Suggestion between benchmark Ahb2, Bob carver crimson 275 and rogue atlas magnum 2 amos

First ever post here. I have a peachtree nova 150 integrated amp, KEF LS50 metas, a Bluesound node, a vintage technics turntable and a schiit mani phono preamp. I am making the move to a separate amp and preamp. I have a preamp (a rogue rp-1) on order and I’m looking for an amp. I think I have it narrowed down to a Benchmark AHB2, a Bob Carver Crimson 275 or a Rogue Atlas Magnum 2. would appreciate any input the group might have or any alternate suggestions.


Are you using a sub or pair of subs with those nice but small and inefficient speakers?

I do not see pre-out/main in on the rogue rp-1 preamp on order. That is what you would want to go out to a stereo pair of self-powered subs, send the bass load away from both your amp and your KEFs.

then, I would go with the Carver, stick with tubes to drive the KEFs, subs drive themselves.

Anyone considering a Carver Crimson should take a good look at this thread:

How Bob Carver is Destroying Vacuum Tube Audio

Since you've ordered a Rogue preamp, your best bet for synergy and success would be to pick a Rogue amp suitable to you speakers and budget.

Stretch a little for a new or used Rogue Audio Stereo 100.

Even though it is rated for the same 100 WPC as the Atlas, the St 100 sounds twice as powerful (better power supply circuitry).

The ST 100 is a reference quality amp that solid state cannot match IMHO. I had the 100 and sold it to buy a Pass Labs amp and still wish I had the 100. Just a dynamic, special sound.

Benchmark for the metas. No doubt. Should be the bees knees. Tube amps may sound good but metas not designed for those. I have benchmark targeted for use with both my metas and Ohms someday when the time comes for new amps.

Bob was highly regarded for his SS equipment. In my opinion, his new tube equipment is not up to the quality that one would expect from such an excellent designer. His claim about how long tubes will last is all marketing. I'm afraid he's just in it for the $$ now ☹

Benchmark all the way! 

I remember the first time I heard the LS50s.  It was partnered with high end solid state amplification and i thought they sounded very good.  The next time I heard them was a dealer that carried Raven Audio tube amplifiers.  

I was stunned at how incredible they sounded, from a 20 WPC tube amp.  So sweet and holographic.  More than enough power.  

I thought now I see why there is such buzz about these speakers.  I bought the amp on the spot and the KEFs shortly after.  

I have owned for a few years now the Carver M350 mono blocks. I have looked at the insides, the wiring, build quality and to me it all looks excellent.

Before the Carvers I owned the Atmasphere M60-3.3 and before that a Pass Labs X350.5 solid state.

The Carvers sound quality was/is a large sonic improvement over those amps. BTW, Bob actually came to my house for a few days. He is getting up in the years, and I doubt he is looking to cash in on his designs these days. The man has a lot of pride!


I have the Carver 275 amp and think it sounds terrific.  It does run relatively cool.  Give it a try as they have a generous return policy.

I can’t speak to the Carver unit, but the Benchmark and Rogue units should both prove fine, but with somewhat different tonality. Also I echo the comment of @avanti1960. The Rogue Stereo 100, which I ended up purchasing, to me is audibly better than the Atlas. The 100 had more clarity and better transient response. More than enough power in the Rogue or Benchmark units. Can you borrow the amps to audition at your home? That will certainly help you decide.

As to adding one or more subs, should you be interested, the REL T/x series are a good match, musical, and REL recommends using high level inputs, wiring to the sub from the speaker outputs on your power amp rather than a low level input from a preamp. (REL provides the necessary cable with their sub or you can purchase an upgraded cable.) So your purchase of the Rogue preamp does not preclude adding one or more subs. I think you will find many if not most Audiogoners with REL subs use the high level output.

Happy listening!

Thumbs down for the Carver 275 amp! It uses 15 watt Edcor output transformers that certainly can't make the claimed 75 watts at reasonable distortion! In fact at 15 watts/1khz it does 1% distortion. At 32hz it is at 2% and rising. Carver's claim that this is a 75 wpc amp is fraudulent and a violation of the FTC rule. This amp can't even pass decent sine waves at reasonable power! For its high sale price it is a rip-off! Buy a nicely restored Dynaco ST70 instead - Dan Vincent has some for sale here on Audiogon.

@cdennison53 : "It does run relatively cool". The 275 amp is seriously under-biased! Plenty of notch distortion! Sure, the output tubes will last forever but at 10%+ harmonic distortion! Clearly a broken product!

The Benchmark AHB2 is the stellar performer here! So what it doesn't have glowing bottles to light up a dark room! 

carver dealer jim clark stereo offers 30 day money back trials for the carver

benchmark does the same for its products

not sure about rogue, but perhaps some its dealers will do the same

so op, you can ask here, and you will get input from unidentified strangers of unknown qualification and motivations, or you can try for yourself and decide what works for you

Will Vincent (autospec) has some really nice ST70’s for sale here! They will outperform and sound way better than the 275!

@pwoodard922 I have 3 preamps

- Topping pre90 ($600)

- Benchmark LA4 ($2500)

- CODA 07x (much more $$)

My KEF LS50 sounds incredible with the Topping pre90 and Benchmark AHB2's. I have AHB2 monos but will be splitting that up because the LS50s do not need monos. I needed to put the second mono somewhere. The Topping pre90 sounds just like the LA4, but with the caveat that, in my experience. it only sounds this good with the AHB2 and the Parasound A21+. I cannot recommend the pre90 with other amps due to the volume being too hot. Stereophile will review the pre90 in the Feb 2022 issue.

