|
|
Post by David Mitchell on Aug 26, 2021 21:53:26 GMT -5
Hi, all! I've been lurking, learning just how much I don't know. Before I ask any further questions, can you all help me understand what I'm starting with? Gut photo: This is a two-humbucker Dean guitar with one volume pot (on the left in the photo) and one tone pot. It appears to be wired "hot" to first lug of volume pot, then to middle lug of tone pot; the cap is on the third lug of the tone pot; and ground runs from pot back to pot back, then out. The only visible lettering on the back of the volume pot is "B," but the tone pot says "A500." The cap says "2A104J." How standard does this appear to be? Thank you! Edit: The wiring diagrams I've seen, as far as I recall, have the tone control before the volume control. I'm not sure if I'm being confused by a physical layout difference that actually doesn't matter, or if this guitar is actually "backwards." |
|
|
|
Post by David Mitchell on Aug 27, 2021 14:02:16 GMT -5
My current goals are to add treble bleed and a bass-cut option, perhaps replacing the existing treble tone control, which I rarely use, but am a little reluctant to get rid of. I don't want to mess with the current tone too much — it's brighter than any other humbucker-equipped guitar I can think of hearing so far, which I like, so if that's due to a quirk in the wiring, I want to maintain or re-create that aspect of it. I recently got a Fender Mustang Micro headphone amp, which has limited onboard control, so now I'm much more interested in learning to make the most of the guitar's controls. |
|
|
|
Post by unreg on Aug 27, 2021 16:24:49 GMT -5
Hi, all! I've been lurking, learning just how much I don't know. Before I ask any further questions, can you all help me understand what I'm starting with?  This is a two-humbucker Dean guitar with one volume pot (on the left in the photo) and one tone pot. It appears to be wired "hot" to first lug of volume pot, then to middle lug of tone pot; the cap is on the third lug of the tone pot; and ground runs from pot back to pot back, then out. The only visible lettering on the back of the volume pot is "B," but the tone pot says "A500." The cap says "2A104J." How standard does this appear to be? Thank you! Edit: The wiring diagrams I've seen, as far as I recall, have the tone control before the volume control. I'm not sure if I'm being confused by a physical layout difference that actually doesn't matter, or if this guitar is actually "backwards." Hi davidofchatham! Welcome! From my limited knowledge: 1.) the A500 on your tone pot specifies that your tone pot is Audio Taper and that its a 500K pot. 1a.) Audio Taper is a type of pot that’s been adjusted to respond in a logarithmic manner when turning its knob. Human ears respond to sound in a logarithmic fashion too; so when an Audio Taper pot’s knob is adjusted, the sound (or tone) level seems changed in a balanced ratio to the turn of the knob. Linear Taper pots adjust unevenly to our ears; even though their resistance IS adjusted evenly. 1b.) 500K is the recommended amount of resistance for humbuckers. 250K is for single coils. My guitar has humbuckers and so uses a 500K tone pot too, but I’ve got transistors resistors soldered between lugs 1 and 3 to reduce its resistance to 250K. The reduction happened bc my guitar was WAY to bright, for me, and I didn’t have talent or money to install a new 250K pot. Therefore, 500K (higher resistance) makes tone brighter; that’s probably a big reason why your guitar is bright. 🙂 2.) Your guitar is set up like mine, with tone near the jack and volume closer toward the center. 👍 Can’t provide anymore info; a definitely more skilled expert should reply. 🙂 |
|
|
|
Post by reTrEaD on Aug 28, 2021 9:29:52 GMT -5
Edit: The wiring diagrams I've seen, as far as I recall, have the tone control before the volume control. I'm not sure if I'm being confused by a physical layout difference that actually doesn't matter, or if this guitar is actually "backwards." David, your treble-cut tone control is configures as '50s wiring. You may have noticed the amount of treble cut and how deeply it also affects the midrange is highly dependent upon the position of the volume control. Personally I dislike that arrangement and prefer the 'modern wiring' where the treble cut is connected to the CW lug of the volume control, rather than the wiper. You can read about the difference between '50s and modern wiring here: Modern and 50's WiringMy current goals are to add treble bleed and a bass-cut option, perhaps replacing the existing treble tone control, which I rarely use, but am a little reluctant to get rid of. I don't want to mess with the current tone too much — it's brighter than any other humbucker-equipped guitar I can think of hearing so far, which I like, so if that's due to a quirk in the wiring, I want to maintain or re-create that aspect of it. I reckon the reason your guitar sound brighter than other HB guitars you've played is due to your pickups being underwound relative to the other guitars. When the volume