Hello... and perhaps a few uh-ohs...

[jte]

Wow...

A. My comments were based on reveiwing Frono's hand-drawn schematic and photo. It CLEARLY shows two resistors in addition to the caps.

B. The caps are there for the treble bleed tone controls that's all.

C. The hand-drawn schematic DOES indeed have a pickup toggle switch. It's the part just to the left of the output jack in the schematic. The output of the neck PUP (labeled "bass") goes through the "tone" switch, then the volume and tone controls, then to one leg of the switch. Same for the bridge PUP, labeled "treble", only without the tone switch.

D. dlenaghan's picture clears things up a bit more. His circuit is different form Frono's. dlenaghan's doesn't have the resistors in the circuit at all. It looks like a standard volume and tone control set up for each PUP, and I'm assuming a PUP selector switch outside the frame of the photos. The caps are paralleled with the PUP's hot which goes to the outer lug of the volume pot. They simply bleed highs off depending on the setting of the tone control pot. All very straight-forward and typical high-impedance guitar electronics.

E. The ASAT is essentially an L-2000 with a much clumsier body shape . There are circuit schematics available that explain what the controls do. You COULD do that, but I suspect you'd have to change pot values, at least as far as setting up a passive bass cut as well as the much more common passive treble cut. I believe the G&L circuit also switched the coils of both PUPs at the same time. I'd probably avoid opening up the pickups to get to the coils (wait- I've forgotten if dlenaghan's bass has 'buckers or single-coils! ). Anyway, I'd skip the series/parallel switching the G&L has, but you might like the bass cut option.

John

 

[jte]

dlenaghan's caps go to ground via the pot. The signal flows via the white wire from the PUP to the left-hand lug of the volume pot. The cap is parallel with that, and goes to the wiper of the tone control. The right-hand lug of the tone control is shorted to the pot housing which is wired to ground via the common ground wire connecting all four pot housings.

John

 

[dlenaghan]

dlenaghan's caps go to ground via the pot. The signal flows via the white wire from the PUP to the left-hand lug of the volume pot. The cap is parallel with that, and goes to the wiper of the tone control. The right-hand lug of the tone control is shorted to the pot housing which is wired to ground via the common ground wire connecting all four pot housings.

John

The caps are paralleled with the PUP's hot which goes to the outer lug of the volume pot. They simply bleed highs off depending on the setting of the tone control pot. All very straight-forward and typical high-impedance guitar electronics.

So.. (and sorry if this is a "Bass 101" kind of question) what would these caps do in addition to the regular tone pot? I've heard tone pots described as variable resistors, which would make sense if resistors are used to filter out certain frequencies. Are they used in addition to the pots to get the signature sound the manufacturer is going for? Can they do this while also doubling as a ground? Though the articles captjuan linked to described capacitors as storing a charge, so is it meant to act as a passive boost of sorts?

I guess the caps confuse me because I hadn't seen them in my previous basses until I got the ASAT, although it wasn't until recently that I even started poking around the control cavity.

 

[fronobulax]

Just to clear up the confusion, my bass has the "tone switch" which was advertised as a bass boost in product literature of the time (even though in a passive circuit, it is actually a treble cut). That switch only operates on the neck PU. My hypothesis was that dlenaghan's bass would have a similar circuit with the bass boost missing, especially since the player visible controls seem otherwise identical. My guess was that the values of the electrical components might differ because the Hagstrom Bisonic and the Guild Humbucker are different pickups and the former is hotter than the latter.

That sketch is many years old but the person who drew it has been a licensed electrical engineer for 30+ years so I presume a certain degree of accuracy. The component on the far right, labeled output, is supposed to be a three way toggle - neck, both, or bridge.

 

[capnjuan]

A. ... It CLEARLY shows two resistors in addition to the caps.
Hi John: I didn't say there weren't resistors in there - what I said was that the objects he was describing - with printed uf values and voltage ratings - weren't resistors.
B. The caps are there for the treble bleed tone controls that's all.
If you say so.
C. The hand-drawn schematic DOES indeed have a pickup toggle switch
You're right, I got hung up looking at the tone switch.
D. dlenaghan's picture clears things up a bit more. His circuit is different form Frono's.
That's right; they aren't the same. I didn't say or suggest they were the same.

 

[dlenaghan]

Well, on a side note ultimately related to this whole fix'er-up business, the new saddles came in today and they're working nicely, even if they are at least 30% taller than the old saddles! The cut that seats them onto the metal paddles screwed into the harp bridge piece are also wide so the fit isn't very tight, but the string pressure holds them nicely in place, even with aggressive playing. I guess I'll just have to take care not to lose them when I'm changing strings...

