TH Black Eye (Soldano GTO) prototype build

Haven’t built mine yet, but I’m curious— of everyone who has built it so far, who’s had this oscillation issue? I feel like I’ve seen of 20 or so people who have mentioned building it, but only five people seem to be reporting this issue. Can we track down what variables are at play here? The 250v vs 400v cap? Tube brand? Source of 555 and/or mosfet for the power section? Wire gauge used?

The people having the issue are no slouches when it comes to building, so building errors can safely be ruled out. I feel like there’s gotta be a common thread between either all of the builds with the issue or all of the builds without the issue.
Or possibly a few bad pcbs. The OP and several others have successfully built this to the bom links it seems.
 
The only sub I made, outside of the linked items on the BOM was I used a wima 1500pf instead of the grey one linked. Everything else was per the BOM links including the 250v instead of 400v. I wasn’t comfortable running a ribbon touching the tube because even though it’s a 12ax7 it still gets warm so I ran the snake to the side. I will say the through holes were extremely close to each other compared to other boards so I took almost double the time soldering just to be careful not to have any bridges. One new tung sol and one old used RCA 7025 for the tubes. I went 12k on the led and the thing is still blinding me. I am running of a one spot cs6 giving it a dedicated line of 9v. Haven’t tried 12v. If it was anyone else besides Betty I’d say break out the magnifying glass and look for micro bridges, but anyone who has built 5,000 pedals knows all this.
 
Or possibly a few bad pcbs. The OP and several others have successfully built this to the bom links it seems.
Certainly possible, but I would expect either a full batch to be bad (and afaik the second batch only just came out, right?) or just one or two isolated instances in an otherwise good batch. A ~20% rate of this anomaly seems like it falls in a weird little valley of likelihood for PCB defects. It’s certainly possible, but just statistically speaking it seems less likely than another unidentified unifying thread. Occams Razor, and all…
 
If the traces are too close why does the buffer correct it on my build? Just lowering the impedance is the trick?

If a high impedance trace (or component) is in close proximity to another trace or component carrying a hot signal that signal can be induced into the other trace, causing a feedback loop. This is a form of parasitic oscillation.

Placing a buffer in front of the pedal forces the input trace (up to the first active stage) to follow the output of the buffer, any potential induced signal is swamped out by the buffer so no feedback can occur.

One way you can determine if a buffer might help is to turn the guitar volume all the way down while the circuit is oscillating. If the oscillation stops (or changes considerably) a buffer might help. This is not the same as unplugging your guitar, that is the opposite extreme and encourages oscillation.

It's also possible for this sort of oscillation to occur further into the circuit, in this case an input buffer won't help.
 
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It's confusing Bricks, because I can't even get to the squeal or no squeal and the 1 major snafu I had, the designer, Vigilante, show me how to correct it! I'll try the 6 new pieces of wire instead of a ribbon. Might also be 1 of the components was a funky batch, I did mention in other threads Tayda is more a warehouse that gets stuff from all over, like Mouser and Digi-Key do. Where did your 2n3904's come from those who have squeal? that transistor is what I see most frequent in DIY signal generators..
 
Certainly possible, but I would expect either a full batch to be bad

Not necessarily... Welcome to my world.

There are many variables at play. I couldn't tell you how many people have built the Tyrian Distortion... but every now and then someone will come along claiming the circuit oscillates. I can't reproduce it, and I've tried. I've built several, not once have I had one that oscillates... not once.

There was a TL074 version, then a completely new layout reworked for TL072's... I've never had a single one oscillate even a peep regardless of how sloppy I wire it up. I've twisted the input / output wires together, run extra long wires to the pots, left it unboxed, etc.... nothing.
 
I hate a PCB that oscillates more than anything else because it can be an absolute nightmare to correct. Sometimes the fix is obvious, other times not so much.

There is a particular version of the Fulltone Plimsoul that I have yet to build that does not oscillate. I've done everything imaginable, down to a ridiculous sized spread out PCB layout that wouldn't fit in a 1590DD, I've even populated my layout with the components from the original PCB.... I've built it from multiple layouts of my own, an etched layout of someone else's, another vendor took a stab at it a few years ago, and two different vero layouts... No go. I can build any other version no problem, and I can modify it to stop oscillating.... but that doesn't help me sleep.

I want to know why I can't build that version without oscillation. It is the one circuit that has haunted me for years.
 
What about the brand, part number and source for the 555 and filter caps?
It's long in the past, but I remember a thread at DIYstomp that included someone with an issue and it turned out some variant of 555 didn't play nice in an SMPS at audio frequencies.
 
If the traces are too close why does the buffer correct it on my build? Just lowering the impedance is the trick?
Yep!!!
What about the brand, part number and source for the 555 and filter caps?
It's long in the past, but I remember a thread at DIYstomp that included someone with an issue and it turned out some variant of 555 didn't play nice in an SMPS at audio frequencies.
The one's I purchase locally are Texas Instruments NE555P.
What is Tayda supplying????
 
Not necessarily... Welcome to my world.

There are many variables at play. I couldn't tell you how many people have built the Tyrian Distortion... but every now and then someone will come along claiming the circuit oscillates. I can't reproduce it, and I've tried. I've built several, not once have I had one that oscillates... not once.

