Do one set of caps in either the amp or pre and listen to it for a while before changing more caps. That way you will have a better handle on how the change sounds. One tweak at a time. Does that make sense?

Thanks, FB. Now I have to "risk" my gear with that minor surgery :scratch2:

The work is easy to do and you should do it yourself. :D

Sure ... What do I need, exactly?

1. Iron,
2. Lubricant/cleaner paste for iron,
3. Copper wick material,
4. Silver alloy solder material.

Unplug the amp for several hours (overnight)
Practice soldering a couple of times outside the amp

Is that it?

I've been away from the site for a few days and wanted to report back. And yes, 5U4G is what I have been using in my Inspire. In trying the 274B in the Dared preamp, I felt pretty much the same way that I did with Gold Lion KT-88's in the Inspire. I can see why people would like the full, solid sound. But I prefer the slighly more delicate flavor that comes with the RCA 5Y3 in the pre and 6V6s. But boy, that Sophia tube looks so good!

My Cambridge Audio story is kind of a sad one. I purchased the unit used and loved it. Yes, it was a multi-channel receiver. Unfortunately, it died a few weeks later, and my trusted repair shop reported that it had massive internal damage (probably in shipping) and was a total loss. I hadn't paid much for it. So, that's not a big deal. But I really liked it. Now, I am back to an old Onkyo that I have had for about 10 years. I do my streaming via a Mac and a Monarchy Audio NM24. Still getting the hang of it, but I like the Monarchy unit very much.

In the Inspire amp I also enjoy the detail and neatness of the 6L6 GC and 6V6 GT, but with the 5Z4 rectifier much more so than with the 5Z3 (5U4G) ... The KT88's are full-bodied and highly dynamic, but the tradeoff with them is the masking of some of the finer details. I like these with the 5AR4, 5Z4 and since last weekend, the 274-B alike. It all depends on the input tube I use and whether it is a low-gainer 6SN7 or the 6SL7.

I'm thinking maybe the KT66 will offer the best of these two extremes (detail mining/delicacy and sound body/dynamics), with the proper rectifier setup. I'll find out soon. I'm using the stock 80 (5Y3) and 27 output tubes in the LP-27a, although I like the 56's here too.

Interesting. I don't have a 5Z4. Is there a particular brand you like? I've been very happy with NOS RCA, including the 5U4G that I'm currently using. My driver is NOS Brimar 6SL7. I don't have KT66, but I do have a set of new Gold Lion KT77s that I have never tried. Maybe it is time to break them out.

I'm not much of a tube roller. If I experience a sound that moves me I leave well enough alone. But it's fun seeing users who swap tubes as often as some of you do.:music:

http://i1192.photobucket.com/albums/...ps9313bcf5.jpg

http://i1192.photobucket.com/albums/...psb9d69089.jpg

For some reason, my two 5Z3 (5U4G) alternatives are rather dull. One is NOS RCA and the other is an even older NOS RAD-TEL, which sounds better than the RCA but not at par with my other rectifiers. Funny!

The 5Z4 I have is a Brimar, mica base (not metal base). Excellent rectifier with all my output tubes. It even competes with the excellent Westinghouse/Amperex 5AR4 when paired with the KT88. I find it a go-to rectifier with everything except, of course, the RCA G ST, which requires the 80 (5Y3) rectifier.

Why is this so? I really don't understand it. The 5U4G (5Z3) is supposed to be the best with 6V6/6L6, but I did not find them even close to the above pairing ... Funny indeed!

The KT77 is supposed to resemble the EL34, which has a specific sound which may or may not convince everyone. In my setup, I find the 6V6/6L6 great but I miss the body and dynamics of the KT88, which in turn masks some of the finer details, unfortunately. So, I would like to try the KT66, which hopefully will bring on the best of those two tube families.

I also found the 274-B that I disliked up to recently to work very well with most output tubes when paired with the right input tube, a variable that in itself opens up a new can of worms ...:D

I think tube-rolling is fun, but not necessary if you are comfortable with the sound you have. In my case, I'm always striving for that next upgrade level ... :sigh:

I apologize if I missed this, but which driver did you find to pair well with the 274-B. I have yet to find the right match.