Circle Labs A200 Integrated amplifier review - It will appeal to both tube and SS lovers……



This review is a reflection of my desire to help those looking for purity of sound in the convenient package of an integrated amplifier. In other words, an amplifier that transcends the usual boundaries of tube vs solid state. The A200 integrated is a unique design and one that I don’t recall seeing before--more on that in a moment. I called my local dealer here in the Nashville area, Colin King of Gestalt Audio Design, and told him I wanted to look into an integrated amplifier. I had too many boxes with several LPS’s, switches and such on the floor next to my Sound Anchors rack. It did not look good in our living room, and since I live with THE Audiophile’s Wife, I decided I better simplify and tidy up our space before she took to the blogosphere and wrote about my slovenly ways.

I also liked the integrated amp concept, in general, as they can offer stellar sound at lower prices than competing separates. I knew Colin carried the Luxman brand, and it has always intrigued me, but to my surprise, he suggested the Circle Labs A200 made in Poland. I had not heard of it, but he felt it would fit my sonic priorities better. In a nutshell, I like beautiful tone and realism and am less concerned about sonic feats of strength that impress initially, but over time don’t immerse me in the music. I guess, for me, an integrated amp appeals to the heart and soul--not just the mind.

Prior to the A200, I had a wonderful sounding $15,000 Mark Levinson 532 preamp and two nice amplifiers. Here’s a little backstory on that:AMPS: One of the amps was a 50-watt per channel, pure class A solid state Clayton Audio amplifier. The other was a 1200-watt per channel, unique class D amplifier. Both appealed to me in different ways.PREAMPS: I recently built a very robust 6sn7 tube preamp that I enjoyed but ended up giving to my stepson as a housewarming gift. In addition to that, I owned a highly modified/upgraded Audio Valve Eclipse tube preamp that was also quite enjoyable.

Suffice it to say the integrated had a significant sonic hurdle to clear to make it onto my audio rack. On paper, the A200 seemed ideally suited to my sonic preferences. The design combines a tube preamplifier and a single ended, pure class A, solid state output stage. While hybrid integrated amplifiers are not new to the scene, one with a single ended, pure Class A output was unique in my experience. In addition, the builder was passionate and intensely focused on short signal paths and keeping the parts count to an absolute minimum. The end goal was sonic purity, in other words, the accuracy of the tone and overtones needed to be precise to the vocals and the instruments. It needed to correctly address the nuances of the recordings like the inflections of the voices, the emotion of the vocalist and the subtleties of each instrument.

The A200 is rated at 100 watts per channel into 8 ohms and doubles to 200 watts into 4 ohms. It uses the rather inexpensive Siemens ECC8100 tube--one per channel and they will last some 10,000 hours. You can read more about this amp online at the Circle Labs site as well as viewing several online reviews of the unit.

This design goal, in my estimation, delivers the sonic purity I find elusive in many pieces of audio gear. This hybrid is different from other hybrid amps I have owned from Blue Circle, Monarchy Audio and Aesthetix Audio. Their designs are wonderful in their own way. They have sonic strengths in areas like warmth, stage size, high power and such. In my opinion, the A200 stands out from the other hybrids in purity of sound and inner detail. The sound reminds me of the “illuminated from within” sound I heard on my past pair of 2a3/300b monoblock SET amps from George Wright. The A200 sonic strengths boil down to a wide open sound, purity of tone and a positively arresting revealing of inner detail and nuance. The bass of the A200 is stellar in both articulation and fullness. If the recording has a meaty foundation, the A200 delivers it, and this is a must for me to enjoy music. The amp does not homogenize recordings based on my experience. Every recording is delivered with its intended sound and personality.

Another aspect I really appreciate is how engaging this amp is at low to moderate volume levels. I think this is simply a reflection of its sonic purity. In the end, the A200 cleared my sonic hurdle, and then some, because it drew me into the performances time and time again. One additional note is the A200 is just plain fun. My wife joins me for pleasure listening, and it scores very high marks on the fun factor.

I have heard amplifiers with more exacting leading edges and crisper highs. I have heard amplifiers with more gut-hitting dynamics at high volume levels, though I suppose if you pair the A200 with highly efficient speakers you would achieve this. I have not often heard the purity of sound and overall illumination of the performance that this integrated delivers. Approximating it would typically require SET tube amplifiers of the 2a3/845 and OTL variety-- at least in my experience.

