Gretsch Chet Atkins: Standby operation - Why a 3 position switch?

[Mars Amp Repair]

I believe this is the G-6160 model but the preamp schematic which seems to match the unit is 6141 which I don't see anywhere.
This unit has a standby switch that is a 3 position DPDT on-off-on switch . The switch is still wired for the stby operation but the pilot wiring is gone along with the pilot bulb socket. The remaining wiring for the stby operation is still there but leaves little hint of why this switch is a 3 position or how the pilot light was connected. BTW, the preamp schematic shows this as an on-off-on switch.
I understand the stby operation in that the schematic shows it puts the grid of the PI to ground to shunt the signal in STB. The other half of the switch I assume is for the pilot light switching. I can easily wire that up to the pilot bulb as long as the socket for the pilot bulb has both wires insulated from ground as there is no center tap to ground for the fil windings. This model dc offsets the filaments via the power tube cathodes.
There is no indication of the other half of the stby switch on the preamp schematic nor is there any indication of it on the power supply schematic. The power switch is wired as a line reversing variety so I'm figuring its pilot bulb is most likely just wired across the filament supply again the variety that has both connections insulated from its chassis mounting.
So does anyone know why the stby switch would be a on-off-on variety? Wiring the pilot bulb would be easy as I'd just wire in to be on in both outer positions but why a 3 position stby switch?
Thanx, glen
gretsch_6160.pdf

[nevetslab]

As I recall, restoring Mike Campbell's Gretch Chet Atkins combo amp this past May, the Power Switch is wired for Polarity Reverse with the Death Cap wired on one of the terminals to ground. Cut the Death Cap off, and remove the 2-wire power cord, replacing it with a 3-wire Grounding power cable. That amp is well over 40 yrs old, so having those non-UL-rated line caps connecting to one of the AC Mains wires is tempting fate. Those do short out, or get leaky, placing high VAC on the chassis ground.

I'll have a look at the schematic when I get into the shop.

Take a look at the thread I posted on restoring that amp here:

Restoration work coming on Mike Campbell's vintage Fender, Gibson, Guild amps - Music Electronics Forum (music-electronics-forum.com)

The work on the Chet Atkins Country Gentleman 6160 amp begins on Pg 3. Further down I got the schematics from one of our members DrGonz78

[nevetslab]

I checked my Gretsch schematic that DrGonz78 provided in the link above, and it does show the 3-position AC Mains switch, it being a polarity reverse switch with Center-Off. So, while not everything on that schematic matches your 6160 model, there are details within that probably do. As I recall, Chet designed this amp, he being very skilled in many areas that supported his many hats as a fabulous musician, mix engineer, electrical engineer, etc.

My initial photos during the service in May 2021 still showed the original 2-wire power cord installed. I had replaced it in late May or early June. I also had to seep contact cleaner down the toggle switch actuator in attempt to exercise/renew the contacts inside, to see if I could get away with bringing the switches back to life, or just repair them. I was under pressure to do the minimum labor on them to keep the service cost down to a minimum, as all of the gear that was sent to me was then going to Reverb.com for sale. I was successful in restoring the toggle switches, which brought the tuner back to life, the Treble Boost switch back to life, as well as the Standby switch. I have numerous internal photos of this amp, as well as the National ValPro, as the company that produced that also produced this Gretsch 6160/6141/6142.

[g1]

So does anyone know why the stby switch would be a on-off-on variety? Wiring the pilot bulb would be easy as I'd just wire in to be on in both outer positions but why a 3 position stby switch?

When I look at that 3 position switch at PI grid on the schematic, I see a standby (mute) switch that is in standby mode in center position, 'play' mode in either other position. I have seen this occasionally in other amps as well. No need for it, I guess they had 3 way switches on hand for something else that they decided to use.

I wouldn't expect the standby switch to have anything to do with the pilot light, unless there is another 'pilot' labelled as standby?