Calling The Grey Experts...MS-250

[KillerBox]

I have (2) Phoenix Gold MS-250 (Grey) with matching numbers. I have owned these amps since they were new and I have never had a problem with them. They are installed in the same 1989 Ford Probe since new.

I have read somewhere about weak caps on the Phoenix Gold MS-275 and I wanted to know if the weak caps apply to the MS-250s? If it does, where do you send them for repair?

I have also read that you should not put them in Master/Slave function anymore? Mine have been in Master/Slave for over 20 years. Granted they only get used once or twice a year. Should I disconnect this feature?


Thanks!

[tonym]

http://www.altser.com/pdf/Car%20Flat%20 ... 2-2011.pdf
110.00+ parts ..that includes shipping back to you

or ericd can do it also..not sure how busy he is ATM though..

I have used both....

both do 5 star work

[brenzbmr@sb]

as far as master and slave are you actually using the cable inbetween the two amps or are u just refering to the postions of switches?

[ttocs]

I thought the switch turned the power supply off on one of them, and that it was not recomended to be used?

[KillerBox]

as far as master and slave are you actually using the cable inbetween the two amps or are u just refering to the postions of switches?

I am using a cable between the 2 and have the switches in master and slave.

[joerg]

Since it is working this way just leave it this way! Never touch a running system. As for the caps: I would suggest to swap em out in the near future as the MS250 is getting close to 20 years of age. It would be a shame if they burn up because of leaking caps.

[Eric D]

The caps in your amps need to be changed ASAP. The real scary part is they can fail at any moment, and it does not matter if your stereo is running or not. With 12V from the battery present at the caps, they could burn up in the middle of the night.

Normally I would be glad to preform this service, but right now I am way to busy to work on amps.

As for the master/slave option, to the best of my knowledge, that option is to synchronize the frequency of the PWM (pulse width modulation) controller in the amps' power supplies. In normal master mode, the amp will generate its own frequency, and operate at this frequency. In slave mode, the amp won't generate a frequency, and relies on the signal coming from the master amplifier for its frequency. I believe the big risk here is running an amp in slave mode with no wire connected for signal. Maybe some amps oscillate at an undesirable frequency when configured like this, which results in failure of the power supply MOSFETs. Just a guess though, as I have not seen an amp die this way before.

[brenzbmr@sb]

eric is correct in that it syncs the power supplies of mulitple amps to prevent hedrodyne noise, which was common with those power supplies especially when running the audio control products out at that time.

my recommendation is if you have hedrodyne noise use it but if you dont then remove the jack and just put both to slave

many people in the day used to install these wrong or if the wire crimps and has some resistance it would blow the power supplies.

so like i was told long ago "dont use it"