Colin is the importer and dealer located in Nashville. The retail price is $8995. He is easy to work with, no-pressure and very laid back. I liked my experience with him greatly, and The Audiophile’s Wife has said, and I quote, "she plans to adopt him into our family if one of our biological children goes missing."

System notes:

Circle Labs A200 on Townshend Pods and with QSA blue fuses installed
Dali Epicon 6 speakers with highly upgraded crossovers
Mojo Audio Evo dac with most all the upgrades including Lundahl Amorphous chokes
Innuos Zenith 3 server
Hapa Audio ICs and Aero USB cable
Acoustic BBQ power cord and speaker cable
Purist Audio jumpers
Network Acoustics ENO ethernet cables and filter
English Electric 8Switch
Several linear power supplies for modem, router switch
Puritan Audio 156 and Groundmaster conditioning/grounding
Townshend Pod products under speakers and gear
Sound Anchors rack
Dedicated twin 20 amp lines
Various tweaks from Mad Scientist, PerfectPath Audio

Link to Circle Labs site,

http://www.circlelabs.eu/a200_en

I should add I listen to most every major genre of music including jazz, folk, female jazz vocalist, classical, acoustic instrumental, solo piano etc…. I love Van Morrison and Rickie Lee Jones and would say they are my top two favorite artists.

Hope you find this helpful fellow Agoners.
Bill
6017afa4 4738 4a9a bf4c 2da38b5f3955grannyring
Post removed 
Thanks Tvad. 
I should also clarify that this amp won’t sound like a SET tube amp in every way. It does not have quite the same delicacy, intimacy and 3D staging. It does deliver in the ways I mentioned in the review. Just want to be thorough in my comments. 
Congrats on the new integrated and very nice review, I'd actually read the review on High Fidelity previously. One note having looked at the website and the review again I'm not sure the power stage is Class A.  From the review:

The power amplifier is based on a circuit called Circle Power, which is a proprietary development of Circle Labs. It uses an unbalanced JFET input stage and current drive of bipolar output transistors. The company materials say: "this solution combines the detail and precision characteristic of asymmetrical systems with the efficiency and dynamics of symmetrical systems".


It would seem to be a proprietary circuit which makes sense as a Class A amp putting out 100 watts and doubling into 200 would weigh a heck of a lot more.

Not that any of that matters it sounds like a cracking amp and you have some of the most experienced ears on this site grannyring. I hope I get to hear it in a show situation some day.
Great review Bill. I think the A200 is a special piece and I'm glad you're enjoying it.

Please let THE Audiophile's Wife know the sentiment is shared.
@jond 

You are correct about the output.  My mistake as I was thinking about the Class A preamp section.  The output is indeed class A/B.  My apologies. 
The technical explanation regarding the output is rather involved and I will ask Colin to explain at some point. 
@grannyring - which version of the Hapa ICs are you using? Txs
Thank you! Very nice review and I appreciate your detailed descriptions of the sound qualities.
Thanks for the enthusiastic review, and congrats!

Here is a very interesting review of the same amp in a Polish publication:

http://highfidelity.pl/@main-1033&lang=en
@facten 

I use the Hapa Quiescence C of late as it matches well with my system. I also swap in my Acoustic BBQ  IC.  The Hapa line is very good indeed with real innovation at its core.   
Regarding the output stage, in keeping with the desire to use as few parts/devices as possible the A200 uses just one pair of high current BJT’s. (bipolar junction transistor). The high current steering control stage does work in single ended class A.

A look inside the amp clearly shows exceptional build quality and a well thought out layout. You can read more about the innovation in the preamp section which essentially  uses just one tube, a polarizing long life battery, one resistor and a high quality copper foil cap. Innovative design with short signal paths and few parts.  I am sure this helps deliver that purity of tone and sound. 
Great review -- thanks for all the hard work. Gestalt audio looks great too; unless I missed something, there is virtually no information on their website -- no details about the store, space, prices, etc. I’m sure this is the "in" place for audio in Nashville, but for the outsider there’s not much to go on (at least on the web) for information about their lines, business, etc. I hope they reconsider their public-facing information strategy (or hire a smart web designer).
@whipsaw 

That is a very well done review and I love how honest the designers are as well as the reviewer.  
@hilde45 - while I agree it would be helpful to be able to read more about the dealership if you click on the respective brand that is displayed on the webpage you are brought to its website for product info.  Also, aside from Gestalt there's Atelier 13 and Nashville HiFi in Nashville


@hilde45,

Yes, Colin is a small one man operation. As you can see he carries some highly respected brands such as daRTzeel, Tron, Lamm and Cessaro Horn speakers. These highly respected outfits decided Colin was a person they trusted. His site is very simple and at this point just serves to let interested audiophiles know the facts. You know, the lines he carries and how to get in touch with him. I am sure it will evolve as his business does.

