TONE control design flaw?

[ingmar808]

 

I recently got a Hagstrom Viking Bass, and am very happy with it - sounds great, very playable, looks cool.

 

It has two pickups, each with its own volume and tone controls. The volume controls work as they should.

 

HOWEVER...  adjusting the bridge tone control also affects the neck pickup tone. Similarly, adjusting the neck tone control also affects the bridge pickup tone.

 

So EACH tone control works as a master tone i.e. one of the tone controls is totally redundant.  Surely it would be simpler, cheaper, and less confusing for Hagstrom to make this bass with a single master tone (as on a Jazz or Tele).

 

Why didn't they? Or am I missing something? 

 

[pfretrock]

Does it have a PU selector switch? There are a couple of wiring diagrams in the link below. In the neck only or bridge only position the other tone circuit should be isolated.There may be some interaction in mix if both vols are high.

Maybe your wiring is different? There are only two models shown .

There used to be a mega pdf with almost every schematic known to man, but I can't find it now. Think it was a German website.

 

http://www.hagstrom.org.uk/Schematics/HagstromSchematics.htm

[ingmar808]

36 minutes ago, pfretrock said:

Does it have a PU selector switch? There are a couple of wiring diagrams in the link below. In the neck only or bridge only position the other tone circuit should be isolated.There may be some interaction in mix if both vols are high.

Maybe your wiring is different? There are only two models shown .

There used to be a mega pdf with almost every schematic known to man, but I can't find it now. Think it was a German website.

 

http://www.hagstrom.org.uk/Schematics/HagstromSchematics.htm

Yes, there is a PU selector switch. It's quite busy, as it allows for each pickup individually as either single coil or humbucker (so total of 4 positions), plus another two positions with both pickups in either SC or humbucking mode. They all sound good - the only bummer being a fair bit of buzz/hum in SC mode. I'd love to be able to eliminate (or greatly reduce) this noise, as having both PUs on in SC mode sounds great, just like a P-bass. Because of the SC noise, I generally use the BOTH Humbucker position, which thankfully is pretty great too.

 

Anyway... here's the schematic for this particular bass. You'd think the tone controls would be independent - otherwise what's the point of having two of them? 

 

https://www.hagstromguitars.com/fileadmin/_hagstrom/downloads/wiring-diagrams/Viking-Bass-Wiring.pdf

Edited June 2, 2022 by ingmar808

[ingmar808]

PS I don't think my bass is faulty, as I've seen a few mentions of this issue elsewhere. No cure or explanations though...

[pfretrock]

That is the weirdest wiring diagram I've seen! Would expect the  (busy) switch to drop out the tone which is not required but they both seem to be always in circuit, the switch only selects the PU hot wires.

There is something odd, there seems to be no hot connection to the neck volume. It is marked White like the bridge vol, but nothing connects to it. - I think there is a missing connection on the drawing. The Blue loom has 4 wires coming from the switch, but only 3 going to the Volumes, (2 to vol grounds and 1 to Bridge vol  hot),  I presume this is only an error on the drawing. But both tones seem to be always in circuit. Never understood why 2 tones are needed on a passive bass, active I can understand.

[Maude]

From reading other sites (ahem TB) it seems that they're all like it. 

There's mention of the PUs being wired in series. 

Does the six way chicken head have a series position, and do the tones only do this when in that position? 

[ingmar808]

1 hour ago, Maude said:

From reading other sites (ahem TB) it seems that they're all like it. 

There's mention of the PUs being wired in series. 

Does the six way chicken head have a series position, and do the tones only do this when in that position? 

I think I've found the TB thread to which you allude... Seems that this tone control weirdness is a consequence of the PUs being wired in series, and that parallel wiring would cure this, but not sound as good when the PUs are used together.

 

Maybe the PUs were in parallel when the thing was designed, with the two tone controls working independently as they should. Then someone discovered it sounded better when wired in series, but it was too late to change the tone control configuration?