Double Bass NS CR4M EUB Magnetic Pickup / Polar Bridge Knob

[scootsmason]

Hey guys I just bought a used 2002 NS Design CR4M EUB in excellent shape at a great price. It sounds and plays killer - way better than the Wav4 it is replacing!
Just one thing - When I rotate Knob 2 (the pickup blend knob) all the way up (clockwise) the volume completely cuts out / mutes. According to the online instrucions pdf file this is supposed to be the position optimal for arco.
I contacted NSD and they sent me a schematic showing me where I could adjust that pot on the circuit board. I adjusted that all the way up and still have no sound. I don't play with a bow very much so it's certainly not a deal breaker but am just wondering how it would sound differently if it worked properly.
Or am I missing something?
Thanks!
Todd

 

[Upfromthesky]

It might be a piezo crystal gone bad. There are 2 different piezo crystals - one for pizz and one for arco in the bridge. They can wear out over time. I had it happen with my NS upright after I had it for more than 20 years.

 

[scootsmason]

It might be a piezo crystal gone bad. There are 2 different piezo crystals - one for pizz and one for arco in the bridge. They can wear out over time. I had it happen with my NS upright after I had it for more than 20 years.

Thanks! Would I be able to fix that or would it need to go to a tech?

 

[Upfromthesky]

Thanks! Would I be able to fix that or would it need to go to a tech?

I would check with NS Design. I can’t think of anyone other than them who would understand the bridge construction and/or have the crystal. Unless it’s some kind of wiring problem in the pot or a connection. Have you taken it apart and looked in there?

 

[scootsmason]

I would check with NS Design. I can’t think of anyone other than them who would understand the bridge construction and/or have the crystal. Unless it’s some kind of wiring problem in the pot or a connection. Have you taken it apart and looked in there?

From what I can see it looks OK and the knob works properly until it gets rotated forward all the way. But no I won't want to take the circuit board out - that's above my pay grade haha. I'll contact NSD and see what they recommend.

 

[adam.beauchene]

When the second knob is rotated all the way clockwise, and you change the bottom switch position (arco/pizz selector), do you get any sound, or is it silent in all modes?

 

[scootsmason]

When the second knob is rotated all the way clockwise, and you change the bottom switch position (arco/pizz selector), do you get any sound, or is it silent in all modes?

Silent in all modes when the knob is all the way forward.

 

[scootsmason]

Wow - Adam from NS just contacted me after seeing this post and is offering to diagnose the issue for me - such incredible customer service!