contact:
Re: 1979 Hiwatt Preamp Cap?
Oops. My comment about which positive was assuming a 32+32...mhuss wrote:The blue wire goes to the 32uF terminal and the red wire goes to the 16uF.

Dave