Clipper Ship Overdrive. This is a dirty boost cascaded into a FET-based booster (a tweaked version of R.G. Keen’s “SRPP,” based on the AMZ Mini Booster). The gain control goes from clean to fuzzy, but the pedal always cleans up with your guitar’s volume, making it a very open and touch sensitive dirt pedal. And the boost stage has gobs of output to push your amp into its own overdrive. A “stupidly wonderful tone control” allows for treble boost clockwise and treble cut counterclockwise. This build used a Russian germanium transistor for the dirt side and germanium diodes. The overall character is kind of Vox-y.
Edited notes from the schematic files:
Q1: Any Ge or Si. Germanium with hfe 40-70 sounded best to me and cleaned up well. Q2 & Q3: 2N5457, J201, or other JFET.
Ge1, G2: Diodes should have a Fv < .3v for best performance. Many schotkey diodes will also work great. Red Ge diode prevents temperature changes from affecting the leakage of a Ge transistor. Omit if using a silicon in Q1.
My prototype of version 2.0 used a russian MP38A Ge transistor in Q1 (~61 hfe, leakage ~ 60uA) and Smallbear "Generic" Ge diodes.
This is interesting: ANY transistor will work in Q1 ... including PNP. I can't really recommend using a PNP without more information on why it worked, though.
What do you mean by D1 is SI ? and can you give an example
ReplyDeleteSilicon. 1N4148, 1N914, 1N4001 etc etc
Deletethanks
DeleteThis looks interesting! I'm curious about trying a PNP in position Q1 as i have a heap of AC128 trannies hanging around and no NPN's. Its been hinted they may work. Would you know if I need to keep the CBE leg positions the same as above and just wack it in?
ReplyDeleteYes collector, base and emitter will need to be connected to the marked points on the board, whatever that means for the orientation of the transistor you use. The AC128 transistors that I have have pins in a triangle formation like this:
Delete--B--
E---C
With the red dot or tab next to the emitter.
Thanks mate, I'll give it a go! Cheers.
DeleteWell, I have no idea what was going on with my test unit OR the breadboard last time, but in verifying the PCB tonight, I have confirmed that PNP will not in fact work. It passes signal -- amplified signal even -- but the gain control doesn't work and it just sounds misbiased.
ReplyDeleteRats! But I'm glad all is right with the world now. Sorry to anyone who tried to build it that way. :(
Jeff: If you don't have any germanium, you can still use a silicon -- it just requires turning down the tone more in high gain settings to avoid the fizzies. Or hit me up on one of the forums or by e-mail and I can try to get a good tested Russian one to you.
Here's the link to the build document with the current BOM.
https://docs.google.com/document/d/1dPlB8Lqn_a1A6Xpb3Lg-2cfTxGCLOkMfNUWALyGE3ZQ/edit
-Jon
Sorry Jon, I just saw your comments then. I'm waiting for some russian germaniuns to show up but who knows when that will happen.... I might give this a go with the silicon Q1 and swap it around later if needed. Its a pity about the PNP. All my PNP germaniums are great and my NPNs are nasty bad, either high super high leakage or very low gain. They might make nice diodes though.
ReplyDeleteCheers.
Still awaiting delivery from mother Russia... I've been rummaging around for some low gain geraniums for q1 but I'm guessing 10 hfe is too low. I found some silicon ones that show done promise. I have a 2n2102 with a gain of around 50 hfe, and I've salvaged some trannies with 223 on them that measure from 40 to 70 hfe. Wouldn't know what the are but might be worth a shot...
ReplyDeleteIt looks to me like there should be two more cuts in this layout, both in the track to which Volume 1 connects. One should be right above D2, and the other should be underneath the 47k resistor. Is that true?
ReplyDeleteI'll check it once i find the time.
Delete+m
This looks correct to me. Otherwise a bunch of stuff is connected where it shouldn't be.
DeleteYEESSSS! you are playing the replacements!
ReplyDeleteYEESSSS! you are playing the replacements!
ReplyDeleteOh wow, didn't realize this hadn't been verified here yet. I just built one off a PCB I bought from Jon and it is FANTASTIC. I boxed it together with his Fallstaff boost in a 1590bb and had a jam session just with Strat->Fallstaff->Clipper Ship->Traynor YCV20 and it was an absolute blast. I'm going to build one from this vero layout to have a 1590B on the pedalboard as well. I'll let you know once I've verified!
ReplyDeleteYou can tag this after you apply Tristan's fixes listed above.
ReplyDeleteJust checked it and you and Tristan are correct.
DeleteCheers John!
+m
Had a wee bit of spare time today so built this and its amazing. Used AC176 in Q1, 1N4148 in D1, OA70 in D2, a totally unknown Ge diode (has a blue and green dot at one end and a blue line on a black case) in D3 and 2N5457s for Q2 and 3. Get some wonderful tones from this. Thanks as always guys.
Delete