The LA4 is of course great with the AHB2. However, surprisingly I found the Topping pre90 sounded better with the KEF KC62 subwoofer I added with the LS50's. A pretty nice system. Maybe I did not setup the sub correctly (cut off at 80 Hz on the sub).

At the moment I am looking to get a very warm preamp (cheap) to pair with my second AHB2 for my RAAL SR1a headphones (for the bedroom). I am thinking of the Schitt Freya+ at $1000, Or maybe this,

Supratek Audio Chardonnay | Tube | Audiogon




Stick with the Rogue Atlas, had the exact set up and love the RP-1 (and it does have outputs for L/R Subs. I replaced my Atlas Magnum II with their M-180 Mono Blocks running into a pair of Klipsch Forte III's ...cant be beat frankly.

@pwoodard922 , I had the Crimson 275 in my system for a couple of weeks. While it was a nice package (small footprint, lightweight, beautiful aesthetic, easy to bias), my unit had a terribly loud transformer buzz. If you go with the Carver, I'd suggest Jim Clark Stereo and their true to word return policy. They were great to work with and had me return the unit to Wyred4Sound who actually build these units.

The amp did no harm to the sound, but I felt my Bob Latino ST-70 was every bit its equal at half the price. However the ST-70 throws more heat and is more work to bias.



Why so angry? Don't be misled from an article based on one of those anti-audiophile web sites. The equipment that was tested is questionable so are the motives.


I’d be reluctant to send my preamp output through a powered subwoofer crossover in order to high pass the satellites. If the Metas can’t deliver the SPLs you want then you need speakers that can. But I suspect that you have already decided they meet your volume needs, so do augment their low end with sub(s), but listen to compare whether using an HPXover kills your soundstage. 

my own experience owning the carver 275, has, like others been positive - i have had mine for over a year, and run it daily - i was sufficiently impressed with the unit i took the time to share my experience and thoughts on it...

i spent my own money to buy the amp, i own it, i have no other relationship with carver, its people, its dealers

the nasty commentary and incendiary linked threads with the nonsense posted earlier needs to be read carefully and followed through to its conclusion... that ’carver ruining tubes’ article has no substantive info itself, other than referring to another asr thread, where a pre-production kit not made by the carver factory was disassembled, calling out ’problems’

at the end of the thread, jim clark, one of the main carver usa dealers, chimed in and put the nonsense to rest

my question is --- have the lame usernames (or should i say mindless ’parrots’) here who highlight these threads to put down the product, have they owned the amp? even with carver providing a 30 day money-back no-questions asked trial?

this is the major problem with forums like this, people without names, identities, backgrounds, qualifications, biographies, not even their actual systems disclosed can throw dirt, bitch, moan, take down products, just by showing a link to another site -- where more nameless, faceless people take potshots and talk as if they are holier than thou... to me, this maddening, cowardly, ultimately lamer than lame

as i said earlier, if the op is serious about learning about the amps his post asks about, it is easy enough to try them for himself and ignore the posters here whom are the figurative ’slovenly four hundred pound loser, wearing the wifebeater sitting on a futon in his dying grandpas basement, with week-old pizza boxes and a circa 2002 emerson boombox as his ’stereo’, yet posting on high end boards, saying "oh man look at this thing, what garbage that is... arf arf..."

in my view, this is the true garbage and pollution on the forum

There is now a serious debate on the Carver Crimson 275 and its stated specifications.  So far it is not looking good, but the jury is still out, with another forum getting a new production unit to test.  

Reports are out there of a serious overstated specifications.

Hopefully this will get sorted out and not ultimately destroy the legacy of a great audio designer.

I’ve had both amps, the will Vincent and carver. Carver was the clear winner. I really don’t understand all this Carver bashing, Bob is one off the sharpest guys in the industry. 

Do a Google search on the Carver Crimson 275 problems.  There are multiple threads showing the amp only produces 15 watts, not the stated 75 watts.  Serious issues with I believe the transformers.  

As this progressed, total silence from the company.

Question:  If your product was called a fraud, and you knew it wasn’t, wouldn’t you be screaming like hell and showing proof the claims were wrong?

Total silence.  Why?

the carver looks lightweight to me, missing the bank of large power supply capacitors that the best sounding amplifiers have.  look at the chassis of the rogue audio stereo 100 or atlas magnum.  

the stereo 100 has a huge sound.  

As a follow up, I ended up getting the Rogue Stereo 100.  It arrived today.  I set it up.  Listened to Charles Mingus -black saint and the sinner lady, the new glass animals, john Coltrane a love supreme live in seattle, and tool fear innoculum. Epic, loud, detailed.  Absolutely marvelous.  Thank you for all of the input.  I am very happy.

also, forgot to mention I have a Cambridge audio sub.


Awesome! Great choice. That Rogue is a powerhouse; it will hit its rated power (honestly) and gives a good dose of the positives of tube sound without any nasties (sluggish, soft sound, weak bass). Rogue support is also stellar, but you probably won’t need more than a question or 2 answered over the years.

There are also nice options to tweak the sound with tube rolling and bias adjustments. Rogues respond really well to tube rolling since they start out as a fairly neutral base with the stock tubes - there's no strong inherent "voicing" that you'll be fighting against. 

For what it is worth, one of the best audio reviewers gave rate perfect 10 ratings to both the Rogue 100 (suggested in this thread as an upgrade to the Rogue amp raised in the question ) and, more recently, the Benchmark amp.



Thank you for pointing me to these two reviews nc03854.  I have been loving my rogue stereo 100 with my KEFLS50metas, and now, and of course, am considering my next set of speakers to pair them with. 🤔


That thread on the Carver build quality was disappointing.   Looking at it, there are obviously a lot of cost saving measures going on there.   Look at the build quality of Rogue or Quicksilver,  it’s much better for less or around the same