I have a PM300 which was working great until a week ago. Evidently, a resistor (part number 45A38) burned up. I tried calling but was told you don't carry that part any more. I knew that...what I need to know is the value of the resistor and what alternatives there are for it's replacement. No one i've spoken to can fix it without the value and all info on the resistor is gone because it fell a part.
The number item is R1 in your schematic, replace kit no: RKC47.
I'd appreciate any help you can give me.
---- 10/03/2001 08:51 AM ----------------------------------------------
Thank you for answering that question so expeditiously. However, your answer begs another question.
Would this particular part - "Thermistor" cause power loss when two mikes are used at once? That was the original symptom. Only one mike would work at a time - if a second were plugged in there was a significant power loss ie: practically no sound amplification at all.
Do I have another problem as well?
At 10/01/2001 10:52 AM we wrote - It is the same thermistor as used in the Vocal Master mixer/amplifiers: Where can I get a thermistor for my Vocal Master?
At 10/03/2001 09:53 AM we wrote - The PM300 is not designed to have a microphone plugged directly into it, be it one or two! The PM300 input is designed to be connected to a high level output, like the AUX out of a tape recorder, or the main output of a microphone mixer.
For proper operation, plug your mics into a microphone mixer first, like the Shure SCM268, then plug the output of the mixer into the PM300. The output of the PM300 is then connected to loudspeakers. The total impedance of all loudspeakers connected to the PM300 should be 8 ohms or higher.
Your entire system will work much better with the addition of a microphone mixer.