Looking for ideas - new mono blocks for stereo music


I am on a bit of a mission to upgrade my equipment and just recently purchased the Esoteric K-01X SACD player.
In my case, the primary focus for critical listening is stereo music (aka red book CD) from the Esoteric.
My current chain is from the Esoteric through the Marantz 8802A into the Bryston 7B-SST2 powering a pair of JBL 1400 Array speakers.
I am very happy with the JBLs and just upgraded to the K-01X (had the X-03SE before).

Right now I would like to hear some suggestions for new mono blocks. I am already planning on adding the Esoteric C-03X(s) to the system to replace the Marantz as (stereo) pre-amp.

The primary focus is detail and resolution as I really love hearing new aspects of CDs that previous equipment couldn't reveal.
Soundstage and instrument placement are also high on the list. Bass slam / impact is not really a priority since I am stuck in an apartment for the time being.
Another factor is heat - I am looking for an amp, not a space heater. Especially considering the already hot summers in Toronto!
The price ceiling for me is somewhere around $20,000/pair

My current short list consists of:
Pass Labs
Mark Levinson

Now it's time for the brainpool (that's you guys!) to have at it :)

Thanks in advance!
If you can get a Grandinote for under 20K, it would have the synergy with the other Esoteric equipment.

That Marantz 8802 is nice, but it definitely masks detail and resolution.  It's great that you are planning to upgrade to the Esoteric pre.  The Bryston SST2 will likely be too dry and forward at this point (bordering on possibly too harsh, depending on system synergy).

It sounds like you are going from a warm/dry sound to a more transparent/sweet sound by transitioning to the Esoteric preamp.  Do you want to follow this route with the amp choice?

Have you thought about listening to the new Bryston 7b3 series?  From what I can gather from tiny bit of listening and discussions is that the new Bryston cubed amps are much sweeter sounding than the previous generations.

Pass Labs is probably the most neutral FET based amp.  It does still have some warmth, so it will not be "sweet" like the Bryston cubed or even something like a Krell.  The normal Pass Labs "X" amps are more detailed.  The pure Class A "XA" models are even warmer sounding.

Levinson amps are very unique.  I would highly recommend listening to one as they definitely have a unique midrange, but I think soundstage is rather narrow and compressed.  You really need to hear it to decide.  Not everyone likes the Levinson sound.

If you are after detail and transparency, maybe you should avoid the pure Class A amps for now.  The Class A will have more warmth, thickness and fullness of sound, but not as much detail, resolution and attack.

The primary focus is detail and resolution as I really love hearing new aspects of CDs that previous equipment couldn’t reveal.
Soundstage and instrument placement are also high on the list. Bass slam / impact is not really a priority since I am stuck in an apartment for the time being.
The new stereo Parasound Halo JC5 would have it all, it’s said to have been bought out for those who didn’t want to go to the 2 box JC1 Halo monoblocks. Still designed by one of the best John Curl up there with Nelson Pass. And won’t put too much of a hole in your pocket.


Cheers George
You should hear LinnenberG Liszt, and maybe Narga. Not sure if Narga Classic monos would be in your budget, but the LinnenberG Liszt fits.
Not even a day in and already got some great feedback - thank you to everyone who took the time to post a reply.

I'll be able to listen to the Bryston 7B3 as well as the Pass Labs here in Toronto.
I already had a chance to audition the Grandinote Silva (single box 'dual mono' design) and was quite impressed with how the sound filled the room and was not tied to the speaker cabinets. Definitely had a lot of bottom end and punch. Hard to tell about resolution and detail as I could at the time only demo it with different speakers and unknown music.

Let me dig into which of the more exotic brands that were mentioned I will be able to listen to locally.
Are you leaning more towards SS or tube? For tubes I like Audio Research, Lamm, VAC, BAT. PS Audio BHK monoblock amps are excellent too.

For SS, give a listen to the Vitus Audio, either their Signature series or their Reference series, and some Tidal and Soulution stuff if you have access to them. They are phenomenal.
The Parasound Halo JC1 or the new JC5 are bargain considering their performances and are highly recommended. The recently discontinued Classe Delta CAM-600 class AB monoblock amps are also spectacular and can be had at discounts nowadays. Some higher end Naim amps are very musical and has very good rhythmic drive and are special. 

