Martex M200 amps

Martex PM Stereo 200

OK ,one of the units is back together with the new amp boards in . I have been playing with my bench stereo (marantz 1060 just the pre and some free AR4 with new mid/woofers so I don't know how efficient they are.) The amp plays loud and the meters seem to be displaying lower than what I'm hearing . I plan on putting a dummy load on and measuring the output . Here some pictures of the amp and my schematic of the meter board . I need some advise on which resistors I can change to safely adjust the meters if I need to .Thanks
 

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better ? I have to change it from sch. bmp. Doesn't seem to work well.
 

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Talkin to Ed right now about Martex amps... stay tuned..
 
calman, pretty ecent job of stuffing those new boards in there..
 
I'm playing both them now . One is driving the highs and the other is driving the lows on these 2 way Wharfedale Harewoods (tweeters not original). Sounds great .I have to tweek the meters and install the speaker protection board next.
 

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Update............. I installed the DC protection boards and small 15VAC transformers to power them in both amps ,and they work. The turn on thump is now gone as DC protection boards have a turn on delay,nice . Now what to do about the VU meters . Amp one has 2 x68k(previous mod) resistors in parallel and amp 2 looks to be factory has 1@300k &1@120k in parallel. I fed in a 1kHz @1V into amp 2(one channel ) and got 26vac on output . With a 8 ohm dummy load I figured 84 watts but the meter was in the +2 red zone. When playing music with these amps amp 2's meters hardly move but the music is loud .Amp 1's meter movement was more responsive . I'm going to do the same output test on amp 1 and see what the output and meter readings are . Any suggestions ?
 
Withouit knowing what the factory had in mind as far as calibrating them to a certain output you're kind of shooting in the dark. decide what you want the meters to read and adjust resistances accordingly. Some experimentation is in order..
 
Hello Phoenix , i've been playing these amps in bi-amp setup. I had to vent the top covers the transformers get hot after an hour at good volume. The amps play loud. With a kill- a watt meter connect the amps draw 1 amp each. The transformers hum but did with original components . Anything I can check to see if I'm overloading the transformers? I will check the power cord for heat tomorrow. Thanks
 
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