Author |
Topic: A little electronics education please... |
Michael Lester
From: Illinois, USA
|
Posted 22 Jan 2014 10:57 am
|
|
Is it common for the 3 way switch on a Stringmaster double 8 to affect volume?
In the middle position, both necks have equal volume.
In position 1 (front neck) or 2 (back neck) the volume of each neck noticeably increases and the attack is crisper...
My simple logic says that switch shouldn't have anything to do with volume or clarity.
BTW, the switch was removed by a tech a couple of months ago after I acquired the guitar. It was corroded from sitting a long time - but it cleaned up nicely and actuates easily. |
|
|
|
Erv Niehaus
From: Litchfield, MN, USA
|
Posted 22 Jan 2014 11:04 am
|
|
When you have both necks activated, it will tend to decrease the volume. |
|
|
|
Darrell Birtcher
|
Posted 22 Jan 2014 11:28 am
|
|
In simple terminology, whenever you put two pickups in parallel with each other (this is what happens when you switch both necks on) you give each pickup's signal a place to go besides the amplifier, so some of the signal travels to ground through the other pickup,
There are other things going on with impedance that will change the character of the sound, but in terms of volume, this is why you hear the volume drop. |
|
|
|
Ron Whitfield
From: Kaaawa, Hawaii, USA
|
Posted 22 Jan 2014 12:08 pm
|
|
Is there an easy way to eliminate this 'problem'? |
|
|
|
Jack Stoner
From: Kansas City, MO
|
Posted 22 Jan 2014 1:13 pm
|
|
The only way would be to have each pickup feed an op amp (preamp) and then be able to switch them individually or together with a "mixer". Way more complicated. |
|
|
|
Darrell Birtcher
|
Posted 22 Jan 2014 1:19 pm
|
|
"We have ways...."
But... I wouldn't do it to a Stringmaster.
One way would be to place a buffer amp right after each
pickup. This would eliminate the alternate path to ground that I described and would remove those impedance issues that come into play when both pickups are on, so the tone would be consistent across your switch positions. If you use a volume pedal, then just advance it a little when you have both necks switched on. Most steel players tend to use the middle portion of the pedal's travel for normal playing, saving the loudest part of the travel for increasing the sustain of decaying notes when needed.
You could put a boost pedal in your signal path and switch that on only when you have both necks turned on. You wouldn't need much. 3 to 6db should do it for most ears. Just some ideas. |
|
|
|
Darrell Birtcher
|
Posted 22 Jan 2014 1:20 pm
|
|
Jack is on the right track. He got his posting in as I was typing mine. Both are describing the same approach with the op-amp. |
|
|
|
Dave Mudgett
From: Central Pennsylvania and Gallatin, Tennessee
|
Posted 22 Jan 2014 1:36 pm
|
|
Darrell is correct. I don't consider it a 'problem' - all one needs to do to get the switched-to-single-neck hotter signal is to switch the pickup to the solo position on the neck one is playing. With two identical sets of pickups wired in parallel, both the signal strength and impedance are cut roughly in half when switched to both-on. The impedance drop also affects the tone - it tends to thin it out, you either like it or not.
As Jack says, an active on-board preamp/mixer could eliminate the effects of the volume and impedance drop. Of course, it's way more complex, requires installing the stuff (including batteries or an attachment for an external power supply) on the guitar, and now you're also dealing with an active solid-state system, which is likely to change your sound.
In principle, one could wire the two necks' pickup sets together in series instead of parallel. With two identical sets of pickups on a single neck, that would roughly double the output signal and impedance. Some Spanish guitars have the ability to run multiple pickups on a single neck in either parallel or series, it can be useful. But with two sets of pickups, each on a different neck, it doubles just the impedance, and not the signal strength from picking on one neck. Beyond this, I wouldn't wire the necks in series on a steel like this because
- It would require rewiring the guitar, which I wouldn't do on a vintage Stringmaster
- The impedance increase would tend to muddy up the sound with both pickups on (the opposite of the effect when wired in parallel) but not increase the signal strength when playing on one neck. In fact, if wired in series, the second pickup set (on the neck not being played) would just act as a voltage-divider, which would also reduce the signal strength.
I almost never use the 'both necks on' position on a double-neck guitar of any kind (steel or Spanish) - it generally sounds inferior to me. |
|
|
|
Michael Lester
From: Illinois, USA
|
Posted 22 Jan 2014 7:10 pm Electronics
|
|
Thanks everyone...I learned something! |
|
|
|