  No doubt you'll get as many answers as there are members here. I use a pair of Sanders Sound Labs monoblock Magtech amps to drive a pair of Apogee Duetta II's. The monoblocks are $11,000 for a pair. I have used them for over four years with no problems, and Roger Sanders is a great guy to deal with. 
As pointed out and to narrow this down a bit let's just go with SS (not really a tube guy anyway - way too OCD for tubes ;) ) and class AB.

Being in Canada does limit my options somewhat and while I appreciate some of the more exotic suggestions, buying, let alone demo, them will be almost impossible.

Parasound has come up twice already, so I really need to look into their options.
Classe is another brand that I forgot to add to my short list.

Having direct experience with Parasound JC1s and A21, I will say that it is a very engaging amplifier for music.  Very thick midrange, especially the horns.  However, it is not a resolution beast.  The Parasound voicing is definitely on the warm side of neutral with softer highs.  It is very smooth and refined, but it is going to be a LOT softer than your current 7Bsst2 amplifiers. 

The traditional Classe "Class AB" amplifiers will be a good choice for resolution.  It's difficult to say whether the Classe is going to be better or worse than Bryston 7b3.  I have not directly heard either.

Check out what's happening now with Classe.  Company is defunct.  To be avoided.

Add to list: PS Audio BHK Mono 300.

Considering that Parasound left the Canadian market at the end of 2013 (I only found out when searching for Canadian dealers just now), I don't think that's a viable option anymore.
Especially combined with the comment from @auxinput above.

Maybe trading up to the 7BSST3 is not a bad idea after all. But at least there are dealers carrying Classe in Toronto. Time to schedule some listening sessions...
But yes, Classe would have been taking a risk but less so now that they belong to Sound United.


It would be nice if production even moved from China to Japan.
Post removed 
By a good margin, the most transparent and open sounding amp I’ve had in my system was the Liberty B2B-100 made by Peter Noerbeck of PBN (my amp is a McCormack DNA 0.5 Rev. A). Liberty is his direct-to-consumer brand that benefits greatly from trickle down technology from his lauded Olympia amps yet are at a much more accesible price. This amp threw the most holographic and airy soundstage I’ve ever heard, which was likely aided by what seemed like a complete absence of background noise -- everything just appeared to be floating freely in completely clear, thin air. One of the really nice features of this amp is that it can be run in low- or high-bias mode. It sounds great in low bias but even better and more fluid in high bias, and although it runs a little hotter in that mode it’s still not hot like a pure Class-A amp. I left it in low bias when not listening and flipped the switch for critical listening so the amp was always warmed up and ready to play. Peter told me the amp sounds significantly better in mono-block form, which is saying something because this amp in stereo was quite special, and even in mono configuration the amps would only cost $6k for the pair. I’d bet Peter would grant you some form of a trial period if you asked, and given what you’re looking for I’d be shocked if you ended up sending them back. His amps are a well-kept secret in this hobby, unfortunately. Best of luck in whatever you end up getting.
@elizabeth those are some good suggestions - thank you. Especially the high gain idea is something I didn't even think of. And also the easiest to test :)

The duplex the Brystons are hooked up to is the Furutech FP-15A-N1 (R) while the power cords are GutWire G Clef 2. The ICs are Nordost Blue Heaven XLR.
So yes, there is some potential for upgrades but I don't really want to spend more on cables (also keeping in mind the state of the Canadian dollar) than what the amps are worth at this stage.
Post removed 
Maybe these: http://6moons.com/audioreviews2/kinki4/1.html ?

My Kinki EX-M1 integrated sounds a lot like what you're after: detail and resolution. The designer of the amp studied extensively Swiss design and brings it to you at a very reasonable price. 

