capacitor values

[hebaton]

Hi, I am going to recap a 1968 Super Reverb. I have on hand 2 Sprague Atom 100UF @ 450V . THe originals are 70Uf @375
WIll feel of the amp change if I use those ? will this make it "stiffer" ?

Thank you !

[martin manning]

I'd say 100u is within the tolerance of the original 70u caps.

[R.G.]

Martin's right. The original caps were probably -20% +50% tolerance.

On your question - will it change the feel of the amp? Probably so, because the amp probably doesn't sound now like it did when the original caps were new. Changing to new caps will restore it toward the way it sounded when the original caps were new.

[hebaton]

thank you both, I decided to order a couple 80 UF@ 450, want to stay as close as possible to original.
I notice a few caps were changed to what looks like Mallory 150s (white cylinders). Is there something now available that would be closer to the Blue Molded ones found in those amps?

[maxkracht]

Sozo makes caps that are blue, though I personally don't think they would be any improvement over the 150s. If you are seeking "originality", some caps would have originally been ceramic. Some of those tend to go microphonic and often get changed with film. C0G ceramics won't go microphonic but I guess that's not original either and I don't know if they are available in higher values anyway.

[WhopperPlate]

thank you both, I decided to order a couple 80 UF@ 450, want to stay as close as possible to original.
I notice a few caps were changed to what looks like Mallory 150s (white cylinders). Is there something now available that would be closer to the Blue Molded ones found in those amps?

Yes

Try the Jupiters and Sozo caps . Mallory150 doesn’t have close to the same character . They have a punchy flat midrange imo. I feel a good ol 6ps orange drop is closer even, a bit more scooped imo .

As far as 70 uf vs 100uf … the difference in feel is more than substantial and noticeable imo…80uf is a good call . Measure caps to know what you are really getting .

[wpaulvogel]

Hi, I am going to recap a 1968 Super Reverb. I have on hand 2 Sprague Atom 100UF @ 450V . THe originals are 70Uf @375
WIll feel of the amp change if I use those ? will this make it "stiffer" ?

Thank you !

F&T makes 80uF that will be better than the Sprague 100uF.

[Stevem]

Another thing to note about Spraque caps and later Fender amps is that there 150 uf 300 volt caps are really two 70 uf filters stacked in the same can, but without 2 balancing resistors which is not a good thing!

[Roe]

70uf caps in series for a total of 35uf is really on the low side. normally, that is not desirable, unless you want plenty of sag and perhaps even a slight ghosting (suitable for blues and some low-fi sounds with a slow attack). still, the tad audio series made in germany offers great 70uf caps that are perfect here. Normally, people use 100uf caps in series for a total of 50uf, which is normally good if you find good caps