Amplifier Upgrade Decision


Hello,
I need some help/feedback with regards to upgrading my power amplifier for 2 channel music. My current set up includes following components
1. Source (Digital)- Oppo BDP-95
2. Source (Analog)- Clearaudio Concept Turntable
3. Pre-Amplifier- Parasound Halo JC-2
4. Pre-Amplifier- Parasound Halo P-7 (using the phono interface for playing the turntable)
5. Power Amplifier- Parasound Halo A-21
6. Front Speakers- Aerial Model-7T
7. Power Cable- Nordost Heimdall 2 and Red Dawn 2
8. Interconnect Cable- Nordost Frey 2, Heimdall 2 and Red Dawn 2
9. Speaker Cable- Nordost Red Dawn 2
10. Wall Receptacle- Furutech GTX-D NCF(R)
11. 2 Dedicated 20 Amp (10 AWG) circuits feeding the entire system
12. GIK Room Acoustics Bass traps/Diffusors
13. Room size- 16’ X 12’
This set up sounds good but I wanted to take it to the next level and wanted to upgrade my amplifier to a better 2 Channel amplifier or a set of mono-blocks. I love Class A/AB sound and would like to stick to this technology. My choices, not in any particular order, are
1. Upgrade to a Plinius SA 103 (125 W pure Class A per channel) and use it as a 2 channel amplifier
2. Upgrade to a set of Class-A mono-blocks. My choices, not in any particular order, are
    a. Parasound Halo JC-1
    b. Pass Labs XA-60.8
My budget is around 10-12K.

I know everything is system dependent but I would love to hear your opinion on these amplifiers before starting on product evaluation.

I am also not sure if my mono-block amplifier choices would provide significant value add from a sound perspective over the Plinius or any other good quality 2 channel amplifier at this price point. So I would love to hear your feedback on this point as well.

indranilsen
If you are locked into just those amps I would say Pass. If you aren't and don't mind buying used this amps looks like a nice fit:

https://www.audiogon.com/listings/solid-state-esoteric-a02-amplifier-silver-new-in-box-2017-04-15-am...

No affiliation just love Japanese SS amps.
Thanks for your feedback bond. How does support/servicing work for Japanese components?

Aerial Model-7T
They measured at 86db so they need a few watts, but also Stereophile measurements said they "drop to 3.5 ohms in the upper bass and low treble, and to 3 ohms in the low bass", so the need a bit of current also from an amp. 

To me the Parasound JC1’s in high class-A bias would be a great choice that you mentioned.

Cheers George
George- Thanks. Given that I have Parasound HaloJC-2, JC-1 would be a smooth transition. I am very familiar with Parasound signature sound and it is good, However I have heard Plinius SA103 at a local dealer's store and it sounds really good. I haven't heard Pass Labs as yet but read rave reviews about this brand.
So I was hoping to hear from folks driving Aerials Model 7T with Plinius/Pass Labs amplifiers.  
Also, I wanted to hear what folks think about mono-blocks over a stereo amplifier in the price range that I mentioned above. A stereo amplifier brings the advantage of managing less no of chassis, power cables etc and mono-blocks are supposed to provide with better channel separation, less noise, separate power supply, etc. But I am not sure how is that delta going to result into audible sound improvement. Any feedback on this point would be very much appreciated.
I second the Parasound Halo JC1 Monoblocks.
Esoteric has great service/support
I had the A21 and JC2. To "my ears and in my system " I submit they are both just average, with the A21 being the better of the two(I know the A21 is an amp and JC2 a preamp), but I'm saying the better value. I haven't heard the Pass, so the best advice I have is to choose your price point, try to listen to a couple of options, and let your own ears decide.


The JC1s are fully differential/balanced on the amp output circuit, plus having a much larger power supply and transformer.  These amps have more of a Class AB circuit (with an option for Class A bias) and are going to have more brute force for bass punch/control and dynamics. Since the 7Ts do drop down to 3.5 ohms, this might be the better choice.
The plinius/pass choices are going to be single ended amp circuits, but the full Class A may have a sweeter or more musical sound to your ears. (Not to say that the JC1s will be bad - they will still sound great).
Thank you guys for your feedback. Very helpful indeed. I think Halo JC-2 is very good pre-amplifier at that price point, at-lease it blended really well in my system. Previously I was using P-7 to drive Halo A-21 but upgrading the pre-amplifier to Halo JC-2 brought a huge improvement all over the audio domain. The most notable factor was the quality of bass coming out of Halo A-21 in this combination. 
I was initially thinking of getting a pair of Halo JC-1s because it is a very good amplifier and would make this transition very smooth for me. However I am willing to give Pass/Plinius a try because of the reasons that auxinput mentioned above. I am really curious to find out what this more musical/sweet (when using a pure Class A amplifier) means from a sound perspective. Any feedback on this would be very much appreciated.
Also any opinion on using a set of mono-blocks over a stereo amplifier? In theory the mono-blocks win but I wanted to hear from folks who have used both and have an opinion on this item.
 
