Author Topic: 10uF to 27uF  (Read 1173 times)

Alex J Kramer

  • Newbie
  • *
  • Posts: 16
  • Karma: +0/-0
    • Kyiv, Ukraine
    • Duma Studios
10uF to 27uF
« on: December 02, 2024, 12:09:23 PM »
Hi Fam,
Hope u r doing damn good there!

I'm about to recap CF82e11 and I've found that 10uF35V are all replaced with 27uF25V
The same situation with VCA (82e13) card, no any 10uF35v installed but 27uF25V
Is there some technical reason for that and should I replace them with what were originally installed or use 27uF25V instead?
« Last Edit: December 02, 2024, 12:20:08 PM by Alex J Kramer »
1985 SSL 6072 E/G+
THD Labs Tangerine
Atomic Instrument PSU S2(with plasma)

walrus

  • Full Member
  • ***
  • Posts: 141
  • Karma: +13/-0
    • London, UK.
Re: 10uF to 27uF
« Reply #1 on: December 02, 2024, 04:40:25 PM »
Does it look like it's an SSL original cap?
Raising the value of C28 will lower the -3dB point, but I don't have any late revision schematics to see if they did change it.
Bit of an odd value, most just use 22 or 33uF. Maybe they got a good deal on them!   ;D
Kevin.

Alex J Kramer

  • Newbie
  • *
  • Posts: 16
  • Karma: +0/-0
    • Kyiv, Ukraine
    • Duma Studios
Re: 10uF to 27uF
« Reply #2 on: December 02, 2024, 04:53:36 PM »
They are not original, that's the case.
Ive found tons of 27uF thru all cards(from Preamps to Recall) inside every of 40 channel strips, where 10uF were expected to be.
Maybe they really had a good deal on them or we've  missed something very important about that)))
« Last Edit: December 02, 2024, 05:21:01 PM by Alex J Kramer »
1985 SSL 6072 E/G+
THD Labs Tangerine
Atomic Instrument PSU S2(with plasma)

radardoug2

  • Jr. Member
  • **
  • Posts: 84
  • Karma: +3/-2
    • New Zealand
Re: 10uF to 27uF
« Reply #3 on: December 05, 2024, 07:40:42 PM »
27 is an odd value, so I am going for the theory that they got a bunch cheap. If they are now faulty, that could also be a related reason. Put back 10 uf, make sure they are 105 degree caps.

amillar

  • Full Member
  • ***
  • Posts: 187
  • Karma: +15/-0
    • United Kingdom
Re: 10uF to 27uF
« Reply #4 on: January 21, 2025, 09:10:31 PM »
27 is an odd value, so I am going for the theory that they got a bunch cheap. If they are now faulty, that could also be a related reason. Put back 10 uf, make sure they are 105 degree caps.

If you don't mind I'd have to slightly disagree - we used the values we did because in those days they were the biggest values we could physically fit in, but these days you can fit larger values. If we'd had todays caps available the low end would have been much better! If I was recapping a 4k (not that I'd have the patience to do it these days :D ) I'd probably be at least doubling quite a few of the coupling capacitor values.

However I say "slightly" disagree because absolutely if in doubt fit the original value.

And totally agree fit 105 degree ones...

Cheers,

Andy
co-designer and project manager G series analogue 1987
channel strip designer J series 1992-93
design "caretaker" 4000/6000 1985-93
analogue team leader ARC/Bertha 1988-92