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Triode Corporation TRX-M845 Monoblocks Tube Amplifier Review

Reference Edition Single-Ended Parallel Monoblocks

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Triode Corporation TRX-M845 Monoblocks Tube Amplifier Name Plate

For recordings that tend toward the shrill, the TRX-M845 seems to temper the shrill just enough to retain detail without the “ouch” that can accompany those upper frequency instruments. This was nowhere more clear than on an early Boz Scaggs recording on vinyl, Down Two Then Left, from 1977, Columbia. The greater the tendency of the recording to muddy the waters of midrange orchestra, the more the Triode will leave the listener hungry for detail. For guitar soft rock…Dire Straits, Mark Knopfler, Eric Burdon, the Animals…there is a huge improvement with the “1” setting of the feedback, but when this is left with the orchestra, there seems to be an increase in ‘muddling middle’ and minute lack of air and resolution when playing the orchestral stuff. I got to where I preferred zero feedback even on pop, unless it was just a spitty-as-hell recording.

The Balanced Kegons, in comparison, are a bit brighter or more detailed, perhaps at different frequencies. Little percussive sounds such as an oboe, or flute, or clarinet playing a couple of measures against the background of the full orchestra might stand out a little more due perhaps to a frequency sensitivity. The increased level of detail elicited by the Balanced Kegon is generally a boon; however, it can make early digital recordings hard to endure and can emphasize the flaws in the recording. On the Triode, the opening cello or lower string instrument at the right of the sound stage on Invitation to the Dance might be a bit warmer, or slightly lower in pitch, or richer, certainly better controlled below 100 Hz. The Triodes at low-to-medium volume levels are not as detailed or nuanced as the Balanced Kegons and really come into their own at higher volume levels. Oddly, when taken by themselves and not in comparison to the Balanced Kegons, which are many times the price, the Triode’s sounded perfectly balanced…full range, detailed and musical.

I think the Triode with 845 tubes borders on smoothness, warmth and musicality, leaning toward less resolved and less nuanced, while the Balanced Kegon in the 300Bs have more of what I would call “inner detail” which will improve placement and dimensionality of the inner voices, especially.

The third time is the charm: As I have perhaps suggested, it is a crime to place Chinese tubes in an amp of this quality. Nonetheless, I am always somewhat reluctant to swap tubes in something that I have in for review, particularly given the often prohibitive cost of N.O.S. tubes. In this instance, the importer was kind enough to provide me with a pair of 1960’s vintage CBS/ Raytheon 6SN7tubes which he had found to rather dramatically, in his own words, enhance the sound of the amps. Given that the 6SN7 provides the initial stage of gain, it seemed at least possible that a change of this tube could have a rather audible impact. The remainder of the listening was done with either the Raytheon 6SN7 or a pair of 1950’s Chrome Dome Sylvania 6SN7’s sourced from Brent Jesse ( Each of these NOS tubes to differing degrees mitigated what I had considered weaknesses of the amps without detrimentally impacting its strong points. This was perhaps most evident with respect to what I described as the bleaching or lack of color. This aspect of the sound was much improved with the Triode, moving closer to the robust tonal palette of the Balanced Kegon.

Each of these tubes has a distinctive sound. The soundstage created by the Raytheon tubes begins farther back and has more depth. Images have a somewhat softer focus. Depending on one’s perspective, you might either say that the Raytheon’s are more laid back or that they have somewhat less detail, although this is not an issue. The converse is that the Sylvania tubes are clearly more upfront with sharper image focus but sacrifice depth. They are somewhat more detailed but can at times sound a slight bit rough/aggressive in the upper midrange and lower treble. This may be that they are merely more accurate. One of the records to which I listened was the 180 gram reissue of the Yes album Fragile which is compressed and may be the source of the roughness. This is to say that the Raytheon tubes are either more natural or alternately smooth over a bit of the top end. In any event, the choice of tubes allows the user the ability to tune the amps to his taste within certain bounds.

Triode Corporation TRX-M845 Monoblocks Tube Amplifier Name Plate


I have thoroughly enjoyed having these amps in my system and will regret returning them to the manufacturer. While they are not cheap, they are clearly a bargain when you consider that to achieve a superior result, it may require the expenditure of four to five times the investment. The extra money will get you more delicacy, refinement, low-level detail, dimensionality and a deeper soundstage with more space around instruments and perhaps, a lower noise floor. However, improvements in these areas will not necessarily be dramatic or even apparent except in direct comparison, and you may sacrifice bass control and dynamics which the Triodes have in abundance. And for those listeners whose preferred listening material necessarily includes less-than-ideal source material, it is always a trade-off between the detail that you want to hear, versus the detail you’d rather not know about. The Triode could well offer an excellent compromise for those listeners, particularly with its ability to dial-in feedback, leading to a more forgiving presentation.

It struck me after writing the review that the extent to which these amps sound different is at least to some extent a function of the difference in the output tubes, a 300B vs. a 211. Each has its own set of strengths and weaknesses. The 211 is a master of tonal density, the 300B more delicate and refined with better low-level detail. It would be interesting to have been able to replace the Shugang 211 tubes with N.O.S. General Electric or even better, United tubes, but I simply did not have access to either.

7 Responses to Triode Corporation TRX-M845 Monoblocks Tube Amplifier Review

  1. Patrick says:

    Interesting review. What loudspeakers and preamp did you use for this review of the Triode TRX-M845 amps?


  2. fred crowder says:

    Einstein preamp and Acapella Triolon horn speakers and Marten Momentos. The Triodes are fabulous for the money.

  3. Ken says:

    I am considering these amps… The conclusion is quite positive, but The overall impression reading The rewiev leaves me thinking that there is too much negative going on with the amps.

    It is being compared to an very expensive amp, is it possible to give some comments where it stands compared to similar prized amps. Creds for an critical rewiev, but i got confused with The positive conclusion (pay three times more for same quality…) versus The overall impression! Are there any reasons to buy these Triode compared to similar prized stuff?

  4. Fred Crowder says:

    Please keep in mind that I compared the Triodes to my reference Audionote amps which are about five times the price. The Triodes are in my opinion superb for their cost so long as you replace the low level tubes that come with them with NOS equivalents and use an after market power cord and appropriate isolation. The importer is an audiophile and can make suggestions with respect to tubes. Two further caveats, 1) I much prefer the sound with no feedback and 2) the 211 output tube sounds very different from the 845. While both are good, one will always work better than the other with a particular speaker.

    I hope this is helpful, but feel free to ask additional questions.

  5. Ken says:

    Thanks for the answer Fred

  6. Lucianoi Musella says:

    Please You can send me brochure or any materials with pricing? Many Thanks & best Regards
    Luciano Musella
    Via Macedonia, 25
    I 80131 Napoli

  7. Edgardo says:

    Hi ken , I have them they really very good , the only problems is the hum when they are not play .. did you experience that ? Thanks

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