Always good for him to see feedback like yours here.

I was able to demo the A200 in my home system which is ideal.



@grannyring 

I agree about the review. There is a very serious audiophile community in Poland, and it shines through in that piece.
Listening tonight to several artists including Tierney Sutton, Paris Sessions, I was struck by the realism of the music I was playing. The artists were right with me and the speakers just disappeared.  The music was so open and free creating a very intimate listening experience. Fun! 
@whipsaw and @grannyring I read High Fidelity too it's an excellent publication and indeed the Polish hifi community seems strong and diverse. Glad you're loving the amp so much I hope it continues to improve and amaze you!
Great review, grannyring. What a beautiful piece of kit, as they say. Your description of a meaty foundation with tone and realism as your benchmarks are clearly apparent in the 2nd video at the Circle Labs site and must be captivating if that's what you're enjoying on a regular basis.

I've always been a fan of High Fidelity and to see they gave the Circle Labs a Red Fingerprint award says a lot as well. The reviewer is a recording engineer with a long history of work in Poland and Europe and brings a great perspective to audio. 

Enjoy your new toy!
All the best,
Nonoise
I noticed in the specs that the A200 has a damping factor of 500 for 8 ohms! That seems very high, and I wonder if members might comment on the practical implications.

Cheers!
And another question: The A200 is apparently unbalanced, yet it does feature XLR inputs. What are the practical ramifications?
The A200 is a dual mono design, but it is not a true balanced design. The XLR input is not truly balanced and there for convenience. 
Here is a good article on damping factor. Damping factor can impact the control an amplifier has on the woofers. Higher damping is said to better control the bass giving it more articulation and tightness. Folks argue this from many different perspectives like most things in audio. Do a quick search and you will quickly see all manner of opinions. All I can tell you is the bass performance I am experiencing is simply stellar. My speakers have two 6.5 woofers per unit and are 5 ohm nominal. Bass is fulsome, tight and very articulate at the same time. I would say it is the best bass I have heard from my speakers surpassing amps like the Clayton S50 and Coda #8. All the reviews I have read also state bass performance is first rate. What I really enjoy is how full and meaty the bass is without sacrificing articulation. This is a hard combo to get right in my experience. Some SS amps are over-damped sounding causing the bass to sound thin.  The A200 does not suffer from this in the least. 
https://benchmarkmedia.com/blogs/application_notes/audio-myth-damping-factor-isnt-much-of-a-factor
Thanks Bill!

Presumably nothing meaningful is lost as a result of it not being a "true balanced" design, and it is a reflection of a particular design philosophy.
If your particular source is built from the ground up to sound best using the balanced outputs, then I suppose it’s possible a little SQ is lost when not using a truly balanced integrated amp. This is the only scenario this would ever come into play and the degree of it would depend on the particular source used.
Thanks for the review on the A200. I think we have alot of similar tastes in what we like in equipment.   TRL, Wright 2a3 mono blocks which I have been using for about that last 10 years!  

I have been also thinking of going to a nice integrated in my retirement years.   Did you look and listen to any other integrated amps?  The A200 sounds like on paper a perfect match for what I am looking for.
Any additional feedback would be appreciated. 
Bob
thanks for the nice review bill

that polish company is pretty clever to use the ecc8100, which is highly specialized tube, 6.3v heater dual triode but with a unique, add’l neutralization screen, specially and specifically made for cascode amp circuits, and as such, helps reduce the problematic miller effect compared standard bjt’s in series cascade circuits - certainly a different take on past, more standard hybrid amps with a tube input or buffer stage commanding a transistor output stage

maybe that is why there is a great sense of inner detail/inner light at lower volumes

cool stuff
Agreed @jjss49 

I just purchased 4 of these NOS tubes for $100 so the price is also right! 
The U.S made Coda CSIB integrated amp  has 3 power choices class leading in many areas enormous 125 amps on demand and doubles down 
to 2 ohms , a potted 3 kva transformer ,the competition not even half that, pure class A preamplifier section ,Burr  Brown  Volume linear volume attenuator.  Mosfet, Fet and 
40 Bipolor transistors on the output section .10 year warranty 
and for $6495 before discounts a great U.S made Integrated amplifier . Stereotimes best of 2020 and great review 
I feel the best integrated out there even at $10k and I have compared several much more expensive integrated amplifiers.
Hi Bill, That was an impressive review, thanks! I was wondering if you listened to the A100 at all?
@audioman58 

