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

@jeffreyw 

I was conflicted about spending that much on the front end but I sounded so great. I remember from my old analog days not paying enough for the front end.  Once I committed to a Linn Turntable and Arm and Koetsu cartridge I was finally satisfied. I didn’t want to go through the endless upgrade path. Plus at my age time is a consideration. 

@jfrmusic I know what I would do.  I would order the 2nd AHB2 and compare it to your single amp and see if you can tell a difference.  I would also get a home demo of the Bryston and demo it against the single and dual AHB2.   That is a perfect comparison scenario.  You may find that a single AHB2 is all you need or pick one of the other two options.

Have you adjusted the gain switch on the back of your AHB2 and can you tell a difference other than volume?  I think the middle position sounds the best - fuller with more body (even when adjusted to the same general volume) - than the lowest gain position.  I have read that technically it should sound the same so maybe it is just in my head.   

@jfrmusic 

You made the right decision on source equipment (end-game)! Now, you just need to put the icing on the cake. I would audition as many amps as you can, and don't just limit yourself to Bryston.

I wouldn’t necessarily categorize the Benchmark as a level below something like Bryston just because it is cheaper.  One way to look at it is those accurate electronics (I.e. Benchmark) will allow all the goodness from your front end to come through.  In all actuality, at that point the speakers would probably become the limiting factor.  But that’s ok if you like them - Harbeth can be magical for sure.  But as for the amps, I’ve owned both AHB2 monos and Bryston 2.5B3 Monos. The Bryston has a bit of a bump in the bottom end, whereas the Benchmarks are very flat. The Bryston has excellent bass, but also a bit more emphasis in that mid bass area. Again, you’d have to try it, but given the sound profile of Harbeth speakers which are slightly warm, I believe the Benchmark will be more synergistic.

The difficulty for me concerning many desirable Amps is many are very large and very heavy. Not sure if can handle a 75-80 pound amp by myself. Getting it home and setting it up. The Brystons are reasonable in weight. And of course the Benchmark is a feather weight.