- This topic has 11 replies, 4 voices, and was last updated 4 years, 2 months ago by
.
-
Posts
-
Sometime I feel the purpose of my life is to serve as a warning to others. The warning here is to be certain of the pot orientation on the new Version 5 PUFF board. Great boards and both builds worked out but my grandson may have learned a couple of new words.
First up is a Tone Bender MK 1.5 – changed R2 to 4.7K, C1 to 4.7U and P2 to A100K, everything else per the PUFF BD. Trannies are 2N517s with hFe at 109 and 67. It sounds like a cross between a Tone Bender and a Fuzz Face.
Here’s the box:
And the guts:
If you build this correctly you won’t be able to see the nice purple pot condoms because they will be under the board. Having not confirmed the orientation (clearly marked on the pot side) I was a bit surprised when my pots worked backward. Fixing that was a challenge so I strongly recommend double checking and installing them correctly.
Next up is a Roger Mayer Classic using parts from a non-working Roger Mayer Classic I bought on ebay. Changes from the PUFF BD include R2 to 18K, R3 to 1K, TR1 to 50K (the RMC used a 47K), and P1 to B2K everything else per the PUFF BD. I drilled the enclosure for this one at the same time as the one above so I had to scrounge some wired pots from my stash. The RMC standard transistors, resistors and capacitors were carefully removed from the damaged RMC board and installed on the PUFF board. The trannies are AC128s with hFe at 52 and 127.
The box:
And the guts:
This one sounds like a slightly louder Fuzz Face.
Thanks for looking,
Chuck
Oh well, we live and learn. Desoldering pots from the board is no fun, even with a solder sucker. I’ve reversed pot values before and had to do some surgery. Oops.
I’m sure you are not the only one on this forum that has done this and I have been guilty of it. I’m currently working on a complex build with 4 switches and 2 pots on just one of the boards. I made a complex diagram of wiring and switch orientation, and then labeled switch orientation and purpose inside the enclosure with a sharpie. Slowly building the pedal to try and avoid mistakes. Have the first board, on vero, built and just got all 4 switches wired to it. Did make one mistake soldering wires to the side of a PCB that was opposite of the side I wanted to. Just going to leave it alone because it is not a functional mistake, just a cosmetic one.
Hi! Your pedals look awesome! Very new builder here (PUFF is my second pedal build, my first was a complete kit)… I also installed the pots in the wrong orientation. Is the fix just switching the outer legs of the pot by desoldering, clipping them and adding a little wire? Also, my pedal actually isn’t working properly either. I get signal to pass through when it’s engaged but no fuzz, and it’s a little quieter than when bypassed. I used 100p caps in c2 and c4 instead of 220p (that’s all I had and thought it may be close enough), could this be the issue? If not, which other components could be bad and need replacing? Sorry if this isn’t specific enough and appreciate any advice.
Thank you!..,
-Chuck
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.
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
Thanks for the detailed response, Chuck! I really appreciate you taking the time to share some of your knowledge.
I will post a snap shot to the support group soon. I used BC108 transistors from Tayda. These are the silicon ones found in the MXR 108Fuzz. I did find the pinout of the transistors (collector and emmitter were reversed) and installed them correctly. I did adjust the bias to -4.5 but thought it was odd that the 50K trim pot had to be turned all the way counterclockwise to get there. (could this be the issue? a different tim pot, perhaps?) I checked all the resistors and solder joints and they look ok to me. I did the crossover wires with the pots, so at least they are working properly now.. but still have the same issue. Thanks again and I found your feedback very helpful! Also, “Steely-eyed Solder Jocky” made me laugh!
-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
Also, quick question… are those transistor mounts of some kind I see in the Roger Mayer build? I’ve never seen those and would like to try them.
Thanks,
-Chuck
Just shows how much of a newbee I am.. Thanks, Chuck. I have much to learn.
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
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
- You must be logged in to reply to this topic.