- Aug 13, 2017
My AV System
- Preamp, Processor or Receiver
- PrimaLuna Dialogue Premium TubePre (2 channel+sub)
- Main Amp
- McIntosh MC152 SS Amp (2 channel)
- Additional Amp
- Yamaha RX-A850 Pro (the other 5 channels lol)
- Universal / Blu-ray / CD Player
- LG BlueRay
- Front Speakers
- Martin Logan ElectroMotion ESL
- Center Channel Speaker
- Martin Logan Motion C2
- Surround Speakers
- Martin Logan Motion 4
- Surround Back Speakers
- Martin Logan Motion 4 (yes, another set of these)
- Martin Logan Dynamo 700
- Other Speakers or Equipment
- Cifte 12AU7 NOS & Genalex Gold Lion Tubes in Pre
- Video Display Device
- Sony TV KDL50W700B
- Remote Control
- Audirvana Plus, Tidal HiFi MQA and DSD128...
- Other Equipment
- Throw rug, saddle blankets and base traps...
Pardon me, and you are quoting an article from 2013 about the Momentum... My comments above are about the current Relentless mono blocks...Oscar Wilde may have had a more cynical view if he knew anything about the audiophile industry.
I was troubled by a number of technical problems with these products. The reliability issues was just one more reason to not be impressed.
The signal to noise ratio is relatively poor and plenty of the problems are in the audible bandwidth. Namely, the amps pick up hum from the power supply. I haven’t had one on one time with these amps to hear how audible this is, but having owned plenty and destined some amplifiers myself, I find this objectionable and fixable. When the amplifier picks up hum at 60hz it’s from the power transformer. It’s almost always a mixture of proximity and wiring and it’s almost always fixable. When expensive products hum, I don’t see a good excuse for that. 120hz hum is caused by the power supply itself not being quite clean enough. This is often what we hear as hum, and this too is fixable in expensive amps. This was one of the main points of contention in my own designs and I could minimize it with a more stiff power supply using a CRC or CLC design.
The distortion is relatively benign in these amps but it’s also not state of the art distortion performance. It’s average at best.
It has switching distortion! That is odd for a D’Agostino design and suggests these are utilitarian Class B amps. Why? Zero switching distortion is very objectionable and is audible at tiny levels. Compared to harmonic or IM distortion, this kind of distortion is a major sound quality concern but is fixed with simple bias voltage.
I can list off a dozen audiophile amps of similar price with tricky superior measured performance. For my money, I’d rather those. And quite honestly there are quite a few megawatt amps in the pro industry that would perform better.