ZPA amps

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stipud
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Post by stipud »

vin78 wrote:I have too many expenses and my job blows at the moment. Thats why adding on to the collection is on hold.
Hehe... blow job.
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Re: item

Post by fuzzysnuggleduck »

dBincognito wrote:
kg1961 wrote:so why the Ms over the Zpa
I really don't think you would hear much differnce in these 2 amp the MS and Zpa lines we all have to remeber the ms2250 was there flagship amp also???
anyone else?
I would not put a 2250 over a ZPA......I will be more precise
and the TA line would not count at all

MS-2125
ZPA 0.5
ZX500
M100

What PG considers their flagship.....and the amps that actually were their flagships are 2 totally different things.....the ZPA was more of a concept amp....IMO....the design was never perfected, and the run didn't go long enough to work out all the kinks...but they still sound great. The ZPA's also have a higher faliure rate(b/c people try to run them to death)

I think YOU may not hear that much difference....but I can hear everything, at this point....there are only certain PG amps that I would buy....I think the difference between a original MS-2125 and a ZPA 0.5 is night and day......people are always trying to say that all these amps sound the same....that is so far from the truth.....I can instantly hear the difference between any PG amp....even different board revisions are producing different responses.....so I know I'm not crazy....I just spend 2 much time with this stuff......without a number of modifications I can't be happy with the sound anyway...IMO...the stock sound is " alright " on any PG amp....there is serious room for improvement...IMO

I buy these amps to use them as a " base " or starting point for what I really want to do to them.....
I'm with Eric on this. If you can't measure a difference, you can't hear a difference. That said, I absolutely am not stating you can't measure a difference between amps. I simply don't know as I don't have the test equipment of the knowledge required to measure, let alone fully understand the results.
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stipud
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Re: item

Post by stipud »

fuzzysnuggleduck wrote:I'm with Eric on this. If you can't measure a difference, you can't hear a difference. That said, I absolutely am not stating you can't measure a difference between amps. I simply don't know as I don't have the test equipment of the knowledge required to measure, let alone fully understand the results.
It's not hard...

The ideal amplifier means output signal = input signal. So you measure what goes in, and what comes out... scale them to the same voltage and see where the differences are. An artificially bassy amp would show greater amplitude on bass notes, for example.

In fact my RTA even has a function for this... it graphs the input signal beside your measured reproduction. This way you account for the speaker's distortion as well.

Now while the measurement of a theoretical "perfect" setup, would be as close as possible to the input signal, I don't think that it necessarily sounds "good" either. Sound quality is very subjective, and most people do not like a flat recording. Let's also not forget that the people recording and mixing the music also rarely have an ideal setup, so they impart coloration on the sound already depending on what they think it should sound like on their speakers. So is the true goal replicating what the artist put down? In that case you would need to replicate their recording setup... not create a setup that minimizes distortion. Because then you only replicate the sound that was recorded, but not the sound they intended you to hear.

Because of all these caveats, I think the quest for perfect measured sound is also somewhat futile. Instead, I think people should focus on making their setup sound good, regardless of what good sounds like on paper. That's not to say that the two factions can't go hand in hand. Certainly measurable improvements will also sound better, like time alignment for example. I do not think they should be mutually exclusive.
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Re: item

Post by Eric D »

dBincognito wrote:I would not put a 2250 over a ZPA......I will be more precise
and the TA line would not count at all
What do you mean about the TA line? The TA amps are actually superior to the original MS amps, even though no one ever wants to admit that.

Yes the 2250TA is less voltage than the original 2250, but it can do 2 ohm mono which the original cannot, so it is built for a different purpose. As far as quality and performance, the TA line overall is superior.
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Post by Eric D »

Tom, I agree with you completely, but as you probably know there is more to the story. The simplest test of an amp is its frequency response, which you could get an idea of with and RTA. But, two amps with the same response may not sound the same. You need to look at distortion (assuming it is actually high enough to make a difference), and phase response. Way back when I did my first A/B between a PG and RF amp, they had nearly the same frequency response. Yet I and others could tell them apart 100% of the time in blind tests. This was likely due to harder to measure reasons, but I am completely certain these reasons are measurable once you find them, and would fully justify the difference in sound.
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Re: item