I'd take your time and research it. 😄

All the best,
I see two others have recommended checking out the PS Audio 300 mono's, and I'd agree that they are very much sonic contenders and worth anyone's hearing, but do be aware that they generate a decent amount of heat.  My room gets hotter from that pair than it did with a VAC Phi 200 (and sounds better in my system, room, to my tastes, etc.).  Also, they do use triode tubes on input, but that is a pretty easy tube usage to manage, nothing like power tubes.  I would not hesitate on that account (but I come from the tube end of the spectrum, typically).
Post removed 
Thanks again for all the feedback, suggestions, and good advice.

After reading the responses numerous times and doing additional research on most of the amps online, I've narrowed it down to these models:

Amps I can demo easily in Toronto:
Pass Labs X260.8 - around 13K USD
Bryston 7B-SST3 - around 11.5K USD
Classe CT-M600 - around $13K USD
Moon Simaudio 400M - around $6.5K USD but they seem more like a lateral move

Others that sound (no pun intended) interesting but will be a lot harder to get a hold of in Canada:
Parasound Halo JC1 - around 6K USD
Liberty B2B-100 - around 6K USD

That being said, let me add a few more details that make this harder (for me anyway).
Class A and tubes are out of the question. My apartment is in an old building and without central ac it's already warm enough as it is.
That's also the reason I don't leave my amps powered up when not in use.
It's definitely going to be mono blocks again. While the current length of the XLR cables is 4m (that's the answer for @elizabeth ) and the speaker cables are 3m, it's always nice to have flexibility in terms of placement in the future.

Time to line up some listening session after the long weekend.

One more thing I didn't mention explicitly but it might have some bearing on the recommendation is that the JBL 1400 Array are horn loaded speakers with compression drivers.
So maybe taming them a bit with a slightly warmer amp is not the worst idea.

This has been a wonderful thread so far and given me some great ideas. Including some thoughts on upgrading the wires on my current amps.
I would consider purchasing a pair of Zesto Audio EROS 300 mono blocks. Then I would consider purchasing a Bricasti M1 SE DAC. Then I would run the Bricasti directly into the Zesto amps using balanced interconnects. Be sure you order the Bricasti with the player built in so you can stream. 

If you're after warmer sounding SS amps in order to tame your tweeters on your JBL I would get the McIntosh MC601 monoblock amps (recently discontinued) or their replacement MC611 monoblock amps. 

Again all the amps that you listed above are great but it's a matter of sonic synergy with your speakers and the rest of your setup gears, cables, etc, etc....
It's all about system synergy as a whole. 
The perfect synergy and best pairings of all your equipments will achieve excellent results. 
Post removed 

It’s not that the JBL 1400 is a "horn loaded speaker" that is causing you to think you may need something warmer to tame it. It is because the 1400 has a titanium dome tweeter as well as an aluminum dome midrange driver. The breakup of metal dome drivers will cause a bright edge to the sound and this can make you think you need something warmer. It’s entirely possible, but also keep in mind that the 7Bsst2 amps are very dry and forward - these can definitely sound somewhat harsh with metal dome tweeters. It could give you a very hard edge type of sound.

Another thing to watch out for is amps/preamps that are very warm will, essentially, smear the high frequencies somewhat. This can also come across as harsh sounding, especially on metal dome tweeters. The Marantz 8802 is definitely very warm and will lose resolution or cause smear in the high frequencies. So, you already have two counts towards a harsher sound.

I would say to get the smoothest amplifier you think you can get. If that turns out to be a Parasound JC1, then fine. It could also be the Bryston 7b3 will be very smooth with its revised Class A input stage (the amp is still Class AB).

Another amp to consider at this point is the Krell Solo 375 or 575 monoblocks (575 is a lot more expensive - but I doubt that you will need more than 375 watts). The new Krell Solo and Duo amps using a sliding Class A bias that will give you the sound of bipolar Class A without the heat. The result is a very smooth sound. It has an ethereal and creamy quality to the midrange and will likely give you more resolution than the JC1s (the JC1s are based on a FET input stage which is not as clean or high resolution). Krell uses all bipolar audio stages. This new series is probably very much like the old Krell FPB series without the massive Class A heat. I think this will be a lot more forgiving on the JBL titanium dome tweeters and will not have the hard edge that many other amps will do.

