Removing the reverb circuit from a Lab L5

[kvandekrol]

http://www.netads.com/~meo/Guitar/Amps/Lab/Images/Lab_Series_L5_L7_L9_L11_scheme.jpeg

I'm in the process of designing & building a Lab Series L5 preamp clone to put in a rackmount enclosure. I think I have everything else figured out but this: I want to remove the reverb from the circuit entirely. I think I know how to do it, but I'm looking for some independent verification that I'm not missing anything!

If I was to eliminate the wire labeled "4" that goes from the preamp board to the power supply board, and eliminate R165 (18k) that goes between the multifilter and the reverb pot, and then remove the whole section between wires 5 & 6 and R165, would that do it? Do any of those components serve a purpose other than reverb, such that I would lose out on anything if they weren't there? Is the multifilter control affected at all by this?

Everything else related to the reverb appeared to be on the power supply board itself, which I won't be using...

[J M Fahey]

Yes, that's about it.
It affects nothing but itself, because reverb signal *usually* is a "parallel loop effect" , meaning the preamp signal follows its own path , *some* signal is diverted into the tanks power amp driver, delayed signal is recovered, and mixed with the original one further up, usually you see some resistors which carry different signals converging into a mixing point.
If you remove the reverb path, the other one is unaffected.
My respect to you, you are getting into a very complex (although excellent) preamp.
Are you building it in full, or chopping some parts off?
Good luck.

[kvandekrol]

I'm building the preamp by itself in a rackmount enclosure (with the power supply you drew up for me a few months ago on the preamp forum!). So I won't be tackling the power amp section at all, but it's complex enough even without it!

Other than removing the reverb, it will be a part-for-part clone. I'll probably post it up here as a project once I'm finished, along with a project file for the PCB, in case anyone is interested. It may be a year from now - we'll see!

[joecool85]

I'm building the preamp by itself in a rackmount enclosure (with the power supply you drew up for me a few months ago on the preamp forum!). So I won't be tackling the power amp section at all, but it's complex enough even without it!

Other than removing the reverb, it will be a part-for-part clone. I'll probably post it up here as a project once I'm finished, along with a project file for the PCB, in case anyone is interested. It may be a year from now - we'll see!

Keep us posted, theres nothing wrong with a long term project.