Welcome, Guest. Please login or register.

November 26, 2020, 06:14:36 PM

Login with username, password and session length

Recent Posts

 

Author Topic: Another guitar tone control  (Read 7755 times)

kikey

  • Regular
  • **
  • Posts: 18
  • Chip Points: 1
    • View Profile
Another guitar tone control
« on: January 05, 2010, 08:52:05 PM »
Here is a circuit I have found interesting.

It is simply an enhanced version of the classic FMV tone stack but without its weaknesses.

First a standard baxandall bass/treble circuit then a mid control allowing only a mid cut to get "scooped" tone.
The advantages are:
- The pot settings do not depend of each other.
- No signal loss.
- Bass/treble boost and cut can be set.
- A constant Q mid scoop.

The circuit can easily be tweaked to simulate any FMV tone stack.
Q (the bandwidth) can be adjusted with R and the frequency with C.


« Last Edit: January 06, 2010, 12:46:18 PM by kikey »

phatt

  • Legendary
  • ******
  • Posts: 2148
  • Chip Points: 262
    • View Profile
Re: Another guitar tone control
« Reply #1 on: January 05, 2010, 11:11:40 PM »
Hi kikey,
           Just done a quick simulation and not impressed.
Giving only 3Db Boost/cut @100Hz and 7Db Boost/cut @ 2kHz.

The Mid sweep is looking like real trouble I can't get a decent mid cut or boost in the audio range and changing values around does little to improve it.
I may have missed something but won't work for me. :'(

If you want to mess around get a bread board and test each new circuit you find.  It's hard work and time consuming but well worth it.
Or cheat a bit like I did and use both a *bread board and a Software simulator*
That way you can weed out the crap a lot faster.
When you do find a sim that looks good you can bread board test it and hear if it does actually sound impressive. 

Frankly my 3rd option is going to save you from years of frustration,
Build my *PhAbbTone box* as I've spent *Many Years* working out the best tone stacks for guitar.

If you feel like I'm bragging a bit,, well I make no apoligies as I've spent years building all these friggin circuits and Although I'm not the most qualified nerd on the planet I've *Done the Time* and put in the hard yards.

If you still need extra EQ after PhAbbTone then a simple graphic (after distortion box) will work wonders.
If you are interested the circuit complete with plots is found here;
http://www.ssguitar.com/index.php?topic=1136.0http://

I'm about to post some sound samples of my whole setup so you might like to hear it.
Phil.

kikey

  • Regular
  • **
  • Posts: 18
  • Chip Points: 1
    • View Profile
Re: Another guitar tone control
« Reply #2 on: January 06, 2010, 08:52:39 AM »
The mid control functions ok to me.
You can also change the values of C and R.
See plot below.

The bass-treble is a standard circuit.
I found this one at this site: www.techniguitare.com
Use another bass-treble circuit if you like.
I admit, I have not simulated this one.

J M Fahey

  • SSGuitar Global Mod
  • Legendary
  • ****
  • Posts: 4142
  • Chip Points: 429
    • View Profile
Re: Another guitar tone control
« Reply #3 on: January 06, 2010, 12:54:59 PM »
Hi Kikey.
The schematic posted has a couple of small typos, which surely account for the response found by Phatt's simulation.:
1)The treble/bass labels are inverted: top one is Bass, bottom one is Treble.
2) C2 (10n) should be a resistor, 10k to 22K . A capacitor there (as drawn) will kill or severely hamper the action of treble control.
3) The mid control implementation is unusual, but it should work as cut-only; with a couple extra components it would be boost/cut, but anyway, if you like it as-is, good.
4) Without simulation , I'm too old for that, I can still see that the mid notch can be around -20dB, as posted. (200 ohms/4k7)
Can you please post the direct link into Technoguitare leading to it?
(Oui, je peut lire en Fran├žais)
Thanks.

kikey

  • Regular
  • **
  • Posts: 18
  • Chip Points: 1
    • View Profile
Re: Another guitar tone control
« Reply #4 on: January 06, 2010, 04:11:44 PM »
1)The treble/bass labels are inverted: top one is Bass, bottom one is Treble.
2) C2 (10n) should be a resistor, 10k to 22K . A capacitor there (as drawn) will kill or severely hamper the action of treble control.
3) The mid control implementation is unusual, but it should work as cut-only; with a couple extra components it would be boost/cut, but anyway, if you like it as-is, good.
4) Without simulation , I'm too old for that, I can still see that the mid notch can be around -20dB, as posted. (200 ohms/4k7)

Thank you for your comments!
I was a little too fast when posting this schematic  :)
1 + 2) Yes, that Baxandall network was strange to start with and even worse since I made some errors in the schematic. xP
That circuit comes originally from this document:http://www.techniguitare.com/projets/ChaosPreamp/Preamp-Schems-V1.1-En.pdf Page 4.
I find that document ambitious and interesting. Especially the pre/post filtering.
3 + 4) I think this mid control is nice since it got constant Q (bandwidth) and allows for a narrow bandwidth cut.
I agree with Phatt that this type of narrow bandwidth cut sounds great.
A narrow band boost is not as nice...

