Blackvibe FX Loop

[Bretly]

Finished my first amp kit. Came out great and I’m looking at building a Blackvibe. I’ve sourced all the parts. Plan on adding the presence and post PI master volume mod.

Using a super reverb chassis and all of those input and controls will use the vibrato channel.

There’s a lot of space so I was thinking on an fx loop. I didn’t have a good guide, I did some research and came up with one.

One issue here. I reversed the send and return from the tube. So my options there are redo the layout, simply switch the send and return jacks or simply get the JJ 823 that reverses the pins. So I know I have a problem to solve there.

I plan to use the normal inputs for the send receive and use shielded wire on those runs

This is a really rough first go at the layout. Just looking for any other issues I might have missed here or if I’m way off base and should abandon this.

Looking to hook in between the pre amp exit cap and the 220k mixing resistor.

Plan on using the normal channel inputs for send and recieve and shielded wire for those runs. All grounds to the pre amp bus. Sorry no schematic. I’m not capable of that yet.

Untitled_Artwork.jpeg

[Ten Over]

Finished my first amp kit. Came out great and I’m looking at building a Blackvibe. I’ve sourced all the parts. Plan on adding the presence and post PI master volume mod.

Using a super reverb chassis and all of those input and controls will use the vibrato channel.

There’s a lot of space so I was thinking on an fx loop. I didn’t have a good guide, I did some research and came up with one.

One issue here. I reversed the send and return from the tube. So my options there are redo the layout, simply switch the send and return jacks or simply get the JJ 823 that reverses the pins. So I know I have a problem to solve there.

I plan to use the normal inputs for the send receive and use shielded wire on those runs

This is a really rough first go at the layout. Just looking for any other issues I might have missed here or if I’m way off base and should abandon this.

Looking to hook in between the pre amp exit cap and the 220k mixing resistor.

Plan on using the normal channel inputs for send and recieve and shielded wire for those runs. All grounds to the pre amp bus. Sorry no schematic. I’m not capable of that yet.

Untitled_Artwork.jpeg

Not much response, eh?

I can't see any reason to use a 12DW7. Using a 12AX7 will solve your pin reversal problem.

Would you consider using the Normal channel knobs for Send level and maybe even Return level?

FX Loop RR763.jpg

[Bretly]

The reason was the low gain side to not overdrive the pedals and thanks for the response here, but I believe I’m abandoning this mod.

After buying my parts my board stretched compared to the layout of the board on the RR site which must be designed with some pretty small caps in mind.

As that occurred I decided not to sandwich more in there and to just give the resistors and everything a bit more breathing room.

From looking at your spec it looks like I wasn’t too far off though. Curios though and maybe it’s my ignorance but it looks here the insert starts between the 220k resistors and not between the cap from the pre-amp to the resistors.

Am I just reading it wrong or is there some advantage to this over where I would have inserted the circuit?

[Ten Over]

From looking at your spec it looks like I wasn’t too far off though. Curios though and maybe it’s my ignorance but it looks here the insert starts between the 220k resistors and not between the cap from the pre-amp to the resistors.

Am I just reading it wrong or is there some advantage to this over where I would have inserted the circuit?

I thought that the 220k/270k load on the second preamp stage was some kind of magic, so I left it there. Actually I messed up and put a 220k/220k divider there instead. It's probably still semi-magic.

The signal coming off the second preamp stage can exceed the capabilities of the cathode follower, but half the signal won't overdrive a properly designed cathode follower.