The sonic signature of Class A differs based on design. The Krell bipolar circuit "Class A" sound is very smooth and creamy and ethereal, with clean clear high frequencies. The Parasound / Pass Labs "Class A" type sound is more warm / thick with textured thick mids and could have softer rolled off high frequencies. It is entirely a matter of taste and desired result here.

Finally, I would be careful of interconnect / speaker wire / power cord selection. With titanium dome tweeters, I would remove any silver or silver-plated elements in your system. Silver will push the upper mids/highs and make those titanium tweeters extra bright. It can also cause the midrange to be pushed into the artificial signature.

Sorry, correction.  The Krell Solo appears to be a full Class A amp, but with cooling fans.  Up to you, but it is definitely a very clean and smooth sound.
Just in case you think the link I provided was for an integrated, it was not. It's for mono blocks made by the same company. 

All the best,
I am trying to keep an eye on synergy as much as possible but sometimes that's easier said than done.
Especially with the decline of local stores that carry enough inventory to demo all the options.
I'd be happy enough to be able to demo the amps with similar speakers and front end.
On the other hand, considering the price tag, in home demos should be an option for sure.

It was most likely the EU that implemented those energy rules - but then I am from Europe originally as well. And nothing wrong with looking out for the environment.
I didn't realize that Bryston dropped the idle power consumption on the cubed. Checking the manual for the two version it's 215 vs 80 watts idle and 733 vs 270 BTU/hour also at idle.
That's some impressive numbers - thanks for the heads up.

Since some of you jumped on my comment about the speakers, let me clarify what I meant.
My thought was that going with a slightly warmer amp might give me a bit of a buffer IN CASE things get a little harsh with the Esoteric C-03X pre-amp in the chain instead of the Marantz.
Right now, with the K-01X SACD player going into the Marantz and then the 7BSST2, the sound is definitely NOT too harsh or annoying. If anything, the K-01X sounds smoother (compared to the X-03SE) while also bringing out more detail.
I think I also have a pretty high 'tolerance' and appreciation for treble - as Elizabeth called it: 'treble freak' :)

Krell is one of those brands that I initially thought of (since my go to dealer carries them as well) but for some reason didn't include in the list. Maybe because I haven't seen much about their latest models.
The specs for the Solo 375 look rather good though. On the other hand, based on the reviews I could find it's not exactly a king of treble - ".. if what makes you happy is a lot of treble detail (apparent or actual), the Solo 375 probably isn't your amp."

I checked the link and got that it was for their mono blocks - strangely enough though, the manufacturers website didn't seem to list them (yet?).

Yes, you are absolutely correct when saying the NEW Duo/Solo Krell amps are not the king of treble. The previous generation EVO amps (such as 400, 402e, 403e, etc) were not pure Class A and had extreme amount of resolution. We were talking about taming those JBL horns, which are very bright metal dome tweeters. There are definitely better amps than the Krell for high frequency air/resolution, but the Krell Class A models will really smooth out those waveforms. It does make the treble smoother/softer, but it may be a very good compensation for those metal dome drivers in the JBL. Honestly, I’m not sure if the JC1 would have more resolution either, as it definitely softens the highs. I think the Parasound JC1 will soften and rolloff the highs. The Krell will just smooth out the highs, but the detail is still there.

Based on your requirements for heat and sound, it may be that the Bryston 7b3 is your best bet. Hopefully, you will be able to hear how it sounds at some point.

On your comments about the Esoteric preamp possibly being too harsh, I would suggest waiting until you have that preamp in your current system. Then you can see how things sound. I think the new 7b3 will be smoother/sweeter than your current 7bsst2, but the sst2 will help you gauge whether you need a warmer amp or not. If the sound of the Esoteric preamp is acceptable with the SST2, then you probably don’t need a warm amp.

Tell you a secret, I just bought a pair of 7b3 a few days ago. They are on their way and I should have them on Tuesday. I can report back on a comparison with the JC1s if you want.

If you get a warm amp, there is no possible way to increase the resolution. You can get a high resolution amp, and then warm things up if you need to with gold-plated connections (speaker wire, interconnects, and even power cord).

