Sorry for asking but I don’t suppose there’s any way you’d consider taking gut shots of the Solid State Reverb & Echo 600 for me would you? Been looking for photos for years.

Either way, great collection

Is that your page? There is quite a bit of incorrect info on that page.

For a start, EHX was closed from around ’85 onwards due to union pressure and the mistress didn’t go back in to production even as a prototype until Sovtek started up which was post ’89.

The filter matrix completely disables the LFO, it’s not sweeping at all and the flange is instead voltage controlled.

The known mod for the volume drop shouldn’t be suggested, changing the wet/dry mix affects the notches and leads to a less than optimal sound.

The Trim adjustments need more background, the trim affected when you “Then set it in the middle of the two cutout points” sets the bias, yes it can be done by ear (although a tech with a scope will do a better job) but the best way to set it is the point where the least distortion occurs rather than an arbitrary point as each chip will have a slightly different bias point.

Etc.

Where are you located? Will help finding someone who can fix it.

Which the big box re-issues also used so you don’t have to buy vintage.

Yikes! Yeah tracing that without it in hand is probably a fools errand.

Thanks for the photos though interesting to see regardless.

If it delays, the 3005 & 4047 are fine.

As EH Man said, nature of the beast that it whines, no companding circuitry and not that great low pass filtering. You can try adjust the high pass trim to get rid of it.

I think what you have might just be normal behaviour, if you don’t want whine you should probably look to a Deluxe Memory Man.

Sorry I haven’t e-mailed back, away from home but quick answer;
1)Post BBD Gain
2)Post BBD Gain
3)Bias
4)Cancel
5)Bias

The photo is too small to trace which Gain & Bias is for which BBD though.

Sent you a PM