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Post by ajent__smith on Aug 3, 2005 12:51:19 GMT -5
in case you havent heard, Fender is putting there new Greasebucket Tone Circut into all of there new Highway One Models. Its supposed to roll off the highs without adding bass. does anyone have any idea on how it works? my guess is they put a crossover(dubble) pot and have one roll the highs and the other roll the bass. any ideas?
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Post by wolf on Aug 3, 2005 19:59:36 GMT -5
Maybe the "breakthrough" that Fender discovered is just something that has been around a while. I know Torres Engineering sells some special tone controls but for those who want to do it yourself here's a good link, www.jpbourgeois.org/guitar/micos1.htmDo you think Fender's new tone control is similar to any of these?
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jester700
Meter Reader 1st Class
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Post by jester700 on Aug 3, 2005 23:05:08 GMT -5
Actually, a regular tone pot rolls off highs without adding bass...
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Post by ajent__smith on Aug 3, 2005 23:17:55 GMT -5
Maybe there using metal film caps instead of those cheesy ceramic ones. IMOHO metal film should always be the standard, since they don't cost much more and the change is substantial. The metal film ones look like buckets too...
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Post by TooManyWires on Aug 7, 2005 17:33:45 GMT -5
Actually, a regular tone pot rolls off highs without adding bass... I as well was under the impression that that was how a tone control worked...
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Post by RandomHero on Aug 7, 2005 18:02:34 GMT -5
Incidentally, metal film caps (which look like buckets) are filled with a form of grease. It would seem to me that the Fender ad department was simply lacking creativity that day.
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Post by RandomHero on Aug 7, 2005 18:06:37 GMT -5
Wow, that torres engineering site looks good. Has anyone tried their variable mid boost/cut? How does it sound?
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Post by UnklMickey on Aug 8, 2005 13:44:38 GMT -5
Wow, that torres engineering site looks good. Has anyone tried their variable mid boost/cut? How does it sound? Haven't tried it myself, but on paper it looks like it will affect the tone and attenuate the signal even at the center of rotation of the pot. If i did try it I'd probably use a switch to completely defeat it when not using it. Additional note: their variable coil splitter is only half of what it could be! add one more wire and you can attenuate either coil. this is especially desirable with covered humb'ers (my personal preference) where only one coil has exposed pole-pieces --because of the distinctly different tonal characteristics of the two coils. Maybe there using metal film caps instead of those cheesy ceramic ones. IMOHO metal film should always be the standard, since they don't cost much more and the change is substantial. The metal film ones look like buckets too... Is IMOHO just a typo of IMHO, or is it yet another acronym that I'm not yet familiar with? BTW ajent_smith, I am also a DRUMMER, so SMILE when you say that, my friend! (re: i think therefore . . . )
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Post by wolf on Aug 8, 2005 22:14:20 GMT -5
Well, here is another tone circuit I found on the Internet. I redrew it because the other one was really huge, I believe that a modem transformer is roughly a 1.5 Henry Inductor. Ever notice that inductors are very tough to find (even on the Internet)? Mouser which supposedly is THE source for electronic parts sells inductors whose LARGEST value is 150 millihenry. When you are dealing with guitars, a 150 millihenry inductor is puny. The typical wah-wah pedal uses a 500 millihenry inductor. Yes, you can string several inductors in series (4 Mouser 150 mH inductors in series = 600 mH). The trouble is, the "ordinary" inductors avalable from electronics suppliers have a pretty high resistance. It also seems the inductors used for electric instruments have a much lower resistance. Here's an idea for an amp modification. Yes, I know there is a special category for amp mods but just take a quick look at the mod and tell me what you think. Would such a modifcation be feasible or practical? Would the type of amplifier make any difference?
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Post by RandomHero on Aug 8, 2005 22:35:48 GMT -5
The question isn't neccisarily how much better the amp would sound, but how much more fun it would be to have around.
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Post by UnklMickey on Aug 10, 2005 12:33:26 GMT -5
Well, here is another tone circuit I found on the Internet. I redrew it because the other one was really huge, Wolf, i suspect that the 1.5 Henry is a misprint. even at low audio frequencies a 1.5 Henry inductor will look like a dead short compared to the impedance of the pickups or the capacitor values shown. haven't done the math, but i suspect 1.5 ~ 15 mH sounds about right. as for the amp mod: Who cares about practical or feasible, Lance is one lucky man!
