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

[dlenaghan]

Hi all,

First, thanks for the forum.. I just got the user/pass registered to honor my new (to me) '71 JS-II.. pics below if all goes well. Knocked to heck, and some fuzz in the pots as well as a (not kidding) balsa wood saddle (replacement rosewood saddles from GuildBassParts.com on the way, I'm not a seller or endorser, just happy to find some reputed replacements) as well as a bridge pickup ring from HangstromParts.se (if they ever answer my email.. PLEASE GUYS!!)..

But all in all the finest bass I've ever played, bar none: an upper register I can actually reach, a narrow neck that's fat, great tone out of the Hagstrom bridge humbucker as well as the neck Bisonic, but a few odd things that I've been wondering about.

I've never had a bass this old, so perhaps it's just 'old' technology:

- the tone rolloff seems to have one point only, with no degrees of in between on both pickups. So, it sounds like there's full bass for 20% of the knob's turn with an abrupt full treble on the remaining 80%. True for both knobs.

- using the pickup selector to get both going seems finicky. Say I've got the Bisonic at 70% volume, set to treble. Any adjustment I make to the bridge humbucker seems to takeover the sound completely, including adjustments to the volume. It's like any setting on whichever pickup was set first is overwritten (absurd it seems, I know) by any later adjustment. This works both ways. Say I dial in a nice dry bridge-heavy sound and back off the volume a bit, but I fill in the low end with the neck pickup. Any adjustment to the neck pickup, whether it's louder, quieter, bassier, or trebly-er (we'll pretend that's a word for a moment here) seems to redefine the sound completely. It basically makes it difficult to dial in repeatable settings, which would be problematic for using different tones for different songs or adjustments on the fly. I don't know if I've described this last one very sensibly..

- separation of tuners from the back of the headstock. It seems that the metal piece that holds the worm gear in place has always pressed against the wood and has slightly bent the base plate that mounts of machine head to the read of the headstock. The screws are all still in place, and I don't want to mess with it, and comparing it to other models online it appears the tuners are original, or at least OEM/original style (not sure if there's supposed to be a manufacturer's stamp there somewhere), but this seems like a poor choice of design. Is this common on the JS-IIs or other Guild models? The tuners don't wobble and they hold the strings in tune wonderfully, more stable, actually, than a few of my newer basses.

I've used search on TalkBass and found a partially similar problem on some Fender Js, but I thought I'd go fishing here and see if anyone would like to weigh in. I have plans to replace the pots (Nobles for the volume and Tonestylers for the tones) and certainly the broken/jerry-rigged bits (pickup mount and saddles), and given the shape she's in I don't mind a mod here or there, because she's a player and it would be a shame to shelter her..

Did I mention the Bisonic came off during shipping? As in, the tape securing it to the underside of the chrome bracket finally gave way? Seems like that might be the easiest fix..

Cheers, and here's hoping Guild sees some sense and reissues these things. I've honestly never been SO satisfied with a bass' initial setup, sound, and playability.

Dan

PS - Couldn't link to the pic... looks like it's time to reread all the guidelines. Sorry guys, she's a real beaut.

 

[fronobulax]

Welcome.

Long version of "how to post pictures" is here. Short version is host them somewhere else and use the IMG tag.

Interesting that you have a a fairly early JS. The switch to Guild humbuckers occurred in 1971. There was an early '71 on and off eBay that was in Rochester NY. Is that now yours or are they coming out of the woodwork all of a sudden?

The person behind GuildBassParts has been known to post here as peteybass. If you need saddles he's pretty much the only source.

I can't say that I have noticed similar problems with my JS II but I suspect you are more demanding. The JS II is pretty much a one trick pony for me and when I care about the sound I tend to use my Starfire I which has the Bisonic. I'll check and verify my memory but I don't recall any serious and unexpected changes in sound using the PU toggle or a lack of variation on the tone controls. It all may be due, however, to the differences between the Hagstroms and the Guilds.

