madbeanpedals::forum

General => Open Discussion => Topic started by: Aentons on April 11, 2023, 01:02:14 PM

Title: I need a bypass board with tails. Please help :)
Post by: Aentons on April 11, 2023, 01:02:14 PM
I'm building the Skoolie and was thinking what else could possibly be crammed in with it... Tails, duh.

Anybody possibly know of a bypass board with tails?
Title: Re: I need a bypass board with tails. Please help :)
Post by: jwin615 on April 11, 2023, 01:30:20 PM
Fuzzdog has a few solutions
https://shop.pedalparts.co.uk/product/truetails
https://shop.pedalparts.co.uk/product/tails

I haven't used either so can't comment on which would be best
Title: Re: I need a bypass board with tails. Please help :)
Post by: madbean on April 11, 2023, 02:33:33 PM
The MemoryMan does not easily allow for tails bypass, unfortunately. Looking at the Skoolie schematic, in order to have tails you have to break the connection b/w R6/C4 to IC1 pin5/R20. However, R6 also delivers the voltage bias input to pin5, so if you remove that connection, you get nothing out of pin7 (or, nothing food sounding at least).

But, if you were to add another resistor at the junction of C23 and R20, then tie the other end of that to VB, it might work okay. It should be at least 220k as to not form a HP filter with C23.
Title: Re: I need a bypass board with tails. Please help :)
Post by: Aentons on April 11, 2023, 08:41:51 PM
Quote from: madbean on April 11, 2023, 02:33:33 PM
The MemoryMan does not easily allow for tails bypass, unfortunately. Looking at the Skoolie schematic, in order to have tails you have to break the connection b/w R6/C4 to IC1 pin5/R20. However, R6 also delivers the voltage bias input to pin5, so if you remove that connection, you get nothing out of pin7 (or, nothing food sounding at least).

But, if you were to add another resistor at the junction of C23 and R20, then tie the other end of that to VB, it might work okay. It should be at least 220k as to not form a HP filter with C23.
That sounds like a plan I can test. Thanks!

I'm curious tho, will grounding the input and leaving the output connected on a buffered bypass board be to noisy, or is there some other reason that doesn't work?


Title: Re: I need a bypass board with tails. Please help :)
Post by: madbean on April 11, 2023, 10:54:42 PM
Maybe this will clear it up:

Insert switch to break dry guitar signal (tails bypass)
Add new resistor RNEW (1M) to Vb
Omit wire from pad3 on S1
Jumper pads 2/1 on S1

This might work. May be better to put RNEW on the other side of R20, but I'm not sure. Best bet would be to just move R6 and C4 off-board to some perf and solder RNEW directly to the audio PCB.