AMP MFG - Rogue Audio
MODEL - M-150
MSRP - $4495 (a pair)
USED MKT PRICING - $2200-2800
SPECS - 150wpc, freq response 5hz - 50Hz +/- 1 db
SPEAKERS - Vantage, and as of 12/9/08 - Spire
My foray into tube power for my Logans began last winter and I have been enjoying these little 55 lb gems ever since. Rogue audio which is based here in Broadheadsville, Pa produces a varity of tube based gear both seperates as well as integrated pieces. Mark Obrien, owner, chief designer is, as all of us who know him, an upfront, easy to deal with kind of guy. I like that, along with the 'Made in USA' label that gets affixed to his products !
The M-150 is a KT-88 output tube based design featuring four of them in each amp. A 12ax7 handles input tube duties while a pair of 12au7's handle the driver stage. Stock tubes are of Russian origin, Elctro Harmonix. My initial run-in was with the stock tubes, after a couple of months I 'rolled in' what is now my 'refrence set-up', more on those later.
Upon taking delivery of these from Mark I had them set up and at that time my Vantage's affixed to the 4 ohm taps and preceeded to break them in (min 500 hrs per "Bernard's Golden Rule"....LOL !). While I didn't rush to judgement it was apparent that something was not what I expected on the higher freq. There was an apparent vail, shroud or maybe even a roll off. The culprit turned out to be the IC's (AudioQuest King Cobra, balanced) that was feeding them from my ARC LS-26. I switched them out with a pair of DH Labs Air-Matrix balanced IC's and my faith was restored !
For the first couple of months I played a bit of a 'switcheroo' with the Rogues and my previous amp (Plinius SA-102) and while I absoultely loved all the midrange magic I was still not sold with respect to the upper and lower registers. So I placed a call to a well known Tube Guru, Jim McShane out in Chgo and after dialogue and research on my part I 'rolled in' Genalex Gold Lions for the KT-88's, the 12au7 is now a 'RFT' and RCA's occupie the 12ax7 sockets.
I must say when I completed that change I have but once put the 'Plinny' back in for comparrison. The presentation these amps provide is trully enjoyable, envolving and they are down right musical. The mids are everything I want, a feeling of being there and being right. The wide bandwidth capabilities of the amps do justice with the tube change provided to both ends of the freq spectrum. Have I heard better....yep, several times, (couple times @ RMAF this past year), but I have yet to hear anything that comes close to these two in their price range.
One other note, for convienence there is a switch on the back witch facilitates the choosing of either Triode operation, for the lowest level of distortion with a sacarifice of power(75-100w)and Ultrlinear for the max power output with 'slightly' higher distortion. I have experimented with both and tend to gravitate towards Triode mode when listening to Jazz, small orchestral arrangements (Chamber Music) and Ultralinear with larger productions as well as rock.
I have provided a couple of links below for further refrence, both Rogue Audio's link and that of a "real" review !