My Uncle Gave Me His S.E.X. and there's a problem

[Fishfood]

Hi- I'm new to all this but I have some minor abilities to solder and follow a plan. I inherited what I think is an early SEX from my uncle and unfortunately the first thing I noticed is the sound is muffled and the midrange is recessed. I've played with a bunch of tubes and found the pair that sounds the best but the problem still persists. When listening, if I disconnect either the right or left input, I still hear sound in both sides of the earphones and the problem disappears, except of course that I'm listening to mono. Does this sound like a familiar problem to anyone? Thanks so much in advance for your help!

[Paul Birkeland]

Hello Fishfood,

Welcome to the forum!

If you plug in 1/4" headphones into the jack, then pull them out slightly, you can bridge the left and right channels with the headphone plug itself, which may appear to be a problem, but is not.

If, on the other hand, you are yanking out one RCA plug and finding that you have sound on both channels, that's an unfortunate issue that needs your attention.

Is there any way you can post a picture of the top and the bottom of this amplifier for us?  This will help us identify the amp for you, and perhaps we can e-mail you a manual so you can begin troubleshooting.

If I had to guess, I would suspect a possible error in wiring from the output transformer, but it'd be best to know that everything else is hitting the marks first.

-PB

[Fishfood]

Thanks so much. How do I post a photo? I have taken a couple.

[Paul Birkeland]

I'd grab an account at a free image hosing site (I use image shack), then you can upload a photo there.  On our forum, there's a little button with a picture on it (2nd one from the left on the bottom row) that will give you the forum code for inserting an image.  Copy the URL of the image you have uploaded and paste it into the coding that button provides.

[Fishfood]

Trying again:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fimageshack.us%2Fa%2Fimg404%2F1179%2Fimg0524cw.jpg&hash=71d3e0ddc3b5ef87fb96b63797676b335e9bbdaf)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fimageshack.us%2Fa%2Fimg72%2F3176%2Fimg0525m.jpg&hash=3d60682e46251ae5e8dc3758d292899e5155bb12)

[Paul Birkeland]

Yay!

OK, you have the Sex from the mid 2000's. 

Shoot me PM with your e-mail and I can send you a manual, then we can debug.

By-the-way, that is exceptionally well built!

[Paul Birkeland]

E-mail sent.  Do be aware that my e-mail address has a very high spam score, so you might have to dig into the junk folder to look for it.

-PB