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pedals 4 pv
Platinum Member
Canada
1351 Posts |
 Posted - 08/12/2007 : 04:47:01
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| when i power up my pedalboard some pedals are in the on state and some are in the off state no one at the music store staffed by failed musicial careers seems to know why. all are boss pedals and it doesnt seem to matter where they are placed in the chain |
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mattoqua
Silver Member
Canada
438 Posts |
Posted - 08/12/2007 : 05:12:41
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It's nothing really. Just some pedals have the switch one way instead of the other. So when it's powered up, it will always turn on or off the same way, and all of the same pedal are made that way.
If you're really interested, you can look around on here somewhere. There was a thread that explained it nicely |
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pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 08/12/2007 : 05:35:17
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| yeah i wasnt too worried about it but after learning the asa psa jive the hard way with my ce-2 i bought a couple more used pedals and it did cause me to ponder |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/12/2007 : 06:59:49
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quote:
Originally posted by pedals 4 pv
when i power up my pedal board some pedals are in the on state and some are in the off state no one at the music store staffed by failed musical careers seems to know why. all are boss pedals and it doesn't seem to matter where they are placed in the chain
Hi pedals 4 pv & Guys
It all as to do with how the 2 transistors in the foot switch flip-flop circuit wake up. or are biased.
(yes that's a real circuit name, not something I just make up  )
Simple fix --- if you can solder:
Exchange the positions of the two transistors that are in the foot switch flip flop.
On a CE-2 they are marked Q6 and Q7 (type 2SC945)
The 2SC945 is a common transistor, in fact any medium gain, or otherwise NPN transistor will work in this circuit.
No audio passes through this part of the circuit.
It is purely toggled by the foot-switch between active & bypass.
Try it pedals 4 pv, and let us know how you went.
Send us-me a list of the OFFENDING pedals, & I will see if I have the schematics & the component reference numbers for the circuits.
Be careful de-soldering & re-soldering the transistors.
If you can't solder or have the tools, maybe you and ChristoMephisto could come to some arrangement, he is also somewhere in Canada.
And is technically very skilled at mods & repairs to:
Pedals & other electronics.
And he is a very approachable & nice guy.
Regards and good luck 
Dr. Bob 
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pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 08/12/2007 : 07:26:31
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| thank dr. bob your explanation makes sense to me. the pedals that are on are:Ph-2 os-2 bd-2 ac-2 pw-1 the pedals that stay off are mt-2 hf-2 cs- 3 ch-1 dsd-2 ce-2 my tu-2 flashes once and then is off as normal the psm-5 comes on red.I will most likely leave them alone as I don't do any live performances it isnt that annoying really, but I just wanted to know what was up. As long as they continue to work I'll let sleeping dogs lay |
Edited by - pedals 4 pv on 08/12/2007 07:57:45 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/12/2007 : 08:30:44
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quote:
Originally posted by pedals 4 pv
thank dr. bob your explanation makes sense to me. the pedals that are on are:Ph-2 os-2 bd-2 ac-2 pw-1 the pedals that stay off are mt-2 hf-2 cs- 3 ch-1 dsd-2 ce-2 my tu-2 flashes once and then is off as normal the psm-5 comes on red.I will most likely leave them alone as I don't do any live performances it isnt that annoying really, but I just wanted to know what was up. As long as they continue to work I'll let sleeping dogs lay
Hi pedals 4 pv
On the OS-2 it's Q8 & Q9.
I don;t have a the full schematics for the
PH-2 -- BD-2 -- AC-2 -- PW-1
maybe the other guys can help out, or mail them to me, & I will then be able to tell you which tranistors to exchange.
Be aware that some pedals use 2SC1815 or 2SC2458 transistors.
The MZ-2 does not use a dedicated flip flop circuit,
the foot switch connects directly to the surface mount dedicated control & audio DSP IC, via an R-C network to ground.
Some pedals use some logic gates from IC's (AND & NAND gates.)
you should be able to find them as they have a couple of very low value 220pf to 470pf Caps near them.
as well as a pair of 56K & 100K resistors.
Are you able to solder & at least do one of the pedals?
Regards Dr. Bob |
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pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 08/14/2007 : 21:08:31
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| hi dr. bob et al. yes I can solder,but I still don't understand the root cause of this problem. Are the transistors getting weak? What would cause this biasing of the transistors to change? Or is this even a problem? I have done some repairs to some pedals like replacing battery clips etc. but these pedals all work great other than that,so I think I'll leave them alone. Unless you think it may cause some problem in the future. And thanks again for your advice. |
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moonmarkcus
Silver Member
Nicaragua
224 Posts |
Posted - 01/18/2009 : 05:21:46
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Dr....
Can I use C1815y instead C945p on any pedal???
I have a problem with CS-3 flip flop ( Other post) and I just reading in this post
quote:
Be aware that some pedals use 2SC1815 or 2SC2458 transistors.
What do you meant with this? |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/18/2009 : 10:20:53
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Hi
I see that cctsim, has already replied in the oher thread:
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=6309
Good luck.
The 1815 is a very Low noise transistor, sometimes used on the inputs of some Boss Pedals.
The 945, is not as quiet.
If you use a 945 in place of an 1815 on an input, or hi-gain circuit, you will be introducing more noise.
Both can be use for switching positions, or if they are used to turn on a LED.
Regards Dr. Bob |
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is this normal?