 @auxinput. A comparison of JC-1 and Bryston 7B3 would very interesting to hear about. The new JC-5 is also out. 
I to am looking for a new amp and confused as ever. I really like clear open treble and soundstaging like the OP. 
Yes, they're relatively new and the site hasn't been updated yet. There is a member here who remarked on having a pair when the integrated was being discussed. I think he got his some time ago from the Asian market (it's been around in various forms) but remarked how wonderful they sound.

All the best,
Krell Solo 375 Monoblocks are by far exactly what you are looking for. They have the auto-bias Class A and just have a softer way of bringing the treble. The treble is not rolled off, just not what some of these so called state of the art amps do to your ears. Krell does Class A right. No matter how many amps I put into my system, nothing sounds better with my Martin Logans. I sold all my other amps and now have 3 Krells. Currently I'm using one with the auto-bias Class A and it really works. I am constantly reminded how much a proper Class A design can produce vocals and instruments with weight and clarity that is non fatiguing. If you can't afford new, just look for used. I don't like the Evolution models, but ones before that have the auto bias technology. Bryston is great for reliability, but can't really give you what Krell does with musicality. I'm sure some like Pass Labs, and power to ya. But back to back, the Krells or D'ags with give a faster decay from instruments, and thus more natural. Let the mud slinging begin.
Yes, hearing your thoughts on your new Bryston 7BSST3 amps would be much appreciated. Especially in comparison to the Parasound JC1s

And you made a good point about resolution. I'd rather have 'too much' detail and tone things down / warm it up with wires and room treatments if necessary than end up with the opposite.

You're also perfectly right about getting the C-03X first and figuring out how the chips fall with it in the playback chain.

I honestly didn't expect to get this much feedback in my very first thread so quickly :)

Thanks for also chiming in @bigddesign3 on the Krell - they're shaping up to be a serious contender.
Good thing my dealer also carries them. Unlike the Bryston, I am not sure he has them ready to demo though.
They are also the priciest option - considering the week Canadian dollar. Oh well...

I would also like to thank everyone for keeping the exchange of ideas and suggestions so civil and on track - it's been a pleasure to read through all the comments to far!
I second the Krell concept. I highly enjoyed a 5ch version of current technology and thought it sounded great w good build and dead quiet fans. Actually very hard to tell that they are on. Worth considering and can be bought 25-30 off. 
Just saw on Ebay and also direct from HiFiHeaven in Green Bay, Wisc. a pair of Krell Solo 375 monos for $4,400.00 each. Mint condition. Authorized Dealer. Just an FYI.
Post removed 
Just an opinion but I think you could really get into some truly great amps if you weren’t going mono. Paying a real premium for two chassis. Would open up Rowland, Luxman and maybe a used Agostino. Seeing used Solution also. There are many. FWIW
I agree with many here...Having mono amplifiers does not make for a significant difference between a good stereo amplifier. The best money spent is on a good sounding system. If you think having 2 boxes is BETTER, then you are not giving a whole world of amp design a chance. Do I want to have 2 Krell mono amps over my 3 stereo amps? Not a chance. Every bit of technology is wrapped up in the proper design of the amplifier itself. I'm sure that many that are "in the know", have an understanding of what it takes to make for an amplifier that does the same thing as 2 mono amplifiers. Amplifier 101 is that there is a way to use power supplies, and transistors in a way that makes them not wanting for help. High Current amplifiers are designed to work in many different ways. But the common denominator is to have an amplifier feed enough current and have a design that brings the sound to it's finest output. If you think that mono amplifiers are superior to stereo, well that is just your opinion. To this day.... a proper Class A design will be the best sound. I am not a guru, but a person that liked a few Class D amps. And then hour after hour, I jumped ship with Class D. Still have not found a replacement for a good Class A sound. The auto bias feature with Class A will save the cooling and electric bill. But if you have to warm up your amp for longer than an hour or two.... maybe you should find another brand. Some of the best amps ever are stereo. And they are also Class A. My take on the mono crap. What if both monos don't match? OMG

@bigddesig3 - I think you are pushing too hard on your sell. There’s many different opinions and actually many different configurations that would work great in different system synergies. There are elements of monoblock amplifiers that will be superior to stereo amplifiers (depending on size and design). One aspect is completely dedicated power supplies. Stereo amps will usually share a transformer and/or the actual power supply. The exceptions are stereo amplifiers that are built as "dual mono" amps (where each amp channel has a dedicated transformer and power supply).

