rafafredd
Well-known member
I have four of these solidstate preamp boards by gates that I want to use for EQ gain make up.
So, I started tracing it by eye and hand just to figure out pinout. I thought it would be easy, but after some hours of thinking and not getting anywhere, I decided to trace it on paper to really see what was going on.
After doing so, I still can´t figure out the pinouts for my surprise. It´s a strange circuit. And to make things wrose, I can´t get hold of any info about the transistors used in the thing.I do not have any transistors pinouts, and I can´t figure out these, specially he the Q2 transistor. I thought it would be really easy to figure out the transistor pinouts as soon as I had it all traced, but again, some things in this circuit is over my head.
So, I was expecting some of you really experienced guys could take a look and maybe that´s something really easy for you. Any hint? I for myself was beaten by this four transistor boards:
As you see, I used IEC to represent transistors. Q1 and Q2 are TZ1218. No info online as far as I could search... The output pair, Q1 and Q2 don´t even have any label on it.
So, looking at this, I can´t say much more other than obvious pinouts, like input (A) and output (J) etc... But B is a big ??
Any inputs welcome. If this is a usable ciruit after all, and if I think it sounds nice ater trying it, I may make another pcb for this, because the original layout doens´t look that good. I mean, if these are really DIY worth, because it would be so easy, with only four transistors. Cpuld work well as a line driver, low mpedance transformer driver, buffers or make-up stage for passive EQs.
About the reversing, I´ve checked 10 times, and that´s really what I have here.
BTW, CR1 and CR2 are MZ2361 wich I also can´t get any info about.
So, I started tracing it by eye and hand just to figure out pinout. I thought it would be easy, but after some hours of thinking and not getting anywhere, I decided to trace it on paper to really see what was going on.
After doing so, I still can´t figure out the pinouts for my surprise. It´s a strange circuit. And to make things wrose, I can´t get hold of any info about the transistors used in the thing.I do not have any transistors pinouts, and I can´t figure out these, specially he the Q2 transistor. I thought it would be really easy to figure out the transistor pinouts as soon as I had it all traced, but again, some things in this circuit is over my head.
So, I was expecting some of you really experienced guys could take a look and maybe that´s something really easy for you. Any hint? I for myself was beaten by this four transistor boards:
As you see, I used IEC to represent transistors. Q1 and Q2 are TZ1218. No info online as far as I could search... The output pair, Q1 and Q2 don´t even have any label on it.
So, looking at this, I can´t say much more other than obvious pinouts, like input (A) and output (J) etc... But B is a big ??
Any inputs welcome. If this is a usable ciruit after all, and if I think it sounds nice ater trying it, I may make another pcb for this, because the original layout doens´t look that good. I mean, if these are really DIY worth, because it would be so easy, with only four transistors. Cpuld work well as a line driver, low mpedance transformer driver, buffers or make-up stage for passive EQs.
About the reversing, I´ve checked 10 times, and that´s really what I have here.
BTW, CR1 and CR2 are MZ2361 wich I also can´t get any info about.