I respect Coda.  Great gear. Owned the #8 amplifier and 07x preamp in the exact same system as the A200.  I happen to enjoy the sound of the A200 more for the reasons shared in my review.  The A200 is simply an option for those looking for the sonic strengths I outlined and differs pretty substantially from the Coda gear strengths. 



@xrayz 

Sorry, I have not heard the small A100, although Colin did mention it. My room is simply too large to consider it with my 89db efficient speakers. 
The A200 I heard it is very good , but I differ in resolution 
I found the Coda more fleshed out not quite as warm but for sure much better dynamics and Bass control the A200 power supply 
is no where near as substantial as the Coda , just compare the specs nothing even at $10k has 125 amp on tap,a  sealed potted
3,000-Va transformer ,and over 80,000 of capacitance ,
and pure class A preamp section , and very important but vastly overlooked the preamp attenuator section ,the Coda uses a very precise Linear volume attenuator from Burr Brown and very accurate up to 99, these are especially important ,if you have a larger room , or demanding speakers like maggi , or the MBL 120
Monitors I am auditioning ,theCoda doubles power even down to 2 ohms 
and almost 20 1st watts pure class-A if you have efficient speakers 
You will be in pure class A . Too many factors when comparing,
unless the equipment has everything exact including cables then any comparison is not accurate ,your perception in your setup maybe different . Ask for a in home audition if possible , and absolutely compare in what’s inside you don’t want a cheap Alps pot that destroys low level detail and resolution ,it’s just a tapered
volume pot with conductive plastic wipers $20 ,having owned a Audio store I had techs modding equipment on a regular  basis 
and I still Upgrade Loudspeaker Xovers and electronics  for myself and friends for 20+ years now, it’s the inside engineering thst count most , and having a 10 year warranty, 5 year transferrable warranty 
gives great piece of mind ,as well as if any problems the 1st year Coda will even pay the shipping to repair it !!

My experience could not be more different than yours. Have you really heard the A200 in your very own system for some days? It is not warm sounding and I find it more resolving and open than Coda. The Coda #8 sounded much more SS like in its presentation than the A200. Some may or may not like this as much. Sorry, but your post does not seem to reflect any real experience with this amp in your very own system.

If you have spent quality time with the A200 in your own system, then we just hear differently and have different sonic priorities which is entirely possible.

Regarding the power supply. The A200 has 200,000uf of capacitance which is more than double the Coda. It has a large toroidal tranny for EACH channel and does not share one like Coda. The A200 is a true dual mono design. The A200 even has a separate tranny for the preamp (3 trannys inside) with the preamp using a separate all film cap power supply. For its power output I can confidently say it is equally robust to Coda and I am being modest here.

These two pieces are very, very different sounding and it will come down to one’s sonic priorities. The A200 is about tone, nuance and purity of sound. They are vastly different designs with a different end customer in mind.
The Circlelabs 200 in some systems having the tube in the preamp 
section sounds very nice in a not too demanding speaker 
it maybe preferred it does sound very good .
it has a sweet nature ,and your speakers and front end will determine what Amplifier best suits your system , that was m6 only point it us a well built Integrated, my point was the Coda integrated is very musical ,an accurate review is at stereo  times .
and has great grip and control of your speakers much better then most , and the power ,bias can be ordered with 3 power choices and amount of 1st watts in class A and total power output 
depending on your speakers efficiency , the MBL speakers are 
exceptional speakers in every sense ,but demanding of current 
where the Coda shines ,that was my main point ,the circle labs 
Is not s good fit for a high current low impedance speaker.
for other speaker types a very good fit.