No problems whatsoever with my tuners.

Hand drawn schematic of my JS II's electronics, although there is no reason to believe the Hagstroms used the same values and I know the "tone" switch is absent.

 

[dlenaghan]

Hi Frono,

Thanks for the reply.. pics will come in the morning, when I'm thinking again. No, my JS II came out of Northern California, though there were two others recently, a beat up black one with the Guild humbuckers, and a pristine version in cherry that has the same transitional Hagstrom pup set as mine has, only it was quite a bit more though it was nice.. but it was a player I wanted, and it's a player I got.

I'll check your specs against my electronics.. in the morning.

Cheers,
Dan

 

[jte]

The electronics are going to interact when you have both PUP's on. There's really no way around it with a passive circuit. The circuit is pretty much like Gibson's with the exception of the two mis-matched resistors (the 220K? on the neck pickup and the 150K? on the bridge pickup). So, with the PUP switch in the middle, the tone control and the volume pots for either pickup are bleeding signal from BOTH pickups. The resistors, especially as they're different values) will alter that response too.

The taper of the pots and values of them will affect how smoothly the tone controls roll-off treble. That's why Gibson has used several different values for the pots on their guitars (most with 'buckers are 500K, but for a long period the stock pots were 300K for some applications in an attempt to alter the roll-off).

John

 

[bluesypicky]

Welcome to LTG Dan!
I'm not a Bass specialist, even though I play it some, but I'm sure you already figured out who was.... :wink:

 

[dlenaghan]

The electronics are going to interact when you have both PUP's on. There's really no way around it with a passive circuit. ...the 220K? on the neck pickup and the 150K? on the bridge pickup). So, with the PUP switch in the middle, the tone control and the volume pots for either pickup are bleeding signal from BOTH pickups.

I guess it might be a switch thing - all of my previous two pup basses have had blend knobs, or were both always on unless I dropped the volume all the way on one. I think Tonestylers will really open up the sound, as they worked wonders on my Mustang, and that's a bass too many people just write off...

Given that the components are in pretty mediocre shape I feel less bad about messing with things, so has anyone tried something to this effect (cue evil soundtrack and wiggle mastermind fingers): Do a 2-tone, master volume, plus blend and use the three-way switch to hook up series/parallel/single coil... wait no, that wouldn't work with a humbucker. Curses. The passive circuit on my old G&L ASAT bass is apparently haunting me and I've been trying to duplicate it on other basses with no success whatsoever. So it goes.

Values on the blue resistor for the Bisonic: .047 250v 10%, and the white one on the bucker: .01 +/-10% ..(can't read) D6W..

Anyone know why they put those resistors on there? I don't seem to recall any resistors on my Mustang or in my Fender MIJ Jazz Special, though I did redo the electronics in both.. As for the G&L, there's so much going on in that cavity I don't even know where to start. I'd like to start at HagstromParts.se, but they've not gotten back to me about an invoice. Anyone got spare parts?! ;-)

Time for a family picture.. where's my camera?!

 

[Happy Face]

"- the tone rolloff seems to have one point only, with no degrees of in between on both pickups. So, it sounds like there's full bass for 20% of the knob's turn with an abrupt full treble on the remaining 80%. True for both knobs."

I use a JS-II with Darkstars (strung with TI Jazz Flats) in tandem with a bass strung with rounds. I use the JS for more than half the songs my band plays.

In my case, there are three "cut" or tone change points on the neck pup tone pot and two or maybe three on the bridge pup tone pot.

But, perhaps because I use two basses, I don't find the need for a lot of subtle tone changes. Generally I find a sweet spot on both tone pots and leave them be. Then i alter the sound using the volume pots. I can get enough sonic variation that way.

But what do I know?? :?:

 

[jte]

I guess it might be a switch thing - all of my previous two pup basses have had blend knobs, or were both always on unless I dropped the volume all the way on one. I think Tonestylers will really open up the sound, as they worked wonders on my Mustang, and that's a bass too many people just write off...

