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So I've got my Mega Chorus up and running. Added a switch to slow rate which is super cool.
What a awesome pedal.
The only other change that would be nice is to make it a bit quieter.
Ive been rooting around in the forum.
To achieve less noise could I use a 3208D IC and lower C9 (.047) a little?
Have I figured this right?

Any other tips or tricks to quite it down a little?

That's not quite right. The idea here is to used a BBD with longer delay capabilities so that you can turn down the delay time while still getting the same amount of delay time from the smaller chip...because longer delay creates more noise.

Using a V3208D would give you twice the delay time as the 3207, so you would want to make the clock driver thing you're only asking for half of the delay time you really want to hear. The cap you want to change is C19 47pF. However, I'm not really sure if you can go much smaller than that. You can try it though.

Really, if you want to get any more meaningful noise reduction from the Mega Chorus, you might want to consider adding a compander circuit. Find yourself a schematic for the BOSS DC-3. There are dual delay lines that are out of phase with one another, but if you just focus on a single signal path, it is almost identical to what is going on in the Mega Chorus. If you compare the two schematics, you should see that the only real difference is the addition of the compander noise reduction circuit. If you got a SA571 or NE570 and some vero boad, you could build a little additional module with wires coming off it for +v, ground, send 1, send 2, return 1 and return 2.

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Hi. I just completed the Mega Chorus and Vibrato and would like to try this mod. I've never added in a module to a circuit before. Where on the Mega Chorus PCB would the send and receive point connect. I was trying to look at the schematic but it doesn't match up totally with my build.

Send and return for what? A compander?

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Yes I'm trying to do what you outlined here:



I couldn't find a schematic for the BOSS DC-3 but I found this http://www.generalguitargadgets.com/pdf/ggg_pt80_sc.pdf
it came from this page https://electricdruid.net/noise-reducti ... ompanders/

It seems to make enough sense but since I am very new to this I was just wondering where the correct place on the Mega Chorus to put it in. Also if that implementation is incorrect for the use case you described please let me know. Thanks for your reply.

https://elektrotanya.com/boss_ce-300_sc ... nload.html

This might be more applicable. Although, it's stereo, so keep in mind that you're looking and 1 input using only half of IC2 as a compressor, and then the two wet signals using each half of IC10 as separate expanders. You could also use the example from the PT80, but keep in mind that it's from a delay, so it has a feedback loop to create repeats (which you could also implement to create a flanger). When you add a compander noise reduction circuit to your bucket brigade delay effect, you are essentially sandwiching your wet signal path inside the compander. So if you're looking at the MegaChorus schematic, you insert the "compressor" at C4 and the "expander" at C11.

It may be helpful to mention that an NE570 or V571 chip is actually two companders on one chip. Aside from the pos and neg, the pins mirror each other, which should be apparent when you look at IC10 of the CE-300. Whether it is a compressor or expander depends on how you configure it.

I googled "compander noise reduction circuit" and got this: https://electricdruid.net/noise-reducti ... ompanders/

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com