Volume issue.

[Gladone]

Ok, so the pickup selector switch went bad on my series 1. Contacted the mothership and got a new prewired switch. Installed switch. Note: I am a goldsmith. Absolutely no stranger to soldering virtually anything. I had mapped out the wires and connections beforehand. Everything works as it did prior to switch being replaced except for one detail. The volume pots  don't seem to do anything from 0-3/4 rotation and then seem to work from 3/4 to full rotation. Both bridge and neck controls, equally in rotation.   As of this writing, I've only tested this at low amp volume as the Mrs. is napping.  Thoughts?

[edwardofhuncote]

Someone else is bound to suggest this, but first, exercise the pots a couple dozen times each. (if you haven't already)

I notice, particularly on my older Distillate, that the volume pot doesn't really seem to do much until 3/4 of the way open. It's a totally different kind of pot than on a Series bass though.

Sounds like something simple... anxious to hear from the expert mechanics on here.

[Gladone]

on exercising the pots, I'd say yeah to that except both volume pots are having issues in the exact same fashion.  I'm thinking that the resistance is different between the old switch and the new, hence the equal problem with both pots.

[JimmyJ]

Hey John,

There are no resistors built into that switch, it's just a multi-pole / multi-position "on or off" which has jumpers in place to make it function as we need it for our specific application.  So it should not have attenuated the audio in the way you are describing. 

Does your bass have a master volume?  And did you cut the existing wires and then splice color to color, or did you try to connect directly to the original points on the various components?  Because it almost sounds like something has been connected to the "wiper" terminal of a pot instead of one end or the other...

My basses all have master volume pots and having just opened one for a quick look, I can't even describe where the switch wires connect without getting out a magnifying lens, a powerful light, and cutting some wire ties...  I do have a schematic of the series wiring harness but it's not very helpful in describing the wiring of this specific switch. 

Probably easier to either post a few close-up pics for us or to have Mica describe where each of the colored wires from that switch are supposed to be terminated.

Jimmy J

[Gladone]

No master volume control. Connected to terminals not spliced. As I mentioned, I mapped out everything beforehand and did one wire at a time.
As is my understanding of electronics, all components, including wire have resistance. Therefore 2 switches made by different manufacturers   could have different resistance values.(maybe Alembic is sourcing from a different mfg. than they did in '79) I emailed Alembic service but have not heard back yet.

[JimmyJ]

Well, that was a good approach to making the repair so something else must be in play here.  We'll have to wait to hear from Mica. 

Wires and switches (even from differing manufacturers) may have a minuscule amount of resistance but it is not nearly enough to effect the circuit in the way you're describing. And Alembic never compromises on the components they use so current p/u selector switches should be at least as good as the original '70's versions.

A couple questions:  Out of curiosity, can you describe how the original switch failed?  And, with this new strangeness, if you have chosen "neck pickup only" with the selector switch, does the treble pickup volume have any effect?  In other words, can you tell if the two pickups are still operating independently or is there some "cross-talk" going on?

We'll figure it out!  In the meantime, I recommend turning those volume knobs all the way up and playing that instrument!

Jimmy J

[mica]

John, check your spam folder. I sent a reply to your email from Monday yesterday. The switch manufacturer hasn't changed, but the first step is to look at what you have as I described in my email so that we can both have the same image to work from.

[Gladone]

Got it Mica. Will be photographing tonight and hopefully it can be figured out. No offense, it's kinda a rats nest in there so I wouldn't rule out that I may have done something wrong.

[Gladone]

Problem solved! I contacted a pal who is an electrical engineer. In a nutshell, he said to check my grounding. Everything looked ok, but I decided to cut the ground junction apart (if you've been in there you know what I mean), strip the wires, and re-solder. Everything works perfectly now!