Looking for ideas - new mono blocks for stereo music

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.

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.

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.

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).

@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.

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.

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:

https://forum.audiogon.com/discussions/finally-took-the-bryston-4b-cubed-plunge

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).