I have a Monster Cable MPA-2250 power amplifier that failed, it power cycles, and this causes loud thumps thru the speakers when this happens. I have read in a Amazon customer review posted in Sep.2015 of the 3-channel version to be ( bad IC chip that caused the power cycling). So its possible that its the same problem causing the problem in my unit. Wanted to have the amplifier fixed, but cannot find a source, any help would be appreciated. This is a design by Richard Marsh, its a very good sounding unit before this problem. I reached out to Monster Cable twice,they do not fix their amps in-house, or have an outside resource. Thanks
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I don't belive monster cable would do such a thing... 🙂
Richard is a member of forum, try to contact him, maybe he can help you. Cheers.
Richard is a member of forum, try to contact him, maybe he can help you. Cheers.
Hi Idad,
It would help to know where you are for one.
Any good audio technician should be able to service that amplifier. This person will likely be in their 50's or older, and likely working from home as I am.
It would help to know where you are for one.
Any good audio technician should be able to service that amplifier. This person will likely be in their 50's or older, and likely working from home as I am.
That is not uncommon these days. The entire service industry has crashed, generally dysfunctional. What is it that bothers you about their agent?
I reached twice to them, and don't fix their amps, if you don't believe, call them, if they say they do, please reply back to me with name of representative, thanks
You want him to reply with the name of every Monster service representative worldwide?
Maybe you shouldn't be combative when asking for help 🙂
I was not trying to be combative, but instead in a positive note to wish that a different manufacture representative here in the US would give a different answer than I received, they would be ideal for this repair.
I do appreciate very much all the help would be able to get. And the suggestion of Richard Marsh (designer) is an excellent one, and would consider this.
Thanks.
I do appreciate very much all the help would be able to get. And the suggestion of Richard Marsh (designer) is an excellent one, and would consider this.
Thanks.
Ilson, I understand this can be frustrating, not being able to find someone who can help you. As others pointed out, that's often the case these days.
Maybe you can give some more info for us to see if we can help you. What exactly is the issue, both channels, with/without speaker, with/without signal?
If it is only one channel, id you try swapping inputs or outputs to see if the problem stays or moves? That sort of thing.
I suppose you don't have a schematic?
Jan
Maybe you can give some more info for us to see if we can help you. What exactly is the issue, both channels, with/without speaker, with/without signal?
If it is only one channel, id you try swapping inputs or outputs to see if the problem stays or moves? That sort of thing.
I suppose you don't have a schematic?
Jan
Hi Jan,
All due respect, and I don't question your suggestions lightly. Never, ever take parts from a "good" channel and try them in a "bad" channel. It's a great way to end up with two "bad" channels, and even end up with more serious faults in the channel that was a problem to start with.
Does anyone know of a really good audio technician near N.J. Middlesex County, near New Brunswick?
Hi leadbelly,
-Chris
All due respect, and I don't question your suggestions lightly. Never, ever take parts from a "good" channel and try them in a "bad" channel. It's a great way to end up with two "bad" channels, and even end up with more serious faults in the channel that was a problem to start with.
Does anyone know of a really good audio technician near N.J. Middlesex County, near New Brunswick?
Hi leadbelly,
Most factories would maintain a list of exactly that. They should have been able to furnish such a list with a minimum of trouble. The fact that they didn't really throws them into a bad light bordering on incompetence. I can't imagine any distributor or manufacturer that is unaware of people they deem competent to work on their product if they have been dealing with them. Some even have a forum attached to their regular commercial site where suggestions for good service people are maintained by the members.
-Chris
Hi Chris, of course you are right. I was meaning to swap speaker cables, inputs etc between channels. Not parts, fully agree, you just end up with more dead parts.
Jan
Jan
Hello Jan, and thank you for your reply, and suggestions.
I will do more different scenarios of how the problem is happening. But so far the power cycling happens when a signal source is attached and on, and also when the signal source is off with the RCA's are still connected. I did not try to yet to also have the RCA's disconnected.
I want to say thanks also to everyone in diyaudio, that has responded to my repair concern, I am getting a lot of good responses that could lead in the future to have this repair go forward.
Thanks, Ilson
I will do more different scenarios of how the problem is happening. But so far the power cycling happens when a signal source is attached and on, and also when the signal source is off with the RCA's are still connected. I did not try to yet to also have the RCA's disconnected.
I want to say thanks also to everyone in diyaudio, that has responded to my repair concern, I am getting a lot of good responses that could lead in the future to have this repair go forward.
Thanks, Ilson
Jan I did a search online and only thing that was able to find was the owner's manual, not the schematic, thanks, Ilson
Hello Jan, no matter if have input RCA connections or speaker leads connected or not,it still power cycles.
What I find strange is that it power cycles once turns on, then it could be ok for a certain amount of time, sometimes for even 1 hour or so, then will power cycles again, no matter how RCA inputs/speaker leads are connected, and signal source on or not.
