Review: Tube Research Labs M-225 mono blocks Amplifier

Category: Amplifiers

I have been in this hobby for 30 years and this is the first time I have felt compelled to write a review about a stereo product. Tube Research Labs has been producing some of the finest and very expensive tube equipment for well over the past 20 years. This review is about their solid state mono blocks the M-225. Each amp is very conservatively rated at 225 per channel but it sounds much more powerful than the suggested 225 per channel. In the past 30 years I have owned more gear than I would admitt. SS, tubes, you name it, I have owned from moderately priced to quite expensive amps. Some of the brands include CJ, ARC, Pass, BEL, Levison, Krell and many more. I have also listened to some ultra expensive systems $100,000+ so when I hear music I know it and when I hear crap I also know it. Usually price has very little to do with the sound.

TRL's M-225 mono blocks are very plain looking black boxes
and weight about 45 lbs each but their sound certainly isn't plain. The TRL M-225 doesn't sound like a ss or tube amp but it sounds like real music. Right out of the box I knew this was a very special amp. My wife who likes music but will only listen to one cut at a time came in for a quick listen and stayed for the entire Alison Krause CD and then we listened for about another hour. Her comment was this is the most enjoyable I have ever heard your system. The only change has been the TRL amps. Are these the best amps I have owned? Absolutely. Ever heard?
Yes they are! Why? Because my system no longer sounds hifi but sounds like real music. Anyone in the market for a great SS amp check out TRL's ss amps.

Associated gear
CJ - CT6 preamp, 9100 Modwright CDP, Salk HT3's speakers
I'd be interested to read the process you went through to hear and purchase these.

The TRL website has no information. No dealers. Etc.
I am glad that you have also enjoyed the TRL M225 immensely. I have been a proud owner myself also for 3+ years. I have also owned a few top brands before, and heard DartZeel, Boulder, Goldmund, ASR battery, Gryphon to name a few at friend's whose systems are no less then $100K. Honestly, I am not tickled at all to change my mono's, especially after upgrading mine to battery powered.

I have found that top quailty PCs would tap its potential further. Feed them dedicate lines when possible. If not, like my current living situation, I have found Isotek Titan GII (with a few tweaks) works well with them also. Good luck and enjoy listening as I know you definitely will. :)


You are right that there is no information on their website about solid state equipment. I was able to email and talk with various TRL owners to get a better feel for the company and their products. I also had many conversations with Paul & Brian at TRL before I placed an order. The majority of the TRL owners claimed their long term search was over and TRL SS was the best that they had heard in their system. Yes I took a chance but these amps to my ears are really that good. I no longer try to analyze the music but simply put on a CD and enjoy. BTW, I live in Oregon and anyone interested in hearing the TRL's is welcome.
How much do TRL M225's cost? I heard they make an integrated amp too. Is that true? I have looked on the web for these also, but I find nothing.
The M225's are $5,500 per pair. Yes they do make an integrated, I am not sure of the price.
Bobheinatz, as I understand it, you purchased them unheard, correct?

Were you offered a home trial period after which you could return them?

Yes I purchased the M-225's w/o hearing them. Am I a risk taker? Not really, I pulled most of my money out of the market over a year ago! Am I the first person to purchase a audio item w/o first hearing it? I did my homework on TRL and Paul has been making some of the finest tube equipment around since the early 80's. Both Paul and his brother Brian believe their solid state gear is just as good as their tube equipment. The subject of a home trail was never talked about and since their product is outstanding I guess there is no concern about returning the amps. Any other concerns?
The subject of a home trail was never talked about and since their product is outstanding I guess there is no concern about returning the amps. Any other concerns?
Bobheinatz (Threads | Answers)

You've answered all my questions.

Thank you.
I recently purchased a TRL D225 amp, the stereo version of the M225 monos.
I would echo the comments above. This amp is simply outstanding. The one
thing that really stood out for me was, it's absolutely dead quiet. Like, crazy
quiet. Like, I can't believe how quiet it is. It was immediately apparent, that
the TRL was head and shoulders above my Belles 150A Reference in every
way, shape or form. It just sounds like music. I can't imagine ever replacing
this amp.

