BOSS CE-1 Stuck in EFFECT mode

[cjlectronics]

Hi Mark,

I saw the pictures Steve Daniels posted of his visit to your home. It is good to put a face to the name. I have been wanting to do the same thing here in the Texas area. There are plenty of DIY'ers around here that I think we could really start a DIY swap meet on a regular basis. Either that or we'll just drink a lot of beer...

A few facts on the 2SK30A failure:
1. All JFETs in this circuit have lasted for a very long time... decades.
2. Why Q13 is a common failure, I would think would require analysis during switching. I find it hard to believe the JFET is stressed or over-voltage during its ON state. If this was the case I think it would have died sooner.
3. Also, I find it hard to believe that it was a bad batch of JFETs. Wouldn't you see Q11 or Q12 go bad. However, the other JFETs may be suspect and on the verge of failure.
4. I've looked at the datasheet for the 2SK30A and it is not stressed by any means in the CE-1 circuit, that is if they are using the 2SK30A-GR??? 2SK30A.pdf

[Mark Hammer]

Inspired by this thread, I started a thread on the DIY stompbox forum about switching FET failure. Jay Doyle and RG have chimed in, as well as some other folks. Might be worth checking out.

The DIY-er party was an absolute blast. The only disappointing part was that Tim Larwill from Retro-Sonic never made it. Tim and Steve Bragg from Empress live in the same part of the city, and in all these years have never met. I was looking forward to introducing them to each other, given the stature that each has ascended to in the pedal business.

Certainly having JC Maillet (the viva-analog guy - Welcome to "viva Analog" ) was a big bonus. JC spotted an issue in my vintage tweed Bassman, threw it up on the bench in my garage (that I had cleared off for the event), asked for a soldering gun and a chopstick, and 20 minutes later it was fixed and re-assembled. Now THAT's a pal.