Or I could shim them.

Oh, did I say shim?! This isn't a Fender forum! Snap!

(No offense intended. Yes, I make stupid jokes for my own benefit. Sorry.)

Photos of the saddles compared side by side to come, as well as more on-topic business regarding the new electronics, though that won't be for at least another week and a half, depending on when the pots from BestBassGear get here, though man, those guys ship quickly.

Thanks to everyone who's weighed in.. I feel edified and I haven't even replaced a pot yet.

 

[fronobulax]

Where did you get the saddles from? I thought Guild Bass Parts made replacements that were the same size?

That said, my Starfire has replacement saddles made by the late Brian Bowdren. They are taller than the originals. I was initially annoyed but installed them anyway. The JS and the Starfire have similar action heights (because the Starfire bridge is as low as it can go) and for whatever reason the Starfire feels different and I prefer it.

 

[jte]

So.. (and sorry if this is a "Bass 101" kind of question) what would these caps do in addition to the regular tone pot? I've heard tone pots described as variable resistors, which would make sense if resistors are used to filter out certain frequencies. Are they used in addition to the pots to get the signature sound the manufacturer is going for? Can they do this while also doubling as a ground? Though the articles captjuan linked to described capacitors as storing a charge, so is it meant to act as a passive boost of sorts?

I guess the caps confuse me because I hadn't seen them in my previous basses until I got the ASAT, although it wasn't until recently that I even started poking around the control cavity.

The pot (short for "potentiometer") is the variable resistor. The capacitor works with the pot to shunt highs to ground. The capacitor bleeds highs to ground, but how much is controlled by the resistance of the pot. A pot is a resistor with a wiper in the middle. At either end of the travel the wiper is shorted to one side of the resistor or the other. It's hard to describe without diagrams, so look closely at Frono's diagram. The part labeled "tone" shows one leg of the pot (it's the squiggly line with an arrow pointing to it- the arrow is the center lug of the pot which is the wiper) wired to the pickup's output and the other extreme of the pot is grounded. The wiper has the capacitor between it and ground. As you roll the pot from one extreme to the other, the path for the signal from the pickup through the cap to ground sees increasing resistance. That alters how much treble frequency is shunted to ground.

Every passive bass with a tone control has a cap for the tone control. They're frequently small disks and there are several ways to wire the circuit with similar results, but they're in there.

John

 

[dlenaghan]

Where did you get the saddles from? I thought Guild Bass Parts made replacements that were the same size?

That said, my Starfire has replacement saddles made by the late Brian Bowdren. They are taller than the originals. I was initially annoyed but installed them anyway. The JS and the Starfire have similar action heights (because the Starfire bridge is as low as it can go) and for whatever reason the Starfire feels different and I prefer it.

Yes, they are taller, almost 1/3 more.. I've never had the chance to play another Guild of this era and I have heard that there's a fair amount of variety among individual basses, but I can't say firsthand. My bridge had been raised slightly with the shorter saddles, and I don't have the equipment to shorten the new saddles, nor do I want to risk breaking one of them by going to a woodworker since that would just add to the bills for fixing this one up a bit. I was able to lower the bridge so the strings have the proper tension, so it hasn't been a problem. The length and width of the saddles is spot on, just the height. I wondered if that was to compensate for a different bridge design, like the style which preceded the harp design on older Starfires.

I would love to get my hands on a Starfire..

 

[dlenaghan]

I was also wondering... the original saddles (and the replacements as well) are said to be Brazilian rosewood.. does anyone know if that's what the fretboard is as well? I know it was replaced by Indian rosewood in the late 60s/early70s due to cost, scarcity, and concerns of abusive forestry practices which resulted in the strict export laws for unfinished hardwoods today. I had looked into buying ebony or rosewood blanks (Brazilian), but they are unavailable for export if the exporter is a lawful person.

 

[fronobulax]

I can't say that I ever cared whether the fingerboard and saddles were Indian or Brazilian rosewood. The acoustic folks seem to have differing opinions as to whether they can be told apart without sophisticated (and destructive) testing. My take on the debate is that Guild did switch from one to the other in the 1970 time frame so you could have either. I'll also note that Guild was known for using what was available, rather than adhering to published specifications, and it is possible that scraps of Brazilian rosewood that were too small for a guitar's sides were used for saddles well past the time when the switch occurred.

