Prescription Electronics Yardbox Teardown! See what's inside!

Hello and welcome back to the bench. Today we're cracking open a sought-after clone of the Tonebender MkIII, the Prescription Electronics Yardbox. Enjoy!
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#prescriptionelectronics #yardbox #tonebender #germanium #fuzz #diypedals #electronics

[@MC-hx6nk]

Looks like you were measuring Pin 3 of the Q3 Fuzz pot, instead of Pin 1. The diagram looks to be correct, but I would make the point that fully CW, Pin 1, 2 & 3 would all read the same. It looks like you have the Fuzz dimed, so the measurement should be correct anyway.

[@martinreid1740]

Nice to see you back Joe.

[@Loscha]

Thanks for another great teardown! Every best wish to your and your family from Melbourne Australia.

[@EJ_Crough]

I've haven't noticed noise from higher gain pedals due to messy wiring, I hate messy wiring due to O.C.D, so I tend to avoid it. My understanding is 90 degree crossings can be a lot more important with circuits that deal with much higher voltages and have seen that for myself in those EHX tube pedals. However, I have noticed noise coming from wires running too close to certain things in bbd circuits and, again, those tube EHX pedals. Shoutout to the Wiggler!

[@DevTechAudio]

Wow that wiring is pretty awful. Love the channel Gray Bench

[@sammo303]

Traces on the pcb looked interesting. Blue film caps is a bit different, I can't find anything marked MF online, could that just be for "metal film" and they're a generic brand? Are the other caps polystyrene?? And a tantalum cap too! Maybe just me but the design seems a bit eccentric.

[@gph2193]

Have an original experience pedal. Only downside was the paint chips easy. Great fuzz.

[@christianjimbomb8204]

Sola sound tonebender Mk 3 circuit. If you want one let me know. I have a few P.E.I. yardbox's... Or something I like better. You would be welcome to compare them. Each his own biscuit.

[@mpfan619]

I was using Duncan's tone stack calculator when I hit like

[@cactus-mcjacktus]

I know there’s another version that has both Gain and Drive controls, possibly a bias control? Time to do some research.

[@oaeoeaoRust]

Yes, some versions have controls for Volume, Gain, Fuzz, & Treble/Bass

[@BlakeC27]

Some PCB stand-offs would be nice.

[@michel333100]

Hi I would like to ask you a question. I have a 2005 Electro Harmonix Electic lady mistress flanger. The problem is it has a really loud clock noise that increases as the rate knob is turned up. Is there any mod to fix thus. The clock noise makes this pedal impossible to play as it is. Any help greatly appreciated thanks from Mike from Niagara Falls, Ontario, Canada

[@sgtrutters5892]

Lollar drive teardown?! 😂😂😂

[@waynegram8907]

What is that stage called that has a Diode 1N34 with Transistor Q3? its Clipping only the Positive Cycle of the waveform

[@Danielallanz]

The Ge diode is for temperature stabilisation and bias..these minium part count germanium fuzzs where vulnerable to performance issue's due to atmospheric temperature changes...the diode in the mk3 was an attempt to get some reliability ..you can see how delicate germanium transistors are when you test HFE gain on a dmm...if you just handle them in test you can see the hfe gain goes all over the place so the diode in the mk3 stabilises bias ..some builders will just use another Ge transistor for that diode..it serves the same purpose