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Post by ChrisK on Aug 10, 2005 21:16:50 GMT -5
Actually, 1.5 Henry IS in the range that you want. A 150mH inductor has a much too low impedance (and internal resistance) and will short out the signal. Mouser sells interstage coupling transformers for a couple of bucks each. These are ideal. Get several values and try them. These coupling transformers have their impedance specified at 400 Hz (methinks at least). One can easily convert impedance to inductance (QED). From one of my posts somewhere in times past: "Bill Armstrong sells a 1 Henry inductor ($20) for this purpose. I do know that one similar (if not the same part) to the Torres is commercially available, it's made by HI-Q and sold by mouser.com for $1.37/1. It really is an audio coupling transformer (that's why you cut leads off, see www.geocities.com/guitarwiring/index.htm for instructions). [YMMV w/ other manufacturers, so pay attention, sparky!] A clever fellow would buy enough of the following to meet the minimum (?$25): 42TL022 1.5K Ohms .56 Henry 42TL021 4K Ohms 1.5 Henries 42TL018 7K Ohms 2.6 Henries 42TL019 10K Ohms 3.75 Henries 42TL025 17K Ohms 6.4 Henries 42TL017 20K Ohms 7.5 Henries If you put two in series, the values add. If you put two in parallel, the value is A*B/(A+B). Same things happen (to the effective resultant passive circuit) when you connect one to a PU(s). I use a 1 to 3 Henry value since I have several inductors left over from the 60's (when they actually were common). I have a 20 to 200 Henry miniature variable one, but that's a different tale." A low-pass tone control (cap thru pot to ground) will attenuate the highs "only", UNTIL the resistance is near zero. Then the cap as driven by the AC generator (the pickup) will form a resonant circuit in combination w/ the self-inductance and resistance of the pickup and create a resonant "hump" in the response. This "boomy" effect is discernable during the last few degrees of rotation on the tone pot. Since it is in the 600 Hz region, this "may" be the bass "enhancement" that Fender has so graciously relieved us from. One can easily effect this by not turning the pot all the way down. (Or, for those that only can operate their tone controls in a binary manner, one could solder a 50K resistor in series w/ the pot.) To be fair, Fender may indeed have included other means (such as inductance and resistance, and most hopefully NOT inadvertently discovered medical benefits of excessive pot shaft lubrication) to effect this "greasy" thing. For instance, a typical SC PU of ~3 H, in conjunction w/ an internal resistance of about 5K, an interwinding capacitance of perhaps 100 - 200 pF, AND a tone cap of 0.022 uF (pot at zero) will create an apparent "gain" (a peaking effect) of about 3 to 6 dB at about 600 to 700 Hz. This comes at the expense of greater frequency response falloff beyond (higher than) the resonant frequency. This can be used to good effect. The aforementioned structure (without the tone pot at zero) w/ a 0.001 uF cap directly across the PU will create a "gain" (a peaking effect) of about 10 to 20 dB at about 2,500 to 3,000 Hz. Again, this comes at the expense of (much) greater/steeper response falloff beyond the resonant frequency. I use this to good effect w/ standard tone controls. Since these are typically a series structure, I add this 0.001 uF (500pH for humbuckers) across the outer two tone pot lugs in conjunction w/ the use of 500K tone pots (an audio taper 500K pot is already down to 250K at about "8"). At "8" and below, all is normal. From "9" to "10", this suBtle effect is present. Holy historical lies Batman, "gain" from a passive circuit. In essence, the spectral energy density of the PU response remains "somewhat" constant. This effect just "redistributes/concentrates" it. You don't believe it (it is counter-intuitive after all)? Run a pSPICE simulation and then try it, you might like it. Software absolutely won't (electrically) shock you. For a free copy of pSPICE, visit the linear technology website. They have SwitcherCAD as a free download (its internal "engine" is pSPICE). Native pSPICE has a fairly churlish user interface at the command level, so expect a learning curve (but it's FREE, Batman).
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Post by wolf on Aug 10, 2005 23:40:39 GMT -5
ChrisKWow that is one serious posting there. It is very late and I don't have time to comment on it -not that it needs my comments because you seem to know electronics thoroughly. Anyway, I was serching the Internet for that passive tone control circuit. (Although quite a simple circuit, Gibson, Craig Anderton and God knows who else like to keep that schematic a secret). Anyway, I found another diagram and sure enough, as ChrisK said, 1.5 Henries seems to be the value. Note that this diagram uses 5 "10 Meg" resistors. I wonder why they are there?
