rcphillips
Member
I'm finally getting around to building a G7 (majority of parts have been purchased and sitting in a box for a decade or so), and after reading the META and META-META, I still have some questions, maybe some of you all could help me?
[project details]
PCBs: Gustav's
Body: Chunger's Alctron MK47
Capsule: BeesNeez M7
Tube: PF86
PSU Case: Dan's PSU case
Transformers: Lundahl LL1538
Appropriate mods: in the PSU pattern switching section 100k+100k resistor becomes 40k + 50k+50k; in the mic itself, the second 470k resistor becomes 282k (maybe higher, depending on actual measurements) to lower the polarization voltage of the capsule - I think the combination of changes should result in the heater voltage being around 4-4.5v for the PF86 (I think that's what I've read, and calculated)
[mic pcb questions]
- For connecting the tube socket pcb to the main pcb, should I just use a bunch of thick resistor leads bent at a close-to-90-degree angle?
[PSU and PSU case questions]
- Should I just use wire nuts for connecting things like the two toroids? Seems like it would be fine.
- I'd like to add a power indicator lamp; it looks like I could get a panel mount one like:
https://www.mouser.com/ProductDetail/VCC/2152A6?qs=I7nE1oQSFs9skzm1Siom9g%3D%3D
https://www.mouser.com/ProductDetail/VCC/2120A3?qs=rHu0DOexXLC4pEbHTBL8Fg%3D%3D
and wire it to the power switch. Does that make sense to do, or would you recommend something different?
- Any preferred pattern select switches? I have some Lorlin rotary 2pole/6position, but I'd have to spend some time widening the hole in the case (the rotary shaft is maybe 1/32-1/16" too large to fit).
- Any preferred standoffs + bottom screws for mounting the PSU board to the case?
- For the panel mount XLR (Neutrik D series) and IEC outlet (Schurter 6200.2100), are some flat 4-40 machine screws appropriate, or is there a better choice?
-----------------
Thank you in advance for any and all help you can give.
Cheers,
-Robert
[project details]
PCBs: Gustav's
Body: Chunger's Alctron MK47
Capsule: BeesNeez M7
Tube: PF86
PSU Case: Dan's PSU case
Transformers: Lundahl LL1538
Appropriate mods: in the PSU pattern switching section 100k+100k resistor becomes 40k + 50k+50k; in the mic itself, the second 470k resistor becomes 282k (maybe higher, depending on actual measurements) to lower the polarization voltage of the capsule - I think the combination of changes should result in the heater voltage being around 4-4.5v for the PF86 (I think that's what I've read, and calculated)
[mic pcb questions]
- For connecting the tube socket pcb to the main pcb, should I just use a bunch of thick resistor leads bent at a close-to-90-degree angle?
[PSU and PSU case questions]
- Should I just use wire nuts for connecting things like the two toroids? Seems like it would be fine.
- I'd like to add a power indicator lamp; it looks like I could get a panel mount one like:
https://www.mouser.com/ProductDetail/VCC/2152A6?qs=I7nE1oQSFs9skzm1Siom9g%3D%3D
https://www.mouser.com/ProductDetail/VCC/2120A3?qs=rHu0DOexXLC4pEbHTBL8Fg%3D%3D
and wire it to the power switch. Does that make sense to do, or would you recommend something different?
- Any preferred pattern select switches? I have some Lorlin rotary 2pole/6position, but I'd have to spend some time widening the hole in the case (the rotary shaft is maybe 1/32-1/16" too large to fit).
- Any preferred standoffs + bottom screws for mounting the PSU board to the case?
- For the panel mount XLR (Neutrik D series) and IEC outlet (Schurter 6200.2100), are some flat 4-40 machine screws appropriate, or is there a better choice?
-----------------
Thank you in advance for any and all help you can give.
Cheers,
-Robert