Trails bypass, would this work

[TieskeP]

I'd like to add trails bypass to an existing pcb (in this case the FV-1 Arachnid), without modifying the pcb itself. Would the concept depicted in the illustration work? The board output is buffered, that's why I only added a buffer to the input signal.

If not, what would I need to change to make it work? Or are there any other solutions already available maybe?

 

[mrguep]

Up!

I’m also interested, I wish to build a Cataclysm Delay with trails.
Did you tried your diagram?

 

[Feral Feline]

That could work, theoretically, @TieskeP.

However, you don't need that extra buffer, just cut the signal-input to the board on bypass.

The buffered output is what makes tails/trails work. Board's output could be routed directly to the 3PDT's lug-8.


There are DIY veros and perfs and how-to articles to add tails/trails, and there are PCBs for it too, such as these from Fuzz Dog:

TAILS - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. Very simple to implement, and a tiny footprint meaning you should be able to fit it in...

shop.pedalparts.co.uk

Tails/True Bypass - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. This has been available for some time as a tiny additional PCB, but implementing it could...

shop.pedalparts.co.uk

Of course, you could just McGyver something from examining the Fuzzdog Tails/TrueTails build-docs and not spend money on the PCB.


Look around DIYSB and FreeSB for more how-tos.


I like the TrueTails style, that way you can have true-bypass when you want/need it and tails when you...

...want...


...need...




...it...





t


However, there may be some feedback or phase cancellation. Maybe take the output from the FV-1's pin that outputs the repeats only. Consult the FV-1 Datasheet PDF, I'm by no means an expert on any of this, let alone FV-1.

 

[Feral Feline]

@mrguep The Cataclysm is PT2399-based for which there are well-established ways to get tails.

Check the Fuzzdog links in my previous post.

 

[mrguep]

Hi @fereal feline,

Thanks a lot for your precious informations and links. Really helpfull!

I plan to build the small "tails PCB" on a vero and add a switch to allow tails or true bypass.

I'll post soon a schematic of what it could be.

 

[mrguep]

Hi there,

I worked on a vero version of the tails PCB (https://shop.pedalparts.co.uk/product/tails) that you'll find the schematics bellow




So I made this thing hopping it could work. This is "designed" to allow to switch (SW2) between True Bypass and Tails mode:



If anybody have time to check this and give me a feedback, it will be really appreciate
I'm still waiting for the Delay's PCB I plan to build so cannot test it in real life.

I will share the vero without components when it will be tested and verified to prevent mistaked reproduction.

By the way, I will build the D'lay V3 from Guitar PCB (because it has an optional tap tempo) that the schematic is below.
For me; decoupling cap is the one cercled in red (C17, 41nf), does anybody could confirm it or tell me which is the decoupling cap?


Can't wait to read feedbacks

 

[TieskeP]

That could work, theoretically, @TieskeP.

However, you don't need that extra buffer, just cut the signal-input to the board on bypass.

The buffered output is what makes tails/trails work. Board's output could be routed directly to the 3PDT's lug-8.


There are DIY veros and perfs and how-to articles to add tails/trails, and there are PCBs for it too, such as these from Fuzz Dog:

TAILS - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. Very simple to implement, and a tiny footprint meaning you should be able to fit it in...

shop.pedalparts.co.uk

Tails/True Bypass - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. This has been available for some time as a tiny additional PCB, but implementing it could...

shop.pedalparts.co.uk

Of course, you could just McGyver something from examining the Fuzzdog Tails/TrueTails build-docs and not spend money on the PCB.


Look around DIYSB and FreeSB for more how-tos.


I like the TrueTails style, that way you can have true-bypass when you want/need it and tails when you...

...want...


...need...




...it...





t


However, there may be some feedback or phase cancellation. Maybe take the output from the FV-1's pin that outputs the repeats only. Consult the FV-1 Datasheet PDF, I'm by no means an expert on any of this, let alone FV-1.

Thanks for the information and the suggestions!

That could work, theoretically, @TieskeP.

However, you don't need that extra buffer, just cut the signal-input to the board on bypass.

