Allan Holdsworth's HARNESS - SECRETS REVEALED!

[@MadScientistGuitarLab]

That phasing effect is just a beat frequency. It's basically an audio frequency heterodyne.

[@VegasCyclingFreak]

Yes. I'd like to build some kind of circuit that would allow the two function generators to be in phase but that's kinda outta my wheel house.

[@Bob-of-Zoid]

Wait a minute! The one legend that played and toured with Allan? OK, I guess you mean his tech, but he played and toured with many legends, and many were also mind blowers! What's even cooler: If you played him a tape, and he liked what he was hearing, then no matter how well known you were, he would record with you or even tour with you if he could fit it in, and he's on many lesser known recordings. What a cool guy! Thanks for part 3!

[@VegasCyclingFreak]

Ha ha not a guitar tech

[@Bob-of-Zoid]

@@VegasCyclingFreak Don't say that without telling me who then? It's torture!

[@VegasCyclingFreak]

@@Bob-of-Zoid 😆 [HINT] He plays keys. [/HINT]

[@Bob-of-Zoid]

@@VegasCyclingFreak Oh dear! He played with so many!🥴

[@VegasCyclingFreak]

@@Bob-of-Zoid Think early 90s. He's on Allan's REH video. 😉

[@LockRocker]

Highly recommend one of those infrared thermometers, they come in handy in the kitchen as well! Alan would be proud and interested in this inquiry.

[@VegasCyclingFreak]

Yeah I need to get one of those... they are so cheap now!

[@z-9693]

You're this close to opening a dimensional portal!!

[@VegasCyclingFreak]

😆Almost feels like it lol

[@MercutioUK2006]

Excellent, I was looking forward to part 3. As usual, great insight!

[@ERYKJACKNIFE]

I believe that this thing is a silent speaker / inductor coil, with an attenuated input… I think? I was telling my friend about a video I saw where they show how to make a speaker louder by adding a coil in between the line in and speaker out this reminded me of that. I just saw another video about the guy as who made that AH drive pedal for Allan in the title it says ( see the harness at the end ) they ask to see one and he busts out this fat four U rack with a bunch of knobs and switches. It also had two sets of the nichrome wire spring terminals and nine of those inductors it looked so cool. Thanks for making these videos. Your lab assistants are really neat too. Cheers.

[@VegasCyclingFreak]

Yeah, the one in that J Rockett video is what I call the "super Harness". It's some kind of 2 in 1 unit... I think one side is straight Harness and the side has some kind of 2-band EQ, probably a high pass filter and a low pass filter. I just came to another realization today - I think he may have been trying to emulate the "back EMF" of the speaker(s) with the inductors. May explain why there's seven of them. Almost like "inductor limiting". I suppose it can also be considered a reactive silent speaker, in essence that's what it is.

[@ERYKJACKNIFE]

Wow man all this is so interesting to me. I really appreciate all of the work you put in to this video. I know very little about electronics but I seem to have a natural ability to understand how certain systems are wired and I’ll circuit bend synths and effects pedals from time to time. Much respect to your process I’ve Leaned so much. That was very cool when you showed the waves with your handmade wand meter. I got chills when I saw the way it does this pulse width modulation when you bring the wand close to the inductor. also when you show the waves inverting on its self one this video. There too. Out of phase 🧐 it also makes me think pedal made by Yamaha called ud stomp. That is discontinued. There are some presets made by Allan on this unit made up of 8 delay lines set slightly out of phase with one another. It almost sounds like a imaging effect, it’s the only thing out there I know of that can achieve what I’d like to call a sustained distortionless tone. Like multiple images sandwiched back together again with an ADSR quality to it like a synthesizer.

[@VegasCyclingFreak]

@@ERYKJACKNIFE I bought a UD Stomp a few months ago... I love love love it!

[@muyeikasamurabi1602]

I discovered Allan because of you. Keep doing this video series please. I want to know, dang it!

[@VegasCyclingFreak]

Ha ha welcome to the Holdsworth universe

[@muyeikasamurabi1602]

​@@VegasCyclingFreakBlowing my mind....

[@musterionsurly]

great stuff, loved it. might have to grab some 1mH chokes and some nichrome and have at it.

