posted 05 October 1999 02:36 AM         

That may be a (switch) option to build into the add on units.

posted 05 October 1999 07:19 PM         

[This message was edited by db on 10-05-99]

posted 05 October 1999 08:42 PM         

I am a bit confused by your statement. Measured voltage has nothing to do with the frequency of the AC signal. BTW: I think if you measure frequency of the AC supply you will find that it changes very little. You are correct that the voltage changes over a wide range.

posted 05 October 1999 09:34 PM         

[This message was edited by Ricky Davis on 10-05-99]

posted 05 October 1999 10:07 PM         

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[This message was edited by Keith Hilton on 10-05-99]

posted 06 October 1999 04:54 PM         

[This message was edited by db on 10-06-99]

posted 06 October 1999 06:21 PM         

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[This message was edited by Keith Hilton on 10-06-99]

posted 06 October 1999 08:18 PM         

[This message was edited by db on 10-06-99]

It is, and always has been aggravating. Especially with amplified instruments. Where the hum comes from has been a subject of hot debate ever since the creation of the microphone/Pick-up.

The most easily stated fact is, "You have a grounding problem". Or, "a ground loop". Maybe, but in most cases maybe not.

Reasons for 60Hz vs 120 Hz is often due to whether the power supply rectifies the line voltage in a half-wave or full-wave configuration.

Hum coming from PU's is one of the most difficult of all. Reason is, you are dealing with an extremely low voltage and ANY other voltage regardless of its source has an easy time invading and "riding" along with the voltage created by the PU. And 60HZ "noise" in the air alone has no problem in doing this. Our world is permeated with 60/120 HZ from all sorts of electrical and electronic devices.

But how does one get rid of the beast? As Keith and so many others have found out, it "ain't" easy! Engineers have been plagued since ole Benjamin and Alexander, where it all started.

"Humbucking" pu's do in fact work on the theory of cancellation. Two identical voltages will cancel each other if they are out of phase.

The humbucking pu does use two coils equal in every respect except the phase of the signal, ie, when one is going positive the other is going negative. This will cancel out any induced extraneous field (60HZ noise in the air), but leave the magnetic induced voltage intact. One, problem. It is still a second coil and as such, it does affect the sound!

Finally how does one get rid of the hum in a single coil PU. I have NO idea. Been thinking about it for a very long time.

I wish Keith, Peavey, Bill and others much success. But I would be remiss if I did not remind us that "cultured ears" like Buddy Emmons, and other greats can hear things an engineer hasn't even dreamed of.

So, good luck,

Pat

[This message was edited by PD on 10-07-99]

posted 07 October 1999 12:38 PM         

My Franklin did have two 6-string Lawrence pickups on it. I did that because at that time (1981) I believe there was no Lawrence 12-string pickup. It sounded great.

On a non-bystander-related note, I tried the L610's at a show and they sounded real 'thin' or 'brittle' to me. However, I like the single coil sound myself. Should I give give them a fair try at home on my own system with my own amp settings?
Thanks.
Steve
(Fessy D-10, Evans SE-150, DD-3)

[This message was edited by Steven Feldman on 10-08-99]

posted 11 October 1999 08:17 AM         

[This message was edited by Jon Light on 10-11-99]

posted 11 October 1999 12:13 PM         

Hi, Everybody.
Here is some information I'd like to share with you regarding this topic, but first, I want to compliment everyone here who responded to this thread. I am impressed with your interest and curiosity you have in these matters and your eagerness to learn. This has been my driving force too. Now, back to the topic at hand.

An easy way to avoid the 60Hz hum with its full harmonic spectrum is to use a humbucking pickup. However, to pick up the signal of the strings at two different spots causes a phasing problem. But, I must clarify the terms, "out of phase" and "in phase". The description "out of phase" is incorrect. If the signal would be 180 degrees out of phase, there would be no sound at all; or if the signal would be in phase, a humbucker would sound like a single coil pickup. The fact is that if you pick up the strings at two different points, some of the frequencies are in phase and some are out of phase. Guitar players use the term out of phase when the first and second harmonics are, to a great extent, canceled, but this is not the case with humbucking pickups.

