STAX input voltage question

What the voltage selector plug does is rearrange the primaries of the transformers so they are reflect the input voltage. It's hard to tell if Stax changed the transformer or if the bypassed the selector switch or if it was some after market mod. The best way would be check if the backside of the socket is wired the same i.e. the same wire from the transformer goes to the same pin on the socket on both units and if there are the same internal connections on the back of the socket. Pictures would be great of both units.

Regarding the shocking part, yes it is a definite possibility but the fuse will protect you. When I'm testing "uncertain" amp I stand well away and turn them on with a switch on an extension cord.

Spritzer, Both transormers and wires look identical. But the wires leading to the back of the selector switch sockets are wired differently (2 wires go to different pins, as I recall). This is where I was asking if wiring the 110V unit the same as the 117V unit would convert it to 117V.
I can take some photos but will have to borrow the right camera to do it.
btw: My ultimate goal is to find as perfect a tube STAX as I can afford. If you have anything in your arsenal that you might like to sell, let me know thru email. Thanks much again.

Since the voltage selector plug is lost, a former owner may have bypassed it since the amp will not receive any power if it isn't there. There are 4 primaries if I remember it correctly, two 20v and two 100v, but I could be wrong.

I don't have any of my tube amps up for sale any time soon since two of them have only been with me for a week. I can recommend the best amp for the job though based on the headphones you will be using. Any one of the Lambdas needs a pretty basic amp compared to the SR-007 Omega II. I use a EL34 based Blue Hawaii as my main amp and it is larger then many power amps but still isn't powerful enough for the Omegas so I'm working on a 845 based design.

Spritzer,

It is the 100V unit that has the voltage selector plug missing and it WILL operate. I bought that unit brand new, from a reputable dealer circa 1986. The packaging seemed factory fresh but I guess someone MIGHT have removed the plug before selling it. I can't imagine that they would have modified any internal wiring though. Also there is a very 'original' looking plate screwed over the voltage selector switch.
It is the 117V unit that will not operate with the voltage selector plug removed. Does that info change what you said before?

On the subject of a tube amp: I am considering an SRM-T1 for either my Lambda Pros or for Lambda Signature Pros that I have access to. What do you think of that combo and do you think that my 61 year old ears could hear the difference compared to what I have? I do love the detail of STAX and the sweet sound of tubes (at least when listening to McIntosh tube amps through speakers).

Thank you again so very much for all of your advice.

Since your 100v amp has a plate over the voltage selector that changes everything. Thats how Stax shipped the 100v amps back in the 80's so they could be converted at a dealer but not by an individual. The simply configured the primaries correctly and then bypassed the need for a plug. There should be the same transformers in both units, if they are the same version (A,B or C in front of the serial number), so there should be a sticker on them with the name "Bando" and then a serial number. If they match then you can hook up the voltage selector as on the 117v unit and then make the same connections internally as the plug would do. That should do it.

I have a T1, mine is modded with most of the wiring replaced with silver and WBT silver RCA jacks, and both the Lambda Pro and the Lambda Signature. The T1 is the work horse of my setup and is turned on 24/7 and it sounds great with most of the Stax models except the tougher loads such as the Omegas, Sigmas and the 4070. It is a clear step up form the SRM-1 Mk2 and it's easy to hear how much better the Lambda Signature is compared to the Pro's.

Happy to help out a fellow Stax nut.