The problem here is playing with Tubes & 200v is out of most Members comfort zone!Sure does seem weird when someone who's built literally 5000 pedals is having an issue though
TH Black Eye (Soldano GTO) prototype build
- Thread starter vigilante398
- Start date
ICTRock
Well-known member
240V ... that number becomes important when you know what the maximum voltage rating is for royal ohm 1/4 watt metal film resistors from tayda and can calculate power dissipation of plate resistors knowing that when you design something you aim for a rating half of dissipation ...
chongmagic
Well-known member
My post was not to point the finger at anyone or anything, I am sorry if it came across that way. It was not my intention whatsoever.
I build pedals for fun, it keeps me from going insane sometimes after a shitty day at work. I think we all come together here as we have a passion for the hobby and just enjoy the banter with like-minded folk. I believe we all enjoy the tinkering and experimentation that comes with it as well.
I think we all know that Tayda is not always top-shelf in terms of components but I have never had an issue that I can recall. If I were to build a production pedal I would most likely stick with Mouser or more expensive. But regardless, I myself am not building production pedals and Tayda gives us the ability to get components that work at a good price and at least for me in the US at fairly quick shipping speeds.
I think as usual we will all come together and figure this out, we always do! And that is what makes this forum one of the best I have ever had the chance to be a part of.
Maybe this should be restarted in a troubleshooting forum, so we can pinpoint what is causing the issue.
Just my thoughts...
vigilante398
Authorized Vendor
I used the MF0W4 from Tayda, max operating voltage is 250V. Plate load resistors aren't going from B+ to ground, they're going from B+ to the plate, so you're not dropping the whole 240V across that resistor. This is why I don't need 250V+ plate bypass caps. The highest voltage I'm reading across any resistor at any point in this circuit is 140V. It's closer to 60% of operating voltage rating so it's above the 50% you would shoot for in high-reliability products, but for a guitar pedal project where the goal is to use easily procured and affordable components I don't have any problem with that.
I'm not an expert and I don't claim to be, but I do my homework.
I have had some great discussions with you over the years & I wasn't offended in anyway!
Cheers music6000
benny_profane
Well-known member
I think the issue is how you’re approaching the issue. There was one poster that wasn’t at your beck and call both in the thread and through DMs. You suggested that they were negligent by not posting everything you demanded. That was rude and unnecessary.
Also, the implicit ad hominem attack on another member who has been extremely responsive in this thread and a very active and helpful member of the community was uncalled for.
I think there may be an issue with your avant garde punctuation. When I see a ton of question marks and exclamation points, that suggests immediacy—that a request is a demand. That may not be the case, but when the same thing is repeated over and over, it seems impatient.
You’re very attentive and helpful with troubleshooting. However, this is an atypical situation since it’s quite different than other pedal projects (i.e., high voltage). This is also @vigilante398’s project. I think they should be taking the lead in diagnosing potential issues. It’s quite dangerous and irresponsible to push folks to start poking around in a circuit they might not be comfortable working on.
Right now, there are some anecdotal accounts of issues that are not present in all builds. @vigilante398 has said they are working to reproduce the issue and will report back.
Cool, Sorry to anyone if I come across as a rude & pushy regarding this Black Eye issue, just trying to Help.
It has certainly gathered some Discussion & I try to help people sort out an Issue so I am bowing out of this Discussion & Good Luck to those with their Build!
Dan0h
Well-known member
It’s wild how differently things can be perceived when reading someone’s post. I thought this thread has been a productive idea storm related to a tricky issue that some have and others don’t have. It’s hard to solve a problem when the variables are all over the place. The cool part is at the end of the day The black eye will improve and it’s all because of forums like this. Imagine if we didn’t have a place like this… no thanks. Keep the ideas flying.
Tubes are expensive, very finicky, and can be “almost” replicated by other components. Those of us who love using them just love using them and we have to accept that circuits with them are not always going to function properly from the start. Probably why you don’t see many options available for them outside of amp builds.
Sit back and pass it to the left, we have to be getting close to solving this Screech issue. Mine works with a buffer in front but once the actual solution is found I plan on applying the fix.
Tubes are expensive, very finicky, and can be “almost” replicated by other components. Those of us who love using them just love using them and we have to accept that circuits with them are not always going to function properly from the start. Probably why you don’t see many options available for them outside of amp builds.
Sit back and pass it to the left, we have to be getting close to solving this Screech issue. Mine works with a buffer in front but once the actual solution is found I plan on applying the fix.
Mentaltossflycoon
Well-known member
fig
Village Idiot
Nice build!
I'm quite content to just add a buffer to my build and call it even. With a buffer it sounds great. I might try shielded cable. I am going to pull out the first tube and see what does. It's one of those pedals that will find a way on one of my boards. I built a STM800 (grind customs) and it works great. The power supply is on a separate PCB and the tubes stick out. I have an extra board and want to do an Atomic 16 on it. Probably, later this year.