The plinius/pass choices are going to be single ended amp circuits, but the full Class A may have a sweeter or more musical sound to your ears.
I'm pretty certain that the Pass XA60.8 is a fully balanced amplifier.

Regards,
-- Al
 

I should add, I had Aerial 7T's when I had the A21 and JC-2.
Your budget is so close to a listed Agostino momentum amp. One to buy and enjoy for years to come. You can also update much later to S250 or whatever is current at the time. A handmade beauty to keep for years. At under 15k it's a very good deal. Truly a buy and check off the list component. 

@almarg - you could be right, I just assumed because most stereo amplifiers are single ended.  Based on what I'm reading on the Plinius SA 103, the Plinius is single ended (not differential).  I'm primarily talking about the output stage.  Many stereo/mono amplifiers will have a fully differential/balanced driver stage on the input side.
Hi Auxinput,

From the Pass Point 8 Owner's Manual:
... both the (+) Red output connection and the (-) Black output connection are live.  There is no ground reference at the speaker terminals. The black (-) speaker terminal must never be treated as ground. This can be important when you are hooking up active sub-woofers to the output of the amp – if you need a signal ground connection then use the white ground terminal provided on the rear panel. The white signal ground connection is not a safety ground.
Also,
If you are using RCA inputs, then you want to use the gold input jumper to short the (-) input (pin 3) of the XLR connector to ground (pin 1)
All of which adds up to the XA60.8 being fully balanced.

I recall seeing similar statements for the Point 5 series, btw.

Regarding the Plinius, I see that it can be operated as a monoblock in what is described as a fully balanced mode, if its input signal is provided in balanced XLR form.  While also being operable as a monoblock in what is described as a bridged mode, if its input signal is provided in unbalanced form via an RCA connector.  I would suspect that the "fully balanced" mode that is referred to in this case is essentially a bridged mode, but without the phase inverter that would be inserted into the signal path of one channel when an unbalanced input is provided.

In any event, regarding the OP's question I see that Stereophile measured the Aerial 7T's sensitivity as being 86.6 db/2.83 volts/1 meter.  Given its 4 ohm nominal impedance that corresponds to only 83.3 db/1 watt/1 meter.  Which leads me to wonder if the XA60.8's rated power capability of 120 watts into 4 ohms would be sufficient, especially if recordings having particularly wide dynamic range are to be listened to.  Such as a lot of classical symphonic music, especially if the recordings are well engineered with minimal or no dynamic compression. 

And relevant to that point I note that the Parasound A21 that is presently being used is rated at 400 watts into 4 ohms.

Although for several reasons I suspect the Pass amp can actually put out considerably more than 120 watts into 4 ohms, but that it would no longer be operating class A when doing so.

Regards,
-- Al    

Slight correction to my previous post:  "83.3 db" was a typo, and should have been "83.6 db."

Regards,
-- Al
 
Folks, Thanks for chiming in... A few comments from my side.

Power requirement, as pointed out by Al, George and others, is very important for me because this amplifier would be used for both 2 channel and HT applications. Although I am a music person, HT need for the rest of my family could not be compromised. I selected Pass Labs XA60.8 because
1. Mike Kelly told me a number of times that Model 7T is relatively an easy load for any amplifier
2. Pass Labs product team confirmed that this unit will be more than capable of driving Model 7T in my room with a plenty of headroom in reserve to support dynamic range

Is there anybody in this group driving Aerial Model 7T with a Pass Lab amplifier XA-60.8?

@ricred- Do you still have Model 7T speakers? If yes, what are you currently using to drive it?

It sounds like Plinius in stereo mode will have double the Class-A power than the Pass Lab amplifier. If the stereo sound output of Plinius is equivalent to Pass Labs mono blocks then that might be a good choice for me. 
Again any feedback on this topic would be appreciated.

Indranilsen,
Aerial 7Ts, great speakers, but my room is 20' x 26' and I sold them. I did have the opportunity to hear them with my current components: Jeff Rowland 625 S2 amp and Jeff Rowland Corus preamp. Significantly more musical than Parasound to my ears, but it should be considering the cost difference.


