Phoenix Gold Phorum

So I've had this recapped MS-2125 with factory silk-screened plexi for a couple of years and finally got around to putting it on the SMD/D'Amore Engineering Amp Dyno. This is my amp, so I decided to put it through multiple tests. Here are the ratings:

4 ohms stereo (12V) - 125W x 2
4 ohms stereo (13.8V) - 160W x 2
4 ohms mono (13.8V) - 510W
2 ohms mono "Dynamic Power" - 1100W or 1250W (depending on US or Dutch literature)

Here are a couple of the Phoenix Gold marketing materials (brochures/ads) from the early 90's:


Advertisement from Feb 1992 Car Audio & Electronics:



closer up view:



Brochure from Dutch PG Literature found on this Phorum:



close up view of the MS-2125 ratings:




Now, I've been questioned here before for posting this info saying these amps were only good for 700W or so. No need to shoot the messenger, I was just recalling the ads I had read way back in the past. So, was PG making up these 1100W and 1250W ratings (and why did the US ad state 150W more than the Dutch one?) I decided it was a great time to find out.

Those who know the AD-1 Amp Dyno know it has 3 modes used for testing amplifiers. See the explanation of the modes below.

The D'Amore Engineering AD-1 Amp Dyno gives us the ability to test 3 modes in several different ohm loads:

1) Certified - Tests amplifier RMS wattage up to 1% THD using either 40Hz or 1kHz tones
2) Uncertified - Tests amplifier RMS wattage up to clipping using either 40Hz or 1kHz tones
3) Dynamic Burst - Tests amplifier RMS wattage using burst tones. The 1kHz test at 14.4V adheres to the IHF-202 certification for Dynamic Power. D'Amore says this mode simulates music playback instead of continuous tones as the certified and uncertified modes use. If you listen to the 40Hz dynamic track, it sounds like a series of kick drum notes.

So, how did the MS-2125 do? See below!

Watch on YouTube in 1080P or embedded below:

I'm excited to see your results.

vwdude wrote:I'm excited to see your results.

X2

vwdude wrote:I'm excited to see your results.

Just updated in the original post...enjoy!

Thanks for this BigD. This is great, thanks for taking the time to make the vid and post here for us to all enjoy.
You Rock Sir


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my only complaint is the vid is way too long.

ttocs wrote:my only complaint is the vid is way too long.

What? The vids are well explained and talked through, you should see mine (main reason why I don't make them public, lol). I don't talk, no music, just meters and scope.....not even the results (you have to do the math with the numbers given) lol.

I have to say im surprised the numbers don't look all that good
Love the amp just i thought it would do much more

What?
First off BigD has more time of his own to make that video and then chose to post for us here. If you can't afford the time don't watch it.

Considering the amps rated power. I think it did very well.
And considering its 20 years old.
What do you expect it to do?


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Agree with drock....its just a 500watt amplifier that is BAD ASS. If you think about it that is 3db of headroom.

I was impressed as well. I knew that 1250W dynamic rating was BS, but the fact it did it's power plus more is more than a LOT of amps I've tested. Not to mention, most of the tests were done at 40Hz, not the ultra-forgiving 1kHz tone amp mfg's have used for many years. Many OS amps were rated across the entire range of 20Hz-20kHz with a minimum "continuous" RMS output.

I know some people want 3-4 minute videos with the tests only and I understand. It just takes too long to make 2 separate videos and I want to provide some information about the amp as well...as just showing the tests can get old (if you ask me). At least they are not 25-30 minutes long as they could be

Drock wrote:What?
First off BigD has more time of his own to make that video and then chose to post for us here. If you can't afford the time don't watch it.


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its a public forum I am free to post my opinion on if I want too, lick if up if you don't like it I don't care.

He can check out the youtube data next week and see how many people watch it in its entirety. Keep it short and to the point or people start fast forwarding.

No offense to anyone.

Bigdwiz, i love the video short or long. The info u give is great! I applaud the work u do voluntarily. Keep up the great work and ill continue to donate when i can.

Thanks again sir!

Jason Janita

I am not going to shoot the messenger, but I question the usefulness of the Amp Dyno itself.

