Hello! I'm new to the forum - but have until now, always been a reader. I'm always on
the prowl looking for the latest and greatest Dynaco and Neo-Dynaco tech talk.
I probably own and have built all of Bob Latino's amps - and the M-125 mono blocks are no exception. With respect to the M-125, you can't go wrong. Simply because they follow the success of the modern day VTA Mark III driver circuit, which in turn is built on the success of the original Dynaco Mark III. The power transformer doesn't get above 130 degrees Fahrenheit after several hours. The rather large output transformer on the M-125 monoblocks has been carefully reverse engineered to offer the best linearity possible for a modern tube amp. Keep in mind, David Hafler, a founder of the later Dyna Company, owned and operated a transformer company (Acrosound) in his early days of hi-fi engineering.
I built my M-125 monoblocks over Christmas of 2010. I originally biased the amps to accept KT-88s but later learned about the success many builders were having with the Tung-Sol KT-120s. I ran the amps for about 6 months - approximately 250 hours before one of my KT-120s came down with the red plates!! "I couldn't be caused by one of these huge KT-120s that could withstand a nuclear blast", I thought to myself, as I’m sure many of we tubies do. Before tearing into the amp, I contacted Bob thinking I was experiencing an amp catastrophe! He said “don't sweat it,” in his always calm demeanor. “Go ahead and check a few voltages and let me know.” At that point, I was, as I'm sure many other tube builders are, figuring something fried in the amp to cause this eventually terminal situation. All readings were perfect - and no noticeable telltale burning smell or black marks anywhere. Don't ya thunk I woulda tested the KT-120s by now? After all those fine readings in the amp, I did. Yup, a KT-120s control grid had touched the cathode I can best surmise. Believe you me, these KT-120s are tough as they are advertised, I just got a bad one. Because of this experience, I should've believed Bob the first time when he said, "these amps don't break down"!
Lessons learned: Bob is always available when and where you need him for advice and answers whether vintage Dynaco, or the new generation amps he sells. He won’t leave you guessing, even if you do have a problem. These amps are tough enough to even take red plating for God knows how long!
Sorry for my digression but they do really, really sound great. Now, if I could just save enough to buy a better than above average pair of speakers! That's how much I believe in these amps...I don't own any Maggies but I can tell you when I play the M-125s through some better than decent Klipschs and Axioms - they shine. Listening to “Dreampalace” Troika IIs title track, I distinctly hear the images shift to the right and left about a meter and a half out from the speakers. I like to play the blasting trumpets from 70’s group "Chase" so I can try to pick out the back-up trumpets and guitar players in the sound stage.
I tried these amps coupled with perhaps 4 different preamps - honestly, the M-125s sound fantastic! For kicks, I hooked an average passive preamp to these monoblocks just to hear a more "pure" form of these amps - and I have to say, I was proverbially blown away! Most importantly, I know now that the imagery is a LEAST coming from the M-125's.
The VTA driver board has been available since 1988, but the full VTA ST-70 amp kit came out in 2006. The VTA ST-120 came out in June 2009. The M-125's in Dec of 2010. Short, sweet and honestly, these amps, whether you go for the VTA ST-70, VTA ST-120, or the monster M-125 monoblocks, you WON'T be disappointed.
Enjoy the glow, Patrick
