TH Black Eye (Soldano GTO) prototype build

Updates on my foray, I found an Orange micro-dark “used” for price at GC that including the tung sols paid the same as a new Micro, my tubes are all good (orange mini amps are close to what i was trying to build with my 10 and 60watt boards easy to test with top off each tube)but flock this thing acts as a mute , gain maxed and Od kicked in same results as the 81s… but i also used the Mouser sourced ne555 not a tayda :unsure: I must be losing power somewhere…..
 
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:
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.
I would be happy to try the TLC555. I socketed the NE555.

The mouser parts might not do the trick, I built the space heater with all mouser and still get noise at higher gain.
 
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:
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.
I just finished mine & it does Squeal with the Gain at near full Clockwise position when plugged from Guitar direct to Amp.
It behaves as Normal with no Squeal at all on my pedalboard as I have a Buffer in front.
I used all parts from Tayda except NE555P & Resistors, This thing has too much Gain for me!!!
 
This thread has blown up since I’ve been gone lol. Mine won’t squeal unless I have the volume up past unity (about 9 o’clock) and the gain maxed. I’m going to try a buffer in front of it and see how it sounds.
 
Sorry I haven't revisited this thread sooner. I have built 7 of these so far. I tested them all on my pedal board and had 0 issues with them. BUT when I took one to my buddy house is was squealing like cray. I realized when I had a buffered pedal in front of it no noise. So I added a small buffer circuit in it, and all is good!Easy fix and it sounds great!!
 
Sorry I haven't revisited this thread sooner. I have built 7 of these so far. I tested them all on my pedal board and had 0 issues with them. BUT when I took one to my buddy house is was squealing like cray. I realized when I had a buffered pedal in front of it no noise. So I added a small buffer circuit in it, and all is good!Easy fix and it sounds great!!
I just finished the last of my customer builds for the month and I still have a few days before I start on the next, so I took the chance to play with the Black Eye build that was sent to me, and I was able to get some oscillation with it, so I have something to start with for figuring this out. As such I've suspended sales of Black Eye PCBs for the time being.

One thing I'm going to play with is a buffer in front, and if I find something that works consistently I think the easiest solution will be to redesign the footswitch board to put a simple buffer circuit on it. So you don't need to modify the main board, just remove the previous footswitch board (easier said than done, I know) and drop in the replacement with the buffer on it.
 
I'm going to try breadboarding this up tonight to make sure it fixes the problem, but this is my idea for an add-on buffer. It's a relatively tight fit, but if I use SMD parts I can squeeze a simple input buffer on the bottom side of the footswitch board without changing the dimensions. The pedal will still be true bypass, this would just come between the 3PDT and the actual Black Eye input.

Capture.JPG
 
for those who will ask, this going to be available separately or only on new orders? and I still haven’t found where i’m losing volume or why only ecc81’s work or needs at least 1 socket filled with a medium gain tube. hope it cuts the squealing for the people who have it.
 
for those who will ask, this going to be available separately or only on new orders?
Both. If this is the fix that makes it work, I'll make it the new standard footswitch board that I ship with all new orders, and I will offer them to anyone that previously ordered at no cost. Figuring out how to fix something and making people pay extra for it would be a dick move :p
 
So I soldered up a simple buffer on vero last night and was able to get rid of the oscillation, but it was super noisy, so I'm going to try a different buffer and see if I can get better results.

Sidenote: I hate vero. I don't know how I used to deal with that regularly.
 
Sorry I haven't revisited this thread sooner. I have built 7 of these so far. I tested them all on my pedal board and had 0 issues with them. BUT when I took one to my buddy house is was squealing like cray. I realized when I had a buffered pedal in front of it no noise. So I added a small buffer circuit in it, and all is good!Easy fix and it sounds great!!
Thanks Matt, I thought that's why you didn't have an Issue & I got reamed for being Pushy to ask you an important point.
Matt, this is not directed at you as written below.
Sometimes it can come back & Bite you on the Ass!!!
 
Upon recommendation from a friend I decided to try Jack Orman's "amplike" buffer. It's not as tidy on the footswitch board, but it still fits without having to resize it. I had to slide the CLR over, but the LED is staying in the same place so it can still be a drop-in replacement without modifying the drill template.

Same story as yesterday, I'll throw it together on a vero tonight and try it with the Black Eye I have on hand, if it works I'll go ahead and order boards. I may order a small quantity first as a design try-out, but it depends on cost difference. Sometimes it's only a few bucks difference between ordering 5 and ordering 50.

300300187_742296466872199_2617815830253976451_n.jpg
 
Upon recommendation from a friend I decided to try Jack Orman's "amplike" buffer. It's not as tidy on the footswitch board, but it still fits without having to resize it. I had to slide the CLR over, but the LED is staying in the same place so it can still be a drop-in replacement without modifying the drill template.

Same story as yesterday, I'll throw it together on a vero tonight and try it with the Black Eye I have on hand, if it works I'll go ahead and order boards. I may order a small quantity first as a design try-out, but it depends on cost difference. Sometimes it's only a few bucks difference between ordering 5 and ordering 50.

View attachment 31550
I have my black eye 98% complete, all but one resistor value as per always. Anyway, if you're looking for guinea pigs when you've verified i'm down. I'll be waiting for the buffered daughter board either way.
 
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