Blending pickups is pretty much a trial and error thing in my experience, because there are so many variables so it's hard to really get a consistent way to do things like that. While my Starfire IV (guitar) has a typical 3-way switch with separate volume and tone controls for each pickup, they do interact a lot so I don't mess with it much. Have separate controls for each pickup is really only useful IMO for presetting things, not for blending.

Given that the components are in pretty mediocre shape I feel less bad about messing with things, so has anyone tried something to this effect (cue evil soundtrack and wiggle mastermind fingers): Do a 2-tone, master volume, plus blend and use the three-way switch to hook up series/parallel/single coil... wait no, that wouldn't work with a humbucker. Curses. The passive circuit on my old G&L ASAT bass is apparently haunting me and I've been trying to duplicate it on other basses with no success whatsoever. So it goes.

In my opinion, two tone controls is pretty pointless unless you're going to be using the pickups separately a lot. Rolling off the treble on the bridge PUP will also affect the signal of the neck PUP if you have both on. The control is simply shunting highs to ground and at that point both PUPs are in the circuit. While you probably could figure out a wiring that'll give you the series/parallel/single-coil, it will require a pretty complicated switch, and the three-way toggle won't do the job. If it were me and I wanted a project, I'd try a blend (a real blend pot, not a generic pan pot- make sure at the center both gangs of the pot are on full, not 50%), master volume, master tone, and a pre-set volume. Use the switch to toggle between the two volume controls as pre-sets, sort of like the Fender Jazzmaster guitar. Or, even better (I've spent WAY too much time rewiring my instruments before the bifocals hit...) just leave it stock and play it. I play a lot better now that I don't try to rebuild 'em so much!

Values on the blue resistor for the Bisonic: .047 250v 10%, and the white one on the bucker: .01 +/-10% ..(can't read) D6W. Anyone know why they put those resistors on there? I don't seem to recall any resistors on my Mustang or in my Fender MIJ Jazz Special, though I did redo the electronics in both.

They MIGHT be bridging resistors used to help reduce the interaction, at the expense of output levels. The original stack-knob Jazz basses had a separate volume and tone control for each pickup, but Fender went to a V/V/T set up within two years of the bass being introduced. Suspicion is that was done because with the bridging resistors the output was noticeably lower. Jaco Pastorious changed his "Bass of Doom" from stack-knobs to V/V/T because he felt the original wiring lacked "punch". When Fender introduced the Vintage Series reissues of the '62 Jazz they used the stacked knobs, but left out the resistors for that reason- and the controls on the VS instruments interact just like any other passive with dual controls in a parallel circuit.

As for the G&L, there's so much going on in that cavity I don't even know where to start.

What G&L is it? A passive L-1000? That's got a series/parallel switch, a dual-coil/single-coil/single-coil with bass "boost" switch (I think- I haven't played an L-1K since 1983), and passive bass and treble controls. It's a bit of wire, but it's pretty simple actually once you chase 'em down. And there's sources on the 'net for real schematics and perhaps wiring diagrams. You might be able to mod that wiring for the set up you wanted.

John

 

[capnjuan]

... values on the blue resistor for the Bisonic: .047 250v 10%, and the white one on the bucker: .01 +/-10% ..(can't read) D6W.. Anyone know why they put those resistors on there?

Hi: if you've typed correctly, those aren't resistors, they're capacitors ... I think you just mis-bungled there :wink:

Together with the controls, they act as filters.

 

[dlenaghan]

I play a lot better now that I don't try to rebuild 'em so much!

Ha! That may be the best advice I've ever heard regarding these sorts of things.. get used to the strange quirks of the instrument and appreciate it! :lol:

They MIGHT be bridging resistors used to help reduce the interaction, at the expense of output levels.

That sounds exactly like what's going on! The overall output with both pups selected with both volumes at full is definitely less than output with either pickup soloed. The tone thing really does make it hard to dial in sounds, and I do switch up sounds fairly often.. maybe that's the problem!

