Which Hagstrom schematic gives blendable pots?

[frank57]

I'm hoping Hagstrom will send me a diagram for what they do now on the Swedes.
But here are two schematics I found.
I think the 1977 is the right one?
The old Swedes were wired with blendable pickups in the middle toggle position.
In other words independent volume controls.
Although on mine the tone cap is going to the in of the volume pots.

[jjasilli]

Not sure what you mean by "blend able".  Checkout the discussion on single coil.com http://www.singlecoil.com/docs/paula.pdf.

The vol pots are decoupled if standard wiring is used -- with signal into lug 1, out lug 2.  They load one another, but per single coil are true vintage and with better hi's, if signal goes into the wiper, and out lug 1.

[frank57]

The old Hagstrom Swede has 2 humbuckers and a filter toggle and pickup toggle as you can see.
When you're in the center position with the pickup toggle, the volume controls are independent.
In other words turning one volume down does not turn the guitar off like on a Les Paul.

The other volume control is still functioning.
So you can create different sounds by setting the neck volume at 6 and the bridge at 5 etc.
Right now I don't think it's quite wired like either schematic but the volume controls are independent of each other.
I'm not quite sure which way is right.
There's also a ground loop on the pots which can't be right but was there from the beginning.

[jjasilli]

I can't tell if you still have a question.  Also, I can't tell which Hagstrom schematic is the "old" one, because they don't both have dates. 
Anyway:

* Swede1.jpg has signal from PU > vol pot lug 1; and .022uF tone caps. This matches the layout in your last post. It also matches Gibson Les Paul modern wiring.

* Swede2.jpg has signal from PU > vol pot lug 2; and .047uF tone caps.  It matches Gibson Les Paul vintage layout.  In this wiring configuration, with both PU's selected, turning either vol pot to -0- will mute the guitar. 

The wiring choice, or tone cap value, is not objectively "right or wrong".  However, different users may have strong preferences one way or the other.

[G._Hoffman]

I can't tell if you still have a question.  Also, I can't tell which Hagstrom schematic is the "old" one, because they don't both have dates. 
Anyway:

* Swede1.jpg has signal from PU > vol pot lug 1; and .022uF tone caps. This matches the layout in your last post. It also matches Gibson Les Paul modern wiring.

* Swede2.jpg has signal from PU > vol pot lug 2; and .047uF tone caps.  It matches Gibson Les Paul vintage layout.  In this wiring configuration, with both PU's selected, turning either vol pot to -0- will mute the guitar. 

The wiring choice, or tone cap value, is not objectively "right or wrong".  However, different users may have strong preferences one way or the other.

Sorry, but  you've got that backwards.  If the pickup is wired to lug 1, then you are grounding out the output when the wiper (the middle lug) is all the way down.  If you want independent volume controls, the pickup must be wired to the center lug of the volume pot.  Gibson has never wired Les Pauls this way - well, it was never the spec, but they were pretty inconsistent about some of this stuff - they have always wired them so the two volume controls were interactive in the center toggle position.  What you want is for it to be more like a Jazz Bass - with the pickup being wired to the wiper, so the pickup gets grounded, not the output jack. 

NOT independent volume controls.  (You can add tone controls anywhere, since they are parallel loops.  If you want separate tones, add them before the switch.  If you want a master tone, add it after the switch.)

Independent Volume controls.  (Here, it is wired without a switch.  You can easily add one, of course, and again you can ignore the tone control easily.)


Gabriel

[jjasilli]

What Gabriel said is correct.

[frank57]

Well I'm still confused but there are dates on the schematics  one is from 77
and the other is from 2005.
So on a Gibson If you turn one of the volume knobs all of the way down,
 it will kill the output of both pickups, in the middle position like on an epiphone copy I have.
Okay that's not the case on the Swede.
You can control the volume of both independently in the middle without killing the output of both
or the tone controls of both.The downside seems to be a bit more noise.
Is either schematic going to do that?
Right now it doesn't quite match either one.