You should consider the Aesthetix Atlas. You could buy mono amps used in your price range.
After listening to a few different PASS, Threshold, Stasis amps popular in my area of NorCal over many years, a few local guys started trying other amps for different sound tastes; one is the Cary SA-200.2. I bought the new Cary 200.2 solid state amp just over a month ago to compare side by side to some of my tube amps. With the right sources, interconnects, and compatible speakers, the new Cary SA-200.2 stereo or larger monoblock amps are really nice sounding for the $ and then some. I put a nice Cary SLP-98 tube preamp in front of my SA-200.2 solid state amp, it really sings smooth after 150-200hrs of break-in. Sound can be tuned using softer or brighter interconnect cables. Just went from silver plated copper back to pure copper interconnects on this new setup, and wow. It’s giving my tube amps a run for the money. Huge, deep base, nice soundstage, very dynamic, and more midrange with good copper cables. I own just one Cary SA-200.2 stereo amp, and its plenty at 200w/8ohms, but I’m running mine at 350w/4ohms. Great value too, my .02 cents. Super bang for the buck $

Dual Cary SA-200.2 amplifiers, found this on youtube (video)
https://youtu.be/IqIS66LvbZ4
Ayre MX-R in old config
or a VX-R might get lucky and find a used Twenty series in your budget
the Aesthetix stereo and mono are awesome amps IMO


Plinius 103 is the way to go.
Drives my Harbeth 40.1 beautifully 

Primaluna Premium. Folks dont understand how good this family is.
I say the obvious choice since you are all Parasound would be to go with the JC-1s. You have everything pretty much dialed already so I am going to suggest something maybe even before an amplifier upgrade. The Oppo 95 are awesome, but you can do better with an external DAC. I say try a Bryston BDA-3 DAC to go with the Oppo. It has about 10 inputs also HDMI in and out. It will do DSD over HDMI from SACDs.
Thank you very much for all of your comments suggestions. 
@darcman- The DAC suggestion is indeed interesting and I have that in my upgrade path as well. I could upgrade either source or amplifier at a time given the budget constraint and I decided on amplifier based on my personal choice. Ideally I should audition each upgrade separately and then decide but that would involve spending a lot of time which I might not be able to spend right now. However in the end I need both a quality source and an amplifier...
I am also interested to find out from the group whether 60W Class A power (mono-blocks) would have enough juice to drive my Aerials 7T, which drop down to 3 Ohms, in my 16' X 12' room. If not how much Class A power (min) I should look for to make this transition smooth? Any feedback on this would be highly appreciated.
hi 
im sorry to throw in a curve ball, but leaving out the current state of the art class D in my opinion is a mistake,
Please consider the UK built but shipped world wide Nord Acoustics, 
they were recently reviewed in hifi pig driving some 120,000 fancy loudspeakers,
I also know John Banford a very highly regarded hifi news reviewer, he now has them driving the Sir Galahads, 
I purchased there top one up reference monos and i believe they are very special,
I have owned some very high end kit ie Edge NL reference monos 2 pairs driving Carls Nola Grand Reference , FM  acoustics 711 and 266, various Krell big boy monos,
sorry i am not bragging and them good old days are gone, but the Nords sound better to my memory than the Edge amps,
and at around 2k your left with serious money to spend elsewhere,
 i gave them a punt and they are fantastic i wouldn't change them for anything right now, like you my budget was around 10k,
im now left with money to spend on better connections, isolation, maybe front end or speakers,
but to be honest they have raised my system to a new level along with some isolation i purchased with some of the change ,
i still have around 5/6k left in the bank and at this moment i am completly over the moon with my system regards john 


Have tried Pass, Plinius, BAT and Krell, ended up going with a pair of ModWright KWA150SE in mono.... plenty of power to drive anything, very nice depth and enough slam to keep anyone happy...
4425 has offered a good suggestion in the used D'Agostino S200, but ricred1 also has brought up the Rowland 625 s2 which should be close to your budget and is a superlative amplifier.  Can't go wrong with Pass either but I think the D'Agostino and Rowland are in another league.
The JC1s seem the default option.  The advantages of monoblocks are (1) forced separation of the two channels - not a biggie - and in any event you do get 'dual mono' power amps; (2) The separate chassis are very useful for heatsinking.  It can mean a particular design can be biased higher.  (3) Speaker wiring can be shorter.  This is beneficial, and said to more important than the corresponding interconnect cables.  I'm not too sure about this latter point but very long unshielded interconnects can be an issue.

 I was in a similar situation to you recently.  I ended up getting a Pass X150.8.  Fab sound quality but it runs hot, and takes a long time to warm up (I know that sounds like a contradiction.  Others on my short-list were David Belles  http://www.powermodules.com/about.html and Pureaudio who have a US presence.  http://www.pureaudio.co.nz/  Plinius is great but Pureaudio can only be better.  I guess that is how I would have gone but the Pass came up at an auction so I had to make a quick decision.  
The Pass XA-60.8 would be too weak for your speakers.

