What to look for when buying an MPS series amp.

[Vmax911]

I've got a friend who is selling his MPS2220 amp. He is willing to let me check it out before I buy it. Is there anything I need to look out for with this amp? Obviously it needs to power on and amplify. Any suggestions are appreciated.

[AVICJR]

Due to the age of the amp, I would recommend changing out the caps inside because of leakage that could eventually lead to fire. You can do a search and find many of discussion and how to's on this particular subject. I'm sure others will chime in on Monday with other suggestions as there's usually less traffic on the weekends around here.

Welcome to the phorum!! I hope the PG amp works out for you so we can have another "addict".

[itchnertamatoa]

yeah, a new addict hehe
welcome

as AVICJR said, cap change

[1moreamp]

It depends on how much your friend is charging you for the amp as it should be serviced after all the years of service it has seen.
Remember capacitors go bad from just sitting, weather the amp is used or not caps fail and leak.
I have yet to see and MPS, MS. MAC. or M amp that did NOT need its caps replaced due to leakage.
These amps have served well over the years but even a great amp needs to be serviced to restore long term and proper operations.

And this applies to all electronics not just PG. C

[Vmax911]

Thanks for the replies. I searched around a bit, and found some info on the caps. I did the "paper under the cap" trick, and I don't see any fluid on the paper. However, during my research I have discovered that 1moreamp is a guru, so I will take his word that they need to be replaced.

Is it just the 2200uF caps that need to be replaced? (I found a link to digi-key with 5600uF to replace them.) Anything else I need to consider for servicing? Does PG do the servicing, or will 1moreamp? I feel I can replace the caps myself, but is there anything else that needs to be done?

As a side note, what kind of power output can I expect at 1 ohm bridged with this amp?

[1moreamp]

Thanks for the replies. I searched around a bit, and found some info on the caps. I did the "paper under the cap" trick, and I don't see any fluid on the paper. However, during my research I have discovered that 1moreamp is a guru, so I will take his word that they need to be replaced.

Is it just the 2200uF caps that need to be replaced? (I found a link to digi-key with 5600uF to replace them.) Anything else I need to consider for servicing? Does PG do the servicing, or will 1moreamp? I feel I can replace the caps myself, but is there anything else that needs to be done?

As a side note, what kind of power output can I expect at 1 ohm bridged with this amp?

I use 6800ufd at 16 volts, and if you look there are 8200ufd that will fit in the same space. If your not handy at this sort of thing you will tear out your thru-hole via's that connect both sides of the circuit board together. Then you got troubles.
You must be proficient at soldering not to damage the circuit board. If you feel you are up to it go for it. If in doubt, PM EricD, or me. We can do it for you, or send it in to PG they can do it also, but you must request it.

The paper test is fine checking for liquids, but I have also seen early leafage where the the has just started to leak at the rubber seal and the paper test will not check this.
Thats why I modified my statement now to say ALL PG amp from back in the day need new caps.

You will also need to replace your 16 volt rail caps, and possible the main rail caps. PG charged me $48.00 for a set of four 10,000ufd 50 volt caps.
So you have been advised as to parts cost on the big blue caps inside. On a 2220 there are two so $24 to $30 bucks just for those two caps from PG.


By the way EricD is the founder of this cap replacement program. Please give him credit as he has been changing caps as long as I can remember. He also does Excellent circuit board repairs

Good luck C

[brenzbmr@sb]

i just did another ms2125

changed all the input caps and rail caps..

i learned on my ms275 to be very careful not to pull the via out of the board.....

good luck

[Vmax911]

Just curious, what is the diffence between the Phoenix Gold $12 10,000uF 50V Capacitor and the $5 Nichicon 10,000 uF 50V Capacitor I see at Digi-Key?

[1moreamp]

Just curious, what is the diffence between the Phoenix Gold $12 10,000uF 50V Capacitor and the $5 Nichicon 10,000 uF 50V Capacitor I see at Digi-Key?

