Topping PA7 Plus Amplifier Review

[Blink Too Fast]

I’ve just hooked up a second PA-7 Plus, 1st in a horizontal biamp config, then today in a vertical config, to a pr. of Musician Knight 1’s. I purchased a second amp after remembering how a fella with Falcon Acoustics, who was previously w/ProAc, had highly recommended biamping the 1SC, of which I own. The single PA-7 was put to use with the Knight 1’s, a really well built 2way, cause that’s what’s in rotation. Very nice on its own, I was a bit startled by the improvement in the horizontal config. Damn, quite a bit more, there there. Increased vocal clarity, density and ummmppphhh as I listened to Dope Lemons newly released Miami all the way thru. I certainly wasn’t missing those little gold bar jumpers between the binding post. Stacked PA-7s seem just fine. Tiny stack that is. One silver, one black, cause that’s what they had and I got each for about $460. Today after knuckle heading around ‘cause I’m using two different speaker wires, I went ahead with a vertical e config. Amos Lee’s Chet Baker songbook is sounding dead quiet, focused and sublime. Very nice ease and flow, effortless. The Musician speakers are just eating up the additional pow. Not a 5-10% improvement, more like 20-25%. The Knight 1s are a beautifully voiced pair of speakers, tonally dense but airy beasties. Feed em well. The little ProAcs are sitting aside for now, waiting for me to remove their silver jumper wires, but that’ll wait. I was a bit hesitant purchasing a second PA-7 Plus almost on a lark, but it really is the way to go if your speakers are designed for such. Oh, both are being fed by the new SMSL PL-200 cd players outputs. Between the PA-7 dip switches and the SMSL menus I’m still sorting things thru, but this config is making a major case for biamping as the way to go. Highly recommended…

Biamping with the crossovers after the power amps (they are still present inside the speakers) does little.
With the gold bars present and a single PA7, the tweeters see half of one channel of the PA7, and the woofers see the other half.
With the gold bars removed and two PA7s, the tweeters see half of one channel a PA7 and the bass frequencies are turned to heat, and the woofers see half of one channel of the other PA7, and the treble frequencies are turned to heat.
Both amps are still producing the entire tonal range, including cross talk, and half of it is being turned to heat inside the speakers.
Horizontal or vertical makes no difference.

It would be more useful to leave the gold bars in place and use more powerful amps, for example by using the PA7s in bridged mode, and use one for the left and one for the right. Before rushing to do that, I have not seen that the PA7s are bridgeable.

Where bi-amping becomes truly useful is to remove the gold bars and to put crossovers before the amps. Crossovers before the power amps can be as simple as passive capacitor/inductor/resistor circuits; can be an active circuit; or can be a DSP such as a miniDSP.
By doing this, you can avoid the bass amp wasting effort on the treble frequencies, and can avoid the treble amp wasting effort on the bass frequencies.

The purist would also insist on disconnecting the crossovers inside the speakers. You may wish to leave a capacitor in series with the tweeter for protection.
Using e.g. a miniDSP, you can then connect the speaker drivers directly to the power amp, and use e.g. REW software to dial in a perfectly flat (or any other shape) speaker response to eliminate room modes or resonances. This would also eliminate any wasted power in the crossovers after the power amp.

The cheapest route for this might be a miniDSP 2x4 HD, a UMIK-1 mic, and the free REW software.
A more automated solution is the miniDSP DDRC-24, which is the 2x4 HD upgraded with internal Dirac software, plus an included UMIK-1.

A "nicer" route might be the miniDSP Flex, UMIK-1, and REW
The miniDSP Flex can also be upgraded with Dirac software.

 

[Blink Too Fast]

excuse me if someone gets upset ... but, after PA5 1 fiasco and that ocassional "glitches" in new PA5 / PA7 ... people continue buying these amplifiers?
hypex solutions with really higher reliability are a few dollars more, i can't understand it

I cannot find a Hypex solution delivered to US for only "a few dollars more" than a Topping solution delivered to US.

Topping US distributor APOS Audio has the PA7 at $449, already in US, with 2 year warranty.

Cheapest Hypex NC502MP I can see is the Buckeye at $695 with 1 year warranty. Much larger, too.

A different question is why do people buy either the Topping or the Hypex when the Fosi V3 exists? It was $87 with 48v PSU in December.

 

[mike70]

I cannot find a Hypex solution delivered to US for only "a few dollars more" than a Topping solution delivered to US.

Topping US distributor APOS Audio has the PA7 at $449, already in US, with 2 year warranty.

Cheapest Hypex NC502MP I can see is the Buckeye at $695 with 1 year warranty. Much larger, too.

A different question is why do people buy either the Topping or the Hypex when the Fosi V3 exists? It was $87 with 48v PSU in December.

150 usd buys peace of mind for me, totally.
Fosi V3 doesn't have PFFB, one of the reasons in their lower price tag

 

[Repdetect]

150 usd buys peace of mind for me, totally.
Fosi V3 doesn't have PFFB, one of the reasons in their lower price tag

Just to clarify- Isn't PFFB really only of benefit with 8 ohm speakers?