control is at maximum, there will be absolutely no difference between having the tone control configured as '50s wiring or modern wiring. Removing the treble-cut tone control will make your guitar sound slightly brighter than it does now. Replacing your 500k volume pot with a 250k volume pot will compensate for the removal of the treble-cut tone control. It will also cause the bass-cut control you plan to add, to be more effective. So I would recommend making that change. I do recommend adding the treble-bleed to your volume control. That does a good job of mitigating the loss of treble due to cable capacitance, when the volume control is rotated away from maximum. Type D is slightly more consistent than Type C, but it's also more complicated. Type C is easy and provides relatively good results. The only question we haven't discussed is the taper for your new 250K volume control. If you're currently using a linear, you'll notice the rate of change is fairly slow from maximum volume to the midpoint. Some people prefer this to an audio taper pot. If you add a Type C treble bleed, this will make the rate of change at the clockwise part of the rotation even slower. So perhaps changing to an audio taper will be prudent, even if you like the current action of your linear volume control. |
|
|
|
Post by ashcatlt on Aug 28, 2021 10:48:56 GMT -5
Treble-bleed IS bass-cut. Win/Win.  |
|
|
|
Post by reTrEaD on Aug 28, 2021 13:32:08 GMT -5
Treble-bleed IS bass-cut. Win/Win. What? |
|
|
|
Post by gckelloch on Aug 29, 2021 0:57:04 GMT -5
Treble-bleed IS bass-cut. Win/Win. Only if you use a relatively high value cap in the 5~20nF range, and it only cuts bass by a few dB and then becomes a mid-peak as the volume is turned down. |
|
|
|
Post by reTrEaD on Aug 29, 2021 8:03:24 GMT -5
First of all, I reckon we all (myself included) owe David Mitchell an apology for taking his thread on a strange and convoluted tangent. Treble-bleed IS bass-cut. Win/Win. Only if you use a relatively high value cap in the 5~20nF range, and it only cuts bass by a few dB and then becomes a mid-peak as the volume is turned down. Uhh, no. Treble-bleed and bass-cut do share an element in common. A series capacitor that gives 'preferential treatment' to high frequencies. Aside from that, they should NOT be equated.
Treble-bleed is intended to mitigate the undesired effect of high frequency loss due to cable capacitance that occurs when the guitar's volume control is turned down from maximum. Ideally the shape of the frequency response curve will remain constant, regardless of the rotation of the volume control. ONLY the overall amplitude of the signal will be affected.
Bass cut is intended to decrease the amplitude of low frequencies while leaving higher frequencies unaffected. Ideally, the amplitude of the higher frequencies will remain constant while the shape of the frequency response curve will be highly altered (roll-off at lower frequencies). |
|
|
|
Post by David Mitchell on Aug 29, 2021 21:46:34 GMT -5
unreg, thanks for your welcome and input! I thought that "A" indicated audio taper, but I don't see why the tone pot would be an audio-taper type and the volume pot a linear-taper type. Either the designer liked it that way, or it was a mistake, I suppose. David, your treble-cut tone control is configures as '50s wiring. You may have noticed the amount of treble cut and how deeply it also affects the midrange is highly dependent upon the position of the volume control. Personally I dislike that arrangement and prefer the 'modern wiring' where the treble cut is connected to the CW lug of the volume control, rather than the wiper. You can read about the difference between '50s and modern wiring here: Modern and 50's WiringAha! Thanks, reTrEaD! I have actually looked at that thread a few times, and thought that might be the case based on the description, but I ... uh ... can't decipher the schematic yet. And why would a guitar built around 2004 come from the factory with '50's wiring? Was that "a thing" already then? Not that you can answer that question.... Interesting! I know that I ought to check their resistance, but unfortunately, when I pulled out my dad's Micronta analog multimeter that I'd retrieved from their attic, I found that the batteries had corroded and the 9V terminal pad looks like it's going to disintegrate sooner than separate from the battery. So I'm working blind for now. Maybe this guitar model was someone's "throwback" pet project. Thank you for your suggestions here. I'm already thinking about a couple of slightly different possibilities that I want to ask about. I don't know forum etiquette: Now that I have my initial question answered, would it be appropriate to retitle the thread and continue with my subsequent questions, or should I start a new thread and/or post in the threads relevant to specific circuits? First of all, I reckon we all (myself included) owe David Mitchell an apology for taking his thread on a strange and convoluted tangent. No worries. I am learning! I appreciate the consideration, though.
