Pass Labs versus Jeff Rowland, Audio Research

As I am considering replacing my trusty pair of Jeff Rowland 7M monoblocks, feeding a pair of MagnePan IIIAs, I am looking at both the current Jeff Rowland lineup, as well as at the latest incarnation of the Pass Labs X series, dubbed the X.5 series, and some Audio Research models.

In the Rowland lineup I am considering the 501 monoblocks, or the 302 stereo amp, while I have already determined first hand that the smaller 201 monoblocks do not drive the MagnePan IIIA pair adequately.

In the Pass Labs lineup I will consider the X-250.5 (already released), the X-350.5 (just out of engineering), and the upcoming X-600.5.

From Audio Research I already discarded the otherwise extremely lovely VT100 as just slightly underpowered for the Maggies, but will consider the VT200 stereo, the new VSM220 monoblocks, as well as the VTM200 monoblocks.

The rest of my system consists of EAD T1000 CD transport and EAD DSP7000 Mk3 (these likely to be replaced by Esoteric X-01, and an Audio Research LS2B.
I most listen to classical, and within it more to solos and small ensambles than to large orchestra.

I'd value all opinions! In particular any comments concerning the relative merits of the newest Pass amps vs the other brands would be very appreciated.
According to Pass and to those dealers that have already the new X.5 models, these new boxes have a more refined and detailed sound than the old X models, and a fuller fleshed-out midrange. But, how do they truly stack up to Rowland and Audio Research?
YOu must be fickle, or suffering the audio 7 month itch. Get some new recordings, or buy a new shirt. Or better get something nice for your wife :-) That can be even more rewarding :-)
Did they upgrade the power supply in the new Pass amps? If not and you go with the Pass...get the biggest model you can swing ($$$).

We have a member of the Apogee speaker forum who had the Pass-600 mono's with his Apogees and they were somewhat light in slam but over-all very good sounding in every other department.

Thanks Dave, the info on the X.5 internal changes are still scant. The best info I have found so far seems to suggest changes in the power supply have been included. Here is an extract from an ad for the x-250.5 on audiogon: ". . . addition of single-ended Class A bias, high speed fast recovery rectifiers in the power supply, and some changes to the front end circuitry have been made."
But we won't really know until someone posts a detailed report. have reasons to believe that such changes will be migrated upwards in the product family. I can only guess that the high speed rectifiers may yield improved performance on transient envelope.
And yes, I am tentatively oriented towards the future x-600.5 monoblocks as the MagnePan IIIAs are 4 Ohm bipolars with a low 83Db efficiency.

But transient response is not all that my admittedly fickle self is seeking in this--not just 7-month but long 7-year itch--but also detail, sweetness, delicacy, microdynamics, and overall glow.
In other words, the new am must be the one I want to marry, not the one which I would date once, to yield raving excitement for a hot and stormy one-night-stand.
Sweetness, delicacy and overall glow were all there, Pass is of the highest order in SS amps...dynamics were limited with the older model with his very hard to drive Apogees. He moved on to an digital amp..first a 250 watt (I think) eAR and is now using H20 mono-block digital amps. I guess these are also 250 watts per and are very tube-like with SS power quality for the bass.

I am still using my old Krell Ksa-250 to drive my Apogee Duetta Signatures so take my input for what I read...I have tried none of these amps with my speakers.

My understanding is that Jeff Rowland also has a digital amp out which also uses this same B&O ICE technology in it's design.

That's me sogood is talking about. I like what I have now, H2O Signature monos, so much more, it ain't funny.
Thank you so much Dave and Muralman1 for the input.
What is the efficiency of the Apogee Duetta and their impedance?
Please tell me more about the H20 Signature.
I have auditioned the Rowland 201 monoblocks, rated at 250W, also based on the B&O chipset. They sound very magical in many ways, but they did flatten out the soundstage at the minimum excitement while driving MagnePan 3.6, which are just slightly more efficient than mine.
are your model 7 the latest specification? If not inquire about potential upgrades from Rowland

My Duetta Sig's are in line with your speakers at 4ohms and dipping. Muralman1 has the Apogee Scintilla at 1ohm...a real amp eater that was a load for the Pass.

