Benchmark AHB2 in Mono Block Configuration


Hi:

I've owned the Benchmark ABH2 Amp for a few years but am now considering one two alternative upgrade paths:

A New Amp or adding a second AHB2. If I purchase a new amp so far I like the Bryston 3BCubed which is a dual mono design with 200 watts into 8 ohms or possibly the 4BCubed at 300 watts. In either case this is more power than the single ABH2 at 100 watts into 8 ohms. However adding a second ABH2 increases the power per channel to 380 watts .

So much for raw power. What about overall sound quality? The Bryston 3BCubed got an excellent review on Absolute Sound as an amp that would require significantly more $$ to better. Another review I read easily preferred the Bryston 43Cubed (300 watts per channel) over the ABH2.

I'm in the process of completely upgrading my system after several years of the same components. I will shortly have:

An Aurender N20 Streamer into an MSB Discrete DAC with dual power supplies feeding the single ABH2 which drives my Harbeth C7es-XD speakers.

Everything will be new except the older ABH2. Hence the consideration of an amp upgrade.

Now Benchmark will tell you that adding a second ABH2 is only needed when the single amp clips. Other than that there is no sonic benefit to adding a second. I Ffnd that hard to believe. I would think having a second would offer improved soundstage, separation and possibly better performance from the speakers. So my question is:

Have any of you added a second ABH2 and if so what were the overall sonic benefits if any? Also any opinion or experience on the Brystons vs the Benchmark? Or any suggestions of a better upgrade path would be welcomed.

jfrmusic

@jfrmusic 

I glanced at Harbeth C7es-XD specs, doesn’t look like they need whole lot of watts to drive them. I think you will get much better result with adding dual subs (like REL S510’s) over mono blocks. 

@lalitk 

I had dual REL T/5X subs but could not get them to integrate to my satisfaction with the Harbeths. The T Series RELs are really low end re enforcement rather than deep below 30 hz subs unless you move up to their bigger units. I liked the low end of the Harbeths which are -3db at 45 hz and my frequency analyzer shows output below 35hz. The RELs we’re just doubling up the natural low end of the Harbeths and it had a negative effect on soundstage and openness. 

@jfrmusic Luxman and CODA are known to have great synergy with Harbeths. Take a look at their integrated amps and even separates. I would definitely not add another Benchmark. It’s not going to be on the level of your digital front end.

@jfrmusic btw worth exploring what folks use with this level of digital and your speakers on a Harbeth forum.