|
|
|
|
Post by David Mitchell on Aug 29, 2021 21:55:01 GMT -5
For the curious, a photo: It is a Dean EVO Tevo. (What an awkward name, right? I don't even know how to pronounce it.) Old Musician's Friend listing for reference. I've replaced the bridge on it due to an issue with the stock one, or more precisely, with the mounting post bushings. But this one is so much nicer and fits it much better than the original one did. I've also changed the knobs. And I think I may have had to have the switch replaced years ago. But, if I do anything with it, these will be the first circuitry modifications. |
|
|
|
Post by unreg on Aug 29, 2021 22:35:04 GMT -5
unreg, thanks for your welcome and input! You’re welcome! 👍 Happy to be helpful here. 😊 And super glad that experts replied too. I don't know forum etiquette: Now that I have my initial question answered, would it be appropriate to retitle the thread and continue with my subsequent questions, or should I start a new thread and/or post in the threads relevant to specific circuits? Umm, I wanted to make a giant thread here, but was encouraged by newey to create a new thread when the current problem is solved. Since this is a problem solving forum, it’s preferred that each question be contained in a separate thread; searching for solutions becomes simpler that way. 🙂 Note: He told me I could write “unreg” at the end of each of my thread titles. That personally helps me reread the given answers when I want to. (“unreg” is only 5 characters, so that was possible for me) |
|
|
|
Post by newey on Aug 30, 2021 5:16:31 GMT -5
And why would a guitar built around 2004 come from the factory with '50's wiring? Was that "a thing" already then? Not that you can answer that question.... It's been "a thing" since . . .well . . .the '50's  Your thread implies (but doesn't actually say) that you have had this guitar since new, but then you also said something about it perhaps being someone's "pet project". Looking at the photos of the wiring, if you obtained it second-hand, I'm guessing this has been rewired. Using audio taper for the Tone and linear for the volume is fairly standard. Again, it might have been changed if the guitar was used when you got it and was rewired at some point. I would not suspect the '50's wiring to be standard from the factory, but I wouldn't necessarily read anything into the Vol's linear taper, that could well be "stock". Not really an issue of etiquette, but a separate thread (with a more-specific title) is more likely to be seen by others, increasing your likelihood of response, and also aiding others in the future, particularly if they are searching for something specific to what you are asking. |
|
|
|
Post by David Mitchell on Aug 30, 2021 6:57:32 GMT -5
Umm, I wanted to make a giant thread here, but was encouraged by newey to create a new thread when the current problem is solved. Since this is a problem solving forum, it’s preferred that each question be contained in a separate thread; searching for solutions becomes simpler that way. 🙂 Okay, I can understand that. Thanks for the tip! Different forums have somewhat different preferences, so I wanted to ask. And why would a guitar built around 2004 come from the factory with '50's wiring? Was that "a thing" already then? Not that you can answer that question.... It's been "a thing" since . . .well . . .the '50's . Haha! I was wondering when it was re-popularized among tweakers. Oops. It wasn't second-hand as far as I know and recall — maybe B-stock, but not used. I bought it through eBay at the time from what appeared to be a dealer. I meant that perhaps it was the pet project of a designer for the company. There was a cheaper model, the EVO XM, that got the catalog space and I think is still in production. This one never seemed to get promotion or attention, but it has the traditional control layout, '50's wiring (assuming that wasn't a mistake), wraparound rather than tuneomatic bridge, and perhaps underwound pickups.... Ah, okay. Thought they would be matched, or the volume pot have the audio taper if not! Okay, I will let the threads proliferate. Thanks! Edited for formatting, mostly. |
|
|
|
