Preamplifier options - seeking help to determine which one

Hello and I've just read your post hence the delay in replying.

I owned and loved a Yamamoto A011 (VT52) amp for nearly 9 years.

I've also listened to both the Yamamoto C03 with the 'normal' and stepped attenuators.

I have a few observations and opinions which you can follow or Ignore as you please. The A011 actually puts out about 1.8 watts, before clipping, as measured on a 'scope with load resistors, not 3 watts. It would simply not drive my Audio Note ANJ speakers at all! I did get a very quiet sound out of a pair of AN Es which are nearer 92db rather than 98db. I think you have to use this amp with a pair of easy-to-drive speakers of at least 100db. I have a pair of Lowther back-horn-loaded TP1 speakers which are 105db and play at rock concert levels with less than half a watt! The VT52 amp was brilliant with the TP1s BUT did hum in between tracks (less than 1mV hum) Speakers around the 100db mark will sound great and not have noticeable hum so are Ideal. So the likes of Klipsch Heritage Cornwalls or bigger. Maybe Zu audio speakers, Most Lowther BHL speakers, Avant Guard, or other speakers with an active bass?.

  The Yamamoto CA03 is a very nice phono stage/pre amp. I've had to clean a friend's  stepped attenuator CA03, a few times, to stop loud clicking noises caused by dc on the attenuator burning the contacts. The 'normal' attenuator CA03 doesn't have this problem and sounds just as good so that would be my choice (and it's a bit less expensive). 

Oh and I still have a complete set of NIB and NOS valves for the VT52 amp

and the CA03 preamp, They would be for sale if you wanted them.

Interestingly for such a rare bird, there’s a Yamamoto A-011 SE 2A3 on craigslist right now, of all places. It’s in Seattle.

Single-digit-watt amps are not my cup of tea, the polar opposite actually, but it’s a sweet-looking amplifier that looks very well built.

I owned and loved a Yamamoto A011 (VT52) amp for nearly 9 years.

Thank you for your reply. I appreciate your experience and reflections regarding Yamamoto and I'm glad that you take my system (Audio Note) into consideration.

I was actually recommended, by Yamamoto, to choose A-011 due to the low stock of VT-52 and ADM-1 tubes. The A-011 is supposed to be made with 2A3 making a fair 4 W per channel.

 I did get a very quiet sound out of a pair of AN Es which are nearer 92db rather than 98db. 

I'm very well aware that both the "45" and "VT-52" amplifiers deliver modest power. The Audio Note speaker I would like is the SPe/HE that should be 98 dB efficient. I will listen to music in a 25 square meter room. I have tried various places to ask if it would be a problem. Most replies I get is that the "45" will probably be difficult, but the "VT-52" shouldn't be. Which pair of Js do you have? 

to stop loud clicking noises caused by dc on the attenuator burning the contacts

This seems like a major problem. Can you elaborate on the problem and how did it occur? 

Hello again, Firstly apologies for the mix up. I quoted the wrong model No from memory! I owned a Yamamoto A010, the VT42 SET amp, not the A011, 2A3 amp. I bought the A010 without the VT52 power valves. I asked for 8 ohm and 16 ohm speaker taps but Shigeki Yamamoto Insisted that I had to choose one or the other! However, the amp arrived with both 8 ohm AND 16 ohm taps! Shigeki also supplied the amp with 4 NOS 'coke bottle' Hytron 80 rectifiers and two Siemens C3M input tubes. A valve/tube pal had a large stash of VT52s, I bought 2 pairs of NIB Hytron 1943 vintage VT52s. I bought another two pairs of NIB Sylvania VT52s off a US seller and two pairs of Tungsol VT52s off another US seller. I sold the A010 with a pair of lightly used Sylvania VT52s and Hytron VT52s. I still have the other unused pairs of VT52s, so 4 pairs in total. Did you know that the A010 will also happily use 6A3 tubes in stead of the VT52? These are what I mainly used as they give a bit more power and are really nice sounding valves (a bit easier to get hold of too) The A010 uses constant current heaters so the 6A3 heaters run at about 6,5V which is fine. you get about 55mA on the meter instead of about 43mA, with VT52s. I had a pair of the cheaper ANJs and had a pair of KIT 3 ANEs. AN rate the dearer ANEs at 98db but reviewers warn that they are nearer 93/94 db. If you stick with Yamamoto I would be tempted to get the KT88 A03 12w SEP amp? The tubes are alot easier to get and it would be a better match, power wise. Another valve amp that I think works really well with ANEs is the smallest Leben EL84 intergrated amp. Also try and hear Audio Notes own EL84 and EL34 push/pull amps.

Hello again.

It seems like you received great service and that you have an excellent selection of exquisite tubes.

How did you land upon Yamamoto? What do you think of the sound?

I don’t think AN OTO can battle with Yamamoto SET designs. I’m not sure though. 
 

I don’t know much about KT88 either but I really like 45. I thought VT52 would be perfect with SPe/He. How come there is so big variation in efficiency?