Parasound 23+

[CyRock]

To add to your thoughts on Parasound:

Parasound power amplifiers use JFET's (small signal transistors) in their input stages. JFET's have much lower transcondance (current out/voltage in) than bi-polar transistors. Ultimately this means that Parasound power amplifiers have 10dB to 20dB MORE distortion than many other power amplifiers at the same price or less.

These sorts of JFET's are evidently no longer produced, but unfortunately Parasound seems to have a large supply. PS Audio also uses JFET's at least some of their amplifiers accompanied by the normal sorts of Paul McGowan claims.

Thanks bigguyca, is this distortion audible? Also, with this in mind, what amps do you recommend at this time that would range in the 2125 to 23+ price range. Thanks CyRock

 

[peng]

To add to your thoughts on Parasound:

Parasound power amplifiers use JFET's (small signal transistors) in their input stages. JFET's have much lower transcondance (current out/voltage in) than bi-polar transistors. Ultimately this means that Parasound power amplifiers have 10dB to 20dB MORE distortion than many other power amplifiers at the same price or less.

These sorts of JFET's are evidently no longer produced, but unfortunately Parasound seems to have a large supply. PS Audio also uses JFET's at least some of their amplifiers accompanied by the normal sorts of Paul McGowan claims.

Being designed by John Curl I am not surprised, but I didn't realize JFETs there would result in higher distortions. I think Nelson Pass likes JFET too. The F5 amp I am going to start building also uses JFET for the input stage.

 

[Martin]

Someone needs to send one to amirm for testing. I used to own a Patasound Halo A23 which I replaced with an A21. Buy them on the used market. They hold there value very well. I had the A23 for a couple of years and the A21 for over 5. I sold both for what I paid for them. I’ve also owned and sold a Parasound Halo P3 and D3.

Martin

 

[Vasr]

To add to your thoughts on Parasound:

Parasound power amplifiers use JFET's (small signal transistors) in their input stages. JFET's have much lower transcondance (current out/voltage in) than bi-polar transistors. Ultimately this means that Parasound power amplifiers have 10dB to 20dB MORE distortion than many other power amplifiers at the same price or less.

These sorts of JFET's are evidently no longer produced, but unfortunately Parasound seems to have a large supply. PS Audio also uses JFET's at least some of their amplifiers accompanied by the normal sorts of Paul McGowan claims.

Do you know what JFETs Parasound uses? JFETs apparently vary a lot. If they somehow still have the old Toshiba low noise ones, the above may overstate the case.

As for as actual difference with non JFET amps. A23+ THD < 0.06% at full power, Monolith < 0.03% the latter being typical. Would it make a difference?

@pma , @restorer-john any thoughts on the use of JFETs from your experience?

 

[MusicNBeer]

That Mononlith does look like the best deal for class AB right now.

 

[peng]

That Mononlith does look like the best deal for class AB right now.

It has lower IMD than the Halo amp too, that's specs, would love to see one bench tested by ASR.

 

[Vasr]

Monolith vs Parasound relative advantages

Monolith: Made by ATI, cheaper, plenty power, better paper specs (power, distortion, FR)
Parasound: Made by Parasound, long-time support before EoL, smaller form factor, variable gain control for matching to pre-amp, auto-sensing power on in addition to 12v trigger, bridgeable, officially stable down to 2ohms, 20lb+ lighter, better paper specs (slew rate, damping factor)

Dual Outlaw 2220s are a good option at lower price than either of the two.

Can't really go wrong with any of them if the features are suitable for the use case.

 

[preload]

Monolith vs Parasound relative advantages

Monolith: Made by ATI, cheaper, plenty power, better paper specs (power, distortion, FR)
Parasound: Made by Parasound, long-time support before EoL, smaller form factor, variable gain control for matching to pre-amp, auto-sensing power on in addition to 12v trigger, bridgeable, officially stable down to 2ohms, 20lb+ lighter, better paper specs (slew rate, damping factor)

Dual Outlaw 2220s are a good option at lower price than either of the two.

Can't really go wrong with any of them if the features are suitable for the use case.

Parasound looks better

 

[MusicNBeer]

Parasound looks better

You mean visually? Yea I'd have to agree. Halo gear is pretty.