Post by newey on Aug 30, 2021 10:08:07 GMT -5
Oops. It wasn't second-hand as far as I know and recall — maybe B-stock, but not used Just seeing the soldering there, doesn't look factory to me, particularly the blobs of solder on the backs of the pots. These were inexpensive Asian-made guitars, mass-produced, and I would expect to see less solder used, and more uniformly applied. I suppose a "B-Stock" might have been returned to the factory for wiring issues and rewired at that point |
|
|
|
Post by reTrEaD on Aug 30, 2021 11:34:08 GMT -5
Aha! Thanks, reTrEaD! I have actually looked at that thread a few times, and thought that might be the case based on the description, but I ... uh ... can't decipher the schematic yet. And why would a guitar built around 2004 come from the factory with '50's wiring? Was that "a thing" already then? Not that you can answer that question.... If you understand schematic symbols and the confusion comes from the modeling of the pickup and the external things like cable and amplifier, identifying those as compared to the actual components may help.  Then again, if you don't understand schematic symbols this might still be difficult for you to understand. Regarding your question about thread creation, just use your best judgment to avoid clutter or chaos. Several threads, each with one single question would create unnecessary clutter. Too many questions in one thread becomes a bit chaotic to follow and track whether all the issues have been dealt with, even if each question has been numbered. Grouping a few closely-related questions together in one thread won't present any trouble. |
|
|
|
Post by David Mitchell on Aug 30, 2021 11:47:49 GMT -5
Oops. It wasn't second-hand as far as I know and recall — maybe B-stock, but not used Just seeing the soldering there, doesn't look factory to me, particularly the blobs of solder on the backs of the pots. These were inexpensive Asian-made guitars, mass-produced, and I would expect to see less solder used, and more uniformly applied. I suppose a "B-Stock" might have been returned to the factory for wiring issues and rewired at that point Hmm ... interesting. Thanks to my personal finance program, I know I bought it from Backstage Music on eBay, but I can't find the transaction emails (they were probably in an old email account), and transaction history doesn't go back more than a few years on eBay, so I have no idea what the listing said now. I might find something in my paper files. |
|
|
|
Post by David Mitchell on Aug 30, 2021 21:37:44 GMT -5
If you understand schematic symbols and the confusion comes from the modeling of the pickup and the external things like cable and amplifier, identifying those as compared to the actual components may help. Then again, if you don't understand schematic symbols this might still be difficult for you to understand. That does help a lot! I didn't even understand that the pickup, cable, and amplifier were part of the schematic. I will compare the two schemes with this in mind and see whether I can grasp it better. But yeah, I am still struggling with schematic symbols themselves. Oh, okay. I had already started the first separate thread before I saw your reply. I will keep your advice in mind and try to group things reasonably. |
|
|
|
Post by gckelloch on Aug 31, 2021 20:35:25 GMT -5
First of all, I reckon we all (myself included) owe David Mitchell an apology for taking his thread on a strange and convoluted tangent. Only if you use a relatively high value cap in the 5~20nF range, and it only cuts bass by a few dB and then becomes a mid-peak as the volume is turned down. Uhh, no. Treble-bleed and bass-cut do share an element in common. A series capacitor that gives 'preferential treatment' to high frequencies. Aside from that, they should NOT be equated.
Treble-bleed is intended to mitigate the undesired effect of high frequency loss due to cable capacitance that occurs when the guitar's volume control is turned down from maximum. Ideally the shape of the frequency response curve will remain constant, regardless of the rotation of the volume control. ONLY the overall amplitude of the signal will be affected.