As I stated, I have not tried any of these digital amps. My old Krell Ksa-250's power supply is much more than the big pass also but I am going to give the H20 digital amp a listen in my system in the near future...not enough H20's for trial at this time in mono-block if any? Maybe Muralman1 can shine some light on that as he owns a pair and knows the designer.

The H2O, unlike the Rowland uses it's own analog power supply. Rowland holds prices down by using the ICE module with a digital power supply. The difference is, the H2O excels in depth, body, and sweetness. Oh yes, and price.

Check the user reviews at
Give the Jeff Rowlands 501s a try. I compared the 501s at home with my 201s and found they tonally sound similar. The 501s with its greater power (600w p/ch) had a touch more ease to its presentation driving my currenty hungry B&W Nautilus 804 speakers. After about a 100 hours of use the 201s sound more coherent, sweeter and even more musical. I suspect the 501s would be the same. The 501s are slightly larger and run just as cool and effecient as the 201s.

I have written much here about ARC gear and my experiences with Magnepan 3.3 and now 3.5 speakers. Indeed, the VT100 is a wonderful amp, but the VT130 from the mid 90s was absolutely incredible ... midrange to die for....and what an awesome tonal match with the 3.3s. But there was just not enough power/ I then tried the older Classic 150s with 150w and these were still not even close....and the CL150s were a huge step back as they had that analytical hybrid ARC sound.

I truly doubt the VT200/VTM200 amps will do it either. The unfortunate side effect of owning the larger Magnepans is that as affordable as they are, you end up spending so much for an amp to hear their potential. And once you hear these with tube magic, there's no going back to solid state.

The Counterpoint NPS400 works incredibly well but for me, but the Wolcott Presence amps were what I had been looking for. These come in at 275w monos. They have all of the incredible harmonic richness and musicality of the VT130 but also have the headroom and dynamics of the NPS400. I can only imagine what a 500w version of the Wolcotts might do for these speakers.

I think you should try to check out the Wolcotts as well as the VTL 450s as I truly think the 200w ARC models will not cut it. And if you like to stay with ARC gear, one other thing you should consider is to upgrade the LS2B. You are not at all hearing the potential of the Maggies with this line stage in your system. The Maggies deliver a most incredible 3 dimensional presentation when the preamp/amp have these strengths as well....and this is one area the LS2B fails miserably. A small investment to upgrade to an LS5, maybe an LS25 MK I, or any number of the excellent BAT models like the VK5i, would be a huge improvement to the musicality of your system.

You mention an ARC LS2B - I had the MKII of that model and found the LS5MKIII to be far better - you can find one used periodically. Used it'd be a real value and you can still change amps. I think it'd get you closer to something great!

Best regards.


I own a Pass X250, and have had some early-model Rowlands like the 1, 2 and 8 models (havenĀ“t heard the new ones.

If I were in your shoes, I would try first to upgrade the source components, the 7 is a great amp where you will surely gain some minor things with new designs and loose some others IMO.

Hope this helps,

Thank you so much Fernando. I am in fact considering very seriously replacing my EAD T100 + DSP7000 with the Esoteric X-01. In addition I may be able to upgrade either my amplifier or my LS2B preamp.

As you have used both Rowland and Pass Labs amps, what did you find to be the sonic differences between the two brands?
Of course, I am also considering ARC for either the amp or the linestage. Thanks to everyone's input this far. Please keep postings coming!

I run 3.6Rs with a VT200 and LS16. The combination is very detailed, dynanmic, and the amp does not clip (easily heard on Magnepans) or distort at listening levels most would consider reasonable. If the VT200 has any downside it's the maintenance that comes with so many output tubes.
I feel that the PASS amp is more musical, with a more liquid midrange and better dynamics. The Rowlands were also great amps, very musical and excellent bass articulation. Honestly.. I can live with either amps and enjoy the music...

The source is a different story, I found great synergy of Rowland amp-preamps with Levinson sources, for my current Pass I am using Metronome tubed CDP, great results as well.

I also was very happy while I had Gryphon amps and preamps, very energetic, full bodied and engaging, there are some good opportunities on used Gryphon units AFAIK.

I am not particulary keen towards ARC, just have had a preamp which I cant recall the model, but not top of the line thou.