Post by Eric D »

dBincognito wrote:I think YOU may not hear that much difference....but I can hear everything, at this point....there are only certain PG amps that I would buy....I think the difference between a original MS-2125 and a ZPA 0.5 is night and day......people are always trying to say that all these amps sound the same....that is so far from the truth.....I can instantly hear the difference between any PG amp....even different board revisions are producing different responses.....so I know I'm not crazy....I just spend 2 much time with this stuff......without a number of modifications I can't be happy with the sound anyway...IMO...the stock sound is " alright " on any PG amp....there is serious room for improvement...IMO
Ok, I really don’t want to sound like a dick here, but I think your statement is crazy. There is no way you can hear the difference between different revisions of a PG amp. The reason I know this is because the changes in the revisions of these amps which I am familiar with do not involve changes in the signal path or the circuit itself. They are changes in the board. Say from point "A" to point "B" on a board exists a resistor. PG realizes they made a mistake and a cap is supposed to be in series there as well, so they disconnect one side of the resistor and put a cap in series with it. This could be REVC of the board. Well when they get to making the next REV of the board they add the holes on the board for the cap and run the trace to it. Now it is REVD. It is 100% impossible for you to hear the difference between a 5mm long part of copper trace compared to a 5mm long piece of tinned steel lead wire from a device.

These revisions are not changes in the design, they are improvements in the board for manufacturing purposes, not sound quality.

Now to further mix it up, nearly every PG amp uses the same circuit. A M50 and a MS275 have the same fundamental design. They are different power levels and different physical layouts. I am confident anyone can hear differences in the power level, but I doubt anyone can hear the difference between say a M50 and a MS275 if they are level matched.
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Post by ttocs »

I think most of us would hate to think that we could not tell the difference in a M25 and a 0.5 but in a true A-B amp comparison it is almost impossible to tell the difference in two quality amps.
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Post by freshkryp69 »

how many on this thread have actually had a zpa installed in their car? and if so what did you run it with,mid's and hi's or sub...? did you use the balanced inputs? and have you ever noticed a sq difference when you installed another amp in place of the zpa?

to me my orion nt200's and zpa's and ms's sound so alike that I wouldnt beable to do a blind a-b test...I dont think anyone would beable to tell which is which..?
maybey super(audio)man.... :lol:
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Post by nutxo »

freshkryp69 wrote:how many on this thread have actually had a zpa installed in their car? and if so what did you run it with,mid's and hi's or sub...? did you use the balanced inputs? and have you ever noticed a sq difference when you installed another amp in place of the zpa?

to me my orion nt200's and zpa's and ms's sound so alike that I wouldnt beable to do a blind a-b test...I dont think anyone would beable to tell which is which..?
maybey super(audio)man.... :lol:
This is kinda what Im saying. I do believe if you know an amp really well you could tell the difference by one amp maybe seeming like its more bassy or something. If you eq 2 quality amps I doubt any human ear could tell a difference. ( Especially people who have been bumpin for 15 or 20 years )
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Post by smgreen20 »

I had a 0.3 running my Elites passively and my 0.5 on sub duty. When I went from the 0.3 to ZX450v2 actively, the only difference I could tell was the output. Where the 450 would stress the 0.3 wouldn't.

It did make a difference sonically as the passages were clearer, at high volumes mind you. Now if I would've bridged the 450 to the Elites passively I'm sure I would hear a night and day difference.

I did not use the balanced input, but I am, well... did use an Audio Control DQS for EQing and for the line driver. Voltage was measured at 10.5 volts going into the amp.

HU is an Eclipse CD8455 w/8v outputs.
"ZPA's will have the same sound essentially as you get from the MS, they just feature a bigger shinier set of balls."

Install:
http://phoenixphorum.com/viewtopic.php?f=10&t=16998
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dBincognito
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Post by dBincognito »

Eric D
I'm not trying to argue with anyone.....but I can hear a difference, and how is a TA superior to a MS in any way ?

As far as I'm concerned the TA line was a " watered down " version of the MS line.....done on purpose to kill the demand for the amps.....I never run anything below 4 ohms so the load level would not be a benefit for me in any way....I feel that the TA versions were built with higher tolerance (cheaper) parts.....I also do not feel in any way that the revisions done to the boards EVER favored the consumer( hence the removal of the master/slave )....I come to this conclusion by examining the amps that come through my hands....there are sight differences in the tolerance of parts that were used between a M50 and a M50 series 2....the M50 series 1 having the better or " lower tolerance " parts inside.....every board revision that I have examined in the MS line shows the same exact thing.....every board revision to me is "cutting corners" and "how can we make a little more money off this".....this is just my personal view, and listening on my ears...which apparently are super human :lol: :lol: :lol:

Please feel free to share any information or shed any light on this subject.

I am looking to place all +/- 1% components on my boards.