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Post by UnklMickey on Aug 11, 2005 9:11:17 GMT -5
Actually, 1.5 Henry IS in the range that you want. A 150mH inductor has a much too low impedance (and internal resistance) and will short out the signal. What was i thinking! of course ChrisK is right, impedance goes up as inductance goes up, duh. my apologies to all, i guess when if i'm gonna shoot from the hip, sometimes i'll shoot myself in the foot!
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Post by UnklMickey on Aug 11, 2005 10:05:41 GMT -5
Note that this diagram uses 5 "10 Meg" resistors. I wonder why they are there? it's a rather common practice to reduce the spikes that could be generated when switching capacitors. they don't absolutely have to be there, but it could get real ugly if you operate the switch with your amp turned up loud.
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Post by wolf on Aug 11, 2005 10:20:11 GMT -5
unklmickey Oh I am all in favor of eliminating the "pop" when turning a rotary switch. However, wouldn't a resistance value that large attenuate so much of the signal (it is in series with the capacitors and those are in series with the inductor) that the tone circuit would essetially be "cut out" and will do little or nothing? Let's take an extreme example. If the resistors had infinte values, wouldn't that totally eliminate the tone circuit from doing anything?
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Post by UnklMickey on Aug 11, 2005 11:02:09 GMT -5
wolf,
look at the circuit again. the 10meg resistors are always connected to each capacitor. the switch directly connects the 100k resistor to the selected cap. so if the switch is in the position shown in the drawing, there is a very very slight effect caused by all 5 caps in series with the 5 resistors. when the switch is rotated to connect any capacitor, that particular cap and the inductor are much lower impedance than the parallel combination of the 4 others with their 10 meg resistors in series with them. so we can effectively ignore them.
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Post by wolf on Aug 11, 2005 12:37:02 GMT -5
unklmickey Yes, I really couldn't see what was happening with that circuit. (You can bet that's another diagram that I'll be redrawing). And now maybe another foolish question - why is the 100K resistor there and what would happen if it were eliminated?
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Post by UnklMickey on Aug 11, 2005 14:39:21 GMT -5
wolf,
there is no such thing as a foolish question!
wait -- i forgot about the one you might ask of a wife or girlfriend. -- better to ask forgiveness than permission. . . . but i digress . . .
the 100k resistor forms the top part of a voltage divider, the bottom being the tuned portion (the cap and inductor)
if you eliminate it, there is no series resistance (if the volume pot is at max) so the cap and inductor don't do much at all above and below the resonant frequency (of the cap and inductor combination). at or near the resonant frequency they will load down the pickup and reduce the level of the signal.
you might not like it so much 'cause it will be a fairly sharp notch. (filter speak: HIGH Q)
the larger that resistor is, the lower the Q of the circuit and the gentler the curve.
you might try using a 100k pot instead. (connect to wiper and one end) then you can adjust it to suit your taste.
or to get really cute,
once you determine the value that suits your taste, get a pot thats closest to (or somewhat lower than) that value.
connect the "bottom" (ccw connection) of the pot to where the left side of the 100k is in the drawing. the "top" (cw connection) to where the right side is, then the wiper (instead of right side of the 100k) feeds the output jack. this will allow you to adjust the "depth" of the filter without much change in the Q ccw=unfiltered, cw=filtered
there isn't a circuit that has been designed that my perverted little mind can't complicate, simplify or otherwise modify - - - and occasionally it comes out better!
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Post by ChrisK on Aug 11, 2005 18:14:03 GMT -5
unklmickey,
There have been some complaints about the Am Dlx Strats being "clicky" when switching. A similar (10M) resistor across the """""""special capacitor"""""" (it ain't THAT special) solves it. (That's why they're there on the Varitone.)
"there isn't a circuit that has been designed that my perverted little mind can't complicate, simplify or otherwise modify - - - and occasionally it comes out better! "
Shoot me an email, I'll confuse the beJesus out of you!
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Post by wolf on Aug 13, 2005 2:38:29 GMT -5
As you can see, I have redrawn the "Vari-Tone" Circuit. Is it correct?
