Gibson-Talk.Com Forum Archive




Memphis tone circuit?

eryque
September 7th, 2007, 01:59 PM
The hype about the new ES-339 talks about the new Memphis Tone Circuit. Anyone know what it is & maybe know where I can find a diagram?

desaljs
November 1st, 2007, 02:08 PM
Reading about the new 339, here is what I read: "Memphis tone circuit preserves the guitar's high frequencies no matter where you adjust the volume contol". Hope that helps.

Jim D

Regats
November 20th, 2007, 11:57 PM
Also seeking schematic.
Thanks.
<R>

eggman
November 23rd, 2007, 11:38 AM
Howdy,

The Memphis tone circuit sounds like a good deal to me. I believe it's a 500K tone pot.

Eggman

BlackLineFish
December 1st, 2007, 10:30 AM
I'm thinking it's a 500k VOL pot, with a treble-bleed.
http://www.acmeguitarworks.com/images/electronics/680_220_400.jpg

Check out this description from Acme Guitar Works (http://www.acmeguitarworks.com/Volume_Kit_P87C13.cfm):

This kit consists of a capacitor and a resistor, which are wired in parallel across two of the lugs on the volume pot in order to prevent treble loss as the volume control is rolled down. The values are 680pF/220K (single coils) and 1000pF/220K (humbuckers). There is nothing special about these components, you can buy them from Radio Shack for 50 cents or less (we're guessing). We charge $2.60 because of the time it takes to order them, receive them into inventory, twist the leads together and cut to length, print labels, print/cut/fold instruction diagrams, and package the resulting kits/diagrams into little zip lock bags and label them. So you're not paying for the parts here, you're paying for the time it takes us to package them and the convenience of not having to track down the parts yourself.

We're telling you this so you don't think we're trying to rip you off. With the cost of gas being what it is (not to mention the value of your time), it's surely cheaper to purchase one of these from us and save your time and gas. On the other hand, if you want a dozen of them, it might be worth your while to stop by Radio Shack or similar and buy the components there, you'll definitely save a few bucks.

That's the kind of truth-in-advertising that is so rare in today's world for your average tone-hound. They get props from me for that.

--gh

workknot
December 25th, 2007, 08:29 PM
Looking inside my brand new ES 339 with the Memphis Tone circuit, I see on both volume pots, one small cap that is about the size of a baby aspirin and is dull orange in color. Just an FYI for all concerned.
Regards; Pop's

Wally
December 26th, 2007, 12:49 PM
Some players do not like what the resistor does for the treble bypass circuit. that cap that workknot has seen is probably a .001mfd(1000pfd) ceramic disc capacitor.

workknot
December 30th, 2007, 11:46 AM
Here is a link to the Gibson site that has most wiring schematics. I did not see the Memphis tone circuit for the ES 339.
http://www.gibson.com/en-us/Support/TechSupport/Wiring%20Diagrams/
Regards; Pop's

Wally
May 6th, 2008, 12:21 PM
Workknot, where is this cap located? Is it across two lugs of the volume pot or is it connected to the tone pot? Also, if it is a tone cap rather than the treble bypass cap across the volume pot lugs, can you tell us where it is located...what lug on the tone pot? Does it contact wither the lead in or lead out of the volume pot?

Jimi-B
May 13th, 2008, 08:39 AM
Hi there, new to the forum saw this and thought I would join in :)

I have a Duesenberg as well as a Gibson Les Paul and the Doozy has this circuitry in it as standard. I looked at the volume pot and it was just a ceramic disc cap not sure of the details of it sorry. I believe the cap goes in between the 'un-soldered' left lug and middle lug.
Is there much difference between the resistor and cap in parallel to the cap on its own?

I think I am going to change the guts in the Les Paul as I really like the sound of the Duesenberg when rolled off and I use the volume on the guitar all the time, unlike a lot of people I see playing now lol

Wally
May 13th, 2008, 06:14 PM
Hello and welcome, jimi b.
Two things...the treble bypass cap circuit on the volume pot should contact the lead in and lead out lugs.
Secondly, if you have a regular production LEs Paul, you probably have 300K linear taper volume pots that yield a fair presence during roll off. I have never put a bypass cap on that type of pot. I am going to guess that he effect will be not as drastic as using the bypass cap on an audio taper pot.
Some folks like the .001 cap alone. Some like to use a different value...some use .068mfd. Some liek to add the resistor, some kdon't. All of these circuits work differently depending on pot values, tapers, and type of pickups.

colimodio
May 25th, 2008, 10:29 AM
Here's minehttp://i213.photobucket.com/albums/cc180/colimodio/P1170017.jpg

left the old .223 not fully connected

Heres the front of this Gibby
http://i213.photobucket.com/albums/cc180/colimodio/P10100254.jpg

And for the 339, check out the TUSQ saddles (part#PQ-8400-00)


http://i213.photobucket.com/albums/cc180/colimodio/P10100263.jpg

A very dramatic tone improvement.:-D

rhomco
December 24th, 2008, 08:14 AM
Colimodio, You should hear a big difference since you went from .022 microfareds to .047. Did it warm up or get brighter? I am also interested in the tonal change in the 339 tuna with those saddles. They look like Teflons from the old days. I found some black fiber ones here in the US from Graph Tech (String Savers).
Regards,
Rob

Davomite
January 7th, 2009, 10:51 PM
I'm thinking it's a 500k VOL pot, with a treble-bleed.
http://www.acmeguitarworks.com/images/electronics/680_220_400.jpg

Check out this description from Acme Guitar Works (http://www.acmeguitarworks.com/Volume_Kit_P87C13.cfm):



That's the kind of truth-in-advertising that is so rare in today's world for your average tone-hound. They get props from me for that.

