Help me find a pre-amp

@oldschool1948

Where can I purchase a Luxman CL-38uC preamp new or used but preferably NOS with US voltage preset?

@tyray Used ones are hard to find.  Call Alex at Alma Audio.  Alex is a good guy and I think he'll work with you on the price. 

Having said that, I recommend the LTA microZOTL preamp.  The microZOTL is lower priced, and it sounds noticeably better than the CL-38uC and my BHK Signature.  I bought the microZOTL and sold the CL-38uC.  I'm going to keep the BHK Signature for now.

With the microZOTL, the sound is more delicate; I hear more micro details; instrument separation is better; cymbals decay longer; chimes sparkle; instruments and voices sound more natural; and there’s no harshness or listening fatigue. PRAT is superb.

Sugden Masterclass LA-4

@oldschool1948 ,when I read your post I was actually ordering (2) Telefunken ECC801S / 12AT7WA’s and had just talked to Andy at Vintage Tube Services about sending my (1) Sylvania 6SNLW metal plate tube back to him so he can send me back (2) matched and balanced Sylvania 6SNLW’s for my MicrozotlMZ3 I had bought from Nichols at LTA. When I first called him to inquire about the MZ3, after our conversation he told me he had one for sale in trade that was two months old and basically brand new. He told me the price, saved me a lot of coin and I pulled the trigger.

At first I didn’t think the MZ3 would work with what I wanted to do because so many users of that kit used it as a headphone amp. But the MZ3 was described as a MICROZOTL MZ3 HEADPHONE AMP / PREAMP / INTEGRATED AMP so I gave it a shot. Turns out it had everything I needed for my rig. (2) outputs and (3) inputs. I hooked up my Clayton Audio amp, (2) PSA subwoofers, my dac at the time, Technics turntable and there was (1) input left for my future streamer. That was all I needed.

And when I first played the MZ3 I was taken aback by the black background and what was coming out of my speakers sounded just as you described. And to me it was Ethereal in the way this thing reproduced music. And this with the stock tubes and not broken in.

Below is some lite reading I found on the MZ3 while trying to figure this kit out.

Review: Linear Tube Audio MZ3 - July 30, 2019 Darren Henly HiFi Reviews The LTA MZ3 is a Class A push-pull amplifier that utilizes two amplification stages (12AT7 input tubes and 12SN7 output power tubes) and no feedback. Of course, the patented David Berning ZOTL circuit is central to the design.

From @twl here on audiogon: Black glass KenRad 6SN7s take the cake

Give me the Sylvania 1940s 6SN7 WGT any day. IMO the best there is. If you really want to hear what a 6SN7 can do, just listen to it as an output triode in a Berning MicroZOTL, driving a pair of Lowthers direct. This is where you really hear the soul of the tube, with nothing between the tube and the speaker but a few feet of wire. Nothing after it in the circuit at all. Pure 6SN7 coming out the single drivers. The Sylvania does it all. And the sound difference was amazing. The observations made by others regarding the delicacy of detail, midrange liquidity, strong bottom end, crystal-clear high end were all there, far better than any other tube I’ve used in it.

Now perhaps with preamps, where it is combined with other circuits, and passed through a power amp on the way to the speaker, there could be some "synergy" considerations that I didn’t encounter on my system. The Berning MicroZOTL is the only amp ever to use a 6SN7 as an output triode, as far as I know, and it uses it in a push-pull arrangement with each 1/2 of the twin-triodes inside the single glass envelope performing the push-pull functions. Linearity is excellent with this configuration, and gives terrific frequency extension on both ends, and of course, no output transformer to saturate or cause hysteresis problems.

Now, as I stated, this is a different application of the tube, but I did not get as good overall sound from the Black Glass KenRad in my application, although it was very good sounding with them. The KenRad, Sylvania WGT, GTA and GTB, RCA Black Plate 5692, all were far superior to the stock Sovteks that came with the amp, and would all be a big improvement. I was more disappointed with the 5692 than anything, as it was well balanced, but did not have any real "twinkle" like these others had.

And there is a definite difference between the Sylvania stuff, as the years went by. The older is decidedly better, and after the 1st couple of years of the GTB, it was a bad downhill slide. The 6SN7 W and WGT from the 40’s are the best, and then the 50’s, and then the early 60’s chromedomes in the GTA version, and finally the early GTB.

I think the MZ3 is a keeper.