After a few days with the net dead and more time to actually LOOK at wtf was goign on, I found my ECC83/ax7 tubes were the culprit, not my murder of the 1st board. I also had a pair of psvane ECC81/au7's(might be at7's.. the mid-gain buggers) for a bass amp project, 1 tube outright dead and 2nd not sure how much is even being fed through, I got all knobs on box cranked, vol on amp,25watt noless and the OD kicked on to get what's normally around 2~2.5 and the 2nd build came to life with the milder tubes . This time it was what Amplfied Parts/Antique Electrics sent me, not Tayda! I didn't get the whine at all and actually it's on the quiet side fed from a 1spot 1700ma
Paradox916
Well-known member
I was really excited about this project as prior to its existence I was contemplating building a SLO clone or looking to find a preamp project…and boom the black eye shows up! So I immediately got one…. Then the mayhem descended, being a relatively new builder, I held back building it to see if indeed there was or wasn’t a problem… It seems to be a very mixed bag of responses, but none that seem to definitively answer the question (at least for me). I might say goofy 
here and there or stir the pot occasionally, but almost never really get heavily involved in situations like this but at this point I feel there is only one way to find out and put this baby to bed… build it… so for those of you in the know be it the creator of the project or just someone in the know, should I build it as per the Build docs(BOM) or should I make any deviations from them? the suggested 1M in R21? Isolated jacks? Specific tubes?
here and there or stir the pot occasionally, but almost never really get heavily involved in situations like this but at this point I feel there is only one way to find out and put this baby to bed… build it… so for those of you in the know be it the creator of the project or just someone in the know, should I build it as per the Build docs(BOM) or should I make any deviations from them? the suggested 1M in R21? Isolated jacks? Specific tubes?vigilante398
Authorized Vendor
That's up to you. The grid leak resistor (R21) in the original Soldano GTO (I have one now and I got to check firsthand) is 100k, but when I design tube preamps from scratch I use 1M there, so that wouldn't be an issue here. I'm not sure how helpful isolated jacks would be, but it wouldn't hurt anything as long as you still provide some kind of ground connection to the chassis.I was really excited about this project as prior to its existence I was contemplating building a SLO clone or looking to find a preamp project…and boom the black eye shows up! So I immediately got one…. Then the mayhem descended, being a relatively new builder, I held back building it to see if indeed there was or wasn’t a problem… It seems to be a very mixed bag of responses, but none that seem to definitively answer the question (at least for me). I might say goofy
There is a note about tubes I can add. I was talking to a guy that had built one that was having oscillation problems and I mentioned that the original GTO that I bought came to me with a pair of 12AT7 in it instead of 12AX7, so he tried 12AT7 in his build and it took care of it. Not sure if you would consider that a band-aid fix as the reports I'm hearing of oscillation are only at higher gain settings and 12AT7 just gives you less overall gain than a 12AX7. Just something to consider though if you have tubes lying around and want to try out.
Paradox916
Well-known member
We’re you ever able to reproduce the squealing/oscillation/noise at any volume or gain settings on ether the original GTO or the black eye?
vigilante398
Authorized Vendor
Nope, I built another one and I'm still not having any issues with either of the units I built or the original GTO. I've offered finished Black Eye builds for customers for a couple years and never had issues with them, they just never sold well as most of my customers are bassists so I stopped offering them.
One of the people that reported oscillations has offered to send me his build to take a look at, and that should arrive this weekend. I don't know that I'll have time immediately this weekend to check it out, but I will of course let everyone know what I find out when I do.
Ive noticed that the ecc81 also warms up a little more when paired with the 83 versus the pair of 81. i’ll see what the local GC has in the case for tubes, try out some tung sol’s the 83’s were JJ’s. Still bugs me tha I need to be at max settings to see unity on the signal.
Paradox916
Well-known member
Thanks for answering back quickly, I appreciate it, Hopefully I can get it all put together in a reasonable timeframe.
TGP39
Active member
I’ll throw my hat in the ring. I just finished building my Black Eye. I’ve been building for about ten years with a few tube projects thrown in there, so take that for what it’s worth. First, the thing sounds killer when you keep the gain and output under 50%. Above 50% for either the gain or output I get the high pitch squeal. Most of my parts for this build were obtained through Tayda including the NE555 chip. Everything was built in accordance with Sushi Box BOM / instructions. I’m using two JJ 12AX7’s I had in my stash. Couple of thoughts on my next try:
1. Maybe try A500K for the gain and output.
2. Try the TLC555 chip instead. I’ve read a few anecdotal reports how this helped an oscillating NE 555 chip.
3 I’m going to try all mouser parts instead.
4. Try out the 12AT7’s
There was also a question regarding NE555 oscillation here:
electronics.stackexchange.com
There was an interesting suggestion about placing a 100nf cap between pin 5 of the 555 chip and the collector of BC107 (in this example). Admittedly, I don’t know if it’s applicable here.
Hopefully we can figure out how to tame this beast because it’s worth taming.
1. Maybe try A500K for the gain and output.
2. Try the TLC555 chip instead. I’ve read a few anecdotal reports how this helped an oscillating NE 555 chip.
3 I’m going to try all mouser parts instead.
4. Try out the 12AT7’s
There was also a question regarding NE555 oscillation here:
How to remove the high pitched noise at the output of my audio amplifier circuit?
I'm trying to simulate an audio amplifier circuit in LTspice. I made this circuit based on the circuit I found here: https://circuits-diy.com/how-to-make-audio-amplifier-circuit-using-555-timer/ . ...
electronics.stackexchange.com
Hopefully we can figure out how to tame this beast because it’s worth taming.
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