BOSS PH 1R Phaser - strange problem

[axeman010]

Hi All

I hope somebody will be able to sort out a problem that I am having with my very old Boss PH 1R Phaser.

When I use the effect with a battery every thing works fine. However if i use a power supply the effect works OK but the LED only just glows and is barley visible.

I have checked the power supply and its OK and works with my other pedals. I have even used a different supply and get the same problem.

I managed to find this schematic kindly provided by R.G.

http://www.geofex.com/FX_images/Boss%20PH-1r.pdf

Any help and advice would be gratefully received!

[oldschoolanalog]

You're using a 9V PS?
The old Boss stuff was designed to use a 12V unregulated PS. IIRC.
Use the search function, all the gory details are somewhere in there .

[Mark Hammer]

Yeah, weird discrepancies sometimes between what is legended on the chassis and what is written in the service manual.  I have a pair of BF-1 flangers.  They both say 9v on the chassis, but the service notes say 12v.  And anyone who has tried it will tell you they work MUCH better at 12v than at 9v.

Worst case scenario, though, you simply exchange the 3k9 current-limiting resistor for a smaller value, like 3k3 or 2k7, OR substitute a brighter LED in there.  It may well be that the audio part of thephaser works identically at 9v, but the control features and status LED (only) work a little different.