NOS Sprague 'black beauties' - Would they still be good?

[KissTone]

My father-in-law had about a dozen NOS Sprague 'Black Beauties' that he was going to toss as part of an effort to clean up his shop, so I snagged them. There are a couple of .05's, .02's, .1's, etc. All are 600v.

I have no idea how old they really are, so should I bother installing them in an amp if the need arises, or just stay with new production to be safe?

[jack anderson]

I have a stash of many decades old Black Beauties that I use for special occasions , in clean-circuit amps.

Every one has tested within specs statically, and none of them have leaked DC. If you have access to a capacitance meter, you can check their value , and alligator-clip them into a circuit, to see if they leak DC across them.

I've found them to be a little fuller and warmer-sounding, compared with Orange Drops and Mallory 150's.

[Trout]

+1 for Jacks comments.

I have a pretty nice stash oh those also. Mine are in the little 5 pack boxes that came with a sprague storage box.

The .022's are very popular with a lot of the Les Paul guys. I have seen good NOS matched pairs sell for in excess of $75.00 a pair on ebay.

I avoid using mine up on genral stuff, But on some of the high end audio stuff they are invaluable. When I restored my McIntosh I used several.

Watch for sprague BumbleBee Caps. Those are worth even more on the world market, Though I like the black beauties more just do to them generally speaking not being as old.

I just added to my stash a couple weeks ago at an auction of a TV shop.

Trout

[KissTone]

Thanks for the replies. I have plenty of new Mallory 150s for general repair and mods, but I thought I might try the black beauties in my SF Champ since it's a simple circuit (thereby making component changes more apparent on the ear).

[KissTone]

Well, I installed the 'bb's' and replaced the treble cap with a silver mica while I was in there . . .

Tone is smoooother----but there is less overall low end. I'm now running the treble at 4.5 and the bass up to 9, but it sounds good so far.

[John Phillips]

it's a simple circuit (thereby making component changes more apparent on the ear).I have no great experience of these caps - they're rare in the UK - but I have to say I disagree with this. Complex circuits make component tone changes more apparent, IMO - at least if they're done consistently. If you pass a signal through a couple of caps, the type used will have less effect on the tone than if the same signal goes through half a dozen. As I hear it, anyway...

NOS caps other than electrolytics shouldn't be a problem - there's no significant degradation of the materials used over time.

[KissTone]

I guess my point is that with so few components in the Champ, changing just a few components is noticeable. Whereas changing just a few components in, say, an AC30 might not be as discernible . . . but I guess that would be apples to oranges rendering my point moot.

Anyway, since the Champ is a player and not a collector, now I'm thinking of converting the fixed SF baffle to floating BF style . . . stay tuned . . .