Lowrider problems - sound but no octaves [solved]

[GhostofJohnToad]

Q1 - j201
Q2, Q3 - 2n5457

[GhostofJohnToad]

Well, looks like this one might be sitting on the shelf for a while.  I'm clueless and bummed that I can't get this working.   

[mgwhit]

To be fair, you found three significant problems in one day, which is (a.) good progress, and (b.) an indicator of how complicated a board of this size can be.  Based on your description of the problem, you've probably got more than one error left.  Definitely take some time away from it -- no sense working on a hobby that is supposed to be enjoyable when you're frazzled.  When you do come back to it, consider using a signal probe.  Good luck and let us know how it goes!

[GhostofJohnToad]

I'm a little OCD about projects I get working on sometimes and can't let stuff go. After thinking...  My next step is to socket the trannys (something I normally do, but for some reason did not this time.)  I'll try a few different ones to see if it makes any difference at all.

[GhostofJohnToad]

Woot! Problem solved!    I went back and socketed Q2 and Q3.  For some reason the 2n5457s that were spec'd out just did not work in my build.  I went through 12 different tranny types to find what I liked best.  The top 3 were 2n5088, BC549, and MPF102. 

The winner... MPF102.  Although a little lower gain than the other 2, it was by far the clearest tracking of the lot.  Only caveat is that while mostly cleaner, it appears to exhibit a slightly quicker note decay.  This becomes more obvious with staccato palm muting.  Another note; with the CLEAN turned all the way down and DOCT1 and DOCT2 turned all the way up the sound has a more ring mod like quality to it.  Give them a try if you have some and you socketed your board.

In case anyone wants to know I can do a full report on all the trannys that I tested and my notes.  The one thing I did not try was mixing and matching different values between Q2 and Q3.  Some later day perhaps. 

Thanks to you all for helping me through this difficult build!

Lessons learned -  always socket trannys and any other components listed with alternates.

[mgwhit]

Wow.  I didn't even know that non-JFETs would work in those positions.  Cool to know.  Glad you got it working.  Have fun!

[wasteofspace]

In case anyone wants to know I can do a full report on all the trannys that I tested and my notes.  The one thing I did not try was mixing and matching different values between Q2 and Q3.

GhostofJohnToad-

I'll be starting a LowRider soon, so this information would be very useful!