Bryston vs Marsh

I currently have a Adcom gfa-555. I am thinking of buying a a Bryston 3bst or a Marsh 200. I have an ARC sp-9 preamp with Vandersteen 2c Spkrs. My question is would I notice a difference between tha adcom and either of the amps I mentioned and if so which is a better fit for my system?
I can't speak to whether you will hear a difference between the Adcom GFA-555 and the Marsh 200, since I have not heard the Marsh 200. My guess is you will hear an improvement, since the Marsh 400 has gotten very positive critical reviews, and the Marsh 200 is just a lower-powered version of the 400. Obviously, the best way to compare amps is to conduct an in-home audition.

I can, however, comment on the Adcom GFA-555 vs. Bryston 3B-ST amps, since I have substantial experience with both of these amps, and with your Vandersteen speakers. The Vandersteen 2c speakers are sufficiently revealing that they benefit from improvements in amplification, and with the 3B-ST you should hear better controlled and defined bass, significant improvement in mid-range clarity and transparency, increased transient speed and dynamics, and better soundstaging and imaging. (The Bryston web site -- -- has reprints of all of the reviews of the 3B-ST done by various audio mags. If you have not read these reviews, you should do so.)

In addition, the 3B-ST should be a felicitous pairing with your ARC preamp. The 3B-ST has vanishing low harmonic and IM distortion and a signal-to-noise level that is far lower than the SP-9 (lower, infact, than CD's). (If you compare the distortion and SN levels of the 3B-ST to the Adcom, you will find that the Bryston's levels are typically 1/10 to 1/100 that of the Adcom.)

The 3B-ST is rated at 120 wpc, but actually produces about 150 wpc. The 3B-ST's minor decrease in power from the Adcom 555 (200 wpc) will not be audibly detectable (to be audibly detectable, there would need to be about a 2:1 difference in the power output), but you will hear the improvement in the overall quality of audio reproduction. The 3B-ST is one of the finest reasonably priced, mid-powered amps on the market, and the 20-year transferrable warranty is, hands-down, the best in the high-end industry.

There have been several used 3B-ST amps for sale recently here on Audiogon, and for around $1200 you won't do any better than the 3B-ST. If you want to buy a new unit, drop me a private E-mail and I'll give you the name of a dealer that offers discounts on Bryston gear.
I don't know the Marsh, but I agree with what SdC said about the Bryston's ability to exert control and definition, yet it is very smooth, not tube like, but not rude in any way and with a great soundstage. My 4B-ST is paired with an ARC SP9-II: they pair well together, In fact if I upgraded the pre I would stay with an ARC, I like this combination a lot. (I'm driving maggies by the way).
The Marsh. I have owned both the Marsh A400 and the Bryston 4bst. Marsh A-400 is more neutral and lively sounding than the Bryston, and has superior bass definition (not quantity). It does not need much warm up time to sound good and would be a good match for the Vandersteens which can sound a little too rich.

Bryston 4BST, sounds veiled, less transparent and less neutral when compared to the Marsh, however, you may still want to consider it for other reasons such as warranty and reputed reliability.
To add to previous posts, you can be assured that there's always a high demand for used Bryston gear especially the ST series amps if you find it opposite to your liking. I am not so sure about the Marsh equipment.

I have had and still has a Bryston 3BST, a pair of 4BST's, and three 7BST's. They are not as refined sounding as Krell FPB series amps but pretty darn close even with the most revieling speakers, IMO.

I find it difficult to understand Ultrakaz's opinion that 4BST's are "veiled, less transparent and less neutral" in comparison to the Marsh. I qualify my opinion since I have not had Marsh amps in my house. However, I have found the Bryston 4BST's peformance opposite to Ultrakaz's experiences even compared plenty with a Krell FPB600c driving both Maggie 3.5Rs and B&W N802's. Maybe Marsh amp is that good and a better performer... I don't know.
The Marsh 200s sounds fast and clear and free of grain or glare. In my setup it does not sound "electronic" if you know what I mean. It does not double power when impedance is halved, but it never strained driving my Totem 1 speakers. The 200s costs less than the 3BST and the 400s is a little more. The Marsh amps are very good, the 400s is more powerful with better bass with some speakers.