Question About Capacitor Upgrade in Tube Amp


Hi,

I am preparing to do a coupling capacitor upgrade on a recently purchased tube integrated amp. The two 0.22uF on the preamp tubes are fairly straight forward. But I noticed another similar model 0.33uF cap on the large filter capacitor for the B+ supply that is installed across the hot lead to ground.

Does this cap on the B+ just block high frequency noise from the power supply or does it have any effect on the amp tone? Is there any reason to "upgrade" this cap?

I know it may be hard to tell exactly what is going on without a schematic.

Also any recommendations on a good cap to use in the upgrade of the coupling caps? I was looking at Mundorf SilverGoldOil for the quality at not too crazy a price. The amp already sounds good but lacks a little clarity that I think a coupling cap swap will help with. It is SET 300B amp.

Thank you!

 

calieng

Lots of good info already post.  Parts are not that expensive so have at it.  If it was me, I would use the V-Cap ODAM as my first choice and see if that floats your boat.  We use them exclusively in our designs.  We have also use the copper Milflex with good results.  One of the best comments above is space.  Be sure to look at the size specs first to make sure things fit in.  Audio Note and Nichicon capacitors are excellent and so are the non-magnetic Audio Note resistors.  Things get a little pricey but if you doing the labor that is a cost savings there.  Last especially for tube equipment, look for AC filter chokes and other chokes to replace capacitors, etc.  All parts have sound but to me, chokes are a big benefit plus a lot cheap!

Happy Listening.

"Owning a Willsenton myself, I‘m curious about upgrade options. Please keep us posted!"

Yes to confirm this is the Willsenton R300. 6SN7 tubes driving 300B in single ended triode with dual 5U4G tube rectifiers.

I just received it and had bought it for a small system in a spare bedroom but when I tried it with my Klipsch Forte IV speakers I was blown away by the depth of the soundstage and the overall realistic and organic tone so I am thinking placing it in my main setup. Diana Krull, Melody Gardot, Leon...never sounded better. Just need to tweak a little more clarity.

The other tube amps I have to compare are Muzisahre X7, X9, X10, R100 300B 845, and past Willsenton R8 and Icon Audio Stereo 40 IV owner.

My other current equipment for comparison are Luxman L-550AXII, Naim Unity Nova, Naim Unity Atom, Hegel H120. Dynaudio Contour 30, Dynaudio Special Forty, KLH Model Five, Klipsch Heresy IV.

The frontend is Lumin U1 and Denafrips Venus II. I also have Matrix Audio for other smaller systems.

I am hooked on tubes though. I also know that a few relativity inexpensive parts can upgrade these Willsenton and Muzishare integrateds which are great values and made in the same factories as Cayin, PrimaLuna, and Line Magnetic but for half the price or less.

 

Thanks again for all the help. I will keep you posted on the results.

 

If your looking to upgrade coupling caps you can also play with the value of the

caps because they play a critical role in output impedance. For example,  I purchased a tube preamp which sounded terrible, no dynamics, no amplification.

Turns out there was an impedance mismatch between my amp(LSA class D) and the newly purchased preamp. After some research, I purchased a slightly upgraded cap with an increased value and surprisingly, it worked and am extremely happy with the outcome. Wanted to give my 2 cents cause coupling caps play a critical role, whether you're upgrading or changing the value, dismissing it's importance is  just anti-audiophile.

I've used most of the caps mentioned here and have found the Duelund Cast, in my case tinned copper version relegates every other cap to  a distant second place, really special cap, future plans for going into my speaker crossovers as well. I also like bypass film cap on electrolytic power supply caps if one doesn't have room for all film caps.

 

Charles is correct, SET circuits low parts count, so every single part change has bearing on sound. Resistor upgrades also worth investing into.