Another aspect is size of power supply - which generally affects the ability to drive certain speakers. A larger power supply can give more muscle in the bass/midbass area. Granted, speakers with higher impedance (such as flat 8 ohms) or easy to drive speakers make it less critical for big power supply. But many woofers nowadays will actually drop down to 2-3 ohms at times. Some drivers are extremely hard to drive. Class A output can definitely smooth out an amp circuit that is usually bright/thin, but only a large power supply will give you that bass heft. I have compared multiple amps with different size power supplies.

Finally, monoblocks are usually a fully balanced differential design on the power output. I totally understand that there is much controversy in the industry as to whether or not balanced differential output is better than single ended, but I usually have found differential is better. There are some stereo amps that are fully differential (many Pass Labs stereo amps are balanced/differential output).

I’m not arguing against the idea that Krell Solo is a very good amp. We just need to keep an open mind and have a complete understanding on what to expect with each amp choice.

To this day.... a proper Class A design will be the best sound.

I actually disagree with this completely. Class A can be very good in some scenarios, but it will not provide the absolute best sound because of different system synergy and different personal tastes.

--More to come on this Class A thing - I’ve been listening to these Parasounds closely this weekend and I’ll write up more on this after I get a good listen to Bryston 7b3.

@auxinput. You are right about that some offer the fully balanced differential design.
I own 3 Vintage Krell amplifiers. The amount of power supply, capacitors, output transistors and protection is pure overkill. The ML Montis speakers drop down to below 1 ohm at times. My KSA-250, KSA-200S, KST-100 have some kind of sound that fills in, instead of applying more db levels. Most volume controls turn up the sound level and thin out what's playing. Not what I own. It's going to get fuller the sound before it gets louder. This is my best way to explain it.

Let's get this straight..... I am fully open to what you have to say about what you are up to, and that there may be a better world than Class A. 
I spent a lot of time (40 years) perfecting Car Stereo to audiophile standards. Since 1970 for my Home Stereo beginnings, and in the back room with many audio circuit designers.
There is not a day that I cannot learn from others. I welcome anything that brings more to the table.

I listen to all types of music on TIDAL quite a bit now. Funny how I used to listen to my CDs or FLAC files a lot more. But now, I like to explore new worlds in what's out there. Latest is from Jamaica artists combining club music with the Island Vibe. Or female artists that are new and exciting. That's what we all are here for.

Been about 8 months since I have finally said my system is finished........ done
You should try a pair of Linn Klimax Solo Chakra 500 monoblock amps. I used to own these in my all Linn Klimax setup and system driving the Linn Klimax 365 passive speakers. But I've moved away from all Linn Klimax setup and system and upgraded my gears couple times since then. I used to be a huge fan of all Linn setup and system or the so-called Linnie. My two-channel rigs used to consist of all Linn Klimax stuff as well as the Linn LP12 Klimax version turntable package with all Linn Klimax PSU. 

But I have no idea how these Linn Klimax Solo 500 monoblock amps will perform and sound on your JBL. They sounded very musical in all Linn Klimax setup and system paired with the Linn Klimax 365 speakers. These are great amps and sounded very natural / organic. 

Let me get back on the whole mono blocks vs stereo amps part. I've never said that mono blocks sound better but I stated my reasons for preferring mono blocks - mainly more flexibility in terms of placement.
Not saying I won't consider a great stereo amp but the initial goal is finding a feasible list of mono blocks.

And that's the other part - feasibility. While I appreciate all the feedback and ideas, please keep in mind that even in a big city like Toronto, there are only a limited number of hifi stores left and I can't try some of the exotic amps some of you mentioned.
Neither will I go down the 'import from the US route'. It's really not worth the hassle, not to mention that aboot (see what I did there?) 95% of the sellers won't ship to Canada anyway. And don't even get me started on the state of the Canadian dollar... *sigh*

I've got a good idea of which amps I can actually listen to and that will be my short list in the end.
No matter how good something might be for another forum member in their system, if I can't demo it somewhere, it's not going to make the list.
Post removed 

Writing up my Parasound comments, since it is so lengthy.

