700B WOPL Audition List

Ok got a ?. What would make my pioneer hum? All amps I've had always have a very low hum but when I first got the 700 it was bad for a day. Then it has been fine. But then tonight it's back. And it's a pretty damn loud hum even with the -20bb on it is still pretty loud. So why would it come and go like that?
 
Intermittant ground caused by a broken cable maybe? Does it occur from one source, a pre or component?
 
Could be a lot of things Jase, old caps, old transistors in the front bdiff stage, flaky ground, lots of things...
 
IIRC that Pioneer was supposedly recapped. Jason, try flipping the power plug on Bertha
 
Hmmmmm...
 
I'm gonna email mattsd off ak who fixed this pioneer and see what he says he did. Because at first he was gonna just get it going. Then he said it would be smarter to do a full restore. I know he changed the big filter caps. But other than that I'm unsure what he did. The tuner is weak and off. It doesn't change the hum by selecting diff buttons like aux,phono whatever. And when it hums loud it starts as soon as I turn the pioneer on. There's the 2 clicks you hear on the pioneer but the hum is there before the second click even!! I'm lost lol
 
That blows Brother... hope he responds to you. This is the first time you used it since you got it back?
 
Northwinds said:
That blows Brother... hope he responds to you. This is the first time you used it since you got it back?
Click to expand...

aftrer i got it back ive had it upstairs.i noticed the hum right away but pushed it off as bieing a old unit and thats what they did,but it gets bad at times and i nvr noticed that until i started using it as a pre.its so weird how it comes and goes though
 
Might be something to do with a temperature difference??? Bad solder joint somewhere and when it gets cold it contracts?
 
That pl pre should be here soon. I hope that makes it easier. Then I can get this checked out. I paid Matt 200$ and 80$ in shipping and I can see dirt and dust from top looking down onto boards!he got it running but that's about all I think. The guy doing my 1250 has is sparkling but not done yet. I would take it to him but it might take him 5 years to fix it lol
 
Not to mention it takes a good hand to pack them so they don't get hurt...
 
It takes about 5 evenings of 3-4 hours an evening to restore a Spec 1 , that means changing out about 79 caps, 27 ransistors , cleaning and a general PITA because of the solid wiring in the chassis you have to work around very carefully to not break it. I cable tie boards to keep them from swinging and breaking wires too, it gets pretty involved but it's not difficult, just tedious...it's a great unit to begin with but after EW's recommended changeouts it's REALLY good.
Jase that 3600 your getting has always been a sleeper, not many around but they're good pre's with one of the best phono sections out there, perfect for you...
 
I'm not sure how the 3600 is comin in mail so I'm gonna go drop off the 700 today so pure brew joe will have it nxt week. Prob like Tuesday I would think. Maybe Monday !
 
I am hoping someone will hook me up with a big shiny preamp!
 
You must log in or register to reply here.
Back
Top