 

[staticV3]

Just to clarify- Isn't PFFB really only of benefit with 8 ohm speakers?

PFFB prevents frequency response changes due to inadequate damping factor. It is most effective with low impedance speakers.

 

[Guddu]

150 usd buys peace of mind for me, totally.
Fosi V3 doesn't have PFFB, one of the reasons in their lower price tag

Does PA7/PA&+ use PFFB?

 

[mike70]

Does PA7/PA&+ use PFFB?

pa7 / pa7+ doesn't show load dependency ... it isn't clear to me if they do it with a PFFB circuit or with a propietary solution (potted circuits)
the question is that load independency have a cost, and Fosi (at this moment) decided for a cheaper product ... that's why i don't add the V3 in the same league as topping / hypex.
Is like claiming why an off-road vehicle is more expensive ... we can't compare bananas and potatoes.

 

[NTK]

Does PA7/PA&+ use PFFB?

Most likely it does. Here is the PA7's FR plots into 4 and 8 ohm loads.

Here is the plot for the 3e Audio with PFFB.

And here is the plot for the Fosi V3, which does not have PFFB and showed load dependence within the audible band.

 

[Guddu]

pa7 / pa7+ doesn't show load dependency ... it isn't clear to me if they do it with a PFFB circuit or with a propietary solution (potted circuits)
the question is that load independency have a cost, and Fosi (at this moment) decided for a cheaper product ... that's why i don't add the V3 in the same league as topping / hypex.
Is like claiming why an off-road vehicle is more expensive ... we can't compare bananas and potatoes.

I was genuinely asking as I didn’t find the info about PA7 PFFB.
Not keeping other TPA3255 in same league as PA7, I know it’s not because I own A07, A07 Pro, A07 Max, ZA3 along with PA7..

 

[Guddu]

Most likely it does. Here is the PA7's FR plots into 4 and 8 ohm loads.

Here is the plot for the 3e Audio with PFFB.

And here is the plot for the Fosi V3, which does not have PFFB and showed load dependence within the audible band.

Thanks, but if it does then why would Topping not advertise it, it’s only add up to a selling point for them.

 

[mike70]

I was genuinely asking as I didn’t find the info about PA7 PFFB.
Not keeping other TPA3255 in same league as PA7, I know it’s not because I own A07, A07 Pro, A07 Max, ZA3 along with PA7..

it's ok, that part wasn't a direct answer to you ... is relative to price tag / features in general that other users mentioned. PFFB IS more expensive.

 

[Vladetz]

excuse me if someone gets upset ... but, after PA5 1 fiasco and that ocassional "glitches" in new PA5 / PA7 ... people continue buying these amplifiers?
hypex solutions with really higher reliability are a few dollars more, i can't understand it

Some reasons for me personally:
- Hypex is not available in my location
- Shenzhenaudio returned me full cost of defective pa5 and shipping
- all my other topping products were flawless, including pa7
- on sales you can get it much cheaper - about 350$

 

[Guddu]

it's ok, that part wasn't a direct answer to you ... is relative to price tag / features in general that other users mentioned. PFFB IS more expensive.

What makes PFFB implementation expensive, from PCB/components prospective?
Anyone who could tell.
@daniboun
@Toku

 

[MAB]

I’ve just hooked up a second PA-7 Plus, 1st in a horizontal biamp config, then today in a vertical config, to a pr. of Musician Knight 1’s. I purchased a second amp after remembering how a fella with Falcon Acoustics, who was previously w/ProAc, had highly recommended biamping the 1SC, of which I own. The single PA-7 was put to use with the Knight 1’s, a really well built 2way, cause that’s what’s in rotation. Very nice on its own, I was a bit startled by the improvement in the horizontal config. Damn, quite a bit more, there there. Increased vocal clarity, density and ummmppphhh as I listened to Dope Lemons newly released Miami all the way thru. I certainly wasn’t missing those little gold bar jumpers between the binding post. Stacked PA-7s seem just fine. Tiny stack that is. One silver, one black, cause that’s what they had and I got each for about $460. Today after knuckle heading around ‘cause I’m using two different speaker wires, I went ahead with a vertical e config. Amos Lee’s Chet Baker songbook is sounding dead quiet, focused and sublime. Very nice ease and flow, effortless. The Musician speakers are just eating up the additional pow. Not a 5-10% improvement, more like 20-25%. The Knight 1s are a beautifully voiced pair of speakers, tonally dense but airy beasties. Feed em well. The little ProAcs are sitting aside for now, waiting for me to remove their silver jumper wires, but that’ll wait. I was a bit hesitant purchasing a second PA-7 Plus almost on a lark, but it really is the way to go if your speakers are designed for such. Oh, both are being fed by the new SMSL PL-200 cd players outputs. Between the PA-7 dip switches and the SMSL menus I’m still sorting things thru, but this config is making a major case for biamping as the way to go. Highly recommended…

You should read up on bi-amping.