[@VegasCyclingFreak]

If you do, let me know how it fares

[@scotthutchens1556]

Great video series! I used to like to use attenuators-first I had an “Atair” brand unit, then a Scholz then a Harry Kolbe “Silent Speaker/Attenuator (reactive load actually using a real mini-speaker) speaker system. Figured with good amp like pedals and master volume amps nowadays, I don’t need and want to abuse the tubes and transformers. Wish we could hear if this unit is actually more realistic in its tone than other reactive load units.

[@VegasCyclingFreak]

I still need some verification on a few things. Working on it. I hope people don't get the idea that using one of these will make them sound like Holdsworth... just doesn't work that way. Anyway, I just learned about that Altair PW-5 today - I guess it was first on the market? Pre-dates Scholz's Powersoak from what I understand. I sure would like to see inside of a PW-5... one page I found says it has wiggly tungsten inside. More likely it's probably is something like the nichrome wire(s) inside of a toaster.

[@augustusbetucius2931]

Had a Harness II in the 90s. I can tell you that it was completely transparent (sorry for the over used buzzword). I used it to allow me to run Tremolux through my rack of effects, and into a power amp, out to a speaker (two 1x12s actually). What it did, was to allow my amp to sound *exactly* like my amp did running without the Harness. Realistic? I suppose so, as my amp sounded just like it would if I plugged it straight into a cabinet (my Tremolux had been cut down and turned into a head). Hope that helps.

[@VegasCyclingFreak]

@@augustusbetucius2931 Nice. Thanks for the info. That's the version I'd be more interested in for myself if I was going to go down that road.

[@michaelcottle6270]

Great job. Thanks for all your hard work.

[@markg1051]

The fact that there are no capacitors in the Harness any resonant effects must be from the inductors winding capacitances. If you look at any real speaker cabinet impedance curve you will see couple of resonant points on it, one quite high in ohms, somewhere between about 70Hz and about 125Hz, depending on what speakers are used and whether the cab is open or closed box construction. This is equivalent to a combination of a capacitor and inductor wired in parallel but is purely caused by the acoustics of the cab and speakers motional impedance. The other, up at about 200 to 300Hz and is at roughly the value of the speaker drivers DC resistance is a series resonance dip caused by the interaction of the voice coil inductance and the R.H. side of the above mentioned parallel resonant peak which is capacitive in nature (the L.H. side being inductive). It seems that the harness is only emulating the voice coil inductance and its DC resistance. It is what it is in the end and whatever the results Allan got is due to his understandinfg or lack of it in what was happening in the real speaker cab as he saw it. Thanks for your videos on this, very interesting.

[@VegasCyclingFreak]

Yes, except voice coil inductance of 0.1mh-0.5mH is very tiny compared to the 10mH of this circuit. Any capacitance present in the circuit will be from the inductor self-capacitance, and probably a tiny amount from those nichrome wire coils too. It seems to me that he may have been attempting to mimic the speaker "back EMF". I don't know at what level Allan's understanding of electronics was... likely this was the result of a lot of experimentation and what "felt good" to him.

[@markg1051]

@@VegasCyclingFreak That's very interesting, I always thought it was higher than that. As I'm currently doing a bunch of measurements of audio transformers inductance I decided to grab a 12" 8 ohm guitar speaker. Tested first using my LC meter II from Almost All Digital and only got few uH, great for small air cored inductors but not much for large caps inductors or audio devices. So next I grabbed my digital multimeter with an inductance mode on it and it showed couple of mH, if I loaded the speaker cone with some weight, reading went up a bit but reached about 8 or 9mH if I pressed on the cone with my fingers in order to reduce the cone vibration, as the meter fed what sounds like a 1kHz signal to it. I then set up an audio sig generator through a capacitor of known value (1.5uF) and ajusted the frequency to the resonance and then calculated the inductance at approx 255uH (0.255mH) which agrees with what you said. Have you done any actual measurements personally and if so what method did you use? I suspect that the magnet and steel pole assembly would have considerable effect on the value. Also when the cone is free to vibrate with any ac test signal it would be very difficult to be certain of what is being measured. I remember seeing somewhere in the past that one method used was to pour epoxy resin into the gap to solidly glue the voice coil to the magnet assembly so it can't vibrate. Sorry for all the questions, just my curiosity running wild. Cheers.

