Beautiful and superb-sounding pair of no-feedback SET amps here. Priced to move! Excellent condition except that one amp top is bowing slightly inward due to transformer weight (you see this a lot with this type of layout). Not too noticeable from the front as the 300Bs hide it.
This pair came refurbished from Coincident about two years ago. No functional issues. Holds bias rock-solid (there are bias and hum pots), dead quiet, and sound truly superb. They also sound ballsier on my not-efficient Harbeth speakers than a 100W Class A solid-state amp did.
I have original boxes. Driver (Sylvania 6SN7) & rectifier tubes are in good shape. 300Bs at my asking price are the stock Valve Art.
These were $5000 amps and look & sound it. If you're after parallel 300Bs (I've had many, many 211 & 845 amps and for ~20W of SET parallel 300Bs beat them all) I think these would be impossible to beat near this price. Audio Note or Wytech - nice, and at least twice as expensive and maybe no better sound (I've not had either).
Below is a review excerpt that can be found on the net:
COINCIDENT MP 300B MONO
I used to be a dealer for this company. This amplifier, and a simpler
stereo integrated version of it, came out the year I left the retail
business (2001), so I never had a chance to purchase one for the store or
even audition it. The proprietor (not surprisingly) raved about it, and I
heard other good things from a number of owners, some who had wide
experience with amplifiers, but I wasn't in a position to do anything more
than mention its "potential" to the readers of this website.
I finally had a chance to hear these amplifiers on a system I was familiar
with, for a period that allowed me to hear it "in-depth", and also afforded
me an opportunity to compare it with some of the other amplifiers on this
list, including the Hurricane. In short, this is a superb amplifier, and
very similar in basic design and performance to the Manley Retros/Neos.
It has exceptional low-level information and purity, noticeably more than
the Hurricane, though it's not equal to what I've heard with the Golden
Tube 300B, which is in Class A of course. It has excellent dynamic
qualities, especially for its power rating, and unexpectedly tight and
impactful bass, but the speaker I heard it with (the Coincident Victory) is
an "easy load", so speaker choice is critical with this design. Of course,
the Hurricane (and even the Topaz) is considerably more dynamic,
"controlled" and impactful at higher volumes, and can be used with
virtually any speaker.
This amplifier is very easy to bias and is very well built for the money. I
think it is manufactured by the same company in China that (ironically)
makes the Hurricane. In effect, it is an enhanced version of the Antique
Sound Labs 300B amplifier.
2003 Update- I heard the most recent version of this amplifier when I
visited Toronto in October 2003. I was very impressed. It was a significant
enhancement over the earlier version, which was already excellent. The most
obvious sonic improvements were in the areas of immediacy, transparency and
purity. There was still a problem in the bass frequencies, which was blamed
on the output tubes being used at the time.
The owner of Coincident, Israel Blume, informed me that he was now using
superior coupling capacitors (oil and paper), input transformers and output
transformers. These amplifiers should still be used only with high
sensitivity and high impedance speakers, like most of the models from
Coincident themselves. That's the only type of speakers I have auditioned
While there, I also heard these amplifiers with very expensive ($ 125 each)
and rare NOS 6SN7 input tubes. The improvement was only modest, so the
stock (Chinese) tubes must be excellent. The output tubes were a different
story. Blume first offered an optional update, but has since replaced the
original tubes with the latest Electro-Harmonix 300B. The new retail price
for a pair is now $ 4,000.
MY JUNE 2004 TRIP TO TORONTO
I made my semi-annual visit to Toronto, where I lived and worked for more
than 30 years. I was there 10 days for mainly business reasons, but I did
spend one entire day at an associate's house, where I had a lengthy,
fascinating and highly productive listening session. I actually had some
unprecedented experiences. One of these experiences, my/our observations
and the final results and conclusions are discussed below.
An Important Comparison- Stromberg-Carlson AP 55 Vs. Coincident MP 300B
Prologue- I've heard the Coincident amplifiers a number of times now, at
great lengths and with both equipment and software I am intimately familiar
with. The last time I heard them, in October 2003, they were simply superb,
though they had problems in the bass, due to (according to the importer,
Israel Blume) their (then) stock 300B output tubes. This time I heard them
with the (now stock) Electro Harmonic Gold Grid 300B. There's no question
they're a noticeable improvement over the former 300Bs. The bass is better
defined, deeper, cleaner and with more impact and punch. There may be other
improvements in the mids and highs, as Blume claims, but I couldn't confirm
them in these limited circumstances.
I made this comparison myself. After a proper (30 minute) warmup, it soon
became obvious that the MP 300B was to the AP 55 as the AP 55 was to the
(described and remembered) Hurricane. (See Vintage Amplifier File for
description.) In short, the MP 300B was cleaner, more transparent, more
immediate, and less electronic than the AP 55. In turn, the AP 55 was still
a little better in the bass and dynamically. This was all easily
noticeable, but a particular comparison of two records demonstrated the
sonic superiority of the MP 300B in a manner I've never experienced before.