Based on the preamp of Traynor TS50B, Rusty Box is a big sounding circuit, perfect for bass and baritone guitars. The layout runs on 18v and has an onboard voltage inverter and voltage regulators for 15v/-15v operation. But it might work well on 9v as well but it will probably have more gain (...and less headroom) and some bias tweaking might be necessary.
That output stage is pretty interesting - I might have to have a play with that at a later date.
ReplyDeleteIt worked OK from the first try...thank you, fuzzhead! You're fabulous, as usually :)
ReplyDeleteI used a 2SK30A for the FET (I have a lot), 2N3906s having hFEs between 200 and 230 and a TC962 instead of LTC1144 (I grounded pin 6 in order to double the frequency of the internal oscillator by adding a link between V8 and X8).
As a clean preamp it sounds very good (a lot of bass very nice compressed) and as a dirt preamp it sounds very "stonerish" :)
Thanks Radu!
DeleteI'll rweork the power section and when it is done, I'll tag it.
Was this ever updated or varified? It looks sooo interesting!
ReplyDeleteI should be able to run a ground jumper to the open pad next to pin 6 of the IC2 as radubor mentioned and I'm good to go?
ReplyDeleteSorry for rambling, I'm just going for it and I'll figure it out. Hope this sounds half as cool as it looks. Thanks guys!
ReplyDeleteHold on! I'll upload the layout with the updated power section during the weekend and tag it as verified since Radu built it.
DeleteThanks so much fuzzhead. very appreciated!. I was going to wait a bit. To many current projects to finish.
ReplyDeleteThe layout is now updated and tagged.
ReplyDeleteHello, if I want to ad a 3pdt switch to use as Boost Switch, how should I connect?
ReplyDelete1 4 7
2 5 8
3 6 9
1 to Boost SW 1 (ground)
2 to Boost SW 2
4 to ground and 5 to Led- ?
Thanks for the great layout. Is it normal to measure 14.7 V on the positive rail and -13.6 V on the negative rail referenced to ground? I'm using two brand new 9v batteries in series to get the 18v supply.
ReplyDeletehey all - I just built this up and thought I would offer a few notes on what is a pretty killer circuit. 1) Per John K's notes on the tagboard layout, you can make a C15k pot for the mids by adding a 39k resistor to legs 1 and 3 of a C25k pot - the total resistance is just slightly higher than 15k and the taper is not a perfect reverse log sweep but it works well enough.
ReplyDelete2) Anders omitted the input signal pad switch but it is worth having since it offers a pretty wide variation in gain potential. I put lug two of an SPDT on/on toggle in between the actual input and the input pad on the board here. Then I added a cut to Row O/Column 4 and put a 10k resistor from Row O/Column 3 to ground, right next to the 15v regulator ground pin. I connected lug one of the SPDT toggle to Row O so that the resistor to ground is added to the input when the switch is flipped. This cuts the input gain considerably which makes this REALLY loud circuit a little more usable with high output pickups (I use Lace Deathbuckers).
Just finished this today, and it worked immediately! Except... I am running it at 9v until I can feed it 18v. And the behavior is the opposite of what Fuzzhead hypothesized... it is huge and super clean, Even with the boost engaged and the gain maxed it is only a hair overdriven. It sounds great, but... is it really working as it should?
ReplyDeleteIC2 is a charge pump that boosts the incoming voltage from 9V to 15V (for which the circuit was designed). Do NOT plug a higher voltage in, especially not 18v, because you'll fry a bunch of shit and have a dead pedal. Just run it at 9V and it'll work as intended.
DeleteAs for the lack of dirt, start double-checking your build with a fine-toothed comb. This is a pretty gnarly preamp, so you should be getting some real filth with the gain maxed. Something must be amiss.
The layout shows 18v coming in... and the regulator plays a role as well. Now you've got me a little confused. Fuzzhead's write up even says it runs on 18v
DeleteAh, yeah—apologies, I built a different layout of this using a charge pump/inverter. I try to err on the side of caution so no one blows up their hard work!
DeleteStill no idea about the lack of dirt, though.