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Topic: Bridging a resistor on volume pedals
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Doug Jones Member From: Canby, Oregon USA
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posted 12 April 2001 01:58 AM
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In an attempt to get crisper lows, I've sought advice from some folks. I've tried thinner sounding pickups, matchbox, etc. Just recently I received a recommendation to place a 500K resistor on the hot and ground either at the output jack of the steel or at the input of the volume pedal. I got a 470K 1/2 Watt resistor and put it on the inbound hot and ground of the 500K pot in my volume pedal. It thinned it out (both highs and lows) and seemed to increase the volume. It also seemed to tighten up the overall tone. Any comments from you tech-wiz-bang folks? |
Bill Crook Member From: Goodlettsville, TN , Spending my kid's inheritance
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posted 12 April 2001 02:36 AM
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Doug....As an Electronic tech,I think anytime you place a resistance or capactiance in front of the amp,you only decrease the output of the P/U. Now,as most of us know,we desire the max signal from the instrument. Therefore,we can EQ it or trim to fit our needs at the amp. To reduce the primary signal from the P/U isn't such a bright idea. O.K..... This info is for the "passive" V/C pedals only !!! Any "powered" pedal such as the "Hilton" or "Goodrich" pedal has pre-amp circuits build-in. (In this case,you don't need to worry about this problem) I am a great believer in the "Myrick" mode of a passive pedal. This modification attempts to present the max signal to the amp at any volumne level. |
Jack Stoner Sysop From: Inverness, Florida
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posted 12 April 2001 04:43 AM
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Placing a resister across the input/output effectively decreases the resistance of the volume control pot. The sum of two resistors in parallel that are the same value is 1/2 the resistance amount of one and in this case by placing the 470K resistor in Parallel with the 500K (when it is at the max resistance point in it's travel) you have reduced the overall resistance to approximately half.The "Myrick" mod to the volume pedal is a similar mod but uses another 500K volume control pot. The volume pedal should not have that much affect on your tone. It can have some affect but not what you are looking for. I use Lawrence 710 pickups on my Franklin, a stock Goodrich 120 volume pedal (500K pot model) and in conjunction with how I set the EQ on my Nashville 400 I can get the lower strings on my C6th neck to be "crisp". I don't get the treble my Telecaster is capable of but then I don't want that much treble on my steel. I think the answer to what you want is more in the amp than in the guitar or volume pedal. One other thing that will have a major affect on tone or frequency response is the cords. You have to have decent cords or everything else you do won't count. I use to use Belden 8410 cable, which is a high quality shielded audio cable, for my cords and I thought it worked good until I bought some George L's cables. It took me 10 minutes with the George L's cables and the Belden was history. |
B Cole unregistered
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posted 12 April 2001 06:47 AM
I have found that if you us the IQ-1200 Made By Bill Lawrence you can enhance the lows or the highs to the point of making the steel guitar sound almost like an acustic. I use one at all times with my L-710-8 L-210 two pickup set up.I would Call Mr. Lawrence and get his input on this problem-- toll free so the call cost you nothing 1-877-647-2651-And have a pen and paper handy at all times when talking to Bill |
Jack Stoner Sysop From: Inverness, Florida
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posted 12 April 2001 07:01 AM
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I would think the Lawrence IQ 1200 unit would do the opposite of what he wants. Bill told me, at St Louis 2 years ago, that it wasn't for someone who played mostly "country" but more for someone who wanted a jazz or pop sound. |
B Cole unregistered
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posted 12 April 2001 09:55 AM
I think the IQ-1200 is for someone who don't mind putting some time into working with it and getting all it can give. I play nothing but country and I mean only classic country and I still havn't stoped finding all the things it can do. But there again it may not be what he is looking for. But it would seem to me that it a lot easyer then trying to alter the amp. or the pickup when turning a knobie maybe can do the same thing. But that is why you fellows with the smarts fix them and us fellows lacking some plays dim |
Keith Hilton Member From: 248 Laurel Road Ozark, Missouri 65721
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posted 12 April 2001 07:09 PM
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Doug, I don't see how the resistor, wired as you described, would help the frequency response of your pickup. I've tried many combinations of resistors and capacitors across a pot. The keys to good sound is making sure the pickup sees high impedance and low capacitance. Like Jack told you, hookup cords make a big difference when using a pot pedal. |
David Rich Member From: Lexington, KY
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posted 13 April 2001 01:20 PM
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This should make the pedal less bright and less volume. Your result seems contrary to what I would have thought. |
Donny Hinson Member From: Balto., Md. U.S.A.