I could be mistaken, but I believe the designer of the Amp Dyno is a previous or maybe even current Rockford Fosgate employee. He should remember the "Powercube" tests that Rockford employed for years in their testing, and the importance of inductive and capacitive testing.

I don't doubt the numbers from this video, but unless I am missing something, the Amp Dyno is just presenting the amplifier with a resistive load, which is very easy on the amplifier. The Powercube measurements placed both inductive and capacitive loads on amps, which was very challenging for many amps, and would really show limitations in amplifier designs.

I guess you can use the Amp Dyno for direct comparisons such as this MS2125 vs some other amp from some other vendor. I would not doubt it though that many amps which measure higher on the Amp Dyno than another perpendicular amplifier may not measure higher with real world SPL measurements in a real world environment.

Now this is totally an assumption from me, but my guess is the Amp Dyno is marketed towards "the folks" who have some cash to burn and want to play with amp measurements. I highly doubt there are any of these in the lab or the production line at any major audio manufacturer. Like I said, this is just my assumption. If anyone knows of a manufacturer using an Amp Dyno, I would love to hear about it.

Either way, thank you for the testing of these old school amps. Even though I question the Amp Dyno, it is far more informative than the testing I do on amps, with my very limited equipment.

Drock wrote:What?
First off BigD has more time of his own to make that video and then chose to post for us here. If you can't afford the time don't watch it.

Considering the amps rated power. I think it did very well.
And considering its 20 years old.
What do you expect it to do?


Sent from my iPhone using Tapatalk

I love the review and the time taken to do this. I have to say I would rather watch the other brands you do as they can make crazy power etc. this really doesn't do anything more than listed.. just me but why love the amp other than looks it does nothing for me. hard to see how this amp helped make the company what it was in the 90's I think a m100 would do the same number and rated at less

well lets look back 20years ago there were a lot of older amp company that come up with huge number vs rated mtx is just on that come to mind etc
I know its a 500 watt amp and it just does over rated the ti line is way underrated vs.

Eric D wrote:I am not going to shoot the messenger, but I question the usefulness of the Amp Dyno itself.

I could be mistaken, but I believe the designer of the Amp Dyno is a previous or maybe even current Rockford Fosgate employee. He should remember the "Powercube" tests that Rockford employed for years in their testing, and the importance of inductive and capacitive testing.

I don't doubt the numbers from this video, but unless I am missing something, the Amp Dyno is just presenting the amplifier with a resistive load, which is very easy on the amplifier. The Powercube measurements placed both inductive and capacitive loads on amps, which was very challenging for many amps, and would really show limitations in amplifier designs.

I guess you can use the Amp Dyno for direct comparisons such as this MS2125 vs some other amp from some other vendor. I would not doubt it though that many amps which measure higher on the Amp Dyno than another perpendicular amplifier may not measure higher with real world SPL measurements in a real world environment.

Now this is totally an assumption from me, but my guess is the Amp Dyno is marketed towards "the folks" who have some cash to burn and want to play with amp measurements. I highly doubt there are any of these in the lab or the production line at any major audio manufacturer. Like I said, this is just my assumption. If anyone knows of a manufacturer using an Amp Dyno, I would love to hear about it.

Either way, thank you for the testing of these old school amps. Even though I question the Amp Dyno, it is far more informative than the testing I do on amps, with my very limited equipment.

No need to shoot the messenger...I'm already full of bullet holes, lol.

I agree the PowerCube is a fantastic way to test an amplifier, but I'd hardly say the resistive tests are "easy" on the amplifier. I'm a big supporter of D'Amore and his tools. If the AMM-1 would have come out before the big Amp Dyno, I'd most likely only have the AMM-1. It does a lot of what the Amp Dyno does, even more in some cases (will test reactive loads, whereas the Amp Dyno only does resistive).

Back to the Amp Dyno and why I use it. I started testing amps for fun about 5 years ago after putting together a relatively simple setup with some resistors and a Velleman O'scope. When the Amp Dyno was introduced, I felt it would be good to have a tool that was calibrated at the factory and was designed by a really accomplished engineer (previous head engineer at RF, developed the T15kW amplifier). I'm not rich, but many donated to the cause and helped me obtain the Amp Dyno (not by my asking, I must say....one of my Facebook followers started a campaign). I'm just a normal guy who is a car audio and most specifically an amplifier enthusiast who has some basic video production skills. The Amp Dyno is not a PowerCube (also doesn't cost $25k), nor is it an Audio Precision One (also doesn't cost $35k)...but it is a well engineered tool capable of measuring wattage of amplifiers. May not give you all of the info as the other two tools do, but it can give you a good idea of what an amp is capable of. It also makes it impossible to "cheat" as it displays the wattage, ohm load and resulting voltage.

