Mojo Vitamin T caps Anyone use em?

[guittech]

I have a few laying around the workshop, a few new ones, a few "lightly used" That i tried in a previous project.... anyone use them? Notice anything awesome or non awesome?

Now that I have my YBA-1 project closer to Marshall 1987 spec, I may try swapping these in for the Mallory's i've been using so far.

[rp]

I've tried old Vitamin Qs in an ST70 and in a real 5E3. I found them very smooth and "liquid" in the Dynaco, but un-dynamic, soft and lacking treble extension and air just zero. In the 5E3 I thought they robbed treble and bite. Those are the only oil coupling caps I ever tried. YMMV and I think you can only get there by trying it yourself. 5E3 is perfect test bed for stuff like this as it has few parts and little effort but has a big enough voice to let you hear things, distorts early so you can hear that too.

[rp]

Forgot: I doubt all oil caps are the same just like film caps aren't. I'd love to hear your results.

[guittech]

Well, I swapped the majority of the coupling caps and the caps in the tonestack for Mojo Vitamin T caps. Overall I like it, it does smooth things out (Traynor YBA-1 redone to Marshall 1987 specs) I noticed a little less treble, but that is a plus for me. Made it so the bright channel was a little more usable. I actually found myself turning the Presence control past zero, which is rare for how i play.... I usually replace it with a Cut!

It smoothed out the amp a little, cut a little treble, and I hate to say it, but it does seem to "feel" a little more "musical" now that they are changed. I put all that in quotes because of course ALL TONE IS SUBJECTIVE! lol.

At 5-6 bucks a Cap they are a little pricey for playing around with, but I do like the sound of them. THey will be living in this amp permanently i think

[rp]

Good to hear they worked out well, first time Ive read of them going into a Marshall - which can afford to loose a bit of treble unlike a 5E3. So much goofy crap on the internets about PIOs. I haven't seen all, but I've only ever seen them in old test equipment, and some old hifi (rare even there) never ever in MI amps. They must have been very expensive in their day.

You reminded me I've been sitting on the Vitamin Qs for years, I should build something around them, maybe when I get around to a 5B6. I'd probably use it as a low powered home bass amp anyway so I might not notice the top end softness.

[martin manning]

I believe some of the Sprague black beauties were PIO. A small metal sleeve around one of the leads is the clue. Those were in consumer electronics.

[rp]

Martin, I'm pretty skeptical of any plastic cased cap, as opposed to metal cans like the V-Qs, having oil inside. Until I hear from someone here or see a post somewhere where someone actually cracked one open and saw the (toxic PCB?) oil with their own eyes. But yes, the black molded Spragues with the little bead of solder on one lead at the body are supposedly oil caps, and I wonder if it's paper impregnated w/ oil or actually encased in oil. The 160Ps are Difilm which I think went on to become the orange drops - probably more hermetic and easier manufacturing. I had some of those supposedly PIO before internet, never knew enough to crack one open then. Anyone got a model # for the Black Beauties w/ the bead? We can try and find an old Sprague spec sheet or ad.

[martin manning]

http://www.33audio.com/enter/data/Sprague56paper.pdf

[rp]

http://www.33audio.com/enter/data/Sprague56paper.pdf

Excellent. Resolved, for me anyway. Bakelite too.

Whenever I see these old product sheet I want to order up some parts

[martin manning]

Another, vintage '72:
http://www.33audio.com/enter/data/1972SpragueFilm.pdf

Queue "Heart of Gold."

[rp]

225Ps have been around for at least 43 years!