Gibsonian's Cherry Pl 700 Ser I, soon to be a PLWO-1000

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
It was all the cables.... latest test. Redid them all.... Now we're gonna get Cathy all horny. These are very good numbers now Scott.
 

Attachments

Gibsonian

Chief Journeyman
Joined
Aug 3, 2011
Messages
847
They'd look mighty nice on Kathy's front side. Glad it was a little old cable. Let's see what your ears say. No bad cables connecting those two transducers!
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
Except for some 60HZ hum i gotta track down, it sounds excellent. The bass is amazing.... I have to trim the holes in the faceplate a wee bit, but it'll be cool.
 

mlucitt

Veteran and General Yakker
Joined
Jun 24, 2011
Messages
3,497
Location
Jacksonville, FL
Lee, that 60Hz might be coming from the protect circuit. Is that yellow pair carrying AC? If so, put a mean twist in it and see if that makes ay difference.

Mark
 

Gepetto

Administrator
Staff member
Joined
May 15, 2011
Messages
14,098
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
Or better yet, get it away from the input wiring. The amp cannot reject signal that comes in through the inputs, it treats AC like any other audio signal.
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
Joe, if you could run through that " How to make a 60Hz receiver with the scope" thing again I would be ever so grateful...
 

Gepetto

Administrator
Staff member
Joined
May 15, 2011
Messages
14,098
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
Lee
Just clip the scope probe ground wire to the tip of the probe and use that assembly as a wand antenna. Set your scope on the most sensitive vertical setting and wand the probe around to discover radiating hot spots.
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
Too simple, thanks Joe!! There has got to be a repeatable procedure for finding these sources of hum in a predictable manner. At least I think there should be.
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
Ok folks, I am totally braindead tonight, need help. The amp IS DEAD QUIET-----=UNTIL_____ you plug in an RCA patch cord. Doesn't matter if it's on the AP, the rack or a stubbed cutoff from an ancient throwaway set. As soon as the +signal pin makes contact instant buzz, and it does not quit when the ground tangs contact the input ground surface....... F*&^%$ up input jacks???
 

Gibsonian

Chief Journeyman
Joined
Aug 3, 2011
Messages
847
Yah, you are up really late for good brain function. Could it be possible that there is a problem with RC network on outputs?
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
75,036
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
sHIT sCOTT i HAD A NAP FROM 8 TILL 11 I'm good to go! The zoebels are the first thing I checked. There has to be communication between sgnal plus and signal ground AND THAT covers some territory, including the front end of the board. The ground shroud on the input rca jacks are floated on this one too so a simple desdolder of the signa ground wires should eliminate the noise IF it's in the jack...
 
Top