Big muff capacitor question (green russian reissue)

[Evilfartman]

Hi, I got a green russian reissue a while back and while I love it, it seemed pretty bassy which didn't work with my already borderline too bassy eq on my amp. I went messing about with it but nothing really worked for me until I disconnected the c1a cap (I replaced it with a huge poly capacitor which came loose and I liked it a lot more when it wasnt connected)

Is there any real problem with having this capacitor disconnected? I assume c1b is still doing the dc current thing (still a noob sorry lol), so it should be fine right?

[Aleph Null]

Could you post the schematic you're working from? That'll make it easier to see what exactly you've changed.

[Evilfartman]

Could you post the schematic you're working from? That'll make it easier to see what exactly you've changed.

It's just the green russian reissue, I assume it's this one but with two capacitors at c1 in series. Or parallel idk
http://www.bigmuffpage.com/images/schematics/V7_V8_BMP_Schematic_TallFontRussian_BubbleFontRussian.jpg

https://sc1.musik-produktiv.com/pic-010098988_02xxl/electro-harmonix-green-russian-big-muff.jpg
^that's not mine (I'm not at home rn) but you can see c1a and c1b at the bottom of it

[jwin615]

You're likely correct.
They probably have a single board made for all the transistor reissues and place the carrying parts on it once it's in NYC to make the different versions.
IIRC, in the bass bmp, they just added another 100 cap on top of/parallel to the existing one, and that kinda looks like what they did on that board as well.
A simple resistance check between the pads would confirm that

[Evilfartman]

You're likely correct.
They probably have a single board made for all the transistor reissues and place the carrying parts on it once it's in NYC to make the different versions.
IIRC, in the bass bmp, they just added another 100 cap on top of/parallel to the existing one, and that kinda looks like what they did on that board as well.
A simple resistance check between the pads would confirm that

Ah right fair, so it's probably fine to leave it off?

[jwin615]

Plug a guitar cable into the input
Turn it on
Check for DC between the tip and sleeve with a multimeter
0DC and you're likely good.

[Evilfartman]

Plug a guitar cable into the input
Turn it on
Check for DC between the tip and sleeve with a multimeter
0DC and you're likely good.

Just got home and checked, it was like 0.001. All seems fine, thanks for the help

[Aleph Null]

If the two input caps were in series, removing one would stop all signal. If you've removed one of the capacitors and are getting sound, they must be in parallel. When capacitors are in parallel, the capacitance adds. So removing one of the input caps means you reduced the capacitance.  Reduced capacitance will increase the cutoff frequency for the high pass filter formed by the RC network at the input. Basically, removing a cap will reduce the amount of bass getting into the circuit. How much will depend on the values of the two caps.

[jimilee]

If the two input caps were in series, removing one would stop all signal. If you've removed one of the capacitors and are getting sound, they must be in parallel. When capacitors are in parallel, the capacitance adds. So removing one of the input caps means you reduced the capacitance.  Reduced capacitance will increase the cutoff frequency for the high pass filter formed by the RC network at the input. Basically, removing a cap will reduce the amount of bass getting into the circuit. How much will depend on the values of the two caps.

It looks like it had a total of 110nf on the input. That's just weird. For guitar, I would cut it down to about 47n, but socket to see what you like.


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[Evilfartman]

If the two input caps were in series, removing one would stop all signal. If you've removed one of the capacitors and are getting sound, they must be in parallel. When capacitors are in parallel, the capacitance adds. So removing one of the input caps means you reduced the capacitance.  Reduced capacitance will increase the cutoff frequency for the high pass filter formed by the RC network at the input. Basically, removing a cap will reduce the amount of bass getting into the circuit. How much will depend on the values of the two caps.

Ah right okay, I remember figuring out that it was one based on some series parallel value calculator site but I couldn't remember which sorry. And yeah that's why I went messing with the capacitors to attempt to cut the muddyness (that and everything else was surface mount)

If the two input caps were in series, removing one would stop all signal. If you've removed one of the capacitors and are getting sound, they must be in parallel. When capacitors are in parallel, the capacitance adds. So removing one of the input caps means you reduced the capacitance.  Reduced capacitance will increase the cutoff frequency for the high pass filter formed by the RC network at the input. Basically, removing a cap will reduce the amount of bass getting into the circuit. How much will depend on the values of the two caps.

It looks like it had a total of 110nf on the input. That's just weird. For guitar, I would cut it down to about 47n, but socket to see what you like.


Sent from my iPhone using Tapatalk

I think I have it at 10nf now which sounds fine, I might put the second capacitor on a switch so I can turn it on if I want to use it on bass