The buffered output is what makes tails/trails work. Board's output could be routed directly to the 3PDT's lug-8.


There are DIY veros and perfs and how-to articles to add tails/trails, and there are PCBs for it too, such as these from Fuzz Dog:

TAILS - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. Very simple to implement, and a tiny footprint meaning you should be able to fit it in...

shop.pedalparts.co.uk

Tails/True Bypass - add-on for PT2399 delays

This neat little circuit replaces a decoupling capacitor on many PT2399-based delays to enable a Tails function, meaning your repeats are still heard after bypass without your current signal being delayed. This has been available for some time as a tiny additional PCB, but implementing it could...

shop.pedalparts.co.uk

Of course, you could just McGyver something from examining the Fuzzdog Tails/TrueTails build-docs and not spend money on the PCB.


Look around DIYSB and FreeSB for more how-tos.


I like the TrueTails style, that way you can have true-bypass when you want/need it and tails when you...

...want...


...need...




...it...





t


However, there may be some feedback or phase cancellation. Maybe take the output from the FV-1's pin that outputs the repeats only. Consult the FV-1 Datasheet PDF, I'm by no means an expert on any of this, let alone FV-1.

Thanks for the information and suggestions!

Wouldn’t leaving out the buffer in the proposed schematic potentially cause issues, since you’d mix a buffered output signal from the effect pcb with the unbuffered input signal?

The kits you suggested might work too. I think I could try replacing a decoupling capacitor just before the FV-1 chip with the in- and output signals of the bypass pcb. That would be similar as to how it’s applied to the PT2399 delay kits.

The only thing I have doubts about is that the mix control on most FV-1 controls is a bit different than in most PT2399 delay kits. In the FV-1, you can go full wet, which would mean that in buffered bypass mode, there is no signal when the mix is set to full wet (after the repeats have trailed off)

 

[TieskeP]

Hi there,

I worked on a vero version of the tails PCB (https://shop.pedalparts.co.uk/product/tails) that you'll find the schematics bellow

View attachment 65705


So I made this thing hopping it could work. This is "designed" to allow to switch (SW2) between True Bypass and Tails mode:

View attachment 65706

If anybody have time to check this and give me a feedback, it will be really appreciate
I'm still waiting for the Delay's PCB I plan to build so cannot test it in real life.

I will share the vero without components when it will be tested and verified to prevent mistaked reproduction.

By the way, I will build the D'lay V3 from Guitar PCB (because it has an optional tap tempo) that the schematic is below.
For me; decoupling cap is the one cercled in red (C17, 41nf), does anybody could confirm it or tell me which is the decoupling cap?

View attachment 65709
Can't wait to read feedbacks

I think your Vero schematics should work like that. Let us know how it works out for you

C17 seems to be the decoupling capacitor that you should replace for the D’lay to get the trails bypass indeed

 

[Bricksnbeatles]

What about an optocoupler to mute the input to the FV-1 instead of one of the poles of the switch? That way you don’t get a big footswitch pop as the last thing in the tails of a long reverb wash when you bypass it.

Anyone have thoughts?

 

[Feral Feline]

I'm going to suggest that @mrguep start a separate thread, as I think the two delay circuits (PT2399 vs FV-1) are different enough to warrant such.
Keep this thread focused on FV-1, and I look forward to checking out the D'Lay mods as I have a few of those PCBs myself.

I'll have to re-read the various ideas later this weekend, right now I've gotta go fetch a car a friend bought.

 

[TieskeP]

What about an optocoupler to mute the input to the FV-1 instead of one of the poles of the switch? That way you don’t get a big footswitch pop as the last thing in the tails of a long reverb wash when you bypass it.

Anyone have thoughts?

With the suggested bypass pcb, the switching is actually done with the JFET transistor, this should mitigate the pop noise issue you’d get with a mechanical switch. But an optocoupler could be an option too indeed. This doesn’t solve the issue I see for the mix knob though - in bypass the mix knob is still in the audio path, which wouldn’t work when set to full wet.