Well, Elroy is back home after an epic summer voyage. Now lets look in side and see what we can do.
ln76d said:
Could you describe pad and hpf connections? I tried from the pics but it's hard to see.
https://www.dropbox.com/s/nwo99nuftcflwu0/Elroy%20Pad_HPF%20Connections.jpg?dl=0
PAD:
1. There is a black wire from the capsule that connects to the pcb. This point connects to one post of R4 on the bottom. On the top it connects to a 1nF film cap.
2. The other lead for the 1nF film cap connects to the PCB at a point that connects to R7 on the bottom. It is jumped over to a point that connects to pin 1 of the tube on the bottom.
3. From pin 1 of the tube there is a ceramic cap (331 pF i think) that connects to the PCB on the top. This point connects to a trace that leads to the middle post of the PAD switch.
HPF:
1. There is a trace that connects to the right pin of the HPF switch. The trace leads back to one of the leads for R11 on the bottom.
2. This same point on the bottom connects to the 22 nF film cap.
3. The other side of R11 is connected by a trace to one lead of R9.
4. That lead of R9 has traces that go to the the positive lead of the 2.2 uF electrolytic cap and the negative lead of the 47 uF electrolytic cap.
5. The 2 red wires coming from the capsule connect to the positive lead of the 2.2 uF electrolytic cap and the negative lead of the 47 uF electrolytic cap from the other side of the pcb board.
ln76d said:
Also there is one blue foil cap, can you check the value and where it's connected?
https://www.dropbox.com/s/pdcaq8lkqovkzg5/Capacitor%20values%20and%20connections.jpg?dl=0
I believe you are referring to the cap that is R7 and R10. The value of the electrolytic cap is 1 uF. The negative lead is connects to R10 and the positive lead connects to pin 5 of the Tube as far as I can tell.
In case you are referring to the other blue capacitor, it is 22 uF (223J) and it connects on one lead to R11 and on the other lead to tube pin 5 via trace.
ln76d said:
R10 is resitor - is there any potentiometer on the board? I don't see any.
Where is connected R10?
https://www.dropbox.com/s/xtzld8la3t95fet/R10%20connections.jpg?dl=0
I do not see any potentiometer. It seems to be connected between the K3 (HPF) swith and the negative lead of the 1 uF electrolytic cap. There are 2 lead from the switch that lead to each side of the R10 resistor.
ln76d said:
47uF electolytic capacitor - is it C4?
https://www.dropbox.com/s/iq5ooe72rqlxvez/Elroy%2047uF%20connections.jpg?dl=0
I don't see any markings designating which capacitor number for any of the caps. The negative lead of the 47 uF cap connected to one of the red wires from the capsule and one of the lead of R9. The positive lead connects to a trace that leads to R9 and a trace to Tube pin 7 at the same point.
ln76d said:
What's the value of small ceramic capacitor at the switch side of PCB?
https://www.dropbox.com/s/g6gwahbxy8ktazy/Tinyasscap.jpg?dl=0
It took me forever to figure this out as the writing was so small and light colored. I finally got a picture of it that I could blow up.
The number on it was 331 but no other markings. I think this means 331 uF but correct me if I'm wrong. (
***I was wrong this is 331 nF... thanks ln76d)
ln76d said:
Is it white wire of transformer connected to ground? It should be
https://www.dropbox.com/s/7w65lp91re168y4/transformer%20ground.jpg?dl=0
The white wire of the transformer connects to the PCB board. From there, there is a trace that appears to connect to the white wire that connects to the 7 pin output connector.
Wow... ok my brain hurts. Please feel free to correct me or educate along the way. I'm finding this quite interesting. Thanks in advance.
Also, I found that shining a small light behind the PCB make the traces on the opposite side more visible. I can take more photos of anything you want to see better. Just let me know.