Bass cut is intended to decrease the amplitude of low frequencies while leaving higher frequencies unaffected. Ideally, the amplitude of the higher frequencies will remain constant while the shape of the frequency response curve will be highly altered (roll-off at lower frequencies). but dude, man, guy, bro...mustafah, I have a ~15nF C in parallel with a ~150k R TB on a guitar and it does just what I said. I'll post a video to confirm, but it's quite obvious to the ear what it does. |
|
|
|
Post by reTrEaD on Sept 1, 2021 10:46:44 GMT -5
it does just what I said. I'll post a video to confirm No need to post a video to convince me. I feel confident it does just what you said. But what you said, definitely isn't a bass-cut control and it doesn't achieve the desired goal as a treble-bleed. When you oversize the cap to change your treble-bleed to a treble and mid bleed, I suppose you could label that as cutting the bass. But the shape of the response curve gets messed up in regards to the mids and treble. The peak that we saw in the treble with the volume at max will get wider and shift downward in frequency, when the volume is reduced. As the parallel resistor becomes a more significant factor, when the volume control is turned further counterclockwise, the increased loading effect it has on the pickup will cause a loss of treble. Whereas, this previously did a nice job of keeping the capacitor of over-compensating at much reduced volume settings, it still does that but doesn't do enough to make much of an effect on the mids. So the relationship between the mids and treble gets really messed up. |
|
|
|
Post by David Mitchell on Sept 1, 2021 10:52:34 GMT -5
I have one more question (for now) about my stock wiring:
When I plug in to my Boss GT-10 (ancient technology!), I get buzz unless I'm touching the strings. This has happened in two different houses and at the church I've played at. Is there a standard fix for this?
I know that there is a ground wire running to the bottom of one of the bridge post bushings, but whether it is working as intended I can't say.
|
|
|
|
Post by reTrEaD on Sept 1, 2021 11:12:28 GMT -5
I have one more question (for now) about my stock wiring: When I plug in to my Boss GT-10 (ancient technology!), I get buzz unless I'm touching the strings. This has happened in two different houses and at the church I've played at. Is there a standard fix for this? I know that there is a ground wire running to the bottom of one of the bridge post bushings, but whether it is working as intended I can't say. It seems like your string ground is working exactly as intended. Your body can help couple external noise into the pickups. But by grounding yourself through the strings, that is reduced. Read: You're just a big ol' Bucket o' Noise |
|
|
|
Post by David Mitchell on Sept 1, 2021 11:45:07 GMT -5
It seems like your string ground is working exactly as intended. Your body can help couple external noise into the pickups. But by grounding yourself through the strings, that is reduced. Read: You're just a big ol' Bucket o' NoiseOhh. I'm the problem. Thanks! I hadn't stumbled across that page yet. |
|
|
|
Post by newey on Sept 1, 2021 12:22:00 GMT -5
When I plug in to my Boss GT-10 (ancient technology!), I get buzz unless I'm touching the strings. This has happened in two different houses and at the church I've played at. Is there a standard fix for this? If the Boss effects processor is being used for a hi-gain sound of some sort, expect more noise in general. Since touching the strings is ordinarily a required part of playing (ignoring amp-feedback stuff, etc.), this usually isn't a problem. If the issue is that one wants to leave the guitar plugged in onstage, so as to be ready to use as a backup, then installing a "stand-by switch" is an option. That would be the only "fix" of which I am aware. Many years ago (I'll never find the thread now), we had someone who, to test the "bucket of noise" theory, tied a piece of bare copper wire to a ring on his finger, and then connected it to (IIRC) a heat register in his house (which is, presumably, grounded). By grounding his body, the noise level was reduced whether he was touching the strings or not. But that was as a test, not really a practical "fix" for the problem. |
|
|
|
Post by gckelloch on Sept 1, 2021 18:36:05 GMT -5
it does just what I said. I'll post a video to confirm No need to post a video to convince me. I feel confident it does just what you said. But what you said, definitely isn't a bass-cut control and it doesn't achieve the desired goal as a treble-bleed. When you oversize the cap to change your treble-bleed to a treble and mid bleed, I suppose you could label that as cutting the bass. But the shape of the response curve gets messed up in regards to the mids and treble. The peak that we saw in the treble with the volume at max will get wider and shift downward in frequency, when the volume is reduced. As the parallel resistor becomes a more significant factor, when the volume control is turned further counterclockwise, the increased loading effect it has on the pickup will cause a loss of treble. Whereas, this previously did a nice job of keeping the capacitor of over-compensating at much reduced volume settings, it still does that but doesn't do enough to make much of an effect on the mids. So the relationship between the mids and treble gets really messed up. ...but you wrote "Uhh, no." to what I correctly described something does. That's misleading. Above, you have just restated what I described in more detail. I did not say it was only a bass cut or a linear TB. My more succinct description may even be less confusing. |
|
|
|
Post by ashcatlt on Sept 1, 2021 21:53:53 GMT -5
K maybe I was playing a little fast and loose with the thing about the treble bleed/bass cut. The one guitar I ever owned with treble bleed got really thin and nasty when turned down a ways. I didn’t know enough about anything to explain why at the time, but I distinctly remember the cap on the V pot. ...a "stand-by switch"...the only "fix" of which I am aware. I mean the Volume pot accomplishes the same thing when turned all the way down. At least, as long as it’s not wired “backwards” like some LPs and such. Let’s please don’t do this. To have a good chance of working, it really wants to be the same “ground” to which the guitar is ultimately connected, and either way, things can get dangerous fast. We mostly don’t talk about the “safety cap” nowadays because it’s a kind of questionable solution to a fairly rare problem, but physically tying yourself to anything in the system so that you can’t possibly let go is a very bad idea. |
|
|
|
Post by newey on Sept 2, 2021 5:22:21 GMT -5
ashcatlt is right, don't try this at home . . .