The saddles that came on my 1967 Starfire are virtually identical to those on my 1971 JS II. Since I bought the Starfire used (circa 1977) it is possible that a previous owner replaced the saddles but the bridge itself is definitely from (early) 1967 and the saddles from the JS II fit it. I know there is some variation in the saddle spec but peteybass made a point of saying he had derived his replacement specifications from numerous examples. Something doesn't quite make sense but as long as the bass is playable then it really doesn't matter.

A Starfire definitely has the "wow" factor but it will be interesting to see whether you find a significant difference in sound/tone between a Bisonic equipped Starfire and your JS.

The Starfires are out there but the problem is in finding an affordable Starfire :wink:

 

[jte]

I was also wondering... the original saddles (and the replacements as well) are said to be Brazilian rosewood.. does anyone know if that's what the fretboard is as well? I know it was replaced by Indian rosewood in the late 60s/early70s due to cost, scarcity, and concerns of abusive forestry practices which resulted in the strict export laws for unfinished hardwoods today. I had looked into buying ebony or rosewood blanks (Brazilian), but they are unavailable for export if the exporter is a lawful person.

Brazilian rosewood was applied to CITES (the treaty governing endangered species use and exports) in late 1992. Before that the main impetus for curtailing use of Brazilian rosewood in guitars was the Brazilian government wanting to build industry in Brazil. They imposed heavy fees on exporting whole logs in order to encourage industries to cut the logs in Brazil. And the wood was more profitable as a veneer instead of cutting guitar-sized chunks of it. So that's why most guitars switched originally to Indian. And now, given the difficulty and cost of dealing with Brazilian rosewood, I doubt anyone would be making items with such low commercial appeal as Guild/Hagstrom bass saddles would make them out of Brazilian. Plus, in this context I really doubt that it matters at all. The primary difference between Brazilian rosewood and Indian in an acoustic guitar is appearance, Brazilian is real purty!!! I doubt there's enough consistency between individual trees to make blanket statements that Brazilian always makes this sound and Indian that sound.

BTW, the store I used to manage has four original Guild saddles I think. I know they were there when I started working there in '77 and were still there when he moved a few years ago. I'll check 'em out and see if my bifocals will allow me to get accurate measurements off them.

John

 

[jte]

OK, the saddles at the store are:

11/16" wide (side to side)
7/16" tall
5/16" thick (front to back)

The slots are 5/32" deep and 1/16" wide

John

 

[dlenaghan]

Hi jte,

Your diligence has compelled me to root up a ruler, though we'll have to settle for metric conversions. The 'original' saddles on my JS (which is practically a parenthetical because only one appears to be rosewood, the other three are certainly not, and one is practically balsa.. ugh..
good for gliders only!) measure as follows:

Width(side to side): 17mm (.66in)
Length(front to back): 10mm (.39)
Height: 8mm (.31in.)

The notch is about 1cm, which measure about the same as the new ones, but the new ones have a notch straight from the base upwards, and the original saddles are cut at an angle and seem to bite onto the metal paddles seated directly onto the harp bridge.

The replacements have almost identical dimensions except for height, which measures a hair shy of 10mm, so not quite what I had said.. though the replacements seem to sit higher on the paddles. In either case, they sound great, and are at least described as Brazilian rosewood on the site, which seems plausible since finished products can apparently be exported. (I have no empirical data on that last remark, however.) I got caught up on the Brazilian/Indian thing mostly because I have a friend, a drummer, our drummer actually, who's obsessed with old stuff, Vox amps (made in UK only), Fender amps (old tweeds, USA made only), and so forth and one of his pre-CBS Fender kicks is apparently the absence of Brazilian rosewood in the fretboard, apparently switched due to cost. But I'm no carpenter or wood worker of any kind - all I know is my JS-II sounds much richer with saddles that are fully intact!

And the HagstromParts guys got back to me.. the pickup ring is on its way! WAAAHOOO!!!

Anyone got a favorite polish for their instrument? ;-)

PS - Those saddles.... they don't need a new home, do they? ;-O

 

[adorshki]

Anyone got a favorite polish for their instrument? ;-)

Yeah, that guy who wrote the Polovtzian Dances, what's his name, Borodin. Except now that I think about it, he was Russian.

 

[jte]

11/16" wide (side to side) or 0.6875" converts to 17.46mm
7/16" tall or 0.4375" converts to 11.11mm
5/16" thick (front to back) or 0.3125" converts to 7.94mm

The slots are 5/32" (3.97mm)deep and 1/16" (1.59mm)wide

I'll check with Jim to see if he wants to sell the saddles.

John