Preamp Deal of the Century

I have made another mod to my Chenin that may interest some. As you know, I have converted it to run 7193 tubes in place of the 6SN7s; that's still humming along fine.

I recently decided to replace the no-name electrolytic filter caps in the power supply with 630V Solen PP film caps. I used the same value caps as the electrolytics - that would be 100uF and 33uF. The 100uF 630V cap comes in a metal can with radial leads, the 33uF is a standard film cap with axial leads. It is a very simple swap, just unglue the old caps from the chassis, remove the wires one at a time, and transfer them to the new caps. I fabricated clamps for the new caps, and also glued both of them down wth "Amazing Goop", a very strong adhesive/sealer. I recommend clamping all power supply caps (even though the stock caps aren't!) as it would be unfortunate to have one come loose and touch a part of the metal chassis.

How does it sound? I noticed a pretty obvious difference immediately. Cymbals and drum thwacks sound sharper, there is more detail in the highs, and the background seems a bit blacker. In general, the sound is more robust and dynamic - I heartily recommend this mod. Keep in mind the rest of my Chenin is not stock, so your mileage may vary. One more bonus: the film caps will last forever, unlike the electrolytics.

If you try this - enjoy!

I did the same thing to my Chardonney, only I used motor run caps. Definitely made the preamp better. Tighter bass, cleaner, more dynamic, better soundstage. I also replaced the stock caps in the linestage with Mundorf Silver/Oil caps - big improvement. I did not have the Auricaps there but, some square blue caps. I tried replacing the other square blue caps near the rectifiers and it messed up the sound. Emailed Kevin Covi about this and he said those caps are not critical and just leave them in. I put them back and the preamp sounds tremendous.

Those square blue caps are probably Wima caps - OK at best, not what anyone would call high end. My Pre has the Auricaps and I'm really enjoying the sound now; I've though about replacing the Auri's a million times, but still haven't done it yet as I like the warmth they bring to the sound.

Now if I stumbled across some Duelunds, maybe I would change my mind...

I bet the Duelunds are more linear not as warm. I emailed another Supratek owner that upgraded to Vcaps from Mundorfs and he likes the change. He GAVE me his Mundorf caps! What a saint! Gotta love him for being so generous! I have read that one reviewer did not like the Vcap upgrade over the Auricaps. Enjoy listening I know I am!

Glad you're enjoying the Mundorfs, Jeff