Great British Spring Reverb Clone

[smilan]

Hi, I would like to build a Great British Spring clone, I found some pictures of the original unit, but I couldn't find any picture that shows how everything is assembled inside the plastic pipe? Especially how the recovery circuit is assembled to the reverb tanks? Maybe someone can post some photos of the inner assembly of those units?
Also I'm thinking of adding balanced inputs and outputs using THAT 1646 and 1606 (instead of expensive transformers) and I'm wondering if I can use a 22V single supply with the THAT 1646 and 1606 ICs (same as the NE5534?)

 

[Whoops]

I guess you can use a single 22v supply but you will have limited headroom, you will have to build a PSU anyway why just don’t build a 2 rail PSU?
It’s really easy and there’s tons of already made PCBs for it.

Also the springs assembly of this units where custom made, it’s not something you will have off the shelf, so I don’t really know how do you want to match the original springs and coils, actually I seeing that as almost impossible, even more if you don’t have an original unit in front of you.

Good luck

 

[smilan]

It's not a problem to build a dual PSU, but I'm thinking of keeping the original design, maybe the limited headroom is part of the unique sound of this reverb.
As far as the springs, I've read on several places online that the original springs were an Accutronics model 9dc1d1e.
What I couldn't find is a picture that shows how the recovery PCB were connected to the springs / plastic tube?
You can clearly see that the metal tanks sit on a metal plate that is held by two rails on the inner side of the tube, it looks like a pretty simple assembly.

 

[Newmarket]

It's not a problem to build a dual PSU, but I'm thinking of keeping the original design, maybe the limited headroom is part of the unique sound of this reverb.

Since the original doesn't have the THAT I/O devices - reduced headroom on these devices is definitely not part of the original "sound" of GBR.

 

[Whoops]

As far as the springs, I've read on several places online that the original springs were an Accutronics model 9dc1d1e.

So that's great, it makes everything easier as that is actually an off the shelf unit,
the mechanical parts of the spring assembly was what I though would be difficult to do, but as it uses an Accutronics tank then you will get there for sure

Have fun and keep us posted

 

[smilan]

There are two things I don't understand from the recovery circuit layout:
1. This 100K (R?) resistor is connected between the positive supply rail of the 2nd op amp to where? (it's not clear if it connected to pin 3 of the second TL071 or to the 0V rail?)
2. The 100uF cap (C?), it's not clear where the negative side of this cap is connected to?
The way I'm understanding it, the negative side of this cap should be connected to GND so R1 and R2 create a voltage divider of the +22V rail so the audio signal will be biased to half of the supply rail.
The layout doesn't show a connection between the negative side of C? to ground, so am I missing something here or it should be connected as I draw it above the layout?

 

[thomasdf]

I have one, the balanced version. I can take pictures and give you info about it but not before the 20th of September as I am away

My layout is different than the one you posted. The original PSU was very noisy, replaced it with a 14VDC SMPS laptop style from Amazon + full recap and it is dead silent now

 

[smilan]

I have one, the balanced version. I can take pictures and give you info about it but not before the 20th of September as I am away

My layout is different than the one you posted. The original PSU was very noisy, replaced it with a 14VDC SMPS laptop style from Amazon + full recap and it is dead silent now

Thank you very much!
That would be awesome, I don't in a hurry and the 20th of September is my birthday, so it will be a nice present

 

[Electrobumps]

I have one, the balanced version. I can take pictures and give you info about it but not before the 20th of September as I am away

My layout is different than the one you posted. The original PSU was very noisy, replaced it with a 14VDC SMPS laptop style from Amazon + full recap and it is dead silent now

This is great to know. Would also love it if you can share info on it.

 

[thomasdf]

tag me here with your questions after September 20th and I’ll see what I can do to help !