1. ottobahn

    ottobahn Guest

    Has anyone ever heard of the Magical 6 as it relates to Fender and Music Man amps?

    I swear this really works.

    This is written by Bjorn Juhl (a Swedish amp guru):

    ------------------------
    It was some time in 1979 when one of the "big guys" showed me how to dial in that Fender or Music Man amp that always seemed to be on stage where ever you played: "Easy" he said. "It's the magic six". Volume to 6, Treble to 6, Middle to 3 and Bass to 2 (6, 6, and 3x2=6). Bright should be on, reverb set for two and master volume (if one) set so that you can be heard above the drums without drenching the vocals. "The rest of the knobs you can just ignore" because no one used tremolo in late 70's and the footswitch was always disappearedÂ…
    The effect was almost like having the key to Holy Grail - I have to admit that he was right and I joined the Magical Six Choir.

    It wasn't until years later, when I was absorbing schematics that I understood why there is magic in the six. In an amplifier with the topology input stage, tone control, volume control, voltage amplifier (tremolo- and reverb amplifier if fitted), phase splitter and output stage it is the first four controls that will set what is going to distort and how much.

    The first stage runs essentially clean if nothing else but a guitar is connected.
    The voltage amplifier will hit the ceiling as volume is turned pass 4.
    The tone controls are placed before the volume control and will control what is being fed into it.

    The purpose of the setting Treble=6, Middle=3 and Bass=2 is to:

    1. Cut a bit of bass to get balance between high E-string and low E-string distortion. The bass-frequencies will have overtones far up in the midrange and may therefore build into disturbing high overtones that can make certain chords (D7) sound out of tune on the top three strings. Some amps will even oscillate when exposed to the combination of high amplification and lots of bass.


    2. To control "The Mud Frequency 249,5Hz". Too much of this frequency and the tone will be muddy and too little and it will sound hollow and thin.


    3. Cut some midrange (approx. 340Hz) to gain output power while keeping inter-modulation distortion at a minimum. Amplification factor will also be highest in the treble (above 2 kHz) and that is compensating the treble-loss of passive pickups. Open E-strings (high and low) played at the same time should now have approximately the same volume level with little more distortion on the top-string. Both strings should be clearly recognizable.

    Inter-modulation distortion is a sort of mathematical distortion in that the sum and difference of two incoming frequencies are obtained as harmonics and will therefore build up so called "ghost notes" (these are notes that are not played and that are not in musical relation to the notes played). This can make certain chords sound dissonant as opposed to what we know as harmonic distortion where overtones follow the pattern of 2x, 3x, 4x.. in upper frequency, something that makes the probability of so called ghost notes being produced a lot lower.

    The risk of inter-modulation distortion is quite high on Fender amps, mostly because of the working-points of the different stages.
    Ironically enough some of the modifications that were performed at the factory to reduce the total amount of distortion will, while reducing total distortion, rise the amount of 7th overtone, which is said to be the least pleasing of all.


    4. Obtaining the correct treble response on most amplifiers made for guitar the treble-control does not work the same way as on your Hi-Fi, regulating the amount of treble. On guitar-amps the position of Treble-knob will very much affect to bass and midrange and it works more like a balance between bass and treble. In fact the tone stack system as used in most amplifiers is derived from a so called "Baxendall type" Hi-Fi circuit. Treble has been set to full while an isolation resistor often placed between the treble and bass controls is used to control treble (or actually tone balance between treble and bass).
    Balance is obtained when the treble pot is in it electrical center - that is between 5 and 7 depending on the taper on the pot. Final regulation of treble is best to be done with the bright-switch.
    The bright-switch seems to work best if the volume is set to between 5 and 7.


    5. If the volume-control is set to 6, stage #2 will be fed from highest possible impedance and there will be certain current limitation. Stage #2 will also be fed with as much as it can take without getting some rather odd distortion as feedback (Durchgriff) through B+ tree that is appropriated as the true distortion generator is the stage #3 (reverb-mix amp)
    Where some peculiarities take place such as rectifier action between grid and cathode and glazing-spikes because of cathode decoupling etcÂ…


    6. And so 6, 6, 3, 2 (2x3=6) The Magical number 6.


    This is a fairly accurate translation of an article in Fuzz-magazine #1 2002
     
  2. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    It's a load of crap.