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Post by JohnH on Aug 13, 2005 3:41:18 GMT -5
methinks all is not well with the 100k resistor, since it is shorted out. Im not sure where it should go relative to the 500k pot however. I downloaded pSPICE, theres a student version that is free that seems it would be able to eat the average guitar circuit, so Im going to try it out. You can get it here: www.electronics-lab.com/downloads/schematic/013/
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Post by wolf on Aug 13, 2005 13:33:55 GMT -5
JohnH I downloaded pSPICE just fine. Were you able to install it? I couldn't.
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Post by JohnH on Aug 13, 2005 17:38:23 GMT -5
Wolf - yes I got it too. File name 91pspstu.exe. This download .exe file is a self extracting zip file, using Winzip (I dont think you need Winzip loaded - its in the file). It then extracts all the pSPICE setup files to a directory of your choice. It does not actually install it though, you then find that directory and click on setup.exe to run the installer.
I got it running and Im figuring it out. Being an engineer, I obviously assumed that I would read the instructions only in desperation as a last resort. Not correct! - theres a comprehensive manual in a pdf on the same site, with a tutorial that steps you through a simple circuit. It looks like it will be user friendly, letting you draw a schematic visually, then set it up for analysis. - good luck.
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Post by wolf on Aug 13, 2005 20:47:16 GMT -5
JohnH Yes, I got as far as downloading it and even having WinZip extracting it. It seems to create a data.cab folder which contains 18 files - NONE of which will install anything. So, as far as this is concerned, it is as far as I'm going to go and the people who wrote pSpice can go %^%$$####$^%&** themselves !!!
****************************************** LATER THAT DAY ******************************************* I was able to install the darned thing but it does seem it isn't the kind of thing anyone can use in about 10 minutes. Well you get what you pay for.
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Post by ChrisK on Sept 6, 2005 19:57:25 GMT -5
"For a free copy of pSPICE, visit the linear technology website. They have SwitcherCAD as a free download (its internal "engine" is pSPICE). Native pSPICE has a fairly churlish user interface at the command level, so expect a learning curve (but it's FREE, Batman). " You don't even want to try anything that is really churlish!
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Post by JohnH on Sept 6, 2005 21:59:52 GMT -5
Ive been using pSPICE these last few weeks. I think it is great, and it has helped me test out some filtering and blending circuits, some bypass caps to preserve treble, the effect of cable capacitance and also some active circuits, such as simple buffers and overdrive circuits. It is really useful for looking at how a wiring arrangement affects frequency response. Theres no substitute for building and testing, but it gives some good insight into what to expect when circuit variations are tried.
John
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Post by CheshireCat on Sept 6, 2005 22:54:20 GMT -5
Incidentally, metal film caps (which look like buckets) are filled with a form of grease. It would seem to me that the Fender ad department was simply lacking creativity that day. Well, perhaps, but, not to play the contrarian, but I think that perhaps Fender's marketing dept. was right on the ball with that one. I mean, think about it! "Greasebucket"!?! That's just the type of term Fender loves in they stuff, with all the retro, bluesy, downhome, hankerin' down kind of kitsch that they thrive on. "Yessiree!!! Got me an ol' Nashville Tele with that Greasebucket tone for that bluesy twang that just sets you apart from all the other wannabe pickers! Yeeehaaawww!!" I mean, this is a guitar company that treats the 60 cycle hum like it's a good thing! (C'mon, you know it's true! ;D ) Chesh
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Post by Mike Richardson on Sept 7, 2005 0:57:03 GMT -5
It's probably very similar to the circuit sold by Stellartone. Try www.stellartone.com. It's pretty cool, but way entirely too overpriced, IMO. If you have a rotary switch on hand, you can do it for a lot cheaper. Just use some small value caps, say 200-1000 pF.
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servant
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Post by servant on Mar 13, 2006 22:18:54 GMT -5
Hello everyone, I've been lurking for a while, had the following a long time ago when I registered (but couldn't log in for the longest time), and thought surely someone would have posted since then. Just did a search and haven't found it so I hope I'm not being redundant. On top is a standard Tele control cavity. Below it is a Highway 1 Tele control cavity with the Greasebucket circuit: C1 (orange) is a .100uf, 50V ceramic disk cap C2 (yellow) is a .02uf, 50V ceramic disk cap R1 is a metal film, 4.7K, 1/4 watt resistor I have a Strat with a master tone control that I have thought about trying this in, but haven't opened it up in quite a while. Electronically, any idea what is going on here? Has anyone tried this yet, or played one in the store? Thanks, Dean EDIT: I updated the diagram to show a solder joint between R1 and C2.
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