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
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