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posted 13 April 2001 03:14 PM
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I need to know what kind of amp you're using. The amp can do far more, tonally, than the passive circuitry you describe. |
Doug Jones Member From: Canby, Oregon USA
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posted 13 April 2001 07:41 PM
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Thanks for all your responses. I A/B'd both of my Zum pedals which have 500K pots; one with the resistor and the other without. There was a definate tone loss; kind of a washed out sound if there's such a description. For the record, I use Carol C-1300 oxygen-free audio cable with Swithcraft plugs. My stage rig is a '92 Lashley, a modified Goodrich 4a Matchbox, Evans preamp, Lexicon Alex, Ibanez DD-1000, Korg DTR-1 and 2 Evans FET-500LVs (power sections only). I'm going back to my regular vol. pedal set up. |
Doug Jones Member From: Canby, Oregon USA
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posted 13 April 2001 07:43 PM
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Hi Jack. Thanks for your input and info. OK to close thread. - DJ - |
Terry Downs Member From: Garland, TX US
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posted 13 April 2001 11:34 PM
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I agree with the responses. The lowering of the effective pot impedance will only reduce highs and amplitude unless of course you have an active setup.HOWEVER, the placement of a resistor across a pot will change its taper. It adds a hyperbolic term to the taper. In fact, if you are out of town and are in a pinch for a volume pot and all you can find is like a 1 Megohm linear, you can put another 1 Megohn or 500K fixed resistor across it and approximate a audio taper pot. Of course this is not optimial, but it brings it closer to a base 10 logarithmic response. I have some graps in Excel that shows that if you would like to see them. An audio taper pot is not the same as a logarithmic pot. The audio taper pot is a logarithmic taper with the asymptotic extents rounded off. Just thought I'd throw that in. I was curious a long time ago about a fixed resistor across a pot, so I graphed it to see. Good post.
------------------ Terry Downs http://nightshift.net terry@nightshift.net |
Jack Stoner Sysop From: Inverness, Florida
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posted 14 April 2001 02:39 AM
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I've never heard of the Carol cables you mention. As an electronics tech, the "oxygen free" doesn't do anything for me. It's the electrical specifications that really count, such as capacitance resistance per foot, etc. |
Keith Hilton Member From: 248 Laurel Road Ozark, Missouri 65721
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posted 14 April 2001 09:34 AM
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OK Jack, if the Oxygen Free doesn't do anything for you, Bobbe Seymour has "GOLD" connection cords. Bobbe Seymour was telling me about the recording studio he had, and it had solid GOLD hookup cords. Think of it Jack, solid GOLD, the sound would just have to be better! I am smiling Jack![This message was edited by Keith Hilton on 14 April 2001 at 08:45 PM.] |
BobbeSeymour Member From: Hendersonville TN USA
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posted 14 April 2001 10:11 AM
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Whats funny is that the George L cords sound as good as the gold did and cost a lot less! Bobbe |
Donny Hinson Member From: Balto., Md. U.S.A.
