• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

RMAF 2012 and Free Urushi Caps

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Here's a couple pics of my system...

The preamp has 5692 input and 6H8C output tubes, both are military versions of the 6SN7, 5692s are American, 6H8Cs are Soviet. The preamp has high quality passive parts including Clarity Cap TC series 110 uF final power supply caps and mono attenuators with both 6 and 1 dB steps.

The amp is a Sylvania 12BH7 tube driving Gold Lion KT77s in triode mode. It also has clarity film caps in the PS, a GE 5AR4 rectifier, gold plated copper input jacks and binding posts, James 6123 OPTs...

system10-24-12029.jpg


system10-24-12005.jpg


system10-24-12007.jpg


system10-24-12018.jpg


I need to build an audio rack next... I have 4 large slabs of walnut that have been drying for a couple years now... :D
 
Last edited:
Dave,

You got very nice looking DIY going there!!

Cheers!
Kenji

Thanks Kenji!

I just made a change to my amp so it no longer requires any coupling capacitors at all. I removed the 12BH7 driver stage and now have the Aikido preamp directly driving the EL34s. The gain structure with a 2V source is perfect, input sensitivity of the amp is about 20V. Now that I can really hear the Aikido, it is amazing... it has a ruler flat freq response, <.05% thd and is dead quiet. Also, this way each amplification stage has it's own power supply and chassis, which is more ideal. Next will be a CCS plate load and fixed bias for the EL34s. :D

Now the Urushi caps are the only coupling caps in my system. It should make the differences between the Urushis and the RelCaps more obvious. I don't want to say much before they burn in, but my first impressions of the Urushis are "neutral and dynamic", the RelCaps are a copper foil cap and have a bit of character to them in comparison. The Urushis seem very promising so far. Another point of comparison is I used to have Solen MKPs in the 2nd output on the preamp before replacing them with the Urushis, and both the RelCaps and the Urushis are significantly better, the Solens do A LOT of harm to the music!

If anyone wants to donate some V-Cap Copper/Teflon or Dueland CAST caps to compare them, I'm all in... ;) The RelCap PCUs are a very good cap, but less than 1/2 the price of the V-Caps and 1/5 the price of Duelund. Kenji, do you know how much the .47 uF caps I won are going to retail for? Also, any details on the construction and materials used?
 
Last edited:
Sorry for the delay, I've been preoccupied w other stuff lately...

The caps are well burnt in by now and I'll make some comparisons with the RelCap PCUs soon :) The differences between the two are subtle, doing a quick comparison there was not a large change in sound between the two. This is a good thing as the Solen MKPs were much worse vs the RelCaps, so it is safe to say the Urushis are doing great, and at 1/2 the price of the RelCaps which is nice.
 
I have done a more thorough comparison, and it is close. The RelCaps are copper foil and are a touch warmer with a little more harmonic texture. The Urushis are very clear and neutral. I could live with either happily and I believe there are more differences than one being clearly better. In my system I have a slight preference for the RelCaps, but they are also 2x the price and only rated to 400V.

I think these are great coupling caps for the price and I'm sure they will be very popular after more folks get to try them out and word spreads.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.