We are about to finish the BJF Universal Reverb kit. A circuit to which you are able to connect any (almost) reverb tank unit to. So it is an analog reverb with two outputs and controls for dwell, mix and tone. The pcb can go in a 1590bb box but the external reverb is of course bigger. Enough to make a pedal board on its own:) I hope we have the kit up by end of Feb. Questions about the pedal, welcome here!
Hi Bjorn. Hope you are well. I wanted to ask you about this reverb. I have a BYOC Tweed Royal amp that I built. Live the amp but there is no reverb. Could use this reverb kit to add the reverb between the pre amp and the power stage?
You can certainly add the reverb circuit to an amplifier. In fact I have three solid state amps that could do with an upgrade and that I am planning to install this circuit in.
Make sure that decoupling capacitors on powersupply are rated high enough so if you have 15V supply mount 25V decoupling capacitors
You can also increase the series resistans in the B-tree to drop Voltage to something suitable or mount a 78XX regulator from amplifier internal supply to
reverb ad on.
Hello Björn. I ordered the "Analog Reverb kit (incl. tank)" from Reverb.com and will be installing it in an amp case I'm building. I have a limited knowledge of electronics, but from the drawing in the manual it looks like the aluminum enclosure connects the grounds of the components. If I'm not putting it in the enclosure or using the jacks, do I connect the grounds from the pots and IN/OUT connections together? Is there anything else I should be concerned about if I build it without the enclosure and jacks? Thanks very much. Thanks for being multi-lingual also, as I don't know a word of Swedish (my loss)!
I never got a response to this, so I had to build it as I saw fit. For the benefit of those with the same question, I had success building this in a wooden amp case, and connected the ground between all of the components. I put a switch on the 9v power instead of activating the power through the stereo jack.
Ok sorry about that due to technical problems and myself travelling reply has been slow
Yes chassis make ground. You will need to wire ground terminals of in-and outputjacks together and connect that with pcb ground and make sure all ground points go together.
Ground in this case is a floating potential ( that will be connected to earth somewhere down the line)but also carries the reference fior the signal and circuit will not work without grounds wired together.
You can absolutely useca wooden box as long as you connect all grounds
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Thanks, Bjorn. I got it assembled no problem. I put it in a completely battery powered full range speaker built from Parts Express items and it sounds great. I appreciate your response.
I love the idea behind a universal reverb circuit. Do you think it is possible to add a tone control to the recovery circuit without modifying the pbc?
Oh tone control for reverb is definitely possible by just adding desired filter outboard inserted at Reverb level control.
I'll have a talk with Albin about making a tone control modification kit and getting schematics up for those that have parts lying about.
Worth mentioning is that the reverb effect from a typical tank has a fairly narrow bandwidth and low frequency reflections have tendency of causing mud whereas high frequency reflections a tendency of causing shimmer: therefore most effective would a treble control be and also limiting low frequency response to make effect appear more as shimmer
A difference between tanks is also how high up in frequency they go so it can be useful to have control for brightness.
Slight caution is again that tanks have limited bandwidth so boosting treble a lot after recovery can be just amplifying noise therefore
making a sort of bandpass boost can allow boosting the relatively important part of response i.e. highlighting where there is energy but not heating for the crows.
At your service
Thank you Bjorn. Your response has given some good ideas to think about!
Hi. I’m having trouble with my universal reverb. I’m not sure where I’m going wrong here. Using a scope, I can see that I have signal all the through the transformer out, into the recovery side, but then the signal just disappears after T6. I’ve checked all solder connections for bridging and everything looks fine. I even went so far as to rebuild the unit in a wooden enclosure so I could connect isolate and connect grounds manually to see if grounding was an issue. Power seems fine throughout, it’s just the signal that disappears. I noticed that my PCB is different from all the pictures I’ve seen, specifically there is no trace connection between R18 and R22? It seems like the tail end of R18 is connected to nothing at all? Any help would be much appreciated! My board version is 1.12.