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posted 14 April 2001 07:15 PM
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Doug, I don't know what kind of "sound" you're looking for, but it sounds like you've got enough "stuff" between your axe and the amp to confuse even an electron! Do you really need all that "stuff" to sound good?If I had to guess, I'd say that all that "stuff" might be part of the problem you're complaining about...just a thought. |
Keith Hilton Member From: 248 Laurel Road Ozark, Missouri 65721
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posted 14 April 2001 08:40 PM
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Now Bobbe, which would make a "singer" feel better? Singing over pure gold, or "non gold" connecting cords? Therefore, we better leave the pure gold hookup cords in the studio for the singers, and hook up our steels with the George L cords. |
Jack Stoner Sysop From: Inverness, Florida
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posted 15 April 2001 02:48 AM
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Although I personally consider gold connectors for instrument cables to be a marketing pitch, gold is an excellent conductor. Plug in printed circuit boards with printed edge connectors which are usually plugged in, many for years, are a prime application of gold connectors as they do not oxidize or exhibit flakey connections as easy as other metal compounds including silver. For guitar cords or patch cords that are being plugged in and unplugged frequently, good grade standard connectors such as the Switchcraft 280 1/4" plug, George L's plugs, more than suffice. The connection resistance on this type of plug is negligible. |
Keith Hilton Member From: 248 Laurel Road Ozark, Missouri 65721
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posted 15 April 2001 08:51 PM
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Ok, I was doing a little joking,kidding and having a little fun. Bobbe knows me enough to know I like to have fun. |
Bill Crook Member From: Goodlettsville, TN , Spending my kid's inheritance
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posted 16 April 2001 12:31 PM
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quote: Ok, I was doing a little joking,kidding and having a little fun.
How did we know that ??? (personally, I too think "Gold" is a sells ploy) Too many times tho,the un-informed has trouble with seperatin' the jokes from the truth. On a one to one basis, I dought very few people can tell the difference between "gold" and plain "metal". |
Mark Herrick Member From: Los Angeles, CA
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posted 16 April 2001 02:37 PM
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I recently received a mailer from George L's announcing the re-issue of "Vintage Red Cables" and unplated brass plugs.Anyone have any experience with these? (Not that I'm rushing out to replace what I already have!) |
Jack Stoner Sysop From: Inverness, Florida
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posted 16 April 2001 02:50 PM
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Mark, I got that mailer too.I rushed right out and ordered the red cables - NOT  Another marketing ploy. I guess red colored cables are better, just like black formica steels are the best sound.  |
Donny Hinson Member From: Balto., Md. U.S.A.
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posted 16 April 2001 05:17 PM
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Unplated brass plugs will oxidize in only a few weeks under the right conditions. It's no big deal to buff them up with steel wool or Scotchbrite, but why bother? Good nickel plated connectors are far more trouble-free. |
Blake Hawkins Member From: Land O'Lakes, Florida
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posted 17 April 2001 09:36 AM
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Donny is right on the brass audio plugs. Over 45 years of making my living in broadcast facilities and recording studios, I've handled more audio patches and plugs than I can count. Professional audio patch panels use unplated brass plugs. In order to keep the noise down they need to be cleaned on a regular basis. The problem wasn't too bad with 1/4" phone patch plugs, but when the industry started going to the smaller "tiny-jacks" which had much less contact area, the required cleaning interval was quite a bit shorter.I did work with an audiophile engineer who maintained that he could tell the difference in sound between gold, silver, and cadmium plated connectors. He did not like the sound of the gold ones. However, he never did demonstrate this ability to me. One time when we ran short, I put some gold ones in the system. He didn't know they were there until one of the other engineers told him.
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Jack Stoner Sysop From: Inverness, Florida
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posted 17 April 2001 03:34 PM
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I was a Tech Controller in the Air Force. Patch panels was one of the things Tech Controllers used to test and substitue teletypes and other comm equipment. The military PL55 and PJ068 and later the smaller plugs Blake referred to were on a regular monthly PM schedule for cleaning. We used steel wool and brasso to keep them clean.The telephone companies used the brass plugs in their manual patch panels for years. They still use them today in their analog test equipment. |
Wilfred Luttrell Member From: DeRidder, LA, USA
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posted 20 April 2001 01:02 AM
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I simply made my pedal hotter by altering the string pull on the pot. Of course my pedal will not "cut off", but then I still have the swell I need and the resistance does not eat up the signal sent to the amp. |