Help with EHX 73 Rams Head Big Muff - SOLVED!

[John R]

https://tagboardeffects.blogspot.com/2012/06/ehx-73-rams-head-big-muff.html

With all three knobs all the way up I get a very faint clean sound. The tone knob sounds muffled at 12 o'clock, but is basically the same at either end. The switch positions make it a little louder on the top and bottom, and quieter in the middle.

Voltages:
Q1 C 7.94  B 0.60  E .01
Q2 C 7.95  B 0.54  E 0
Q3 C 8.43  B 1.46  E 0
Q4 C 8.05  B 0.95  E .36

i haven't used these 2N5133s before -- there's no flat side, but the legs are like a triangle. I put the side where the center leg is on the "outside" where the transistor bump is in the drawing. Is that correct?

Thanks in advance for any help or advice.

John

[Ciaran Haslett]

Pinout again looks like.

They have a slightly flat side.  This side is nearest the emitter so it looks like a few of them need flipped.

[John R]

thanks for the reply.

wow that flat side is SUBTLE. I never would have seen it if you hadn't said it was there. :) The only one that was wrong was top right. Flipped it, and now there's no sound whatsoever. :(

john

[John R]

So I found this:


which helped, except that one of mine had the flat side on the bottom side of the E instead of the top. But whatever,  I tried every combo of rotating them around, and finally got it to where it sounded somewhat like a distortion pedal, but only with the knobs all the way up, and even then still quieter than bypass.

For sake of testing, i replaced the 5133s with 5089s and voila -- cranked fuzzy goodness! So the pedal is OK.

I then added the 5133s back in one by one, and discovered that the odd one was actually rotated off by 90°! Correcting that, I got 'em in there right, and it sounds even better than the 5089s (less harsh highs when the gain is past 12 o'clock).

RAWKING! Thanks for your help!

John