[Matt]

Wanted to circle back and confirm that this was a case of cut traces, nothing more.
I had quite a few in this batch of pedals I made, must have flown too close to the sun (trimmed too close to the board).
Anywho, this build still rocks and is a (not so) secret shoegaze machine for those of us who long for blown out, wall of sound-esque tone.

[Matt]

Additionally, I have linked the art file I used for the enclosure here if you would like to use it for yourself.
The PDF should be Tayda ready as is but let me know if you have any issues.

[Matt]

Had some time to dig further into this build today.

Re-flowed all joints on the phaser and replaced all capacitors, both transistors, and a couple resistors. After reflowing I put a little rubbing alcohol on a toothbrush and brushed around to clean up some of the flux and any possible bits of stuff that could bridge pads.

I have left the pots bent so they aren’t getting moved back and forth

Below are the voltages for the transistors:

Q1

• .4v
• .3v
• 0v

Q2

• -6.9v
• -4.4v
• -3.78v

Here are some better pictures of the build, my phone’s camera isn’t great but hopefully these can get you a better idea.

[Matt]

Update here: Replaced the transistors with no change in performance.
Went back through checking continuity and found a cut trace between +C8 and -C9 but repairing that didn’t solve the problem.
I checked components with a multi meter and visually against a picture of a working build of the DSOTM that I did last year. The only difference is I used 25v electrolytics for C11 and C12 as opposed to 50v in this build.
Another thing I’ve noticed, I don’t think the Intensity knob is affecting the led at all (which makes sense if I can’t get it to oscillate).
Typically I am able to audio probe my way through troubleshooting a build but this one has got me stumped as there is no instrument signal in this side of the circuit. I think part of the problem is I’m not totally sure what I am supposed to be looking for from an electrical perspective (aside from voltage oscillation makes the LED strobe).
Is there some stupidly basic, troubleshooting step I’ve missed by over-analyzing the problem?

As always, any help is greatly appreciated.

[Matt]

Checked components on both boards and can’t find anything wrong, only consistent thing is the Tayda transistors.
Planning to try more from a different supplier and see if that is where my issue lies.

[Matt]

Voltage not oscillating on any transistor legs.

Tested another build of the same pedal I was doing simultaneously to the same issue, i’m wagering it’s a component/orientation issue. Will check everything again and circle back.

[Matt]

Swapped for new transistors and same issue.

if it’s helpful at all the LED immediately lights up (without strobing) as soon as Q2 is inserted, regardless of the status of Q1.

Removed sockets and soldered transistors directly to the board with the same results.

[Matt]

For the downtuned knuckle draggers

The Nihilist

DS-1 Style distortion > Boss HM-2 style distortion (ideally modded with mids knob) > Peavey Studio Pro/Bandit/Supreme preamp or a JCM 800 pre

Inspired by the Swedish Chainsaw tone of the late 80s early 90s famously Entombed used the HM-2 and Studio Pro (both dimed) to create the primary guitar tone for their record Left Hand Path. What is often forgotten is some parts were doubled with a Boss DS-1 into a Marshall combo to prevent recorded guitars from sounding too thin.

Entombed also used the DS-1 and HM-2 together into Marshalls in live settings to make the chainsaw sound more manageable. I’m torn on which pre would be best because the Studio Pro can emulate the recorded tone but the JCM probably has better live application.

There are so many HM-2 style distortions out there but using the HM-2 and making it sound good is so much harder than maxing all 4 of those orange knobs, in theory this triple would give you all the tools to dial in an awesome chainsaw tone.

As a bonus for reading all that, pairing the Rat and the Brit in a Dual Nostalgiatone could replicate the Obituary guitar tone pretty well.

[Matt]

New transistors arrived today and I dropped them in to a pleasant surprise. I’ve got the voltage sitting around -8.5v with no volume loss. Sounds absolutely wild.

Q1 – western Electric 12 Series hfe 73, lkg 220ua

Q2 – Western Electric 12 Series hfe 94, lkg 128ua

Q3 – Same as above, GI8G 6438, hfe 181, lkg 144ua

[Matt]

Dug into this with an audio probe over the weekend and believe I solved my problem. The gain pot was a little funky so I replaced it then was able to fine tune the Ruetz mod where I think some of my high end frustrations were coming from.

I started by going for the same configuration i had on my last couple builds (1K trimmer, 100ohm in R7) but found myself preferring the 100ohm trimmer with a jumper across R7 this time.

[Matt]

Had some time to get back to this one today and I’ll try to answer everything here:

Voltage on pin 5 = -8.95
voltage on pin 8 = 8.99

As I forgot to compensate the the center post on the 1590DD enclosure my DC jack is going through the post. When I took the picture it wasn’t glued in so it was floating around. At this time the posts are not contacting the enclosure.

I purchased my transistors in a set from an Ebay seller and verified Q1 and Q2, the MP42bs, pinouts a few different places (small bear for example) and Q3 has the markings “GI8G 6438”. I cannot find any other transistor with those exact markings but I believe the tab on Q3 is indicating the emitter and it’s possibly a 2N6438

I did a deep dive onto many forums and saw a handful of posts about bender builds that seemed quiet and an issue that came up was too much leakage in Q2, with that in mind i ordered a handful of other transistors to hopefully try some mixing and matching to see if the issue lies in the transistor set.

[Matt]

Following up here. Replaced the diodes and re-flowed every joint.
Circuit is still generating tone when enabled. When I pop the opamp out the noise stops (i’ve tried multiple op amps) which leads me to believe the problem is in the gain stage. I’ll keep working on this and follow up when I have more updates.

[Matt]

Thanks Barry! I’ll clean it up, reflow joints, and circle back this week.

[Matt]

What a great idea to put a whole guide together!

I shot you an email with a couple small edits otherwise but what you’ve got is pretty comprehensive. The biggest thing is just double and triple checking every step in the process.

More related to the pedal, I found a decent Smashing Pumpkins Siamese Dream–esque tone by diming out the Wattamp gain, fuzz and fuzz volume then tweaking EQ controls to taste. You can even dial in a subtle vibey sound on the Phaser for the clean parts.

[Matt]

I haven’t had much play time on it since I finished it in the wee hours of the morning (whoops) but I was pleasantly surprised with the variety of tones I could dial in with the Fuzz and Wattamp. I must say tho the Phaser takes the cake for me. I love some weirdo modulation and this one can do anything from tasteful, almost uni-vibey, sounds to some total nightmare type stuff.

Admittedly, I’m not a huge Floyd fan myself but I am floored with how versatile the board is, I will absolutely be building one for myself in the future.

[Matt]

Here’s a link to the artwork for those interested.

It’s Tayda ready and should line up perfectly with Barry’s drill template.

[Author]

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