Premier Rock Forum

Well i'll tell ya ben it was pretty scientific.

I started w a bag of LND150s, and then asked "what should I do with these." I googled "depletion mode mosfet bias," saw a few examples and was like "oh that looks like a SHO minus a resistor" (dep-fets don't need the D-G bias resistor turns out). So I just started w/ stock SHO values and then adjusted until I got the same basic thing out of the LND150 - Vd that swings from about 7V at min gain to about 4.5V at max gain, good cleanup from the volume knob, highs are rolled off a tad as gain goes up and input impedance goes down.

From there, I was like "I guess I'll stack them?" And then basically just copied some ideas from a Vox AC50 preamp. Didn't love the eq, so I used a James stack instead. I tried tacking BJT emitter followers onto the SHOs, but I honestly couldn't tell any difference between A and B so I figured why bother (checked some zvex schematics and noticed they don't use them either, and those pedals stopped blowing up a while ago). The interstage caps and resistors are sort of random-ish depending on where they are - a lot of stuff to try and deal w switch popping.

The diode-biased stage is cribbed from a spaceman pedal - the saturn boost. I used a different diode than he does which sets the Vd a little higher, and used the pot to starve it down further. I like the way it works with the sag applied to only that one stage better than when it's applied globally but ymmv. FWIW, fairfield seem to have switched from one to the other in the revised barbershop (a very nice pedal!).

For the switchable boost(s) I was like, "2-in-1s usually don't work very well b/c when you drive the front end you can't control the output volume and when you boost after you don't get any extra dirt." So I did both, which in retrospect might be overkill as I probably could've just swapped between two different volume pots instead of adding an entirely new output stage but c'est la guerre and this way you get even more grit.

The LND150s are quieter than BS170s for sure, the pedal doesn't feel overly loud, and if you're using the boost sparingly the main OD section isn't louder than anything else.

But yeah, tldr I just sort of futzed around until I thought it sounded ok.

SCIENCE!!!

benadrian wrote: Tue Oct 24, 2023 4:00 pm SCIENCE!!!

ol' asbestos-hands is doing a great job soldering in surface mount components freehand with a clunky 60w iron

I've been taking an IPC certification course this week and that image has been brought up multiple times.

I wish I had known you could do this years ago.

desoldering, swapping, and resoldering pins 2 & 3 for all the XLR ins & outs of my Otari so it will use a standard balanced snake

Music Man 115 Sixty-Five:



I've been trying to sell this thing for months. Had a couple people ask if I had the original grill cloth for it. Whatever the PO put on here reminds me of Dr. Dre's suit from his World Class Wreckin' Cru days.



So I ordered some new OG-style cloth. But I didn't want shiny new cloth on a 44 year old amp, so I tried some light "aging" on it using 100 tea bags I picked up at the Dollar Tree. Boiled the tea bags in a couple of batches, then soaked the cloth overnight until it looked like it had spent some time in a club.




You can see the slight difference here:



Disassembled the baffle, removed the old stuff and the staples, and installed the new stuff:



Took the opportunity to put the knobs in the ultrasonic cleaner, rebias the output stage, calibrate the trem. and remove a questionable reverb tank output tap mod.

That's funny... I grabbed some well worn, vintage Traynor grill cloth from a dude in Ontario to replace the plastic-y black stuff on my YS-15P and have been putting off cleaning it to closer match the newer stuff on the amp.

Replacing this tuner on my pedal steel
How am I supposed to fit a 10 mm hex here?!

I got it most of the way there, but it’s not snug compared to the others.

edit: found a smaller wrench and got it. Still seething though

llllllllllllllllllll wrote: Replacing this tuner on my pedal steel

How am I supposed to fit a 10 mm hex here?!

I got it most of the way there, but it’s not snug compared to the others.

edit: found a smaller wrench and got it. Still seething though

Socket wrench woulda been my first suggestion for that but even then depending on size/thickness could end up w/ same problem.

Bad design there for sure. Recessed 1/4" jacks sometimes have this annoying quirk too (looking at you strat). Anyway, hopefully you never have to deal w/ it again - put that wrench in the instrument's case - maybe even flag it w/ some tape.