Boss flipflop help!

Started by the3secondrule, February 09, 2016, 04:06:38 AM

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the3secondrule

I picked up a cheap boss CS1 the other day which is behaving weirdly.
Initially I thought it wasn't switching on, but in fact it switches between fx and bypass fine -
However the LED will only light up WHILE the footswitch is held down

Any ideas?
I can get voltages, just let me know what you need to see,

Cheers!
"Rock music is mostly about moving big black boxes from one side of town to the other in the back of your car."

lukeferg

How are you powering the pedal? My guess is you're using a power supply not a battery.
The older boss pedal used an ACA adaptor for power which put out almost 12 volts. If you're using a 9v adaptor the LED won't light properly.
If you daisy chain pedals from the power supply it will light though. Got something to do with the shared ground or something.

the3secondrule

Yep, I'm well aware of the ACA/PSA power supply guff, and it's been modded to run a standard 9v supply now.

Further research indiates the behaviour of the LED is normal.... It is supposed to only light up when the foot switch is pressed, and will turn off again as soon as the switch is released.

Apparently is a "feature" not a fault ;)
"Rock music is mostly about moving big black boxes from one side of town to the other in the back of your car."

Preben Hansen

The LED that only lights up when pedal is pressed, CHECK, is a feature by design of the very first Boss pedals. Somewhere on the net, you can find a solution, so the LED stays on, when the pedal is switched on. I hav seen a description for an old DS-1.

Hatredman

Take any newer boss pedal schemo and rewire the led circuit. On older releases the LED is not connected to the flip flop. Why they did it is something beyond my understanding.
Kirk Hammet invented the Burst Box.

duck_arse

a look on the huge circuit shown here:
https://www.gearslutz.com/board/attachments/geekslutz-forum/324273d1357587184-loooking-service-manual-boss-cs-1-boss-cs1-compressor-sustainer.jpg

sez that the led current flows through the NO bypass push-button. you'd need to add a transistor buffer to drive the led, just like boss did, and connect it to the flip-flop transistors, just like boss did.

basically, look at an older boss circuit, copy the led drive part of that, like hatred sez while I'm type.
" I will say no more "

Hatredman

There's an OD2-R schemo here:

http://www.sugardas.lt/~igoramps/article20/boss_od_2r.gif

Compare the two flipflops:

OD2-R


CS-1


So, just take the LED, the Zener and the 1k resistor out of the CS-1 PCB, wire them offboard in series according to the OD2-R schemo, and then connect the open lug of the LED to +Vcc and the open lug of the Zener to the collector of Q7. Polarity matters, so  check! If the LED functions backasswards (i.e. lights up when the effect is bypassed) connect the Zener to the collector of Q6.

Have a good hunt, little wolf!
Kirk Hammet invented the Burst Box.