There was a TL074 version, then a completely new layout reworked for TL072's... I've never had a single one oscillate even a peep regardless of how sloppy I wire it up. I've twisted the input / output wires together, run extra long wires to the pots, left it unboxed, etc.... nothing.
Ever get your hands on one of the ones that reportedly oscillates to see if it oscillates in your environment— same electrical grid; power supply; enviroment; lighting; rig as one of your many functioning builds of it? If one that oscillates for someone else doesn’t oscillate when you get your hands on it, would one that you build that doesn’t oscillate start oscillating when they have it in their playing environments?

If the oscillations with the Tyrian are uncommon but still happen notably often enough, wouldn’t that still not rule out the potential for it to be one of the other variables? If it’s an issue with say, 20% of all reported builds, then if it was a PCB manufacturing error, you could reasonably expect ~20% of your own builds of it to exhibit the same issues. If you’ve tried many times but never encountered the issue, then wouldn’t it stand to reason that, while PCBs errors are still a potential culprit, the most likely cause is a variable introduced outside of your workshop (such as power, component maker or batch, wire, environmental factors, etc.) that you do not have. Surely board defects could be cause for issues like this, but being deductive, it seems improbable that a PCB issue would be both widespread enough for it to be considered a noted issue (like you said, not just a one or two time thing, but also not a full batch) while also being unable to be replicated.
 
I've built 4 now. No issues at all.
Cool, what was Tayda supplied & what was sourced elsewhere????
Are you using a buffered pedal in front of your Builds????
This needs to be sorted as the topic could get out of hand & we like harmony!!!
 
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Yep!!!

The one's I purchase locally are Texas Instruments NE555P.
What is Tayda supplying????
My Tayda 555s are TI iirc (didn’t build this pedal yet, just to be clear tho), but they do list their 555s manufacturer on their site as “various”, meaning each of us could order 555s and be getting a different manufacturer/batch depending on which they have on hand at the moment (or they potentially even have different manufacturers on hand at the same time, and it comes down to which selection is nearer in the warehouse for whoever is packing your order at the time). I’ll be building mine soon, and my 555s were Tayda-sourced in May of this year. I’ll report back after I build it, but it’s probably worthwhile, if people who have built it are noting where they sourced components from, to mention when they sourced certain components if they were ordered from Tayda. Many of us have stashes of some of the components for this project already, and a 555 from Tayda from March May is quite likely a different batch, and may be a complete different manufacturer compared to a 555 from Tayda from this month or a 555 from Tayda from last November.
 
Cool, what was Tayda supplied & what was sourced elsewhere????
This needs to be sorted as the topic could get out of hand & we like harmony!!!
Agreed. Perhaps it would be a good idea to have a thread specifically for noting if one’s build has oscillation or not, as well as noting which PCB batch it came from, and the sources, manufacturer, and relative timeframe of purchase for the different components, so the data can be compiled into a spreadsheet and searched for trends.
 
My Tayda 555s are TI iirc (didn’t build this pedal yet, just to be clear tho), but they do list their 555s manufacturer on their site as “various”, meaning each of us could order 555s and be getting a different manufacturer/batch depending on which they have on hand at the moment (or they potentially even have different manufacturers on hand at the same time, and it comes down to which selection is nearer in the warehouse for whoever is packing your order at the time). I’ll be building mine soon, and my 555s were Tayda-sourced in May of this year. I’ll report back after I build it, but it’s probably worthwhile, if people who have built it are noting where they sourced components from, to mention when they sourced certain components if they were ordered from Tayda. Many of us have stashes of some of the components for this project already, and a 555 from Tayda from March May is quite likely a different batch, and may be a complete different manufacturer compared to a 555 from Tayda from this month or a 555 from Tayda from last November.
These are Fakes :
FAKES.jpg
Real Texas Instruments NE555P:
Real TI 555P.jpg
 
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Think I've been saying that, my Mouser and stompbox supplies are TI's, and not knocking Tayda, they got a shipment that was cheapish, it could be on the maker for not giving 2 rats in QA. ANd IF it does come down to those IC's.. instead of this build, use them in like the relay pcb's that Rob has? If my order from Tayda has non-TI's, I won't be upset, I'll just put them out of the audio path. The 1 not on pink is from Mouser and doubtful it's a fake.
 

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I can confirm, now with normal amp volume (kid is awake), that relocating the Black Eye from front of the chain, (where I always test new builds mostly due to all the fuzzes) to almost the back of the chain, and after a buffered pedal there is now zero squeal zero feedback and the noise is gone all except when gain is maxed then I get the classic high gain noise in the background. This thing is amazing and nothing else I have built or bought comes close to this sound. I can see why @vigilante398 has two on his board, the low gain setting and high gain setting are both phenomenal. I hope the other issues are found with other squealers. This one has made its way onto my board permanently!

Ok Someone make a delay pedal with a tube section!
 
Stick one of the mini buffers on the input and you can put it anywhere in the chain you want.
For some reason I kept thinking this had to go in the front of my chain (mind in fuzz land) but it sits nicely next to my rat which is towards the end and after a buffered pedal so I’m all good now. Just fighting the urge to order another one. Lol.
 
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