I have just bought a boss ph-1 on e-bay. Price was really interesting and it is in an amazing shape. It sounds simply great. Even better than my MAXON PT999 (I think it's a PT999...one knob only)
BUT ther is a problem. I am not an electronic specialist but I thinnk it could come from the two rate and depth knobs.
I explain myself: all is vintage in it. NO modifications at all so I think knobs are too old now and give bad electric response. First knobs are only working if position is more than half distance. under this point there allmost no effect at all and nothing change. Then effect sound really great it's amazing on my small fender super 210. But effect fade off after some 10/15 seconds. It's really strange. Effect is still on but only provide direct sounds. Then I only turn a little one knobs and then effect is back. So...
So I wanted to replace the two knobs but specification are not written on it (it's only written 'japan'). Of course Icould put my metrix on it to mesur it but if they are out of order I could make a mistake.
So is there someone who can help me finding schematic somewhere ? Maybe someone knows about this kind of problem.
Cool score on the PH-1. In regards to the momentary switch, totally normal on first model Boss pedals. It was obviously changed later, but these early models feature the momentary LED. Nothing to worry about in the least and probably cool to have at least one Boss pedal like that in the collection. Good to have visual aids when you teach the kids the history of Boss.
I've never seen a PH-1 schematic so I'm afraid I can't help you with the potentiometer values. I've seen posts on other forums where people have been looking for it too but there doesn't seem to be one floating around.
Your best bet may be to call Roland France. They will surely charge you a little but I'm sure they have the schematic.
I haven't modded mine, but I have (somewhere) a mod sheet by Craig Anderton. This is from 1980 or 81 I think, when it wasn't such a big deal to mod a PH1. I don't think I would ever mod one myself either!
PH-1 problem and schematic
Posted - 09/12/2005 : 14:37:24