I also want to answer a question regarding the interaction with Monster Cable representative, it was a very good one, and was explained very well how their resources work, so cannot fault this,it is what is in place for them to give, they cannot offer something if its not available.
So at this point I have to look for a resource somewhere else, if want this repair to go forward, thanks, Ilson
What I find strange is that it power cycles once turns on, then it could be ok for a certain amount of time, sometimes for even 1 hour or so, then will power cycles again, no matter how RCA inputs/speaker leads are connected, and signal source on or not.
I also want to answer a question regarding the interaction with Monster Cable representative, it was a very good one, and was explained very well how their resources work, so cannot fault this,it is what is in place for them to give, they cannot offer something if its not available.
So at this point I have to look for a resource somewhere else, if want this repair to go forward, thanks, Ilson
I wanted to also mention that I find the design of this amplifier by Monster Cable and Richard Marsh to be very impressive. I find to be very good sounding, at the price vs performance level of diminishing returns.Not being an expert, the use of dual toroidal power supplies, the dual channel design to be in a way suspended from the bottom chassis, to minimize vibration to the circuit boards. Last but not least, the dual digital meters, which I like much, an find very cool, to watch the power requirements of well recorded music, of peaks vs quitter passages. This feature has different levels of illumination, or off. Its an amplifier that been discontinued for many years, but still very good sounding.
In the mid 80's I also had a Heybrook TT-2 belt drive turntable with a Monster Cable Alpha 1 moving coil cartridge, this was an excellent sounding cartridge by Monster, but no longer have this, I sold, and regret doing this.
In the mid 80's I also had a Heybrook TT-2 belt drive turntable with a Monster Cable Alpha 1 moving coil cartridge, this was an excellent sounding cartridge by Monster, but no longer have this, I sold, and regret doing this.
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Ilson is your preamp output DC coupled? Is the Monster input DC coupled? There may be some caps in there that need to charge first, and a short term output offset due to that may trigger the protection initially.
Jan
Jan
Jan, I do not have a preamp at this moment, I used to have a NAD 3050 integrated amp, which could have been used as a dedicated preamp .
I used a NAD 5000 Monitor Series Compact Disc Player thru the variable outputs. As of now, don't even have this cd player anymore, but been just using the outputs of Dish network receiver as the preamp outs, using a resistor on each of the car woofers to lower the sound volume.
I have two other fine cd players, very probable to be superior sounding to the one above, but only fixed outputs.
What I want to get in near future, would be a high performance preamp/DAC/ possibly a built in streamer also.
This way would hook up my other cd players via the digital outs, and use the DAC which would improve the sound further.
I don't use my main speakers any more, for this amplifier turning on and off by it self, could very easily fry the tweeters.
This amp problem happened with these different speakers, being connected or not. So its seems to be an inconsistent internal problem in the amplifier.
I read the thread above 'MPA 3250', and a schematic is available, I responded to this, of how to get one.
Also had found interesting what read there, of the extra grounding bolt behind the chassis, at first not understanding why was there, but will find a way to also use this ground, and see if makes a difference. The power cord in this amp, is of very good quality, but in my case the grounding plug was broken, I did repair it and tested to make sure the grounding was going thru from the amp to the receptacle, and it seemed to be so, but I might actually replace this particular part with a new heavy duty one, instead of the repair. But will try out this extra ground and see what happens,
thanks, Ilson
I used a NAD 5000 Monitor Series Compact Disc Player thru the variable outputs. As of now, don't even have this cd player anymore, but been just using the outputs of Dish network receiver as the preamp outs, using a resistor on each of the car woofers to lower the sound volume.
I have two other fine cd players, very probable to be superior sounding to the one above, but only fixed outputs.
What I want to get in near future, would be a high performance preamp/DAC/ possibly a built in streamer also.
This way would hook up my other cd players via the digital outs, and use the DAC which would improve the sound further.
I don't use my main speakers any more, for this amplifier turning on and off by it self, could very easily fry the tweeters.
This amp problem happened with these different speakers, being connected or not. So its seems to be an inconsistent internal problem in the amplifier.
I read the thread above 'MPA 3250', and a schematic is available, I responded to this, of how to get one.
Also had found interesting what read there, of the extra grounding bolt behind the chassis, at first not understanding why was there, but will find a way to also use this ground, and see if makes a difference. The power cord in this amp, is of very good quality, but in my case the grounding plug was broken, I did repair it and tested to make sure the grounding was going thru from the amp to the receptacle, and it seemed to be so, but I might actually replace this particular part with a new heavy duty one, instead of the repair. But will try out this extra ground and see what happens,
thanks, Ilson
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Very possible other damage inside the plug exists. Plug it into an extension cord and then fiddle with the plug and wire near it to see if you can find an intermittent connection in or at the plug.
I will be replacing this part with a commercial plug and see what happens. But first will try this suggestion of using an extension cord as you described. My amp had suffered shipping damage, will also check to make sure if the toroidal power supplies are intact, thanks, Ilson
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