Thank You, Randy
Last edited by dBincognito on Wed May 20, 2009 8:17 pm, edited 1 time in total.
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Post by ttocs »

dBincognito wrote:Eric D
I'm not trying to argue with anyone.....but I can hear a difference

Thank You, Randy
and I got shit for saying I can hear speakers out of phase?
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Post by stipud »

ttocs wrote:
dBincognito wrote:Eric D
I'm not trying to argue with anyone.....but I can hear a difference

Thank You, Randy
and I got shit for saying I can hear speakers out of phase?
We gave him just as much shit, if not more...

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Post by dBincognito »

and I don't mind taking it....I'm a good sport :wink: :lol:

I just want to have a open discussion 8)
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Post by Jacampb2 »

Out of curiosity, Randy, what parts are you talking about? 5% resistors replacing 1% ones in earlier revisions? Tighter tolerance electrolytics (and if so, how did you find the tolerance on the original part)? The fact of the matter is that not all resistors, for example, need to be 1% parts. A 5% part for a current limiting resistor is not unusual, and is likely not going to affect the signal in the places they were used. If you found boards with different tolerance parts, there is a better than even chance that PG was just using back stock-- Some of my amps have pre-driver BJTs that were obsoleted by the manufacturer before the amps were even built.

As for caps, it is entirely possible that PG matched cap pairs for both ESR and Capacitance for the boards. I know a lot of techs that do this, whether or not PG did. The point being, even if it is a +/- 20% electrolytic, it could be a much better choice if its a "pair" in the circuit than a much more expensive +/- 10% pair that were not matched.

As for output BJT pairs, and pre-driver BJT's, I have seen several different parts used, but all were very similar electrically.

I agree with Eric on the board revisions. I have not yet seen a different revision with significant schematic changes. I have some early revision TI amps, with no test points on the board, and later revisions which do. There were also screen changes to the boards during revisions. I have three very early, perhaps prototype, 800.1 boards that have stacked SMD parts, as well as cut and jumpered traces on the back of the board. My latter 800's have been fixed.

I believe the MS TA amps were optimized for lower loads, because that was the trend at the time. It still is for the most part. As a manufacturer, PG realized that regardless of whatever they specified as a minimum impedance, a lot of people were going to drive the amps into a lower load. In that case, it simply makes good business sense to build the amp to handle the lower loads. I am sure they would rather have had a rock solid product, then have a rash of destroyed MS amps out there because owners could/would not follow instructions.

Later,
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Post by dBincognito »

Jacampb2
what parts are you talking about?
Nothing worth writing home about.....a few resistors here and there...a few small caps....other than that, all of the PG amps are very similar. I just want to say I have all 1% parts on the board :roll: :lol:
how did you find the tolerance on the original part
by looking up the parts, they still have datasheets even if they are not making them any longer.

I also believe the TA line was aimed more for the lower impedences and was not aimed towards SQ, and in that sense I feel the original MS line to be superior.

I am curious as to just what the differences are in all of the parts that were used between the original MS and the TA versions...down to every little difference.
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Post by Jacampb2 »

dBincognito wrote:
how did you find the tolerance on the original part
by looking up the parts, they still have datasheets even if they are not making them any longer.
I know that, I was specifically asking about looking up caps-- It is rare, especially on small electrolytics, to find any more markings then WV, temp and value. Larger electrolytics sometimes have series or part numbers on them, but it seems to depend somewhat on the whim of the manufacturer.

Later,
Jason
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Post by neverman »

freshkryp69 wrote:how many on this thread have actually had a zpa installed in their car? and if so what did you run it with,mid's and hi's or sub...? did you use the balanced inputs? and have you ever noticed a sq difference when you installed another amp in place of the zpa?

to me my orion nt200's and zpa's and ms's sound so alike that I wouldnt beable to do a blind a-b test...I dont think anyone would beable to tell which is which..?
maybey super(audio)man.... :lol:
I've got half the equation down... I'm running what's in my sig. One .5 running passives components and one running subs in bridged mono. I'm using a line driver, and an active EQ. Not a single rca cable past the 1ft pair running from the HU to the TBAT. I have not installed any other amps in the car. I suppose I could I have an M25 lieing around somewhere and an old Alpine 4 channel. The problem would be level matching them as I'd have to use the rca's out of my ZPX2.

The ZPA's I have leave me desiring very little regarding power. I sometimes wish I had better speaker enclosures, the ability to further EQ the setup and the ability to remove my legs from my body while listening to music in a parked car. When I'm driving, I lose alot of audiophile crap to road/car noise.