[G._Hoffman]

So on a Gibson If you turn one of the volume knobs all of the way down,
 it will kill the output of both pickups, in the middle position like on an epiphone copy I have.

Yes, exactly.


The second one (with the pickups going to the wiper of the pot, i.e. the center lug) is the one you want.



Gabriel

[jjasilli]

here's more diagrams:  http://www.dominocs.com/AshBassGuitar/WireLibrary-Gibson.html

[frank57]

So the second one from 2005 makes it like a gibson and the first one from 77 which is close to what's in there,
 makes it with two volume controls that don't turn each other off?

[G._Hoffman]

So the second one from 2005 makes it like a gibson and the first one from 77 which is close to what's in there,
 makes it with two volume controls that don't turn each other off?

Look at where the pickups are wired.  If it is to the wiper, then they won't turn each other off.


Gabriel

[G._Hoffman]

here's more diagrams:  http://www.dominocs.com/AshBassGuitar/WireLibrary-Gibson.html

Looking through that quickly, I wouldn't listen to anything he says - he appears to be an idiot.  At one point he suggests breaking the ground on a volume control, which would make it not work.



Gabriel

[frank57]

I see now,I get it now.
So the only difference on my guitar compared to the 77 schematic is that the capacitors are going to the in of the volume as opposed to the out of the volume pots.What difference would that make?
There's also a rather odd ground loop around all the pots for some reason.

[G._Hoffman]

I see now,I get it now.
So the only difference on my guitar compared to the 77 schematic is that the capacitors are going to the in of the volume as opposed to the out of the volume pots.What difference would that make?

None.

There's also a rather odd ground loop around all the pots for some reason.

Don't worry about it.  Guitar wiring is very forgiving, presumably because they are so simple and the signal levels are so low.


Gabriel

[jjasilli]

Ground loop:  Yes, the physical presence of a ground loop is undesirable, in theory.  But in practice, if it doesn't hum it doesn't matter. 

the capacitors are going to the IN of the volume as opposed to the out of the volume pots.What difference would that make?   This is the point of this whole thread.  More clearly stated, signal comes from the PU.  The signal is split in 2 directions: one side goes to the vol pot, the other side to its companion tone pot.  (This is not always immediately obvious from the schematic, or the physical layout.)  The vol pot can bleed all, or just some, of the signal to ground.  The tone pot would like to do the same thing, but the cap prevents this.  The cap blocks lo's from bleeding to ground, and only allows treble to bleed to ground.  The tone pot controls how much treble can bleed to ground through the cap.  This is called a "treble cut", or a "treble bleed" type of tone control. 

Now, wiring variations come into play.  The designer can choose either lug1 or lug2 of the vol pot as the Input.  Per the above posts, this will determine if dual vol pots are fully independent, or interactive.  (Either way they are "blendable", which word still leaves me confused.)  Whichever vol pot lug is chosen as IN, the signal is split from there to the tone pot. 

The tone pot is wired as a variable resistor. Often, lug1 has no connection; or lugs1&2 can be jumpered.  Either way works for a variable resistor.  Now, more wiring variations come into play. The cap can come before the tone pot's input, or after the tone pot to ground.  Either way works just the same.  Also, the tone pot's input is usually lug2.  But sometimes lug3 is used, in which case lug2 goes to ground.

So, to split the signal from the PU, the input of the vol pot must be connected to the input of the tone pot.  This connection can be: i) a wire; or ii) it can be the tone cap.  If i) a wire, then the tone cap comes after the tone pot, and completes the ground connection of the tone pot.  If ii) a tone cap connects the vol & tone pots, then the ground lug of the tone pot goes directly to ground.

[G._Hoffman]

...snip...

The only thing I'd add is that it doesn't make any substantive difference where you put the tone control or cap, other than before or after the switch, which will change it between either a master tone or a pickup's separate tone control.   


Gabriel