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yeah it could be 2N2222. the atlas DCA55 will tell me when I get it hooked up.

LCR tweezers arrived. I'm working on this as a top priority. this is the oldest project I have so it is #1 on my list. I'm not in school right now. all good. I will update you when I am ready to release the schematic. then the PCB then the custom build.

hello, sorry for the delay. reverse engineering continues. there are 5 of these Hfe 195. 2 of Hfe 953. I believe there are 5 of 2N2222. also 2 of 2N5088 or 2N5089. there is a small chance MPSAXXXX. over 850 seems high for a 2N5088. I don't think you would hand sort sot-23 package 2N5088. usually my DCA55 will auto detect a darlington silicon transistor. this did not detect a darlington. that is the best guess I can make as to what transistors are inside this thing. I can make the PCB soon. I have to trace it some more on my own. this will take time. then I can make the PCB after all the correct cap values are in the right places. I have the cap values on the PCB but I did not get a copy of C1 C2 C3 etc. that was on Jon's computer. maybe he can help me out?

what exactly do you need? In the schematic/kicad file I sent you did I not send one with reference designators added?

Interesting.

Devi did use a lot of MSPA18 as well, but yeah, if your magic thinger didn't detect Darlington :shrug:
I wonder how critical the current gain is for those 2N5088s. Maybe they're not sorted at all and they just happen to right at the higher end of the typical gain spectrum?

goroth wrote:Interesting.

Devi did use a lot of MSPA18 as well, but yeah, if your magic thinger didn't detect Darlington :shrug:
I wonder how critical the current gain is for those 2N5088s. Maybe they're not sorted at all and they just happen to right at the higher end of the typical gain spectrum?

in my life, I have seen 550 to 850 Hfe on a 2N5088. I can't remember 2N5089. those were the high gain version? so yea this is pretty well known to be a high gain variation of a 2N5088 or 2N5089. 950 is really close to 850. darlingtons start at Hfe 2000 but they are less when damaged by heat. maybe there is a darlington with Hfe 950? it was many years ago when I would buy every transistor to test them out.

imJonWain wrote:what exactly do you need? In the schematic/kicad file I sent you did I not send one with reference designators added?

you did not send me the locations of C1 C2 C3 on the actual PCB. I sent you resistor values and locations for resistor values in relation to the PCB. that is how you were able to trace it. now that I have measured the cap values, I can post them but I can't add them to the schematic on my end without completely starting over from scratch with the trace job. reference designators as you call them were on the schematic. I did not receive a PCB from you.

Oops ! I'll add labels to that image you sent me and get it back over to you.

imJonWain wrote:Oops ! I'll add labels to that image you sent me and get it back over to you.

perfect thanks

emailed

I'm working on the PCB design now.

Are you going SMD or through hole?

Through hole so I can sell kits. I do make some really compact through hole layouts. But also, I think people can solder 0603 resistors at home. I will probably make two PCB's actually. Always a good idea to make it through hole first so that easy changes can be made after some guitar playing. Many people told me that they didn't like this pedal. I think there must be some way to fix whatever it is people didn't like. Almost every guitar pedal is hit or miss because it does not fit exactly with how bright or dark all the other gear is. The best selling guitar pedals have an average voicing that fits both humbuckers and single coils but not bass players. There is a formula.

I finished drawing the schematic in eagle based on the kicad drawing that Jon provided. I am now desoldering all capacitors to ensure that the capacitance meter is not giving erroneous measurements. One of the caps reads 54K Ohms! I will get to the bottom of this. The PCB right now is a very compact through hole layout. If I run out of space then I will use 0603 for the resistors only. I think everyone can solder those by hand.