 

[Fastfwd]

Do you know what JFETs Parasound uses? JFETs apparently vary a lot. If they somehow still have the old Toshiba low noise ones, the above may overstate the case.

As for as actual difference with non JFET amps. A23+ THD < 0.06% at full power, Monolith < 0.03% the latter being typical. Would it make a difference?

@pma , @restorer-john any thoughts on the use of JFETs from your experience?

I'm not sure this answers any questions, but Zero Fidelity did a review on the JC5 (2018) and cracked it open to discuss the internals and at 9:40 he notes the 'vintage' Toshiba JFETS:

Obviously, not the A23+ in 2021. So, idk if that is relevant to this discussion.

I'm really enjoying my A23+. I've been contemplating if a class D amp with higher signal to noise would have been a better choice for SACD playback, but other than that it nailed what I was looking to improve in my system.

It has even improved it in ways that I wasn't really expecting. For example Miles Davis Bitches Brew was a bit of a struggle for my Denon to playback well imo. The A23+ made me put in an order for the MoFi remaster of it in SACD. I'm not dissapointed.

 

[tyreman]

I have the Parasound A23+ seems to work fine
running DM2000 speakers on it

 

[Digi]

First of all, the best way to buy Parasound equipment is via the B-stock (Factory refurb with full warranty, they do a very good job of making sure that it looks brand new and their customer service is excellent if you should have problems) or open-box (customer returns re-boxed but full warranty) at Safe and Sound. A 23+ can be as low as $1250 free shipping if you wait for it to come into stock.

https://www.safeandsoundhq.com/collections/parasound-b-stock
https://www.safeandsoundhq.com/pages/search-results-page?q=parasound+open+box

A23+ is a cut-down version of the original John Curl A21 design but it does not include all the circuit wizardry of the expensive amps and so that should be taken with a grain of salt. However, the build, reliability and customer service for it is excellent. They seem to build in a lot of protection into their amps. They are very good for driving difficult speaker loads and stable. The earlier A23 made some component choices that weren't great and it had some issues. The A23+ appears to have fixed it. These will be better than any AVR's internal amps for most speakers but like most amps, it is not something that you are likely to say wow necessarily when you hear it. Difficult content into difficult speakers is where they are likely to make the most difference. But if you want an amp you can keep for decades this would be it like most Parasound equipment.

If you just want an external amp to escape out of limited AVR amp capabilities, I am not sure dual Outlaw monoblocks wouldn't do the same job either for several hundred dollars cheaper.

The non Halo series of Parasound are in a lower tier (in design, component choice and build quality) and would be similar to the above Outlaws in that aspect. They have it to occupy the lower price brackets but they do recommend the Halos if you can afford it.

Hello & How? How can I identify if my Parasound A21+ amplifier and P6 pre-amplifier are B-stock or open box items? Can I send the serial numbers to Parasound who would be able to identify what they are? Thanks.

 

[David9323]

I'm on my third A23+ in two years. I love the sound, but the first two failed for reasons unknown and now the third one takes about 10 minutes to activate after the switch is turned on. I leave it on 24/7 to prevent the hassle, but I really wish I knew why these are so fragile. The sound is fantastic, don't get me wrong. My experience with Parasound has been ... irritatingly love/hate.

 

[bigguyca]

I'm on my third A23+ in two years. I love the sound, but the first two failed for reasons unknown and now the third one takes about 10 minutes to activate after the switch is turned on. I leave it on 24/7 to prevent the hassle, but I really wish I knew why these are so fragile. The sound is fantastic, don't get me wrong. My experience with Parasound has been ... irritatingly love/hate.

Get the thing fixed and then sell it.

Electronics aren't a marriage. There is little paperwork involved to eliminate the problem and a short waiting period until the unit is history. You can even keep your dog, no negotiating required.

 

[Pdxwayne]

I'm on my third A23+ in two years. I love the sound, but the first two failed for reasons unknown and now the third one takes about 10 minutes to activate after the switch is turned on. I leave it on 24/7 to prevent the hassle, but I really wish I knew why these are so fragile. The sound is fantastic, don't get me wrong. My experience with Parasound has been ... irritatingly love/hate.