--gh
That's not what we do.

Teobeck
February 20th, 2009, 11:18 AM
I replaced my ES-339 Memphis Tone circuit with an RS Guitarworks vintage kit and like it much better. The kit consists of:
What's in the kit:
# (2) 500K RS Short-Shaft Superpots- We designed these pots in conjunction with CTS. Used for the volume controls in the kit, these pots have a custom taper that gives you a noticeable difference between each number on your volume control. You can finally roll your volume down to 2 or 1 and not loose any clarity, even in the neck position!! Mil-spec construction and a smoother resistor path make this the best pot to ever be used in the guitar.
# (2) 500K CTS Short-Shaft Audio taper pots
# (1) RS Paper and Oil GuitarCap® by Jensen .022. Some of our customers have asked us for a good vintage cap option for some time, so we went to Jensen and asked them to make a paper and oil capacitor as small as possible for that "woody" tone and they nailed it! The .022 microfarad GuitarCap® is best for the bridge position tone control of your guitar.
# (1) RS Paper and Oil GuitarCap® .015 - This is the same great GuitarCap® as above, just in .015 microfarad. This is best used for the neck tone control.
# (1) Length vintage-white wire- Used for the grounding in the circuit.

Wally
February 20th, 2009, 12:12 PM
Colimodio, You should hear a big difference since you went from .022 microfareds to .047. Did it warm up or get brighter? I am also interested in the tonal change in the 339 tuna with those saddles. They look like Teflons from the old days. I found some black fiber ones here in the US from Graph Tech (String Savers).
Regards,
Rob

Rhomco, those larger ..047mfd tone caps will pass more lows. Most people do not go larger than ..022's with humbuckers. IN fact, as mentioned in Teobeck's post, some folks go to a .015 on the neck to cut the mud....gain articulation in the low end. Those RS pots have some type of linear taper that maintains presence down through the range. Gibson has used 300K linear taper pots since some time in the '70's that achieves the same thing. I don't know why Gibson hasn't gone to a linear taper in their 500K pots, which are what a humbucker really wants to see...500K that is.

Davomite wrote: "That's not what we do."

DAve, I haven't seen the workings on a 339, but I am suspecting that ya'll use what is called the " '57 wiring circuit". This circuit takes the lead form the volume pot to the tone pot off of the 'out' or middle lug on the volume pot instead of the 'in' lug. IT changes the reaction of the volume pot. I have ;tried both ways, and I prefer the treble bypass cap. Others have different preferences. A person can google '57 Gibson wiring scheme and find the circuit.

vcartier
April 24th, 2009, 07:15 PM
Ok, I am very confused. As an owner of a 339m I read all about the memphis tone circuit, but I still have no clue how it works and why? It seems like a lot of conjecture as to how the circuit is atttached, does anyone really know?

vcartier
April 24th, 2009, 07:16 PM
oh yea, I don't have a degree in electronic engineering...is there a way to communicate this to someone like myself?

Joe-Bob
April 24th, 2009, 10:10 PM
That's not what we do.

OK, Dave, throw us a bone, huh?

I'd like to know what to do to my guitars, because I don't like the drastic tone change when the volume is rolled off. It would be much more useful without that annoying little characteristic.

Wally
April 25th, 2009, 10:22 AM
Joe bob, what guitar/s are you wanting to modify?
IF you have a regular production Gibson, as I noted earlier it will have 300K linear taper pots. These provide some 'maintenance' of trebles as the volume is rolled off. However, they don't provide the highs that a 500K pot will. IF you are using bright pickups, you mihgt like this. IF not, and if you want a vintage Gibson approach, use 500K pots. You can use either a linear taper(which will maintain highs as the pot is rolled down) for the volume or do some variation of the treble bypass situation on an audio taper pot. THe '57 Gibson wiring also accomplishes a different result for the volume pot vis-a-vis singal maintenance.
For the treble bypass cap arrangement, I personally favor a .068mfd-.001mfd cap across those volume pot lugs...'in and out', not the grounded lug. I don't use a resistor. That seems to make the volume pot's action come on strong at about 2.5 and there is little variation from there on up. That is kind of the reverse of what an unbypassed audio taper pot does, which is all of the usable action is from about 7.l5 -10 on the dial.

Joe-Bob
April 25th, 2009, 12:12 PM
Well, I've got several actually, the LP Studio in my avatar, an LP Jr. Spl. w/P-90s, and a GOTW Explorer Pro.

Wally
April 25th, 2009, 12:35 PM
Joe Bob, if original, the LP Studio will have the linear taper 300K pots. Those pots have a 'good' taper for maintaining 'presence' when the volume is lowered. IF those pots have been changed to audio taper 500K's, then you are losing highs when the volume goes below say 7.5, right? A treble bypass cap will resolve this problem. Try a .001 or a .068 and see what pleases you.
The other two guitars??? IF they are modern, they may also use the 300K linear pots.
The GOTW Explorer?? IF it came out of the CS, then it will probably have 500K audio tapers.