[@markg1051]

...I guess if emulating a speaker voice coil it hes to be without any changes in its operation as if we do, it will not be realistic.🤔

[@VegasCyclingFreak]

@@markg1051 I didn't personally do any measurements... just rounded up info on various 12" guitar speakers to see what numbers they range between. I think you are correct about the magnet & voice coil assembly. Seems that is partly how they tune a speaker to have a certain frequency response. Your findings are interesting. It seems to support my current theory of the seven inductors simulating "back EMF", otherwise known as counter electromotive force. I guess that amount of inductance you measured is about what you would get from a speaker at loud sound levels pushing a lot of air? If that was Allan's thinking, it could explain why there are seven inductors in these things.

[@carbonsnail014]

@Vegas Cycling Freak: Last night, I watched some of your Summerlin 215 Beltway riding uploads from 4 years back. Time flies by fast. It doesn't seem like it's been that long since you posted these. Hey, in the future, can you make one riding from the intersection of N. Rampart and W. Lake Mead Blvd up towards the 215fwy? I'm looking at a condo that is on the right-hand side of Lake Mead Blvd. Thanks again. Stay safe and healthy.

[@VegasCyclingFreak]

I did one a long time ago. Not fun going up Lake Mead between the cars going 60 MPH in 45 MPH zone and 800 ft of climbing in 3.5-4 miles. The 215 trail is nice to have but it could be a lot better.

[@carbonsnail014]

@@VegasCyclingFreak: Thank you. I'll search your uploads and find it. Stay safe.

[@hadleymanmusic]

14:20 why its wound tight? As one continuous resistance?

[@VegasCyclingFreak]

Did you not see the first few minutes of this video where I showed that the coils being close or even completely touching makes almost no difference? Nichrome wire is dozens of times less conductive than copper wire. Also, I'm just replicating what Allan did in his units. You could slide a piece of paper in between the coils on the real one or my "replica".

[@ludmilascoles1195]

Considering nicrome wires a non ohmeric conductor what else did you expect heating it up? This is why they use it in toasters. I think you should do a little more background reading on physics

[@VegasCyclingFreak]

At what point is a conductor considered non-ohmic? The resistance of nichrome wire *almost* does not change with a change in current and voltage - but it does change a small amount as temperature increases. Tungsten is definitely a non-ohmic conductor. All of the charts I can find regarding resistance start at 400 deg F with some amount of current in a certain gage wire at a certain AC line voltage. I was trying to determine what, if anything, happens at low temperature of 150-200 degrees, where there is no data available. I don't have a good way to pump 3-4 amps thru these coils.

[@ludmilascoles1195]

@@VegasCyclingFreak yes that is my point you would need a much much larger heater the effect it. Goodness only knows how many amps to hear a thick wire like that to red hot 🥵 Maybe in the original design the designer was trying to use that property?...

[@VegasCyclingFreak]

@@ludmilascoles1195 Probably would take 6-7 amps to get it red hot. In this application I think it would only be dealing with maybe 2-3 amps at the most. Depends on how hard you want to be on your guitar amp. I don't know why he liked the nichrome wire... he must have had a reason. Your guess is as good as mine.

[@Jonathan_Doe_]

Are you 100% sure the coils are all supposed to be in series?

[@VegasCyclingFreak]

@@Jonathan_Doe_ Yes

[@markg1051]

If you want to see how much the nichrome coil resistance changes with temperature best way I can think of is to pass enough current to heat it up uniformly. Start by measuring the cold/ambient temperature resistance of the coil. Then wire a 5 or 10 watt 0.1 ohm resistor in series with the nichrome coil, the higher the nichrome wire resistance above the 0.1 ohm resistors the better, as this will ensure all or most of the heat will be in the nichrome and not in the 0.1 ohm. Connect two DC voltmeters, one across the nichrome coil and the other across the 0.1 ohm resistor. The voltage across the 0.1 ohm will tell you how much current is flowing from I = V/R while the other will give you the ohms of nichrome from Vnichrome/I, you will also know the watts disipated by the nichrome coil by multiplying the voltage across it with the current through it.

[@VegasCyclingFreak]

Yeah... problem is I don't really have anything that can pump enough current thru it to heat it up. I think it would take roughly 3 amps or so to heat these coils up to 200 degrees.

[@markg1051]

@@VegasCyclingFreak if you uave a 12 volt car battery and you wind a 4 ohm nichrome coil you will get 3 amps if the resistance remains at 4 ohms, but will settle at something less than 3 amps if the resistance rises which I suspect it will do as it heats up.

[@VegasCyclingFreak]

@@markg1051 ha ha why didn't I think of that? I may give that a try. Thanks...

[@infectionsman]

Did you ever confirm the inductance value of the inductors from one of Alan's harness units?