People like to say all amps sound the same, or that they should. But every amp has some flavor of color to it. Even Nelson Pass can't reach his desired goal of a "wire with gain". I've listened to several thousand dollar amps trying to decide what I want to hook up my Aerial LR5's and 7B's to. Bryston doesn't sound like Classe' which doesn't sound like Parasound which doesn't sound like Mark Levingston/Marantz/Krell/etc...

I'm thinking I'll end up with SimAudio Amps at home. I think I'm pretty content with my car amps. I'm still shopping drivers for the car or considering going active. All of those things will make a far greater impact than which PG amp you run (insert any quality amp manufacturer).

Regarding tolerances... it's far more important that 2 components match one another than the spec being a certain value. I could install 2 crap components and as long as they were identical crap they in theory are far better than your 1% parts for one another. Specs are more for replacement purposes where it'd be far more impractical to match components that are in working circuits. When in the repair business you typically repair the broken channel and leave the good one alone. It's nice to assume the 1k resistor you put in is 1k and the .05 farad cap is such. You don't measure them for tolerance you do a quick spot check to make sure you're not wasting your time installing a bad part is all.
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Post by Eric D »

The original MS amps were built back in the early 90's, right? The TA amps came around the change of the millennium?

Since they are the same exact amp other than the years between construction, and the newer MS2250 runs at a lower voltage (only a change of part values, not part tolerances to get lower voltage), the only difference is the time when the parts themselves were created. Well, I would think it is pretty obvious to most people semiconductor production gets better with time, not worse. There is a reason why we as humans can now build Core 2 Duo processors instead of 486DX processors.

When I fix an amp I want new parts. I don't dig around the web looking for old less mature parts with less reliability, I want the newer more mature and "better" parts.

I have not seen a MS2250TA with a newer than REV E board, and I have a very old MS2125 and MPS2500 both with REV E boards. So, if the board used is the exact same and the parts chosen are the exact same, but the TA has newer parts in it, there is no way it is "watered down" as far as SQ is concerned. This just does not make sense. Stating that a TA is not as good as an older one is like stating that no amp better than an original MS will ever be constructed again in the history of man, since we will no longer ever make those older and inferior parts again.

Now, if you are going to make the claim you can hear the differences in revisions of PG amps, you have to back that up with something. You must have some evidence. That is such a bold claim you cannot expect anyone to just accept it and move on. I mean if you are right, that makes you the best listener I have ever heard of in my life. Better than anyone I have ever read about or met, and better than the limits of humans ears I was taught in biology. It could quite possibly make your ears the very best on the face of the Earth, and if true, you need to market that ability, as you will be very wealthy in little time.
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Post by waynehead »

and I got shit for saying I can hear speakers out of phase?
What a sad day that was. I remember making myself look like an ass. :oops: I no longer get into these discussions because I am a wanna be audiophile with now money and I cant put a zpa against a m series and "hear the difference" for myself.
We don't need no stinkin' bass boost!
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ZPA amps

Post by Littlejln213 »

I am getting ready to do an all zpa build. I have 5 of them now. 2 0.5s and 3 0.3s. I also have doubles of all the zx series including nib recapped of each one. A fully custom dual mps2500s, nib recapped m25, m50 and 2 m100s. One fully rebuilt my Steve mantz. I also have all the fun smd toys so I can set them up and test them for what they actually put out in real world conditions. The amm1, dd1+ and cc1. And I have a spl lab spl meter to take measurements that way. As well as a umik 1 with rew on a laptop. Pg has always been my favorite. But I like a lot of different 90s era gear.
Let me know of there are any specific tests you would like to see done. I only have one tbat, but I have an eq 232, bass cube, multiple 2xs, 4xs, etc. So I will be able to test feeding it the juice with hopped up rcas vs tbat. One of my 0.5s is a fully customized one by Jason Campbell and the other is rebuilt by David Werner. So the one might be a bit of a ringer. But the other should be a good representation of what they can really do. I will probably have them hooked up to a pair of freshly rebuilt with new old stock cv stroker 18ds. So I will have that bummer 2 ohm issue. But I can also try them with other sub setups to really test them. I think I have around 90 different subs.
I probably should have joined this a long time ago. I may have. I toured the factory in 2000 with my friend Brian of exile audio now days.
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Re: ZPA amps

Post by ttocs »

one of the shops I use to work at had done a large zero point install in a 300zx that was pretty sweet. They had come/gone before I got to PG at that shop but they always looked like a good time.
what else can I say I am a grumpy asshole most of the time.
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