Which power supply?

[LeftyStrat]

Looking at the Kelly schems (thanks again David!), it uses two parallel 40uf caps versus the two 160uf caps in serial shown on the other schematics. Both give 80uf, but I'm just wondering if anyone has experiemented with both and can tell a difference.

Also, I have a transformer that is a little on the high side (375-0-375), and I have been debating using a tube rectifier and choke like the Komet. So the Komet has 4 80uf caps. Does anyone know if they are in series/parallel? I would assume two pair in series and those two pair in parallel with each other to give 80uf. Isn't the highest cap rating of the GZ34 60uf?

Has anyone tried something closer to the Komet or used a higher voltage PT in a Trainwreck?

[glasman]

Also, I have a transformer that is a little on the high side (375-0-375), and I have been debating using a tube rectifier and choke like the Komet. So the Komet has 4 80uf caps. Does anyone know if they are in series/parallel? I would assume two pair in series and those two pair in parallel with each other to give 80uf. Isn't the highest cap rating of the GZ34 60uf?

Has anyone tried something closer to the Komet or used a higher voltage PT in a Trainwreck?

You will be at 470+ for B+ with your tranny depending on the filter. You could place a few zeners in the center tap to reduce the B+. I used a 345-0-345 and ended up at 460v with the standard wreck configuration. I am planning on adding 5 10V 5w zeners to the center tap of my amp to throttle it back a bit.

And you are correct, about 60uf is the upper limit for that rectifier.

I bet the Komets caps are series/parallel. As I remember from the pictures some of the filter caps are mounted on the bottom of the board.


Gary

[dms]

From the research I have done: In the Komet, there are two sets of series-connected 80uF caps (in top/underboard pairings) with 220K bleeder resistors, but the first set is for B+1 and the second set is B+2 with the choke between them, so they are not series/parallel, and you basically have 40uF at B+1 and 40uF at B+2. The Komet tranny is putting out more than the 450v rating of the Mallory TC80 capacitors, so if you just gotta have Mallories, you have to do the series stacking. The Komet has a 500v cap at B+3, and then gets to 450v-rated caps by B+4,5, so you can piece it together... Would a single 500v Sprague 40uF sound different than two Mallories in series? You wouldn't think so, but remember, there have been strenuous debates over whether a Cherry cabinet sounds different than a Maple one... Mallory also makes 160 uF caps, so Komet could have chosen to put those in series as well if 80uF was the magic number, but they didn't, and for a $2-3k amp something tells me part cost wasn't the reason. The lowest price I've seen on TC80s is about $20 a piece.

[glasman]

Mallory also makes 160 uF caps, so Komet could have chosen to put those in series as well if 80uF was the magic number, but they didn't, and for a $2-3k amp something tells me part cost wasn't the reason. The lowest price I've seen on TC80s is about $20 a piece.

After thinking about it, the 40uf makes more sense than the series / parallel arrangement. I usually run two 100uf in series for the first bank and 20uf's for the rest of the stages. Deemed entirely on what stock I have on hand.

I had been looking around for the Mallorys to try in my amps. RF parts has them for ~$11.00. I have been buying the 100uf/350v Atoms for less than half that price. F&T's about in the same range as the Atoms.


http://www.rfparts.com/caps2.html

I am not affliliated with RF parts, only had book bark to thier site from some previous searches.

Gary