@chuck
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Either an On/On or an On/Off/On will work. On/On is a bit “slicker” and will save you the frustration of flipping the switch to the middle/Off position and puzzling out why your pedal doesn’t work (don’t ask how I know that).
Chuck
From Big O
“Instead of a TB Mk1.5 I am going to build a Vox TB with the PUFF. The input cap value of 0.15uF or 0.22uF (both were used) should make this a little more trebly than the 1.5 or FF. Interestingly there are different values of output caps used as well, as seen in gutshot photos on the internet. The output caps on the Ge versions can be 3.3nF or 4.7nF. These were mixed and matched, with IP caps of 0.22uF with both OP values and 0.15uF IP cap with both values. This was likely related to parts availability at the time of building. I am going to socket and see what I like best when I get around to building it.”
Dang it! There you go suggesting another variant I overlooked. Socket-and-See is the way to go with the odd builds.
Chuck
The sockets I normally use for germanium transistors (and Barry stocks in his store) got real scarce about the time I started that RM build so I resorted to SIP36 In-line Sockets – I think my current stash was purchased on Amazon. On the RM/PUFF build I cut a three segment piece and pushed the middle pin out to bridge the widest holes then added a single pin for the third hole.
Chuck
The BC108s aren’t going to work in the PUFF because they are NPNs (negative ground) and the board is designed for PNPs (positive ground).
Sorry to be the bearer of bad news.
Chuck
Chuck,
Knowing there are much smarter people than me hanging out on this board, I strongly recommend taking some photos of the front and back of the board, and posting on/in the GuitarPCB Build Support board/group. Some Steely-eyed Solder Jocky will likely spot an issue in a couple minutes.
Snipping the outer legs on each pot and adding cross over wires will work. Having the pots backward will result in some volume loss. C2 and C4 are optional – they are there to reduce excess noise if needed. 100p vs 220p won’t make a whole lot of difference and won’t result in volume drop or lack of fuzz. First questions are what transistors did you use and where did you get them? If you got a pair from Barry, Small Bear, the gentleman from Australia, or some other reputable source those are probably not your issue – if you bought a random bag of Russian transistors off eBay from a seller in eastern Europe they could be the issue. What ever you’ve got check the pinout of the transistors you have and confirm they are installed correctly – there are some odd balls out there and Google can be your friend. Did you bias Q2 to -4.5v using a multimeter? Without correct bias you’re not going to get fuzz. The dirty secret of germanium transistors is that they don’t all work the same so you may need to tweak the trimmer up or down a little (or a lot) to get the fuzz you want. Using that clever color chart that Barry sends with all his orders and the Build Document check to make sure your resistors are all the correct values and in the right place. Double check all your solder joints are smooth and shiney.
Chuck
Roger on the sockets. The resistors surrounding Q3 are kind of odd between the three variations of the circuit – the DSTOM has a 2.7K and 10K, Madbean’s Cosmopolitan (with a Germanium Q3) has an 8.2K and 2.7K, and the thus far unnamed variant (also with a Germaniun Q3) has a pair of 5.1Ks. Hopefully I’ll be posting a fine example of outstanding brilliance in the near future.
Chuck
There is a sweet spot on the trim pot where it works with maybe just a little not so much and too much on either side. In most cases that is dead center. Sounds like you got it.
Chuck
Steve, Yes, when using the 3PDT board the In and Out Ground pads on the main board are not used.
Chuck
Good job both of you. I have a rather large auxiliary table on my drill press that catches most of the debris. After each session I clean it up with a shop brush. Of course it helps that it is out in the garage.
Chuck
I have done that with two different versions of the PUFF. Used PNP Germanium transistors in both. They are interesting and different, very vintage-y sounding.
Chuck
Based on personal experience, check orientation of D3 – diodes sold as 1N34s aren’t always marked the same way.
Chuck
Bias voltage with Germanium transistors, in my experience, is really more of a suggestion than a hard and fast rule. It can also vary with temperature, humidity, time of day, phase of the Moon, color of your socks, ….
Chuck
Mack it looks like you have SW1 wired to S4, S5, S6 – these are used for wiring the stomp when you’re not using a 3PDT Board. The toggle needs to be wired to the SW1 pads on the left side of the board.
Chuck
I’ve never seen that on any of Barry’s boards.
Unless you are really steady and absolutely always on target I’d advise against a high speed rotary tool (although you can find small bit sets on Amazon). I use this for clearing solder errors:
I’ve had it for years. Probably came from a hobby shop. The blue is painters tape wrapped around the bare aluminum shaft for better grip as well as preventing discoloring of the fingers.
Chuck
