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That's actually not terrible. The hFE 63/383µA is a good candidate for Q1 in a Tone Bender Mk. II (with a 10k base-ground resistor). The hFE 107/484µA and hFE 104/512µA is within spec for Q3 in a Tone Bender Mk. III-style circuit. The others are probably useless for anything other than as...

Sounds like someone knows that they're selling junk and is trying to fend off the inevitable refund requests. Caveat emptor!

Get a bag of D9 diodes from Sovtek on eBay and you'll be set for germanium diodes. They're functionally interchangeable with 1N34A.

Are you sure that the Chinese germanium is new production? I've bought some on AliExpress and they all had date codes from the 70s and 80s and oxidized leads. (The 3AG1B in your picture have a 1983 date code.)

The newest germanium transistors that I've seen are Soviet transistors from 1990. I haven't seen anything that's currently being produced.

It's possible that the ones that I received were rejects from someone's stash; I got mine from minifux1 on eBay, not an electronics retailer. I'd be interested to see how yours measure up.

NPN germanium is much more of a pain to source. For one, it's really hard to find anything with an hFE between 70-150. Most of the European devices that I've received (AC175, AC187, GC521) are ridiculously leaky—over 1500µA at room temperature. NPN germanium tends to be anywhere from 2-4x more...

The layout is my design. This is the third iteration of the hardware, and version 5 of the code. It started off as a derivative of the MAS Effects relay bypass system. Over time I've made some changes to reduce power consumption and to let boards "talk" to each other so that additional...

Good eye, that's exactly what I did. I'd originally designed the PCB for a planned enclosure with the holes for the bottom pots directly under the Level and Fuzz pots, but realized that it looked better if I moved the pots towards the center of the enclosure.

Blue > Yellow > Red. But all of them look really good to my eyes.

Bottom line up front—this thing is seriously awesome. For those not in the know, it's a modified fuzz face that uses an op amp servo circuit to keep the bias stabilized at a wide range of temperatures. So having said the most important part, on to the build. I went slightly premium on this...

Dylan159 over at Free Stompboxes put together three interesting all transistor overdrive circuits.

I do. I just DMed you with details.

What a cool build!

Are you measuring those voltages against ground, @yazooligan? Or are you measuring the voltages between the transistor terminals? If you aren't doing so already, I'd recommend connecting one probe to ground/the positive battery terminal and using the other probe to check the voltage at each...

The BOM (including package sizes) is here: https://forum.pedalpcb.com/threads/1590a-tone-generator.22400/

I have no idea what this is, but the layout is beyond cool, so put me down for one. If it’s a ring modulator or YATS, so be it.

They're for grounding the input and output jacks. In this build, the jacks are grounded to the I/O PCB, so they don't need separate individual connections to the main PCB. But you should probably ask that question in a new, separate thread, rather than hijacking @The Gator's excellent build report.

I’ve used 309s with hFEs in the 160-180 range in several builds (Trumpet fuzz, high gain fuzz face), and they sound great. The 700 ones sound suspicious, but @jwin615 is right, you should try them socketed or on a breadboard before tossing them in the diode bin.

The collector and bass voltages are the same? That should not be the case. and what units are those? You should be getting around 3.2v on the collector and 1.5v on the base of Q4/5.