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Western Electric Model 91A 2A3 Stereo Clone

Completed on 5/14/2016

Built for Patric Kennedy, MN 

Personal Feedback:  


Hope all is well.  The 2a3 has been burning in for 4 days.  Today was the first day I listened to it.  Here are my initial impressions:

  1. Easily the blackest background I have heard.  Absolutely no noise floor.  Undetectable.
  2. Surprisingly, it is driving my Quad ESL-63 speakers quite well.  More to come as I test other genres of music.
  3. Perfect, beautiful tonal palette.  I don’t want to change anything tonally, which is quite a compliment as I usually like to tinker.
  4. Widest and deepest soundstage I have heard in my system.  This is likely due to the hugely diminished noise floor.

This is great stuff, Min.  You should be proud.  Thank you!

I do have some items I wish to possibly change in the future, but more on that later.

Happy listening.

Over the past 2 years I had an desire to match an SET amp with my Quad 63s. Nearly everyone in the industry that I talked to said this would be a poor match. However, with some encouragement from Mikey Samra and Kent McCullum at eStat Solutions, under the right conditions, this is quite a beautiful match.

I purchased a 2A3 DHT SET from Tube Audio Labs. Min Yang, owner of Tube Audio Labs, worked with me to configure a 2A3 schematic with components to my desire. The build quality of the amp was very good. Point to point wiring was well executed. Out of the box the amp sounded very good and only improved over time as I tweak a few caps and resistors. (FYI: if you are shopping for a DHT SET, please contact Min at Tube Audio Labs. He is first rate, honest and will help you.)

The first thing that should be noted is my listening environment and musical preferences. I have a 14'W x 17'L x 9'H listening room. The Quads are about 8 or 9 feet from the listening position. Most of my listening is done with about 85-88db. 90% of the time I listen to chamber music and classical solo, including piano. I sometimes push the amp above 90db when listening to rock or large scale orchestra.

So, can a DHT SET amp drive the Quads. Yes, absolutely, within sound pressure limits of about 90-95db or less. For me, this is quite loud and the older I get the less I listen to loud music. Within the 80-90db range, the 2A3 3.5 watts is just perfect with my Quads. I get a natural tonal palette, very very good dynamics and transients, super clean and smooth hi frequencies. Low end is as fast and clean as I have ever heard in my system. And yes, within its limits of 80-90db, the low end has great punch. Is the low end as good as my former Boulder 2060, no. But I don't need a low end playing below 30hz. Very very little chamber music at 30hz or less. Unless you listen to large scale orchestra or organ music, you will not miss the bottom bottom bottom below 30hz. Yes, the amp will clip when pushed about that 90-95db range on my Quads.

I am tweaking the amp continuously including some power supply upgrades that have really added to the dynamic range of the amp. For the first time in 30 years of audio, my system can play piano with near lifelike quality. Especially the lower piano register comes thru with clarity and impact.

The thing I like most about the 2A3 amp is that it allows me to easily hear differences between tubes, caps, resistors and cartridge changes. It is a very transparent amplifier with neutral and natural tonal balance.

So, if you ever wondered about whether or not a SET can drive Quads, I say yes, within limits. It can be quite captivating. Highly recommended.






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