Bi-amping 101

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

www.audiosciencereview.com

Specifically passive bi-amping. It has no effect on the sound.

Bi-amping 101

Thank you Don, Is DENON addressing your point (#6) in their user manual? Yes. Whether or not bi-amping helps, or to what degree, depends greatly upon the output impedance of the amplifier, cable resistance (impedance), and speaker load (impedance). If the amplifier has low enough output...

www.audiosciencereview.com

It does not reduce IMD in a measurable way as some have proposed.

If you have listened to the two configurations level-matched and blind, you would not be able to tell the difference. Unless an amp was malfunctioning. And passive bi-amping doesn't even give more headroom. If you need more power or SPL, get a bigger amp. Or more efficient / better speakers.

Those bi-wire terminals on speakers are there to sell you things you don't need, like extra wires, or in your case a redundant second amp.

 

[mike70]

Some reasons for me personally:
- Hypex is not available in my location
- Shenzhenaudio returned me full cost of defective pa5 and shipping
- all my other topping products were flawless, including pa7
- on sales you can get it much cheaper - about 350$

If a defective amp burn your tweeters / crossovers ... that have not refund. And depending on your speakers price tag, the fix will cost many pa5s

 

[daniboun]

Just in case anyone was interested, I asked Topping customer support about this, and the answer is: yes.

This is native for all TPA325X chips )

 

[Iluzun]

You should read up on bi-amping.

Bi-amping 101

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

www.audiosciencereview.com

Specifically passive bi-amping. It has no effect on the sound.

Bi-amping 101

Thank you Don, Is DENON addressing your point (#6) in their user manual? Yes. Whether or not bi-amping helps, or to what degree, depends greatly upon the output impedance of the amplifier, cable resistance (impedance), and speaker load (impedance). If the amplifier has low enough output...

www.audiosciencereview.com

It does not reduce IMD in a measurable way as some have proposed.

If you have listened to the two configurations level-matched and blind, you would not be able to tell the difference. Unless an amp was malfunctioning. And passive bi-amping doesn't even give more headroom. If you need more power or SPL, get a bigger amp. Or more efficient / better speakers.

Those bi-wire terminals on speakers are there to sell you things you don't need, like extra wires, or in your case a redundant second amp.

Bullshit, u know not of what u speak…. If the internal crossovers are designed properly, inductors and drivers designed to deliver, you r dead wrong and parroting what is a common misnomer, a fallacy. I’ve spent 3 days sorting, ordering, and rearranging a well sorted setup. Even a horizontal config is readily noticeable. The verticle simply stomps! I’ve rotated thru 2 pre configs, a Denafrips Athena w/dual balanced and single rca output and Benchmark 3 Dac preamp w/dual rca output & single balanced output. Done properly, if you can’t easily differentiate, get another hobby, you r deaf. The spatial legibility, separation, clarity and drive are unmistakable. It’s simply far superior.

 

[Toku]

What makes PFFB implementation expensive, from PCB/components prospective?
Anyone who could tell.
@daniboun
@Toku

For a long time, many companies could not adopt PFFB due to patent barriers. The patent has now expired and anyone can use it.
PFFB itself is not technically difficult and can be realized at low cost by adding a few parts.
However, along with the adoption of PFFB, manufacturers are upgrading their products to even better products by adopting high-quality inductors in the output filters in order to make products with better characteristics and more attractive features. That's why the price is a little high.
PFFB amplifiers such as Topping, 3e audio, and JLE are such products. I'm all for using quality parts, even if they are a little more expensive.

 

[Iluzun]

Just to kick a hornets nest. If I had to live with the horizontal config, I still prefer the tweets run w/a quality tube amp vs the second PA-7. There’s a liquid dimensional depth & sweetness you don’t get horizontally w/a 2nd PA-7. It’s flatter and not as emotionally involving, drier. Vertically the 2 PA-7s come out superior, everything just comes together. The verbal content of lines become legible in a way a single amp can’t discern. Tones and textures have additional body becoming more palpable, impactful. These benefits are quite easily heard. Musician Knight 1’s weigh 34lbs each and substantially benefit from being run in a verticals biamp configuration. Oh, so do the ProAc 1sc, a legendary monitor, w/their rhodium speaker connects & copper phase plug. Both two-ways internal crossovers provide a substantial upgrade that can be explored with these new affordable amps. Blanket statements regarding active vs passive speakers are unfounded as absolutes like everything else in this hobby they require ‘qualifications’.

 

[daniboun]

Not keeping other TPA3255 in same league as PA7, I know it’s not because I own A07, A07 Pro, A07 Max, ZA3 along with PA7..

The last 3E audio modules play in the same league and for a modest budget you can do this :

"Bamboo Project" : Dual Mono 3E Audio 480-1-29A Amplifier

Hi amigos, Following the ASR review of the 3E Audio 480-1-29A Module, I decided to roll up my sleeves and show you that with a little elbow grease, you can create a very beautiful amplifier based on these nice 3E Audio modules. I called this project, "Bamboo"> the pictures will speak for...

audiosciencereview.com