[@VegasCyclingFreak]

No but on one of his personal units "1mH chokes" is scribbled on top with marker. Based on that I think it's likely that is what he used in all the units he made but I'm still working on trying to get that verified. Don't know if I'll ever get confirmation on that.

[@augustusbetucius2931]

Do you think the 10mH inductance was intentional? I kind of hope there is a part IV, after you miraculously acquire an actual Harness of your own. So, do you still feel these units are unsafe to use with an amp? I have been entertaining getting another Harness for a few years now, but after these videos, I'm not so sure. As an aside, you said Allan wasn't a guitar pedal guy. I'm not so sure. For a long time, he had a number of pedals on a small board that he put on a table top beside him, when playing live. So, he did use the Magic Stomp and that Yamaha multi delay pedal. He didn't use overdrive pedals, as far as I know. Yet J. Rockett made a signature overdrive for Allan. Did Allan even ever actually use one of those? I wonder. Anyway, really cool and very interesting videos. Liked the needle across the vinyl record sound during one of the transitions. Nice touch. I wonder how many people actually know that sound anymore... FYI, my Harness II didn't have the toggle switch on the front like the one in your video did.

[@VegasCyclingFreak]

Yeah in later years he did have a few pedals, after the huge rack unit days were over. I meant by my statement that he didn't use some kind of distortion pedal, it came from the amp. J Rockett did make that signature pedal but I don't know that he ever used it. If he did it would have been mostly as a booster. My understanding is that only a few of the Harness II units had the pad switch. "Unsafe" is a relative term. If people are giving you amps that's one thing... blow up one and another one will come your way soon. If you live in a place with an ever increasingly higher cost of living with your pay not going up with it, well then any amp that blows up is kind of big deal to replace. I think it's generally safe if you don't "dime" everything and use it for 6-8 hours straight. You're supposed to use your amp as you normally would. Anyway, I have an idea about possibly acquiring one, or most of one. Will look into that. My circuit isn't built per a verified schematic, so I am reticent to connect it to any of my amps. If I am correct about the 1mH inductors is still unverified. Yes, I believe it was intentional to use seven of them. Thing is when you take an air core inductor and mount it onto a metal baseplate with steel screws and large fender washers, it increases the inductance. So the (7) 1mH inductors add up to 10mH. That would increase somewhat with a steel baseplate. Don't know how much... maybe another 5-7% or something like that.

[@666pinkster]

Hey Paul man try using a 9 volt battery across the nichrome wire I bet you that'll make it heat up

[@VegasCyclingFreak]

Need about 3 amps…

[@chembrew1822]

Time to find an amp and try it. Worst case is You can fix your mistakes. Not using it is also a mistake. What would Allen do? He Most likely fried an amp or two prior to getting anywhere near where you are in his ideas. Rock on.

[@12afael]

same as with his music it is hard to understand what Allan wanted to do with it. you did not have the function generators syncronized there will be some error on the freq or time and they would produce that phase effect. I´m not sure you measured the impedance correctly that diagram is misleading. you need some resistance to be able to measure the voltage in it (both ends) to calculate the current and the voltage through the harness. you don´t need a load resistor and the variable resistor should not be changed during the measurement. usually a 100ohm fix resistor should work ok. I´m thinking that maybe you measured the impedance adding that extra resistance. the coils and the nichrom wire should not be that high.

[@12afael]

what value you get if you just use a DMM to measure resistance? that should be the DC resistance.

[@VegasCyclingFreak]

@@12afael Basically it's "Craig Anderton method" of determining input impedance - feed circuit a signal of 1-2 volts PTP, change the variable resistor until the voltage is exactly half of the voltage and then measure the resistance across the pot (wired as a variable resistor) after disconnecting from the circuit (that's what all the switches were for on that gizmo I made). Allegedly at this point the impedance and resistance are approx. equal. Towards the end I showed the online calculator thing- DC resistance measured around 10 ohms. Seven inductors each at 0.73 ohms (per the labels on them), one nichrome element out of circuit is 2.7 ohms and the other one is 3.1 ohms. DCR changes slightly every time I mess with disconnecting/reconnecting the nichrome coils. The apparent inductance I measured across the spkr in jack was 10mH. I just threw the phasing thing in there because it was an interesting accident. I came to another realization today - I think he may have been trying to emulate the "back EMF" of the speaker(s) with the inductors. May explain why there's seven of them? Almost like inductor based limiting if you will.