The big problem with humbuckers is the wide band resonant peaks between 3 and 5 kilo hertz which cause an undesirable harshness. The heavier a guitar and the closer a pickup is mounted to the bridge, the more these resonant peaks correspond with the harmonic spectrum of the strings. Single coil pickups are also faced with this problem but to a much lessor extent.

In 1973, I designed the Gibson L6-S which was endorsed by Carlos Santana. This was the first guitar that had a passive inductive tone circuit to reduce the impedance above 1200 Hz to eliminate the wide band resonance peaks. This is basically the same system I use in the IQ-1200. Gibson marketing called it a Midrange Control. In October '75, the patent for this system was granted to me.
(FYI-all my patents are filed under my birth name - Willi Lorenz Stich.) In the patent, it says, "The midrange frequency tone control is used to suppress the harshness found in that frequency range in transistorized audio amplifiers." US Patent 3,915,048/Oct.28,1975.
This patent was filed on August 8, 1974 after the guitar was already ten months on the market. This was quite a few years before Craig Anderton adopted my idea. ( By the way, the IQ-1200 is not a notch filter.)

Michael, your note about split coils is not new and has some problems. The sound of a pickup depends on the physical dimensions of the coilform and on the distance from the bridge. The coil of a standard steel guitar pickup is about one inch wide. The pickup would be two inches wide, and the distance from the bridge would be one inch for half the strings and two inches for the other half. I'm using this system in my 610/612 Series. The poles are only .600 apart and had to be wound with 45 gauge wire. This is about as close to this idea as you can get. Twenty-two years ago, I made some 12 string pickups by using two split L-500 guitar pickup coils which sounded pretty nice.

Keith, you mention Nikola Tesla. I have copies of his patents on file, starting with his first Patent #335,786/Feb.9,1886 through his last Patent #1,655,114/Jan.3,1928. I've studied Tesla's work into detail. If you want more information, give me a call.

Pat, you show some theoretical knowledge, and about twenty years ago, I would have agreed with you 100 percent.

First of all, there is no hum in a single coil pickup. If you go far enought away from transformers and other external sources, there is no hum. Or, put a single coil pickup on a one inch thick aluminum plate, right next to an amp, and the hum is gone. The aluminum plate does not need any grounding. This I found out in 1979. Soon after, I designed the first humcanceling system with an inductance of .3 Henry, but it was far too large to put into a guitar.

You are right, you can make a humbucker with two identical coils, but it's not the only way. At my workshop, I have several humbuckers which I've made recently that are much quieter than conventional humbuckers where the secondary coil has only 10% of the inductance of the primary coil, and they sound like beautiful single coils. (In my work, I never use the word "invention". I like to use the word "discovery".)

Keith, when Hartley visited me last year at my factory in Bethlehem, I demonstrated for him three different products:
#1. The Antenna which eliminates the hum without altering the sound.
#2. Patent #5,789,691/Aug.4,1998 which allows you to mix high and low impedance where you can reproduce all the sounds of a strat, a les paul, and even the sound of an acoustic guitar, with a single humbucker in the bridge position.
#3. A guitar equipped with the system like the IQ 1200.
On my first visit to Peavey in November '98, I left an older design of the Antenna with them which is protected by a non-disclosure agreement.

Jack, I enjoyed meeting and talking with you at the St. Louis show this year. I have to disappoint you, though - the Gibson Les Paul Recording was a true Low Z guitar ( below 150 ohms). The guitar was offered with a Low Z amp, but the amp did not sell so they put a Low to High Z matching transformer into the guitar and defeated the purpose.

To explain simply, " HUM is like a disease. First, we must discover its cause, and THEN we start to find its cure. The Humbucker is a good medicine for hum but has some bad side effects. The IQ-1200 is a medicine to eliminate the side effects. Finally, the Antenna is a cure without side effects."

I'm preparing some material on impedance and sound which I will post soon. But, before then, if you would like to contact me with any questions, please feel free to call using our toll free number - 877-647-2651.

With best regards,

posted 11 October 1999 02:10 PM         

[This message was edited by Ricky Davis on 10-11-99]

posted 12 October 1999 06:33 PM         

[This message was edited by db on 10-12-99]