Holton amps electrolytic caps experiments

[D3nsityD3nt]

Originally Posted by jameshillj

There's a surprising difference in the amp's sound with different power supply caps too although it's not often mentioned - Panasonic, Nichicon, Elna, Kendeil, Kemet, Mundorf, etc, etc.
It's not just the amount of capacitance - bigger is not automatically better, especially in class AB amps.

Truth. I opted on Mundorfs as a mail filter bank. This is not the first amp I do or modify. I found after many amps that Mundorfs are actually my favorite caps for that task.

[D3nsityD3nt]

Originally Posted by analog_sa

Not necessary? A separate supply for the front end usually makes a dramatic improvement.

Originally Posted by jameshillj

Yes, the extra front-end supply generally makes quite a bit of a difference but with the restricted bass freq response (30 - 160Hz) for these modules in my setup, I hadn't considered it of much benefit.

Yes. That input stage psu in my incarnation consist LC filter (Lundahl+Mundorfs) to super fast and silent Salas shunt boards. I think, that with that setup the problem with bass restriction should be eliminated. But I do it only for the high/mid section of the speakers amps NXV200. No no worries for bass problems.

[D3nsityD3nt]

Originally Posted by alwaysHiFi

Hence why remove cap from pcb and link out. Fit cap at input socket for easy / fast swapping.

This is a great idea. I used it on my dac construction experiments with caps.

[D3nsityD3nt]

My experience says to mix the caps. To get the most neutral timbre. On my shunt input psu I already have things sorted out. I was just curious of eventual outcomes of other builders on the main amp boards. Any tips or tricks you guys came up. The problem is that very often the same caps, even electrolytics sound different on different amps/board/constructions. Before I spend the money for many caps, I just wanted to know which direction to take in choosing them :-)

Maybe you guys changed the electrolytics with some film caps? How did that go?

[jameshillj]

Could you supply some details about building the Salas shunt regs for the front end of your mid/treble amps? I've got some spare board but didn't think about this - I think I'd need about 60 volts for the input stage if the main rails are about 50.

[D3nsityD3nt]

Salas SSLV1.3 UltraBiB shunt regulator
Here you can find the post of the 60V modification of the Salas Ultra BiB board.

In between the bridge diodes and filtering cap I have added Lundahl LL1673 or LL2742 choke, didn't decide yet. Snubber, bridge diodes and choke on separated board of course. Salas board consist Mundorf M-Lytic 4700uF, Nich Muse 220uF and Pan FR 100uF

I think you can get of with 55V for the input stage easly

[analog_sa]

Me thinks you are not really in need of cap advice

[jameshillj]

Aah, yes! I'd forgotten about that one - I vaguely remember it going up to about 40 volts but I'll go back over the thread again and especially that post area that you indicated.

As I've got the boards, why not put them to work, eh!

Thanks for you words and assistance ... James