Here's what I wrote in another thread.
Keep in mind the amp is essentially brand new and not burned in at

There is no part of the spectrum that is exaggerated, it is smooth from top to
bottom, like I haven't heard before. Even at really low volumes the amp
sounds full. It sounds the same whether I'm at 1/8 volume or 3/4 volume,
just louder or quieter. More so than any amp I've ever heard. The Nuforce Ref
9 V2 was the previous best I'd heard at this. The D225 blows it away.

This amp is absolutely, positively, dead quiet! Like, amazingly quiet. Like I
have never really heard a quiet amp before in my life, quiet. Maybe because
it's so quiet, details come thru like I've never heard before. By detail I don't
mean the typical, more treble, etc, I mean, background sounds, breaths,
movements on instruments, the recording environment. On Jason Mraz's I'm
Yours, which I listen to all the time, at the beginning of the song there's the
sound of waves hitting the shore. I've never heard any hint of these before,
but with the D225 they were as clear as day. On Jack Johnson's Banana
Pancakes, in the beginning there is the sound of rain falling. Normally it
sounds like a little trickle in the background. When I listened to it this
morning, I actually paused the song because I thought someone had turned
on the water in the bathroom above where I was sitting. That's how
pronounced it was, it sounded like it was literally raining out the window.

At this point, I've only listened for a couple of hours total, so that's all I have
for now. But it is clear this is the best amp I've ever heard and it's not even
burned in yet.

Glad to see another happy TRL owner. My M-225's are still improving and you are right about how quiet TRL amps are.
They are also the most nonfatiguing amps I have ever heard.
BTW I have owned class A amps before and they always ran very hot, the TRL's even after hours are cool to touch.
It sounds like these are stellar amps. Is there any Achilles heel, like anemic bass, etc.? It sounds like the answer will be "No" but your thoughts would be appreciated. Another A'gon-izer whose opinion I highly respect is also intrigued by these.
The TRL's produce the most natural articulate bass I have ever heard. There are no exaggerated frequencies just natural flowing music. These amps also lowers the noise floor so details on some CD's come thur quite clear where my past amps were either muddied or nonexistent. If you live in the Pacific NW you are welcome to come over and listen. If you have any other questions please don't hestitate to ask. TRL has been in business for 20+ years and they know what they are doing. BTW I really enjoyed your review on the Intuitive Designs speaker.
That's the answer I expected, and I believe you. It's also good sign when people favorably compare these to such iconic names as Gryphon, etc. I'm still very happy with my Odyssey amp and preamp, but the TRLs are now on the short list should I ever choose to upgrade.

Thanks for your kind comment regarding my loudspeaker review.
The most important part of our hobby is to enjoy listening to music. Only your ears can tell you what sounds good. I have been guilty like some on this site for always looking for that next upgrade. If you enjoy your current set up then just enjoy it. Upgrades can be made by purchasing more music. Enjoy.
I can't believe that I am putting these great amps up for sale but I am. If you are interested please check my ad here on audiogon.
Why are you selling them?
I am selling them because I got a great deal on a Air Tight 300b amp. I almost got it for free. So I bought some high efficent speakers and I like the sound and 300 watts per channel from the TRL's is an over kill. So like most audiophiles I am trying something different.
Are these the best amps I have owned? Absolutely.
Ever heard? Yes they are!
Bobheinatz (Threads | Answers)

Here's what's difficult to reconcile...selling the best amps you have ever
heard, particularly if the Air Tight replacement amps were almost free.

Why not keep the TRL amps in storage for the day when you might be ready to
go back to solid state (or bi-amp)?

There is a very simple answer, I need to sell the TRL's because I want to pay off my credit card bill with the new high efficent speakers I bought for the Air Tight. You seem to be interested why not buy them yourself!
I understand the reallocation of funds to speakers. Makes sense.

You seem to be interested why not buy them yourself!
Bobheinatz (Threads | Answers)

A few reasons.

1) They are not balanced, so they are not optimal for my system.
2) Specs are not published.
3) Several prior owners who have posted about the excellence of their TRL amps
have subsequently sold them.
Thanks for your reply. It is always a balancing act with our systems especially when we make changes.