Phase Linear X20 Crossover

wattsabundant

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Apr 26, 2011
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Central Ohio
#1
I have a living room with almost all P/L electronics. "The worlds first WOPL 400II" that Lee did a few years ago is in there along with a 3300 preamp and 5100 tuner. Until last weekend I was running ESS 1A's. I got a little carried away this weekend and took out the Heil diaphragms.

've got a pair of JBL 4412's that replaced the ESS's and added a JBL B380 subwoofer that's been sitting disconnected for a couple years. The sub is running on 1 channel of a full blown 700B. The only non P/L item is the electronic crossover which is a BGW Model 20. I installed several of the BGW's in clubs in the 80's. They're versatile and high quality.

I was in the process of installing the BGW and the sub when a musician friend at work mentioned a local music shop had a P/L electronic crossover for $40. It's the pro X20. I don't need it but I had to have it. I have the manuals for pro gear so I wasn't to concerned if it needed some work.

In the pics below there are several blue electrolytic caps in series to make a non polar. The question of the day is what is a good 50uf non polar, or is there such a thing? Also the opamps are NEC4741 which is apparently an improved quad 741 intended for audio filter circuits such as a crossover. They're in sockets so replacement would be easy. I'm open to suggestions for an upgrade. The outputs of the crossover uses one section of the opamp as a unity gain buffer if that matters.


 

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Gepetto

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#3
Hi Don
4741's are very poor audio op amps by todays standards. If the pinout is wonki, then I would recommend you use the brown dog adapters to get some Burr Brown devices in there instead.
 
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