I am an avid reader of your e-zine and always appreciate the impartiality to the various products that are reviewed each month. Elsewhere I've seen paper magazine reviews of the Musical Fidelity Class A transistor amp but it might have been useful to have been given some sort of comparison with the only other Class A UK manufacturer, Sugden.
I appreciate that the MF is much more expensive but all the same both amps are Class A and as I am about to consider buying such an amp for my new system, the considerable cost difference is very important to me in these difficult, economic times.
Well, as you say, it's not fair comparing the IA4 with the nearly double in price Musical Fidelity AMS35i, but I'll try! The Sugden is a superb amp at the price, inasmuch as it offers a truly clean and open window on the world in the way that only a serious Class A amplifier can. It has air, space, pace and grace–although the latter is a little lower down its list of fine qualities; in a revealing high end system it can sound a touch brightly lit. It's not harsh and hard like most high end Class AB fare, it's just as if someone's turned the contrast up a little too much on the telly. It's ideal for vinyl or smooth sounding speakers, but can 'set off' a system that was always going to be forward.
The Musical Fidelity builds on this, turning the contrast down a tad and adding a fuller, more barrel chested bass. It's also musically more lucid, approaching that of a good tube amp. There's a lovely texture to this amp; via speakers with uncoloured drive units (i.e. high end Martin Logans) you can hear right into the recording as if the sound was translucent. It's really lovely and this, allied to real punch and dynamic ease, makes it a stunning 35 Watter.
I almost feel embarrassed to be so effusive about this amplifier, but certainly in my system it was magnificent. I'd been looking for something to truly work with my NS1000Ms for nigh on fifteen years, and that was it. Think of the Sugden as the first step to solid-state perfection, while the Musical Fidelity could well be the last for many people. As for the AMS50 power amplifier, I suspect this would truly be the ultimate.
Eventually though, before I sold the Yamahas and replaced them with Vandersteen 2CE Signatures I used various Accuphase class A power amps – all pre-owned because prices for new ones exceed my budget. Overall, my preference was for the Accuphase. Nowadays I use a Jeff Rowland integrated, the Continium S2.