Flipster Troubleshooting Request (with Photos)

[deschete]

Well, I finally got my Flipster build complete and I'm not having a lot of success.

Using an audio probe, I can hear good strong signal through the first JFET stage, through the Vol pot and then into the Gate portion of the second JFET socket.  If I plug the second JFET in to the socket, the sound at the Gate and Drain loses considerable volume.  I also have no voltage at JFET #4's Gate.

Here are pictures of the front and back.  Any suggestions where I should start troubleshooting?  I really wish I understood how to do this better, and I'm trying my hardest... just I'm reaching the boundaries of my electrical knowledge.  It all looks like I've done it okay to me, and I triple-checked that the pot values/connections are correct.

[nordine]

Seems OK,

first Question: did you set the trimpots right?

what are the voltages at every Q's drains?

[deschete]

Seems OK,

first Question: did you set the trimpots right?

what are the voltages at every Q's drains?

I was able to get 4.5v at the drains of Q1, Q2, and Q3.  I don't see any voltage at the Gate of Q4 and I can't get more than .5-.9v out of the drain of Q4.

[deschete]

Okay, I figured it out.  I had the JFETs backwards...  oops.  That's 2/2 in the past few weeks thwarted by something that's backwards.

I found two conflicting data sheets saying which way the G, S, D were for the JFET.  I decided tonight to flip them around and voila... sound.  I feel like so much less of a failure now.

I biased the JFETS to 4.5v and found it broke up a little too early for my tastes.  I rebiased to 7.0v and there's more room on the pre-gain before distortion happens.  Tomorrow when my wife isn't sleeping, I'll try some other experiments with it and report the results.  I've also got some alternate JFETs to try.

It's exciting when things finally work, isn't it!!!