Biyang - CH-8 Analog Chorus  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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wikwox
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Post by wikwox »

Despite some glowing reports on this shiny rascal I rather dislike it, sounds brittle and not rich at all. I'm playing a strat and despite the tone knob it just does not warm up. Has anybody modded this pedal? Any adjustments inside? Lastly although it says it's analog It seems distinctly digital to me.

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Post by IvIark »

I've never seen the guts of one of these, so if you can post some high res gut shots it would be very useful.
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Post by wikwox »

I'll see what I can do but my cameras not that good.

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Post by roseblood11 »

You´ll find some higher quality parts (wima caps...), but also a lot of smd resistor. Absolutely not impossible to mod it, but it´s not easy. I would guess that the circuit is a clone of a boss chorus, maybe you can check that with a schematic.

Why don´t you build a clone of the Boss CE-2 into the Biyangs enclosure, using the tonepad layout? That would probably be easier and give a better result in the end.

http://www.tonepad.com/getFileInfo.asp?id=101

regards, Immo

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Post by LaceSensor »

Based on the CE-2
Has rate and depth as well as a tone control, and fast/slow toggle
uses panasonic mn3007 / 3101, as well as Wima caps, alpha pots, True Bypass (millenium I think)

Cant fault it for the price.
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Post by RnFR »

i was just going to ask you for this! i still have yet to build my buddy a chorus pedal, so i might just tell him to buy this thing. if it sounds good, i can't really deny it to him. just seems like too good of a deal. too bad i already bought the chips! maybe i'll mod it for bass.
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Post by LaceSensor »

RnFR wrote:i was just going to ask you for this! i still have yet to build my buddy a chorus pedal, so i might just tell him to buy this thing. if it sounds good, i can't really deny it to him. just seems like too good of a deal. too bad i already bought the chips! maybe i'll mod it for bass.
The tone control isnt that useful for me, but i can see how it might be. Its a worthy addition. Ive got the chips to make Madbeans CE-2 so ill compare them after the fact.
The only doubt for me of this pedal is the footswtich. its the same as old EHX reissues, so I expect it to flake out first of anything.
They look really nice though, the boxes are very impressive. Not that i use batteries, but tool free access too!
Incredible in the scope of the price, and I would say only $5 of parts away from bulletproof.

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Post by LaceSensor »

https://www.freestompboxes.org/viewtopic ... 49#p150249 sorry for the repost. A mod can merge?
It sounds lovely to me. Maybe the OP got a dud.

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Post by RnFR »

merged. can you post both sides of the board? looks like it would not be too hard to mod.
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Post by LaceSensor »

its 2am here. ill try to get to it over the next couple days

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Post by LaceSensor »

Hi

Full images of both sides of the board now here

https://s1178.photobucket.com/albums/x3 ... r1/biyang/

sorry for the delay.

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Post by LaceSensor »

Few more if people need them
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Post by fedeza »

hi there. I just bought this pedal, and I have a nasty problem: when I play it through a clean amp, the sound becomes distorted. Like a saturation, but in the same volume level.
Could I do something? I'm thinking to throw it to the trash!! :cry:

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Post by Fender3D »

hmm...
no bias trimmer... you'll have a hard time...

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Post by Dirk_Hendrik »

fedeza wrote:hi there. I just bought this pedal, and I have a nasty problem: when I play it through a clean amp, the sound becomes distorted. Like a saturation, but in the same volume level.
Could I do something? I'm thinking to throw it to the trash!! :cry:
Fender3D above is right. The fisrt thing to do would be to verify your chorus is correctly biased. I find it hard to expect that a pedal in this price range, probably built by production employees with a minimal salary, goes through a quality control that ensures all products that leave the factory are optimally set up.

So,
get a sinewave, get a scope, and readjust the BBD bias.
Sorry. Plain out of planes.

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Post by fedeza »

thanks for the clues... but I don't know how to biasing... neither have a scope or sinewave :roll:

Is there any other way to do that? someone has the schems or any datasheet?

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Post by Dirk_Hendrik »

Life ain't pre-chewed.

Study laddie. Study hard and you'll find out this task is rather simple in the end. But it does require some effort from you too.
Sorry. Plain out of planes.

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Post by fedeza »

nice advice!! but that's why i'm here in the forum, to find some help from this particular problem. If i want to know full electronics formation then I would have signed at university
If you don't know how to solve this particular problem, please help me with some link or place to refer. :block:

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Post by Dirk_Hendrik »

here you go:
https://www.freestompboxes.org/

And use the search. What you're asking is someone to do the work for you. It's your pedal. That means effort is to come from you too instead of having it spelled out.
Sorry. Plain out of planes.

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Post by LaceSensor »

if you do bin it, pull the IC first ;) they are worth saving.

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