As for mfg's using the Amp Dyno, Skar Audio uses one to test their amps. I realize they are a "new school" company and probably can't afford a PowerCube or AudioPrecision, but at least one mfg does indeed use this tool.

Thanks for all the comments and feedback, I appreciate it all

Like i said love the review just thought ms pg amp did alot more than rated or very close to
Thanks again for the time

I was kinda expecting more dynamic power at 2ohm after seeing the zx1200ti dyno video. Maybe thats just because a MS 2125 looks so much stouter and has more hardware in it like driver transistors and capacitance and a huge heat sink. But I guess that is just progress and the difference in power is in line with the specifies power.

And anyway I mostly care about the great sound quality. For example I used to have a JBL Power P180.2 amp for my sub. It made 360 watts bridged mono, but I kept going back to using just one channel for the sub. The sound quality was not good enough bridged. I swapped it wit a MS275, and the sound quality is much better even bridged and the power is there too! 240 Phoenix gold watts sound louder and much better than 360 JBL watts.

You can't compare two ZX600ti amps to one MS2125, the ZX1200ti has 16 output transistors while the MS2125 only have 12. One amps is rated for 1200watts and the other is 500watts.

Oh and I did see the other test video for the ZX1200ti and I have a hard time believing that each ZX600ti produced anywhere near the 1k mark yet alone anything over it got me a bit skeptic about the amp dyno.

Nice video. When I have time I want to go through your other vids.

I thought this amp would have been at least slightly under rated. It's nice to see it giving rated power but I think we all had expectations.

I was comparing a single ZX600ti to a MS 2125 in my mind, my apologies.
They both do rated at 4 ohm bridged 40Hz.
At 1khz dynamic burst into 2 ohm bridged zxti almost doubles that, and so does MS-2125.
But the zxti has a bit more headroom and this is no news. It just does what the ms series does, and then some, with less parts and overall weight. That is progress.

I like the looks and simplicity of the ms-series, but not so much the weight of them. The zx-series came with good processing built in, but these days this complexity is often unnecessary and invites problems. Processing is often done in the HU so simple old school amps are just what is needed.

The offroad is just 2 600.2? so imo it the same as a ms2125 per side

this is why I feel the ms is weak
the ti does more than rated ms just does rated this was the day of cheater amps and almost all company doing more than just rated.
I always thought the ms did more like 20% more than rated but I was wrong. and this has killed me love for them. they just look nice.

as for this statement they were both done by the same test and person so I would have to believe the numbers are right

You can't compare two ZX600ti amps to one MS2125, the ZX1200ti has 16 output transistors while the MS2125 only have 12. One amps is rated for 1200watts and the other is 500watts.

Oh and I did see the other test video for the ZX1200ti and I have a hard time believing that each ZX600ti produced anywhere near the 1k mark yet alone anything over it got me a bit skeptic about the amp dyno.

Yea mike, like the zx950 where one side is a 450 and the other is a 500.

This is 2 600.2's

I'm not sure what people are complaining about with the MS series not producing power output much above what is published in the manual. Yes, the M/MS/MPS series were considered "cheater" amps in the day, but only because of IASCA rules of amplifier ratings at 12 volts or 12.5 volts. The MS2125 was rated to do 125 watts per channel at 4 ohms at 12 volts. In reality it produced more like 160 watts per channel at 4 ohms and 13.8 volts. The MPS series were even more cheater amps, as they were rated at 12 volts and 4 ohms but in reality could drive lower impedance loads and produce more watts. The fact of the matter is, the MS2125 pulls 60 amps of current. At 13.8 volts, the max power the amplifier could produce is 828 watts and that is at 100% efficiency. At around 60% efficiency for a class A/B amplifier, you're right around 500 watts. No surprise bigdwiz saw 540 watts at 4 ohms.

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