Question About Capacitor Upgrade in Tube Amp

I can definitely hear a difference in the clarity of vocals and the separation of instruments between the X7 vs the X9 and X10. So let’s see how this upgrade works out once I get the parts.

There’s a lot more going on than just the caps. Power, impedance, source, cables, loudspeaker, tube age, wire, sockets, etc. etc. Change one thing, change everything.

To those who don’t like the tone:

Are you fine with people being seen off by charlatans that give bogus reasons with ZERO supporting evidence other than their say so? They think their system sounds the same every day or that they can turn it off for some time, make a change and then determine a delta. Ha! Qualified engineers listen for weeks, making comparisons between a reference unit and the changed. Confirmation bias plays a huge part in an awful lot of opinions.

I’ve been at the HiFi game for more than 50 years, Grammy nominated engineer and if you saw a movie from about 1990 to 2010, quite possibly the soundtrack was recorded through something I designed.

Some posters blather on about changes without the slightest regard for rigor. To boot, they evaluate whilst intoxicated and at injurious levels. I endured too many sessions with doped up musicians to have any tolerance for audiophools.

PAX.

Engineers with ears pick caps where the evaluation circuit and signal allow them to be fully formed… in many cases those big monster caps never get fully formed… or stay formed…especially at reasonable listening levels…

Applaud the OP for diving in and trying….and learning…

Enjoy the music and the journey

Hello calieng!  Nice photography!  That cap looks pretty good. It's purpose is to keep high frequency noise from riding out on the B+ line. I would add a .01 capacitor in parallel as well. Keep the leads as short as possible. I'd use the fanciest Mundorfs (gold foil etc) with a voltage rating at least 100v higher than your B+ supply. I have lots of experience with power supplies and the noise that can show up on them. I used to live near a Navy base and discovered 2 volts of HF & VHF garbage on unused, unconnected phone lines in a rental house. How it got there, I don't know. I used to run a computer lab that had 51 PCs driven mad when someone plugged an extension cord through an open window and fired up a hedge trimmer outside! It took two days to get the lab back to normal. There is so much electronic stuff around these days that it is good to be as careful as possible. Please forgive those respondents with negative comments. This may be their only outlet for their hostility and it keeps them out of the bug house. Happy Listening.

@boomerbillone 

Hey thanks for the reply.

The 300B tubes are around 300-350v with max plate voltage of 400V.

I see most of the caps being used in these type of amps at 600VDC and up. I ordered the 1000VDC Mundorfs just to be safe. The power in our house is pretty clean and all the amps are dead quiet. So I think primarily the coupling capacitors on the preamp tubes with show the most improvement in clarity but i will do the filter cap bypass as well.

@tomic601 

Interesting point on some caps being too big for the application.

But in this case I think the Mundorf Supreme SGO are in a similar size range to those being used - just better quality.

On the Muzishare X7 model I suspect the Muzishare silver label on the coupling caps is covering a Mundorf EVO silver cap. They refer to the cap as Germany in origin and has the same 1200VDC rating. I may have to try to peel the silver label off to see what is underneath. Maybe someone on here knows which caps Muzishare is rebranding?

The Muzishare X9 and X10 are using Mundorf labeled caps - EVO Supreme Oil.