Stock – JC1 has a very refined sound, midrange is very smooth and refined. Emphasis is tilted slightly towards the upper midrange which causes the audio to sound just a little bit thin in the midbass area. Sound is soft. Overall, sound to me is just a little bit low fidelity. It’s very smooth and refined, but just doesn’t sing or have that effect of sounding real.

Main A/C fuse (on back panel) replaced with Furutech 15A – This significantly improved things. The attack and resolution is much better and tonal qualities are much more real. Instruments and vocals ring out with more truth. Sound is no longer tilted so much towards the upper mids and it is fuller sounding. The high frequencies are just a little bit jangly sounding (best I can describe), but overall a significant improvement. Bass is a significant improvement. It is still somewhat soft sounding.

All internal fuses replaced with Furutech (there are 6 fuses inside each JC1 that affect audio) – This is the best and most natural sounding result so far. There is no grain or jangly resonance heard in any of the frequencies. Bass is just absolutely amazing – oh my god! I cannot stress how much tight deep and strong bass you get with this particular configuration. It’s a serious “punch you in the chest” type of bass – hits really hard, but sounds natural and deep. Resolution and attack are still soft here. I think the soft attack also extends into some of the high frequencies as well.

In actuality, I discovered my Emotiva XPR-1 amps (also loaded with Furutech fuses) just beat the crap out of the JC1 with regards to resolution and detail. However, the Emotiva is not the cleanest sounding amp and I can definitely hear a slight element of grain in the sound.

So what’s really going on here? I think it’s a combination of things. I have listened very closely this weekend and I think the main thing I am hearing is that the Parasound amps have a very soft attack on midrange and early high frequencies. I believe this is mostly due to the Class A biasing. Even though JC1 is not a pure Class A amp, it is still Class A biased into 10 watts (at low bias setting). This is still enough Class A biasing to soften the attack on the midrange waveforms by smoothing out the response to the waveforms themselves. Class A circuits will tend to have a very gradual curved response when it receives a waveform spike on the input. This is less sensitive with analog preamp circuits, but when you are working with speaker level voltage, the response curve is much more gradual (based on slew rate response). This has a result of making angular waveforms (like a snare hit) more rounded or curved. Again, it depends on the engineering of the Class A circuit and how it responds to spikes on the input.

A comment on the high bias (25 watt) configuration of the JC1. The only time in my system that the 25 watt high bias Class A setting sounded good was with the stock fuses. The High Bias actually provided a more engaging sound. However, with Furutech fuses, it just made things too slow and mushy.

Another possible reason is my speakers, which are B&W 805 D3 diamonds. They are not a very fast responding speaker (they are actually hard to drive from an amp standpoint), but they are very natural sounding (the reason I went with them). So the combination of a neutral responding speed and the difficulty of pushing the drivers and magnet engines could contribute to the slow attack on the midrange and highs.

Finally, it can also be from having too many Class A stages. I have found through extensive testing with DAC/preamp stages that if you have too many Class A stages in a row, the sound becomes too slow and soft. So, my configuration:

HT Processor – Krell S1200U discrete Class A analog stage

JC1 – discrete JFET Class A input stage, MOSFET driver stage

JC1 – high biased Class A output stage

In my case, I think all of the above items contribute to a soft attack on the mids/highs. It does sound very nice and pleasant. Music is nice and pleasant (such as with a tube amp), but just doesn’t have that extra bit of attack and resolution to make things stand out. For home theater purposes, I just don’t have enough attack/detail to make movies exciting and engaging. It’s definitely not an optimum amp choice for my system.

I think the Parasound amps would work very well with speakers that are extremely fast responding and no decay. The Martin Logan panels are one example as they definitely have a tendency to sound bright/thin/harsh. They require the waveforms to be further smoothed so that it fills out the sound. Other speakers that might excel are the Monitor Audio Platinums (with the very fast ribbon tweeters) or maybe the Focals with their extremely light and fast responding midrange/woofers. Or add a JC1 if you have a very thin/bright sounding preamp/source.