As for the G&L, it's a (it was, anyway, sold it to finance the shorter scale instruments and I have no regrets, except for those awesome circuits G&L has going) 2002 ASAT bass, same circuit as the L2000, which apparently is very unusual for a passive circuit in that you can cut either treble or bass independently, even in passive mode, instead of being confined to rolling off the treble. That combined with the series/parallel switch (I never bothered with the two active modes, too noisy for me) made for the coolest combinations between the two pickups.

That's what I'm trying to do with the JS-II, get that same flexibility between the pickups because they DO sound so different, but in dual mode the Bisonic just drops in terms of bite and output.

What makes this harder is that I'm completely clueless about circuits in general. I had a go at Ken Baker's G&L site for wiring diagrams when I had the ASAT, to try to add the single coil option to the series/parallel switch but gave up.

Hi: if you've typed correctly, those aren't resistors, they're capacitors ... I think you just mis-bungled there

Together with the controls, they act as filters.

Yup. I'm pretty clueless about the fine points of the electronics. It's something I'm trying to change

 

[capnjuan]

Values on the blue resistor for the Bisonic: .047 250v 10%, and the white one on the bucker: .01 +/-10% ..

They MIGHT be bridging resistors used to help reduce the interaction, at the expense of output levels.

That sounds exactly like what's going on!

They might be bridging resistors if they were resistors; but would either of you agree that if they aren't resistors, they can't be bridging resistors?

Resistors: Read about them including the use of color codes. What resistors look like:

Capacitors: Read about them including what uf / microfarad means. What capacitors look like:

Polyester:

Mylar:

Polycarbonate:

Resistors: Every resistor up to 2-watt rating has color-coding bands on it and are tubular less than a 1" long body and 1/8" diameter. If these are resistors; what color are the bands? Power resistors ... normally larger than 2 watts, are big enough to have their value - expressed in Ohms - and their wattage - a measure of their ability to dissipate heat - printed on them. Small signal resistors - if this is what you have - are too small to have any print on them at all.

Capacitors: are rated for microfarads (uf), voltage handling, and precision and normally have printing on them ... even small silver micas have lettering. They can be anything from lumpy to boxy or in the shape of a chicklet like the mylar capacitor in the pic above.

You said one of the caps was:
.047 [uf] 250v [voltage handling] 10% [precision: allowable variation in rating]
Note the printing on the cap below:
2.2 [uf] 160V [voltage handling] 20% [precision: allowable variation in rating]

There might be bridging resistors in there but the objects with printing on them are caps ... tone caps ... not resistors.

 

[dlenaghan]

Here's what's going on in the control cavity..

 

[dlenaghan]

Grr.. is this one bigger?

 

[dlenaghan]

Follow-up question: if I replace the pots, as it seems these capacitors(?) link the vol to tone of each pickup rather than linking the pickups together, what happens if in the new setup the pickups are just wired directly to the pickup selector?
I have a 4-knob passive vol/blend/tone/tone on my MIJ Fender J Special, no capacitors or resistors and everything's good..

 

[dlenaghan]

Here's a shot from the opposite side - as you can see, the capacitors link the vol pot of each pickup to the tone pot. The blue links the pots for the Bisonic, the brown links the Hagstrom humbucker.

 

[dlenaghan]

Sorry for the torrent of additional comments, I keep forgetting a detail - in the first large shot, where the blue linking the Bisonic appears on the top, the right of each pot pair is the tone, the left being the volume of each pair. The input jack you can see on the far right of the shot and the three way selector is on the left, just out of the shot.

 

[fronobulax]

The blue links the pots for the Bisonic, the brown links the Hagstrom humbucker.

My guess is that the capacitor is "linking" to ground rather than contributing to some interaction that is exclusively between the tone and volume pots of a pair, but it has been a long time since I had to explain what a circuit did rather than just test continuity and show that it worked.

