Am I or the tech wrong?

Goodlawdy · #1 03-18-2011, 06:08 PM

I took my bass in to have a new pair of Bartolini MM pickups, 4 conductor humbuckers installed to a new Vol/Blend/Bass/Treble prewired harness.

I supplied the following two diagrams.

Go to pick it up today and the tones aren't working at all, the 3 way switches aren't doing what the diagram says. They are silent in the center detent.

He said he wired according to the diagram and got no sound at all. He took it back to try again.

What do you think the electrical problem could be?

**line6man** · #2 03-18-2011, 06:19 PM

If the middle position is off, that means you used an On/Off/On switch instead of an On/On/On switch.

i_got_a_mohawk · #3 03-18-2011, 06:26 PM

If the Bass/Treble controls aren't doing anything, I'd be thinking about that preamp.

Does the internal gain pot have any impact on the overall volume?

Regarding the switches, I haven't seen it done that way.

http://cachepe.zzounds.com/media/4_C...9cb3bd5781.pdf

That's the way I have seen it done normally. It's a Friday night and I can't get my mind kicked into gear. However, one thing I will suggest, you say it's off in the middle position. Are you sure you got the right 3-way switch?

While you do get on-on-on ones (what you want), you also get on-off-on ones too.

**line6man** · #4 03-18-2011, 06:32 PM

Quote:

Originally Posted by i_got_a_mohawk

If the Bass/Treble controls aren't doing anything, I'd be thinking about that preamp.

Does the internal gain pot have any impact on the overall volume?

Regarding the switches, I haven't seen it done that way.

http://cachepe.zzounds.com/media/4_C...9cb3bd5781.pdf

That's the way I have seen it done normally. It's a Friday night and I can't get my mind kicked into gear. However, one thing I will suggest, you say it's off in the middle position. Are you sure you got the right 3-way switch?

While you do get on-on-on ones (what you want), you also get on-off-on ones too.

No, that's regular series/single/parallel switching, they just swapped the bottom right terminal with the bottom common.
It's the same switching, it just looks a little different.

Goodlawdy · #5 03-18-2011, 06:34 PM

They're the existing switches that were on the bass. It's a Kawai F2B. They were for 3 way mid frequency selection originally. The orig. pickups were active. These are passive. Do they make active vs passive on/on/on's?

Goodlawdy · #6 03-18-2011, 06:49 PM

Quote:

Originally Posted by line6man

No, that's regular series/single/parallel switching, they just swapped the bottom right terminal with the bottom common.
It's the same switching, it just looks a little different.

That's what I'm wanting here. I'm thinking he's never wired this setup before.

fleabee · #7 03-18-2011, 06:56 PM

This is gonna sound far fetched, but is there anything touching the output jack that shouldn't be. That could cause a handful of audio loss issues. I'm speaking from personal experience wiring Bartolini pups/pre's

Goodlawdy · #8 03-18-2011, 07:02 PM

Quote:

Originally Posted by fleabee

This is gonna sound far fetched, but is there anything touching the output jack that shouldn't be. That could cause a handful of audio loss issues. I'm speaking from personal experience wiring Bartolini pups/pre's

As a matter of fact, that was the first thing he looked at when I brought it back to the counter. No eq, no blend, incorrect switching were the probs.

I'm giving him the benefit of the doubt to get it right. Aside from the switches, everything is new components.

Could the blend be a problem in conjunction with switching?

Goodlawdy · #9 03-18-2011, 07:06 PM

Can a battery fry anything if it's not separated from the electronics? He mentioned that he'd wrapped the battery in electric tape.

fleabee · #10 03-18-2011, 07:09 PM

If the battery was causing any kind of problem it would be like touching a lit match when you opened the control cavity

i_got_a_mohawk · #11 03-18-2011, 07:19 PM

Quote:

Originally Posted by line6man

No, that's regular series/single/parallel switching, they just swapped the bottom right terminal with the bottom common.
It's the same switching, it just looks a little different.

Right enough, I'm being blonde tonight.

Quote:

Originally Posted by Goodlawdy

They're the existing switches that were on the bass. It's a Kawai F2B. They were for 3 way mid frequency selection originally. The orig. pickups were active. These are passive. Do they make active vs passive on/on/on's?

The switch is still a switch.

Depending on how it was used in that circuit, it could have been an on-off-on.

Simple way to test it is to see what the resistance is between opposite pins;

Say you have it like so:

123
456

With the switch in the middle position, see what the resistance between 1 and 3 (or 4 and 6) is. If it is near enough 0 ohms, it's on-on-on, if it's an open circuit, it'll be on-off-on.

(also, it's usually stamped on the side IIRC).

Goodlawdy · #12 03-18-2011, 07:54 PM

Quote:

Originally Posted by i_got_a_mohawk

Right enough, I'm being blonde tonight.

Depending on how it was used in that circuit, it could have been an on-off-on.

Oh

I assumed that on/off/on doesn't permit sound in the center position.

You're saying that when it was a mid frequency selector, the middle selection was simply not affecting the mid frequency. I think.

Wish I had it now to look for the stamp.

Thanks

BadB · #13 03-18-2011, 08:02 PM

So, why is the tech returning the instrument to you when he should be fully aware that it is not functioning properly?

Goodlawdy · #14 03-18-2011, 08:06 PM

He didn't return it. He took it back right after I tested it and realized it wasn't right.

Just thought I'd ask the guru's around here for some insight. Sounds like I may have the wrong type of switches.

Still doesn't explain why the blend or tone knobs aren't working though.

BadB · #15 03-18-2011, 08:22 PM

Quote:

Originally Posted by Goodlawdy

He didn't return it. He took it back right after I tested it and realized it wasn't right.

Just thought I'd ask the guru's around here for some insight. Sounds like I may have the wrong type of switches.

Still doesn't explain why the blend or tone knobs aren't working though.

That's fine, but he still should have realized that something was amiss and worked to resolve it with you before you wasted time going to pick it up. How much experience does this tech have with active preamps? Does he normally only deal with passive setups?

Goodlawdy · #16 03-18-2011, 08:28 PM

Glad I tested it.

i_got_a_mohawk · #17 03-19-2011, 03:24 AM

Quote:

Originally Posted by Goodlawdy

Oh

I assumed that on/off/on doesn't permit sound in the center position.

You're saying that when it was a mid frequency selector, the middle selection was simply not affecting the mid frequency. I think.

Wish I had it now to look for the stamp.

Thanks

It really depends on how the preamp was setup. In the center position, it would mean there isn't a connection between the pins. This means no sound, if the signal is going through it. But on a preamp, it could have been implemented in a number of different ways.