A switch under the hood?

[mauroj]

I recently purchased a Seduction with C4S installed used but did not receive the assembly instructions with it. I ordered the instructions from Bottlehead with my Quickie but the C4S instructions were not sent with them. I took a good look at the underside yesterday and saw a slide switch under the hood. I have not tried it yet because I do not know what it is for. Do any of you have pictures of your Seduction I can compare to? I will post a picture later but I am wondering what its use could be.

Thanks in advance.

Jeremy Mauro

 

[fullheadofnothing]

Your post is a bit unclear. Did you buy a Seduction, a C4S upgrade kit for a Seduction, or a Seduction with a C4S kit installed?

If there is a switch installed, it is not part of a stock build. Ask the builder what it is for. The forum readers may be able to determine its function with clear enough photos.

 

[mauroj]

You're right, it was unclear so I modified the op and added a photo. It looks like the switch is connected to 2 grey wires at least and the C4S board. I think it might be a switch for the C4S but I cannot be sure. I did ask the gentleman I purchased it from about the switch but have not gotten a response yet. Thanks again.

Jeremy Mauro

 

[mauroj]

The original owner responded to my inquiry. He said that the switch was to change the RIAA EQ for use with the 6N23P/6H23N from the regular 6922 curve. I do not know exactly how this would work, but it is most assuredly aftermarket. Does anyone have any idea how this could work? Or why this would be necessary for these tubes?

Jeremy Mauro

 

[Grainger49]

The 6N23P is a drop in equivalent for the 6922.  However a 6N1P needs more heater current and requires a different resistor load.  This is most likely what he was working to do.  The 1M ohm resistor to ground after the 0.1uF interstage coupling cap changes to, I believe, a 500k ohm resistor.

The key is that the 6N1P can overheat the transformer's winding because it is not designed to deliver that much heater current.

 

[mauroj]

Thank you Grainger. That makes more sense for sure. I don't plan to use any 6N1P tubes at all but it is nice to have the option available.