Choral Reef - Intermittently not Chorusing

[mingus1013]

Hi All -

I recently completed a VFE Choral Reef build, and am having some issues.

Notably, it seems to only 'Chorus' at certain times (randomly, usually after being 'rebooted'). The Mix knob seems to have strange functionality - with both extremes seemingly functional (although with some chorus sound, even on the lowest setting) and  the center position only having a slight volume drop.

I'm defining this as a 'lack of chorus' due to the fact that the rate knob does not seem to have any impact on the sound, when this intermittent issue occurs. I do get flange-style sounds from the feedback and width controls.

I've checked the IC pin voltages, with the CD4047 and LM358 being close to normal.
The TLE2074 seems to have some lower than normal voltages on pin 10 (4.07, should be 6.06) and pin 12 (1.3, should be 3.86).

The MN3008 Also has low voltages on pin 6 and 7 (both are 5.0, and should both be 6.09), pin 9 (4.02, should be 4.16) and pin 13 (5.19, should be 5.99).

I got the MN3008 from a trusted source (Smallbear). I am powering this from a good-quality source (Truetone CS12)

Any thoughts on where I should troubleshoot, next?

Thanks!

[zgrav]

When the chorusing works after powering it on, how long is it until it stops chorusing?  Seconds?  Minutes?  Three songs later...?    And is that a relatively consistent time? 

[mingus1013]

Usually it remains 'on' until I'm finished - and it is powered down.  Definitely not a consistent duration. Thanks!

[zgrav]

Have you tried taking it out of the enclosure to test it?  That is one way to see if something is grounding out to the case that shouldn't be, and it also gives you a chance to see if handling the pcb and touching different components while playing something through the effect (great use for a looper, btw) will affect whether it is chorusing or not.

[mingus1013]

Good idea - thanks!