I picked up a Yamaha PB-1 and can't seem to get the Parametric EQ working. The light is on for the parametric EQ but nothing I do changes the tone. Also the pots are really scratchy....all of them....Scary scratchy at volume. Do they just need cleaning? I am using the balanced output into my amp.
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PB-1 Owners
- Thread starter bizzaro
- Start date
Have you open it up and compare the schmeatics on the top cover to the actual wirings? May be there's a lose connection point or cold solder after the parametic switch relay. I have a PB-1 too but I haven't use it for a while. I can open mine up tonight and check for where a potential problem could arise.
No I haven't opened it. It also distorts really easy when I bring up the bass eq. I am getting weary that it may be spent and I got screwed. I haven't owned many rackpreamps. I tried to down load a owners manual from here at TB that someone graciously posted but I got an error message. With the light on the Parametric eq should be working at any rate?
After having a looking at mine, it looks like the light could come on even if you have a faulty relay, as it's the case with your preamp. Have you try to use the front output or the headphone output when testing the parametric eq?
Thanks pedro. I did send you a PM but not sure it went through. I think I may try and the return the unit. It is pretty clear to me the Parametric EQ is not working. That is a significant loss to this unit. It really gives you a whole lot of tones that aren't available without it. And the bass EQ is really sensitive and distorts if I move it above 9:00 and cuts out just under that. All the Pots are really 
scratchy. What kind of shape is yours in. These units are all pretty old by now so maybe this is what you get 
scratchy. What kind of shape is yours in. These units are all pretty old by now so maybe this is what you get
pedroferreira said:
I guess I was wrong in this thread:
http://www.talkbass.com/forum/showthread.php?t=151990
May be you can hook him up with the manual too?
So I went in to the belly of the beast and found someone had already been there. Some really ugly soldering with epoxy over it! 
And I found someone had inadvertantly switched the wires going to the Parametric EQ so the light came on but it was not in the signal chain. Switched the wires back to the proper place and Bango 
I got the PEQ working. Cleaned up the pots(is that what they are called?) with electric cleaner stuff and they are pretty smooth now. The Bass eq is still a little funky and seems to distort a bit. It also can really overwhelm the tone. Maybe that pot has been replaced cause it seems really sensitive. The Treble and Mid sweep is much wider for tone adjustment than the Bass. I can really drowned the rest of the frequencies with the bass above 10:30 or so. It seems way to strong compared the the rest of adjustments. Maybe it is characteristic of the unit. Could the distortion be the unit was designed for passive Bass Guitars I am using active Basses. PB-1 Users could you post your settings/observations?? PLEASE 
I am still experimenting and have a practice tonight to really test it out. 
And I found someone had inadvertantly switched the wires going to the Parametric EQ so the light came on but it was not in the signal chain. Switched the wires back to the proper place and Bango I got the PEQ working. Cleaned up the pots(is that what they are called?) with electric cleaner stuff and they are pretty smooth now. The Bass eq is still a little funky and seems to distort a bit. It also can really overwhelm the tone. Maybe that pot has been replaced cause it seems really sensitive. The Treble and Mid sweep is much wider for tone adjustment than the Bass. I can really drowned the rest of the frequencies with the bass above 10:30 or so. It seems way to strong compared the the rest of adjustments. Maybe it is characteristic of the unit. Could the distortion be the unit was designed for passive Bass Guitars I am using active Basses. PB-1 Users could you post your settings/observations?? PLEASE I am still experimenting and have a practice tonight to really test it out.
Just out of curiosity, which two wires were switched? Are you talking about the wires for the 2 pin connector?
As for the funky bass pot, may be your active bass is a bit hot on the low end frequency. You can try keeping the PB-1's bass knob down and then compensate by boosting the low freq back up on at the parametric EQ. I only use passive basses so I never really have any distortion problem.
As for the funky bass pot, may be your active bass is a bit hot on the low end frequency. You can try keeping the PB-1's bass knob down and then compensate by boosting the low freq back up on at the parametric EQ. I only use passive basses so I never really have any distortion problem.
Tommy,
The wire I changed was the one that goes to the light for the PEQ. The wires come out of the light and go into a plug with three slots. The top of this connector just pinches down on the wires. So you have two wires but three connections in this thing. (sorry I don't know the technical name) I was carefully looking it all over and trying to trace board wiring etc and noticed that the board had line diagrams going to this connector and the wire appeared to be in the wrong spot according to the line. So I switched it and it worked. Just to be sure that was it, I reversed it again, and sure enough it stopped functioning. So all I did was move one of the wires coming from the light in the face of the PB-1. I am pretty sure someone else inadvertantly put it in the wrong slot.
I will have to do more experimenting with the bass EQ. But I ended up doing exactly what you said and it gave me better controll. Maybe I am just not used to it. I had it at practice tonight and it was fun but I like my Sansamp RBI better so far. But the PB-1 definatley is versitile with lots of great usable tones.
Thanks for help
The wire I changed was the one that goes to the light for the PEQ. The wires come out of the light and go into a plug with three slots. The top of this connector just pinches down on the wires. So you have two wires but three connections in this thing. (sorry I don't know the technical name) I was carefully looking it all over and trying to trace board wiring etc and noticed that the board had line diagrams going to this connector and the wire appeared to be in the wrong spot according to the line. So I switched it and it worked. Just to be sure that was it, I reversed it again, and sure enough it stopped functioning. So all I did was move one of the wires coming from the light in the face of the PB-1. I am pretty sure someone else inadvertantly put it in the wrong slot.
I will have to do more experimenting with the bass EQ. But I ended up doing exactly what you said and it gave me better controll. Maybe I am just not used to it. I had it at practice tonight and it was fun but I like my Sansamp RBI better so far. But the PB-1 definatley is versitile with lots of great usable tones.
Thanks for help