|
|
|
|
Post by David Mitchell on Sept 3, 2021 16:32:47 GMT -5
If the Boss effects processor is being used for a hi-gain sound of some sort, expect more noise in general. Since touching the strings is ordinarily a required part of playing (ignoring amp-feedback stuff, etc.), this usually isn't a problem. If the issue is that one wants to leave the guitar plugged in onstage, so as to be ready to use as a backup, then installing a "stand-by switch" is an option. That would be the only "fix" of which I am aware. I normally play with a clean-to-light crunch sound. I got into the habit of putting the volume pedal all the way down when I needed to take my hands off the guitar for a little bit, which certainly works well enough. I just assumed that it was an issue with the grounding. Would better shielding of wires and cavities make any difference? ...a "stand-by switch"...the only "fix" of which I am aware. I mean the Volume pot accomplishes the same thing when turned all the way down. At least, as long as it’s not wired “backwards” like some LPs and such. Apparently it is backwards at this point, but I'm going to be working on that! Yeah, if I need to "cut it off" on-stage, turning the volume all the way down is fine. Will do. I mean, won't do. 🙂 |
|
|
|
Post by ashcatlt on Sept 3, 2021 19:58:00 GMT -5
Apparently it is backwards at this point... Not the kind of "backwards" I meant. You've got that 50s tone wiring thing happening, but from the most recent picture, it looks like the connection to the jack is on the wiper, like it's supposed to. This way, when you turn it all the way down, the jack itself is shorted, and no sound can happen. On a guitar with two V pots like an LP or SG, if those pots short the output when turned down, then turning down one of the V pots will silence both that position on the switch and the middle (both) position. Some people don't like that, so they swap the wiring around so that it shorts the pickup itself, but leaves the jack (and the cable to which it's connected) floating in the cosmic wind, which can be a lot noisier. |
|
|
|
Post by David Mitchell on Sept 6, 2021 21:05:17 GMT -5
On a guitar with two V pots like an LP or SG, if those pots short the output when turned down, then turning down one of the V pots will silence both that position on the switch and the middle (both) position. Some people don't like that, so they swap the wiring around so that it shorts the pickup itself, but leaves the jack (and the cable to which it's connected) floating in the cosmic wind, which can be a lot noisier. Thanks for the explanation, ashcatlt. I can see why that would seem desirable, but also why it can be bad. Happily I only have one volume pot to worry about. 🙂 |
|
|
|
Post by David Mitchell on Sept 6, 2021 21:12:38 GMT -5
I was wondering if I could reuse this cap, and finally tried searching for the code (I didn't know if it was a model number or a value code). Turns out that's a 0.1uF cap. 100nF. Not even in the range charted by JohnH in " The effect of Tone Capacitors." Uh ... wut?! I thought maybe it was because of the '50's wiring, but even with that it doesn't seem like a popular choice. The only mention that seems related from my brief searching is in this TDPRI thread: " .1uf Capacitor or Not?" |
|
