Anyone experience of Solen FEP Tin/PTFE caps?

[RJKflyer]

Having just repaired a rectifier problem in the heater supply of my MV-55, I also took the opportunity to replace the PSU Solen caps, which showed signs of aging, although I suspected this was just label adhesive leaking out at the periphery.

FWIW, applying full WVDC to the removed 30-year old specimens actually showed fractions of a µA leakage, which points to them being first rate.

Now that it has all soak tested back in, it is sounding terrific.

I am looking at those 0µ22 grid coupling caps in each phase of each channel and wondering if it would be worth swapping them for some rather expensive SOLEN FEP Tin/Teflon caps?

I'd value any feedback from anyone who has done this in this amp or a similar one - it's a lot of money so I'd want to be convinced it is worthwhile, and not just vanity in a relatively mid-range amp.

Thanks.

[admin]

I haven't done those specific swaps, but I have swapped Solen caps into other equipment. I've never been disappointed.

Having the MV-55 already on the bench and having easy access to these components makes it an opportune time to do upgrades. Time is money so being able to do upgrades all at once is worth something as well. Not sure how much those caps would cost, but replacing them could improve the sound and at the very least protect against failure for decades to come.

[RJKflyer]

Well, yes, it would make sense from a workbench point of view, but it's a GBP240/USD300 mod for the 4 caps.

Hence, I'd quite like some opinions as to whether I would be modding beyond the ability of the amp.

[admin]

Ouch, that is expensive. Don't know what to tell you? The ones in there may last a lifetime and give excellent sound quality, or they can start to fail in the near future and then you'll kick yourself for not replacing them now. I can see going either way on this.

[roberto]

Hola,

Definitely I would replace those caps for better ones. It looks that you know what you are doing, so do it!...you might get lucky. Those new caps are expensive, but coupling caps are very important in the signal path.

Happy listening!

[RJKflyer]

Greetings Roberto,

Thank you for your encouragement. I think the MV-55 is pretty good as stock, but those two caps do stand out as worth considering, even though C-J have used proprietary items - which I assume are probably still 'only' polypropylene?

There's also the 1µF from the 6SN7 'second half' grid to ground.. Space is a limiting factor here, plus a 1µF Teflon cap will be REALLY expensive, so here's a question:

I was considering a ODAM V-Cap in this position, but can anyone see a disadvantage in mixing dielectrics at this point?

It will obviously work 'electrically', but I'm not enough of an expert to judge whether the difference in e.g. tan ∂ between caps around this area might be disadvantageous versus where I started from with the three apparently similar C-J proprietary caps.

[admin]

Whatever you use, make sure that the caps are the same type for each channel. Beyond that, I don't have any experience with the ODAM V-Caps. I've used Solen caps in my equipment and I can vouch for those.

[SolderSlinger]

I haven't heard the ODAM V-Caps. My $0.02 is to use a Teflon capacitor. Your amps will respond well to a Teflon upgrade. The Solen Teflon caps are considerably less than V-Cap, especially when you consider the 1,000V rating.

I buy parts from Parts Connextion located in Canada. Not sure if they ship to the EU. They have a number of sales throughout the year. Last was 25% off during Christmas holiday.

https://partsconnexion.com/products/sol ... cafa&_ss=r

While $47.00 for a part seems expensive, when compared to the price of a dozen eggs in the USA, it's a bargain. Local US$ to 12 egg exchange rate is
$1.00 = 0.307 dozen.

Another thing to consider is finding a local Conrad Johnson dealer that is authorized to perform service and upgrade work. Conrad Johnson provides parts to authorized dealers outside the USA. You may find that it's not much more expensive to have a CJ dealer upgrade with CJ Teflon capacitors than to buy Solen or V-Cap. A CJ upgrade will have greater resale value than one that uses non-CJ parts.