The Plinius is a good choice. The other better choices that I would look into are:

1. A pair of Benchmark AHB2 in mono configuration. Save money for something else while getting a sound you may never want to change.

2. Gryphon Diablo 300 - performance and sound near the very top high end

3. Hegel H30 - Sound, full control and power - upgrade to monos later 

My personal discipline concerning speaker/amp matching, besides having all the obvious sound qualities, is to get amps that are much higher in power than recommended by speakers (one must discern between ClassA and AB of course). I believe that audiophiles dont take this enough into account when choosing amps. Many many amps out there have a real good sound, but control of the speakers is paramount if you want to have real dynamics and continued separation of instruments on complicated pieces at fair volume levels.

@hddg- I completely agree with the power criteria and it's importance that you have brought up... Initially I thought 60W would be too less for driving the Aerials but Pass Labs product team confirmed that I would be fine with it in my relatively small room 16' X 12' room, specially with Class A power. I am trying to find out how much Class A power I need in my room to drive the Aerials w/o loosing dynamics and bass. Is there a way to find that out before buying the amplifier?
Thanks
the Pass X250.8 would do a great job...many prefer the X to the XA
series
Fwiw

have owned the very fine A21 twice now, also own the JC2 in system 2, also a fine piece of gear 

recently bought a Pass X150.8 and prefer it to all other amps I've owned; would have preferred purchasing the X250.8 but its size and added cost just didn't seem necessary, of course I could be mistaken 

Put a check mark in all the boxes you rate amps with; the Pass delivers in spades and as a class A-AB design compares favorably with SET, class A ss, push pull tube, class D, mono designs or one box configurations, it's impossible (for me at least) to fund fault with it 

no it is not inexpensive nor does it run cool, it does take up some space, though not that of monos, but sonically it is excellent 

what I have noticed is it better reveals what is on and in a recording; poor recordings don't sound 'worse' but I am more aware of their flaws, and conversely good and great recordings are that much more appreciated 

@markmendenhall Thanks for your feedback. Glad to hear that you like Halo JC-2 pre-amplifier which in my opinion is a great product at that price point. Just curious to find out how does Pass Labs 150.8, which is less powerful that Halo A-21, compare with Halo A-21.
Now coming back to pure Class A power it seems like you have to really spend a fortune to reach to the level of 150W or 250W and even then you might not get it because almost all Class-A amplifiers leave Class A domain beyond a threshold. So it is unclear to me why audiophiles spend so much  on Pure Class A design instead of a Class A/B design. I know everything in audio is system/environment/user dependent but is there a thumb rule of X Watt of pure Class A which would be good enough for most of the users in a small/medium room under a regular listening environment?

The Pass just sort of ended my amp quest.  I can't tell if or when it switches from A to AB, if indeed it ever does.  I've often considered spending big coin on VAC or Burmester for example, and my SF Oly 3's are 4 ohm speakers, so the X150.8 delivers over 300 watts to each speaker which my prodigious ears (and very patient and lovely wife) tell me is plenty of power.   It's fun, and often expensive, to remain on the merry go round, but at some point, and maybe it's because of my advancing age, it's really about the music, not so much the gear.   I'm focusing more on my vinyl collection rather than hardware right now.  Can the Pass be 'bettered'?   Who knows. At some point it's about preference, not superiority.   The A21 is a great amp, as were/are several others I've owned or currently own.   Personally I prefer the Pass.  
OK

droped the dime and traded the X150.8 for the X250.8

its not the wine, it's not the company, it's not anything else new in the room

its clearly better than the X150.8 
@indranilsen 

OP, did you finalize on a choice?
@david_ten: I haven't made my final decision yet, got side tracked by a room acoustic issue which was more urgent to address. I might go for  Pass Lab amplifier (mono blocks) as soon as I can. 
Thanks. Let us know which Pass and how it all works out. Hope your acoustic issue is resolved.

"...dropped the dime and traded the X150.8 for the X250...its clearly better than the X150.8"

You just proved the old car guys adage that there's no replacement for displacement. 

Better in what way?

More SET like in the mids and highs, just sounds sexy as all get out

bass is deeper and better defined

soundstage extends further in all directions

a very pure, detailed, natural presentation that just 'eases' out of the speakers effortlessly with extreme musicality 



Would like to add that working with Mark at Reno Hi-Fi is a great experience.  Along with many other fine dealers I've worked with, Mark is just a pleasure to deal with.  Highly recommended!