Parasound didn't explain to you why?

I have 3 original a23 for years and none fails so far.

 

[Rip City Dave]

OP, all the amps on your list will sound indistinguishable from each other in a proper blind test. If you have a speaker with a low impedance, then the A23+ should be your choice.

 

[Gary_G]

I'm new to all this, but after a year and a half of COVID induced research, reading, studying and dreaming I have decided on the A23+ P6 combo as the basis for my new 2 channel system. I upgraded to Focal Aria 926 speakers and just the amp recently and am in awe of what I'm experiencing. The preamp is not in stock so I'm using my old Sony receiver as a preamp. I keep reading that the A23+ is A/AB but I cannot find at what wattage the amp goes to AB.

I have to say this is the most informative venue I have found for not only data driven reviews but opinions and experiences. Thanks @amirm .

I look forward to continuing my learning here and I will post my setup when complete. Oh, and the wife's on board. LOL.

Gary

 

[warnerwh]

@Gary_G An email I received from Parasound claims the A23+ bias is 2-3 watts. The A21+ is 5-6 watts.

 

[Gary_G]

Thanks @warnerwh appreciate the info.

 

[MetalDaze]

Do you know what JFETs Parasound uses? JFETs apparently vary a lot. If they somehow still have the old Toshiba low noise ones, the above may overstate the case.

As for as actual difference with non JFET amps. A23+ THD < 0.06% at full power, Monolith < 0.03% the latter being typical. Would it make a difference?

@pma , @restorer-john any thoughts on the use of JFETs from your experience?

According to the marketing material the Halo line uses Toshiba 2SJ74 J-FETs, on the input stage.

Jumping in with my own experience, coming from an Emotiva XPA amplified L&R, to a Parasound A21+. The results were a bit startling.
The Parasound really gave my system the sound signature I was seeking. Not colored in any way. Just honest, clean, authoritative and low bass like I hadn't heard before. From any of my speakers (sans subwoofers).

The Halo line uses JFets on the input stage, Mosfets on the driver stage (JFets for the "voicing", Mosfets to drive the outputs, since the JFets can distort and don't like being driven hard as another member mentioned), and finally Sanken BJTs as the output stage. It is this combination that provides low distortion, a slightly warm, yet largely transparent sound and coupled with 16 - 24 or more bipolar transistors for the big power numbers. I have not heard audible distortion of any kind from the amp, at any level I push. It sounds great.

I have called Parasound directly a couple different occasions after I bought my A21+, just to pick their brains and ask some questions that had come into my mind during the first week of ownership. Each time the phone was answered in the first few rings, and I spoke with a gentleman whom was part of the engineering/design team actually in the shop where they test the outgoing products. I think his name was Phil? He was more than happy to talk shop, & answer any and all of my questions regardless of time constraints. Truly great customer service.

I asked him about the bias point on my A21+, and he agreed it was around 6 watts. But that is PER CHANNEL! I thought It was total. So that was a nice surprise. He went on to state that on the (+) line they really beefed things up, so even with that 6 watts class A per channel, the magic is minimizing the crossover point distortion. So once the bias point has been achieved, the transition begins. However the change from A - B is gradual such that, the class A power is more like 10 watts/channel. Taking into account the amp idles at 160watts when on with no signal input, I believe this wasn't an exaggeration.

I've also watched several interviews with John Curl where he states in reference to the Halo line, they all use the same parts. Just the larger, more expensive amps make use of more parts. More output BJTs, more heatsink, more capacitance (the exception I believe is use of Nichicon Gold Tune in the JC1+) a larger power supply. Pretty cool.

After my positive experience with their Halo line (P5 preamp and A21+) my Dad was in search of an amp for his workshop and home gym area. Even though supply chain issues elevated the price, at my suggestion we tried a 2125 V2. For a 'lower' wattage amp, the thing is still pretty darn big. For a Class A/B design, to a point I guess it has to be. But the pictures can be deceiving. Some empty chassis space may be seen, but there are slots for cooling throughout and It runs warm, but not hot. Connected to a TA-100 preamp he's back blasting all his music the way he likes it.

What may be held back in 'premium parts' for the lower cost amps from Parasound, the design philosophy still trickles down.