Need a part number for physical size and temp rating cross match, and possible ripple current measurement cross reference,< the latter being very important to its lifespan>, and ESR rating. Also color matching for original art deco reason, they need to be blue with white tops, or Black with black tops for original issue MS-2250 & MS-1000 pre TA. Also the PG cap is Nippon Chemi-con as the ones I saw in the last M-100, and my MS-2125 that I just bought and paid $48.00 + shipping for.

PG has a right to make money, for exact replacement parts from the factory. A 60% margin is pretty common place profit for a end user supplier. I am a end user to them, not a big time dealer ( not a dealer at all). How do you think 7-11 stays in business ???

I am quoting PG prices so people who want PG parts understand PG pricing to ME + shipping. I have little but my integrity left at my age, but thats very important to me when it comes to people who trust me

I get lots of price quote requests for restoration services, and unless they want after-market parts, I spec PG parts price to me. I only make money on labor, and intellect, and quality of service < basically me>. BMW and Mercedes parts are quite high I have heard also

The caps your looking at might be just fine, and maybe they will explode after 20 minutes of playing loud music, who knows. You must make the choice to gamble on printed spec's and zero real world play time. Some folks don't want to do these sort of things, and most of my clients ship out of state and country to me. The gamble gets a huge amount larger when your shipping to Norway, and theres 14 restored and tested PG amps in the crate. A return besides embarrassing is expensive, time consuming, and risky for loss of item by the carrier.

If my clients want Digi-key parts, I will buy them, as long as they are fully aware of the risks involved with cross-matching untested parts in their amps. And I do try to explain this to them

Especially since they or you want that $7.00 back in their pocket, not mine

I hope I have explained myself and PG's pricing to me. With the amount of amps I am restoring they (PG) should consider making me a branch operation, with quantity pricing on my purchases, but thats pushing it for a company that just got bought out by local business people up in Oregon...........C

[Pedi]

The caps your looking at might be just fine, and maybe they will explode after 20 minutes of playing loud music, who knows. You must make the choice to gamble on printed spec's and zero real world play time. Some folks don't want to do these sort of things, and most of my clients ship out of state and country to me. The gamble gets a huge amount larger when your shipping to Norway, and theres 14 restored and tested PG amps in the crate. A return besides embarrassing is expensive, time consuming, and risky for loss of item by the carrier.

Shipping to Norway? It looks like you are thinking of me here (which I can understand, so much I have been PMing you )

I have said it to you many times, and can surely say it to the others in here that is doubting...

Go for the caps that Cecil uses. Why save two bucks and use "no-good" capasitors, when you can do the right thing at once...

I will, for those who does not know it, send all my beloved MS-amps to Cecil (1moreamp) for him to do (as I call it - with all respect) his very own "Cecil's touch".

I fully trust the one-and-only Cecil to do what I will pay him for. With his enourmous knownledge and love of PG and what he does for a living - I therefore ship my amps out of the country and overseas to know that my amps are fully taken care of. This will be an expensive operation, but in my eyes it is totally worth it.

All my best goes to Cecil. Thank you.

[nico boom]

I've been looking at this thread, it beeing about MPS amps [everything that has MS in it is viewed by me, with special interest haha]...
All I can say; You never stop to amaze me Cecil, beeing the only one i trust my amps to, and for having an answer on every question asked around here.
For all of you, having to replace caps for the first time; if you don't have 100% confidence in your skills, or have a trashed amp to learn, DON'T TAKE THAT RISK.
I had some sleepless nights over my first MS2125, just because I couldn't get my board out of the heat-sink; the fets really stuck to it
Beeing used to do some high-quality solder-work, it still was quite a job to get the caps out in a gentle way, and not to disturb the board.
So for your own sake; don't let money decide; let long-term quality do it!
[GO TO CECIL].
nico
[old] pic;[ first one done, 105c , 68oo]]