 

[capnjuan]

Hi dl: about the caps ... Guild used Mullard 'mustard' caps (your .01uf) in guitars and amplifiers. In amps, if the amp was wired point-to-point, they used mustard caps (member Zulu's T1 RVT):

But it used those foam-green polycarbonate caps (like your .047uf) on amps with printed circuit boards - see upper left-hand corner (member Rwood's Quantum Thunderbass):

jte used the term 'bridging' to describe resistors in the control cavity. This is the sketch Frono posted. That configuration uses resistors to couple the output of the pickup to the controls. The term 'bridging' ... and this may seem like hair-splitting ... is more commonly used in the up/over/around ... bypass sense. In circuits with active components; tubes, ICs, or transistors, each stage is 'coupled' to the next ... most commonly with capacitors because they allow AC to pass but block the DC that the active components run on. Anyway, jte may have meant 'bridging' to mean the same thing as 'coupling' ... bridging the gap between the pickup and the controls. Before leaving the subject, Frono - as he often is - is correct about tone caps typically having one end grounded as shown in the sketch:

There's a tone switch on the bass pickup. It has three positions; as drawn, the bass pickup is out of the circuit; if the little arrows are straight up, the signal passes through the 220K resistor ... I guess it's an attenuator ... damping the signal. When the little arrows are straight down, it takes the 220K R out of the signal substituting the 3200 pf (picofarad) capacitor for the resistor ... I guess this is kind of a bright switch.

[comments about no selector switch edited out] J

The common use of tone caps is to filter whatever you want filtered out; although it's counter-intuitive, increasing bass is not a matter of turning up the bass, it's a matter of filtering out high frequency. Likewise, to get more treble, it's not about dialing up more treble, it's about filtering more bass out; one cap lets bass through but impedes treble and the other passes treble but blocks bass. That is; we don't make the air colder, we remove the heat; ok ... it's dumb to say it that way but that's what's happening.

Nothing wrong with coupling controls with caps ... it's a common way of tying them together; I have no suggestions on what might happen if you do this ... or do that. There are dozens of ways to wire pickups and controls; they all work and they all sound different ... what you might like or not like ... it's hard for anybody else to know but whatever you do, you can't really break anything ... the worst that can happen is you get nothing at all or you get tone poo going into your amp. Good luck with new bass!

 

[dlenaghan]

The common use of tone caps is to filter whatever you want filtered out; although it's counter-intuitive, increasing bass is not a matter of turning up the bass, it's a matter of filtering out high frequency. Likewise, to get more treble, it's not about dialing up more treble, it's about filtering more bass out; one cap lets bass through but impedes treble and the other passes treble but blocks bass. That is; we don't make the air colder, we remove the heat; ok ... it's dumb to say it that way but that's what's happening.

Not at all! I remember that exact principle from my high school science courses regarding thermodynamics. It also brings to mine Ken Baker's excellent article on what he calls 'relativistic tone' on his G&L basses site. Basically there's a full signal across a broad spectrum of frequencies, the common tone knob reduces or 'rolls off' the treble, essentially. That it seems louder by changing tone is a trick of the ears, correct? With passive pickups, they are always producing whatever signal is created by the string vibrating through the magnetic field; you can only reduce that signal either with the volume or tone knob. It's one reason I was so intrigued about the G&L circuit, because they have a passive bass roll off as well as the standard (from what I understand) tone knob which rolls off treble.

As for the capacitors linking to the ground.. isn't the soldered wire running across the top of each pot the ground wire?

Thanks for the info! This (and the Wikipedia articles) are going to keep me going for days! I'll report back when the new setup is complete - the order just went though so it might be a while.

Cheers,

Dan

 

[capnjuan]

... As for the capacitors linking to the ground.. isn't the soldered wire running across the top of each pot the ground wire?

Yes; but as you've noticed - yours don't go the ground but the one's in Frono's sketch do .. there are dozens of ways to wire p/u's and controls.