EB3 Position 4 Question

[fuzzy645]

I tried out a 70's EB3 bass in a local music store today and I didn't like what I heard in position 4.  Position 4 sounded awfully thin and trebly with a bit lower output to my ears.  The 1st 3 positions sound great, with position 1 being by far the beefiest and best sounding.  Is that the way position 4 is supposed to sound?

Thank you.

[Basvarken]

Welcome. You may find this useful

http://www.flyguitars.com/gibson/bass/1961gibsonEB3soundclips.php

[fuzzy645]

Welcome. You may find this useful

http://www.flyguitars.com/gibson/bass/1961gibsonEB3soundclips.php

Ahh, thanks for the link.  So it seems as if the 70's is most different than the 60's layout.

According to your link above, position 1 is the neck pickup with the choke, while position 4 is the neck pickup alone.

However, using this other link here of 1978 wiring: http://www.flyguitars.com/gibson/bass/EB3_controls.php

It seems the opposite.  Position 4 is the neck pickup with the choke (midrange notch), nad position is neck pickup alone.

Thanks!

[chromium]

Welcome to the forum!

If it helps at all, I describe the settings like this:

The early EB-3s up thru late-1971 used a circuit design that would result in:
Position 1 - Neck pickup with lowpass filtering (heavy lows, not much in the way of mids or highs)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup with "choke" circuit applied (thin nasal sound)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

The late-1971 and up basses used a different variation of that circuit:
Position 1 - Neck pickup (wide open, no filtering)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup (wide open, no filtering)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

[fuzzy645]

Welcome to the forum!

If it helps at all, I describe the settings like this:

The early EB-3s up thru late-1971 used a circuit design that would result in:
Position 1 - Neck pickup with lowpass filtering (heavy lows, not much in the way of mids or highs)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup with "choke" circuit applied (thin nasal sound)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

The late-1971 and up basses used a different variation of that circuit:
Position 1 - Neck pickup (wide open, no filtering)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup (wide open, no filtering)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

Thanks for your reply Chromium!! As you have described position 4 (thin / nasal), that is certainly consistent with what I head when I play tested the EB3 in the store.

Please clarify one thing for me though.  In the description of the 1978 model by Gibson (as posted by Fly Guitars), position 4 is described as a "midrange notch".  Perhaps it is just semantics, but I would expect a midrange notch to dip midrange frequencies only, and leave the highs and lows in tact.

Here is the link to Fly Guitars I was referring to:  http://www.flyguitars.com/gibson/bass/EB3_controls.php

Thanks!

[chromium]

Please clarify one thing for me though.  In the description of the 1978 model by Gibson (as posted by Fly Guitars), position 4 is described as a "midrange notch".  Perhaps it is just semantics, but I would expect a midrange notch to dip midrange frequencies only, and leave the highs and lows in tact.

I think in the >1971 circuit, that position 4 setting does indeed implement a notch filter (aka band-stop, or band-reject).  Being a simple passive implementation, however, that notch might be fairly wide... and I suspect its tuned in a way that some low end is being impacted in the process.  It sounds more like a bandpass filter to my ears, but that's probably because that pickup is midrange heavy to begin with, with not a lot of high end.

I had come across a nice whitepaper that gets into more of the theory behind the varitone circuits:
http://www.gtvnyc.com/okguitars1/varitonepaper.pdf

The author's description of the EB-2/EB-6 circuit would apply to the 60s EB-3 - similar filter topologies at play there (e.g. RL lowpass filtering in position 1, and RLC bandpass in position 3 & 4)

Confusing stuff! 

[exiledarchangel]

Very interesting read! 

[uwe]

Welcome to the forum!

If it helps at all, I describe the settings like this:

The early EB-3s up thru late-1971 used a circuit design that would result in:
Position 1 - Neck pickup with lowpass filtering (heavy lows, not much in the way of mids or highs)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup with "choke" circuit applied (thin nasal sound)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

The late-1971 and up basses used a different variation of that circuit:
Position 1 - Neck pickup (wide open, no filtering)
Position 2 - Bridge pickup (wide open, no filtering)
Position 3 - Bridge pickup, and neck pickup (wide open, no filtering)
Position 4 - Neck pickup with "choke" circuit applied (thin nasal sound)

Most helpful and comprehensive synopsis on the subject I have ever laid eyes upon.  Secrets of the varitone finally laid bare!!!