Benchmark AHB2 in Mono Block Configuration


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 The watts are higher in mono but those watts cannot be used continuously (say 30 minutes) at 2 Ohm, which some speakers dip too. The single AHB2 can continuously drive a 2 Ohm speaker but at 190 watts (I think).

I see some posts above on the CODA. Let me chime in on this too.

I used a Benchmark LA4 on the CODA #8 and the CODA #16. They both are good with the #16 approaching great. The #8 lacks some clarity that I like with the #16 and AHB2.

Another amp that I like more than the #8 is the Sanders Magtech. I recently heard from someone with informed knowledge on this that CODA was involved in the design of that amp. The power supply is from Sanders. This amp, which I bought from Sanders used for $4k, is even better than the #8. I think it is the top end that is better than the #8. I love the Magtech on my Magnepan LRS+. The #16 is also great on the LRS+, but I use it elsewhere.

@zlone I am currently listening to the Schitt Mjolnir preamp (from 2023) with the Sanders and the LRS+. Great sound, a bit too warm for me for long term listening, I like the Holo Serene and Benchmark LA4 for long term preamp duties. The Mjolnir is a pure Class A preamp and a very nice unit. It is a 2-channel preamp and headphone amp, though the headphone amp does not work well with my funky RAAL CA-1a phone. Do not let the price fool you.

Schiit Audio: Audio Products Designed and Built in Texas and California

Edit: I am doing some testing on my office with the Holo Serene preamp and the Schitt Mjolnir. I cued up the Isley Brothers 3+3 on both preamps and for my ears the utter neutrally and clarity of the Serene wins over the warm Class A of the Mjolnir. The only thing the Serene lacks is a balance control. If I can make my off centre seating work without the balance control I am keeping the Serene with the Sanders. A great combo.




@yyzsantabarbara Thanks for info on the Mjolnir, it is tempting, but without a remote, it is a non-starter. I wonder how the Kara compares?

Note I came from a Freya+ -> Coda 07x - Benchmark LA4 progression, similar to yours. I just tried out an Ayre K-5XEMP, and it adds quite a bit of body to the sound. It is not quite a fit for me, but made me aware of another house sound.



@zlone I was looking for the remote for the Mjolnir (though I do not need one). No wonder I could not find it.

The Holo Serene may work for you. It is a bit warmer than the LA4 but has all the other sonic attributes of the LA4. 

The Mjolnir is a much better sounding unit than the Freya+. The Freya+ was a fun listen but would not have worked long term for me.


When one of my monoblocks (Monarchy  SM-70Pro) went out for repair, I used the single as stereo for a couple weeks and noticed quite a degraded change.  Upon return  of the second unit, it became apparent that having the monoblocks in place made everything tighten up; imagining, separation, detail... everything sounded organized and made me appreciate them together. 

Caveat, in monoblock configuration, I can also bi-wire and run balanced, to which could add to the elevated performance.