I am working on an updated schematic.

phatt

  • Legendary
  • ******
  • Posts: 2148
  • Chip Points: 262
    • View Profile
Re: Another guitar tone control
« Reply #5 on: January 07, 2010, 06:01:12 AM »
Hi kikey,
           I was interested because it looked like it would impart a similar curve response like my PhAbbTone box and I wanted to sim the two shapes to see if there was any better performance.

So I've done the best I can to make it work.
I've Simmed the original you refered to as shown by *Daniele Savio* (GREEN trace)
   (The YELLOW Trace is as per your posting).

And here is the result, I've added the PhAbbtone response (BLUE Trace)
to give you some idea of what goes on.

I lack the knowledge to be able to forsee the deeper technical errors so it maybe capable of far better.

Re Daniele Savio's Universal Guitar preamp stuff.
I've never built it so I can't speak for it.

I will say that it's very complex compared to my setup.
Geez He's got 32 knobs on the front panel!! And I was concerned that mine with 7 knobs and a 7 band graphic was to much. :lmao:

Note the otherwise flat response of Active baxendall type tone circuits when compared to the PhAbbTone Rounded response.
ie, flat line boost all the way down to DC,, to the best of my understanding this is good for HiFi and likely close to useless for guitar.

A little side note,
If you care to simulate the classic Valve circuits you will see that most have Massive Bass response in the prestages but often have quite dramatic rolloff below 100Hz at the power Tubes. (ie, 40 to 60Db down at 10Hz)

Generally SS Guitar Amps have all the rolloff in the pre stages and Close to nil in the powerstage., almost the oppisite.
I can't prove anything as I'm no maths expert but I have a hunch it does effect the final result some what.
Thank for posting it all, Have fun Phil.

kikey

  • Regular
  • **
  • Posts: 18
  • Chip Points: 1
    • View Profile
Re: Another guitar tone control
« Reply #6 on: January 07, 2010, 09:50:35 AM »
Hi

Here is my latest sim.
I hope I got it right this time  ::)
I am sure it can be tweaked some more.
It got some similarities with the resonse of your PhAbbTone.

Phatt, I do not think this circuit is better or worse than other tone controls.
I am no expert but I think it got some nice details.
Its just a circuit idea. ;)

The nice thing about trying out these circuits is the knowledge you get about what is needed to create the sound you want. To me it seems much harder to create a good sound with a ss-amp than with a tube amp. But on the other hand you can really fine-tune your design in an easy way. 8)
Many people like their boutique (ss)stompboxes but tend to prefer their tube amps for poweramp.
I suppose tube amps got its own characteristics when it comes to damping-factors, distortion and power supply sagging...
When simulating these charcteristics I think this post was interesting:
http://www.ssguitar.com/index.php?topic=1177.0
Unfortunately the sound clips are gone :'(

There are MANY ways to go when it comes to creating a good guitar sound and the sound some people like is terrible to others, its about taste. :loco


phatt

  • Legendary
  • ******
  • Posts: 2148
  • Chip Points: 262
    • View Profile
Re: Another guitar tone control
« Reply #7 on: January 09, 2010, 08:23:22 AM »
Hi kikey,

"There are MANY ways to go when it comes to creating a good guitar sound and the sound some people like is terrible to others, its about taste. "

I Agree. :tu:

Only When you build it then you will know,, sadly you can't hear simulations. :'(

Problem for me is that a lot of circuits work BUT more often than not there is something that's not quite right and you only notice it *After* all the hard work of building it all.

Notice I did not post my Tone box untill I had built and sold 7 of them to mostly *Working* musicians.

If I posted all my ideas I would fill all the pages with circuits that at the time seems like they had potential but now reside in the bottom of my spare parts bin.  ;)

Heck it took me 10 friggin long years of painstaking doggered persistance just to perfect a SS stand alone reverb unit. It was disaster a plenty for 7 years or so but I picked up books (that may as well have been written in hyrogliphics) but ever so slowly I absorbed some of it ,,, well enough to at least build equipment that when displayed at my local music club turns heads a plenty.

Call me slow :lmao: But Geewizz I learnt so much from that experience by not giving up.

I agree if it works as your graph shows it will indeed come close to what you want.

The **Arh Huh** moment for me was when I was able to grasp that it is a culmination of tone shapes (Not just one Wizz kid circuit at one point in the signal path)

It's simply creating a shape that is then imposed onto another tone shape and so on.
Knowing just which part to tweak at which point in the magical mystery signal path is the hard bit. :loco

My Amp setup is the tone box shaping into a simple limiter clipper then the *big mid boost* which is the shaping of Valve power stages.
OK it's just a cab sim circuit but I find that misleading as both F and M type amps have similar tone shaping in the power stages, just more noticed in marshalls.
(speaker design also plays a part)

The rest is of course just simple Graphic EQ.

Other roads will likely lead to the same end,, I just find my way works for me and *importantly* it's not beyond the novice guitar player to grasp the concept.

Then the bonus,, it can be done with relitively cheap gear that may already be laying around in your pile of collected gear.

A point that may interest you;
I Swap the *Clipper and Cabsim* for a small EL84 Tube amp and that becomes my *ReAmp system*.

*Reamp* meaning resistive loading the speaker terminal of tubeamp output and tapping off a line level.
It's debateable which sound better. 0:)

My thought's,, it's just different.
Cheers, Phil.