@bigddesign3 – this could also be the reason that the Krell Class A works so well with your Martin Logan panels. If you read Whitecamaross’s amp thread, he states that the JC1 does everything right from top to bottom. Reading further, he found that the huge Pass Labs 200 watt full Class A monoblocks were the best sound he heard (though I am suspicious of his continued “this is the best” posts). He also was listening with high end Martin Logan Panels with those two amps.


Thanks for the write up on the Parasound JC1 - very insightful and I love the amount of detail you went into.
Can't wait for your comments on the 7BSST3s :)

Further comment on bigddesign3's speakers.  The Martin Logan Montis is an active woofer design, meaning that frequencies under the 340hz crossover point are sent to the internal Class D amplifier.  This means that the main Krell amp does not need to carry the load of the woofer impedances.  Bigddesign3's comment that he may not necessarily need a huge amp power supply can be true here.

The JBL 1400 has a big 14" woofer.  It only drops down to about 5 ohm around 100hz, which is not too bad, but this speaker will still benefit from a huge amp power supply - to support bass strength/heft.

Bryston 7b3

Okay, here’s the low down.  The amp is actually smaller than the Parasounc JC1. It is lighter as well.  It does have a sizable transformer, but the JC1 transformer is bigger.  However, it has a larger capacitance bank in the power supply sections (16 x 10,000uf = 160,000uf!!).  Initial assumptions that it works only off a circuit breaker are incorrect.  There is actually a small 12.5A fuse on the board close to the IEC plug input.  It is covered by a rubber grommet that is easy to remove with pliers.

Stock – initial listening showed this amp as very clean.  It is definitely cleaner and faster than the Parasound.  I thought that it sounded somewhat thin, but it might sound different in other systems.  Extended initial thoughts seemed that this amp sounded a bit clinical and just a tiny bit sterile in presentation.

With Furutech fuses.  I had one 10A and one 5A that I put in these two 7b3.  The 5A is undersized, but I am not going to consume more than 600 watts of A/C for my tests, especially since these will drive my bookshelves, which are crossed over at 80hz.  With the Furutech fuses, it definitely filled in more of the midbass body.  Made things better and just a little bit more natural over all.  However, extended listening told me that this was still too clean and fast.  There was too much attack and it pushed it over the edge into the “too solid state” characteristics.  Bass was extremely clean and clear, but just bordering on a tiny bit harsh.

Isoclean 5A fuses (5A was the biggest I had).  Isoclean uses gold-plated endcaps and conductor wire.  Much much better!  The amp sounds more neutral now.  The upper mids and highs are not so push hard and it gives you a sense of tonality.  This is great because it tells us this amp can be tamed if it is too bright and hard edged.  The bass was very good here.  Overall, this was the best this amp sounded.  It does not have the slam and bass punch that the Parasound has.  I would describe this as a very gentle and delicate sound – extreme amounts of resolution and detail.  Even with the Isoclean fuses, this amp was extremely clean and resolving.

Here’s a note on others that have had extreme success with the new Bryston cubed amp series:


That being said, the Bryston in my system was very good, but it was still just slightly thin.  It was very clean and clear, but did not have the organic life that the Parasound JC1 had.  Since the Parasound had more body, the overall sound was fuller and, as a result, louder.  I could hear more of dialogue and voices in movies.  I think that my system is just way too high resolution for the Bryston amp.  I have rhodium plated everything.  Audioquest Rocket 44 with Furutech rhodium spades. Rhodium XLR connectors and power cord connectors.  The Krell S1200 is definitely not a warm preamp/processor.

I suspect the Bryston 7b3 would excel in a system that had a warm tube amp or something like a NAD or B&K preamp.  My Krell and cabling is just not warm enough to transfer to the Bryston.  With your Marantz processor, it might just be warm enough to give the Bryston a fully rounded signal.  However, with the Esoteric preamp, the Bryston might come out being too thin.  You’ll have to wait and see.  I will say that the Bryston is just about the highest resolution and highest resolving amp I have heard.  That being said, it will not add anything (which could be bad if you need something added into the signal).