    For a start, the Deluxe, Vibrolux and other amps with 'no' midrange control do in fact have one - it's a preset resistor inside, the equivalent of the midrange knob set at 7, not 3 - and these amps are highly thought of.

    Secondly, it's purely dependent on personal taste, what guitar you're using, what effects (if any), what room you're in, and what volume you want to play at. What if you don't want to play at a volume of 6? You then may need the tone controls set differently too.

    Treble 6, mid 3, bass 2 would be horribly thin and treble for my taste.

    Use your ears, listen to what each of the controls do, and set them to give the sound YOU need, and forget this sort of numerology BS.

    FWIW, my favorite setting on a Twin Reverb is 5/5/5/5, bright switch OFF, tremolo ON (subtly) and reverb on about 3. Why? Because it sounds best like that to me, not because I think the number 5 is 'magic'.

    [/pet peeve]
     
  3. ottobahn

    ottobahn Guest

    I certainly would not characterize it as "numerology". The numbers just seem to work out that way. Besides, the article states that the volume and treble sound best between 5 & 7 with bright on. With single coils I usually turn the bass up to 3 anyway.

    That comes very close to your 5,5,5,5. Try turning your bright switch to 'on' and drop your mids to 3. You might like it.

    I adjust my overall output with my Tube Zone volume control as 6 is a bit too loud from a Twin Reverb in the environment I play in.

    People at HC have tried it and said they like that setup a lot. I would use it as a benchmark and go from there. Give it a try before you dismiss it as "crap".

    BTW, I downloaded a couple of your band's tracks. I like your playing. Very tasteful.
     
  4. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    No, I do not like it. I am very familiar with the controls on Twin Reverbs (and other Fenders), and I've probably been through all the combinations - I do with most amps, although I definitely have 'go to' settings with ones I'm familiar with.

    I'm dismissing it as crap because it implies there is some kind of scientific basis behind setting the controls in what is a purely personal-preference way... which produces a tone I don't personally like - I have tried it.

    It's numerology because it uses "3x2=6" to justify calling it 'magical 6'. That has as little real meaning as saying that if I set my volume to 5, treble to 5, mid to 10 and bass to 2, that's "magical 5" because 10/2=5. You can make spurious patterns out of numbers in an infinite number of ways.

    Also, the controls on most amps are interactive and don't have precise frequency centers like "249,5Hz", their range and effect varies depending on the settings of the others. There is also quite a lot of difference in basic tonality between (say) a Twin and a Super, so the same control settings will give different tones anyway.


    Thank you! :)

    Just for interest (not to prove a point, it isn't a Fender amp anyway) a lot of the tone settings I used are different from my 'go to' gig ones. I simply set the amp how I wanted it to sound at the time in the studio... that's what the knobs are for! There are no 'magic' settings that cover all situations, styles, and players.
     
  5. TheAmpNerd

    TheAmpNerd Member

    Messages:
    1,062
    Joined:
    Sep 23, 2004
    Location:
    Tejas
    Oh come on John,
    tell us what you really think!

    I really want you to put your Twin volume
    on 6, treble on 6, mid on 3 and bass on 2.

    Holy Smokes.


    Hey Ottobahn, will you volunteer to sit
    3 meters in front and center of the amp?


    I think with the axe on 10 we could hit
    some pretty consistant 130db - 140 dbs.

    Given enough time, one would have to
    keep turning up the treble because you
    would lose your HF hearing. I'm wondering
    if we could center it around 666.666 Hz and
    hear who the great satan really is.
     
  6. hasserl

    hasserl Member

    Messages:
    4,734
    Joined:
    Oct 24, 2004
    Location:
    So Cal
    Besides, most guitar amps DO NOT use a tone stack based on the baxandall stack. Some amps do, but the most common Fender/Marshall type tone stack is far different from a baxandall stack, and responds far differently.

    But I do typically like the Treble set to about 6 - 7, the Bass betweeen 2 - 3, and the mids up around 5 though that will vary depending on the tone I'm reaching for.
     
  7. ottobahn

    ottobahn Guest

    That is why I use the volume control on my Tube Zone as a kind of master volume.
     
  8. mockoman

    mockoman Member

    Messages:
    1,992
    Joined:
    Jun 9, 2005
    Location:
    Beneath the Blue Suburban Skies
    An interviewer once asked Lindsey Buckingham how he approached studio production.

    His reply-"I turn the knobs till it sounds good!"
     

Share This Page