This has me thinking more about my time with the A200. It is not the sort of amp that wows the listener in the first minutes of listening with sonic feats of strength. Some amps will do this initially, but over time other imperfections begin to reveal themselves. 
With the A200 I find myself listening to more music than ever before. I am also listening to new artists and engaging in music more as a whole. I find this aspect of having more fun with music an interesting outcome of owning the A200. I find myself growing more fond of the amp with each passing week.  So the A200 is all about a longer term relationship as opposed to a one night fling 🙂. 
I should mention my speakers are 5 ohm and 89db efficient. My room is large being 24 feet wide by 32 feet deep with 10 foot ceilings. The A200 drives the speaker and room to listening levels beyond most any audiophile needs. As I have mentioned,  I really enjoy hearing the musical nuance and details at lower listening levels with the A200. 

This has me thinking more about my time with the A200. It is not the sort of amp that wows the listener in the first minutes of listening with sonic feats of strength. Some amps will do this initially, but over time other imperfections begin to reveal themselves.

With the A200 I find myself listening to more music than ever before. I am also listening to new artists and engaging in music more as a whole. I find this aspect of having more fun with music an interesting outcome of owning the A200. I find myself growing more fond of the amp with each passing week.  So the A200 is all about a longer term relationship as opposed to a one night fling 🙂.

This strikes me as an important distinction, and is well-stated. That's not to say, of course, that some listeners shouldn't prefer amp A to amp B, but I suspect that it is a goal of most audiophiles to find the sort of happiness that Bill is apparently experiencing with the A200.
Hi @xrayz the A100 is a discontinued model. The A200 is the only integrated amplifier in the Circle Labs lineup currently, with the M200 stereo/mono power amplifier and P300 fully balanced linestage just launched.

Cheers,
Colin
Hi Bill,

Still enjoying the A200?  I am asking because I will be looking at the M200 when its available. 
I am liking it more every day.  Still listening to more new music and loving it. It also responds well to higher end power cords.  
It is a joy to listen to! 
@bobheinatz hi, the M200 is available, along with the P300 linestage. Feel free to give me a call if you'd like to hear it.
Post removed 
Wanted to update folks on a new power cord I purchased based on it’s wonderful synergy with the Circle Labs A200.  The Hijiri Nagomi power cord.  Colin of Gestalt Audio Design is the importer/dealer for these cords. I tested many power cords both from Colin and other sources ranging in price from $400 - $4000.  In the end, the Nagomi was magic on the A200. Great depth of soundstage and natural tone that drew me in even deeper.  There are some reviews online as I understand many of us may have never heard of this Japanese brand. 
I placed an order for the A200 with Colin at Gestalt Audio, which I hope to receive in the next couple of weeks. Look forward to comparing to my TRL Dude/KR Audio Kronzilla combo. 
In addition to the reviews in High Fidelity and Positive Feedback, I found this interesting review on a Polish website, which you can read using Google Translate: https://www.audiostereo.pl/magazyn/recenzje/recenzje-wzmacniacze/circle-labs-a200-r1098/ 
It came out about a year ago and there are some interesting comments, particularly about the 50% price increase after it the A200 was initially available in Poland.  Although the translation of the review is a bit clumsy, it provides interesting details that I didn't see in the other reviews. You can find some other reviews in Polish as well. 
I should be receiving mine no later than next week. Bill's review catalyzed my initial interest, and I think that I've found and read all of the related Polish material.

Interestingly, there is a GATO sub-forum on one of the Polish audio sites, and some comparisons were made by listeners to the same amp that I currently use (AMP-150). Some even preferred it.

I am prepared for the possibility that the A200 would be a "diminishing return" purchase, but I also have two weeks to auction it at home before keeping it. 

I'm excited about it, in any case, and look forward to listening to it.
Seems you guys are getting brand new units! I imagine they will
need some play time before the tubes and amp sound their best. Should be a fun time for you guys. Can I ask what speakers you guys are using? Love to know. 
Seems you guys are getting brand new units!
Not easy to find a used one, I would say!

How long of a break-in period would you suggest before confidently assessing the amp?

I’m currently using Harbeth 30.1, but am considering upgrading (awaiting an audition of Fink Team Kim, which I find intriguing).
I have Duke LeJeune’s Audiokinesis Jazz Modules 2way speakers with wave guide and TAD woofer. I’ve had them about15 years and although I’ll be overhauling much of my system in the next few weeks I have rarely thought about replacing the Jazz Modules.