Hope this helps,

if you like arc,but feel power is the only drawback,may i suggest you audition their new 300.2.all the arc sound,but with conservatively rated 300w into 8ohm,500w into 4ohm.too further enhance sound and perceived power,use anaconda alpha power chord from shunyata.this chord also will help power problem if yo go for a tube amp.
Good point RMDH. Have you compared ARC 300.2 with Rowland 501 monoblocks? Excellent idea about Shunyata Anaconda. I have tried this chord at Andy Singer's shoppe in N.Y. recently and I am totally sold on it.
I've had all three makes of amps. I am quite happy with the sound of PASS Lab Aleph 1.2 amps. Very tubey and warm sounding for solid state. Great dynamics with a midrange is the best I've heard in all my many years of listening.
Mfslgold, I'd love to heed your advice, if I were not addicted to MagnePan, that regretably are such unrepentant juice guzzlers.
Could I ask you to comment on the sonic characteristics of the Rowland(s) and ARC(s) that you owned? Thanks, Guido
Rowlands were too colored and washed out (Rowland 7 series 3 mono blocks). ANd the Audio Research Classic 150's had little detail in the mids and sloppy bass. The Pass Aleph 1.2's have the best of both worlds . Great detail , superb natural midrange and accurate bass dynamic. (Bass is not your typical slam solid state bass) but very defined and exteneded.
I know that this thread is old and that nobody might read it, but Jeff Rowland Model 201s and 501s are not using the old B&O chipset. I have talked with a guy named Rich at Jeff Rowland and asked him this question before I bought the 501s. He said it is nothing like the B&O chipset. He said that the B&O setup was rated class D and that their technology is rated Class A. Also, he said that it takes 300 hours before the amps are broken in and start to sound the way they will stay. How man of you have listened to them after they were broken in by 300 hours? I just feel like so many people comment on things they heard for a few minutes or that the are just spouting off opinions they read or heard from a dealer and saying they are their own experiences. I just wish people researched things more before they comment to someone with questions. He does them an injustice.
Eliahu, my experience is somewhat between cursory and extensive. I spent about 4 hours with a dealer and the 201 were among three amps I listen to. I am not sure how much the devices were broken in, but I know they had been running for several days. I loved the 201 monos, but they could not drive the ManePan 3.6 speakers enough. If the recording got a little excited, the soundstage flattened down. I suspect the 501 pair would have done a lot better. It is worth investigating the 201 and 501 chipsets further. the Rowland web site suggests that 302 and 301 are in fact using the IC chipset, which is made by B&O.
I have a Rowland 2 chasis version of the model 8t.Although it is human nature for all of us to justify our own equipment,let me tell you a bit about my experience.I have owned,happily, CJ tube Equip as well as Audio research.I try to hear all current stuff so as to keep up to date.I switched to the Rowland because I wanted Stability(no tube problems)and was tired of the heat associated with tube amps.Originally my second chasis housed the battery power supply,which performed superbly.However,I noticed,on the Rowland website,that I could update my battery chasis to the new SWITCHMODE POWER SUPPLY technology.This was supposed to be even quieter than the pure d.c. battery,and give me a power rating that doubled my battery power(from 100 wpc to 200 wpc).I may as well state that I had zero complaints about the performance of the battery on my AVALON ASCENTS(a very easy load).What I was REALLY not prepared for was the incredible improvement,in virtually every area,that was brought about by the NEW power supply technology.I mean it was now even quieter on backgrounds than the already DEAD QUIET battery,which I still can't figure out.I can only imagine how fabulous the newer Rowland stuff must sound,and he has found a way to reduce size and offer real value in seemingly low prices,as compared to some of the other overpriced stuff.Let alone NO HEAT and GORGEOUS build and metalwork.More importantly,I really can't say I hear any real improvements in music reproduction with the better tubed stuff,as compared to my Rowlands.I still love the sound of QUALITY tubed equip.,but my Rowland sounds,to me,and without rationalization,as accurate at reproducing musical notes as anything I've heard,AND I don't have to sit in my bathing suit(in January,in N.J.)!!
I have just posted a brief update on the development of the upcoming Pass X600.5. Please see: