New Design of Dr Boogey. Noiseless and Effective Tonestack.

[ubaid88]

If you feel the original Dr Boogey tonestack is "useless" (you may have to expand on that description to give a clearer idea of what you don't like about it) then I'm not sure that you'll like it running into a Tonemender either. Perhaps what you don't like is having an amp-style tonestack running into an amp with another tonestack of its own, given the mid-scoop that occurs will be happening twice. The Tonemender just has a recovery gain stage at the output - the treble/middle/bass topology is essentially the same as what's already in the Boogey.

Something like Mark Hammer's Stupidly Wonderful Tone Control might be all you need.

I want something like.
I will be using Dr Boogey alone as preamp for chip/mosfet power amp or with cab sim. Not as effect pedal. So i want responsive tone control which Dr Boogey lacks. Problem with Dr Boogey is that its mid is kind of master tone control, bass is not responsive at all and treble dont help much. If you search in this forum you find lots of similar experiences. If i was using this with another preamp then i had no reason to complain. I want Dr Boogey with better eq controls. Becuase of this i removed its passive and want to replace with active one.

You may suggest any other improvement or solution for this.

[bancika]

I'm using my DrBoogey directly into palmer pdi-09 speaker simulator, so we're kinda in the same boat. I find it hard to dial exactly what I want with standard tone stack...hopefully graphic EQ will solve it.

[anchovie]

Becuase of this i removed its passive and want to replace with active one.

The issue isn't whether it's passive or active - putting a gain stage after a Marshall tonestack gives you the same frequency response with a higher output. Perhaps you could dowload Duncan's Tone Stack Calculator and play with the resistor/cap/pot values to see how the response changes.

[ubaid88]

Becuase of this i removed its passive and want to replace with active one.

The issue isn't whether it's passive or active - putting a gain stage after a Marshall tonestack gives you the same frequency response with a higher output. Perhaps you could dowload Duncan's Tone Stack Calculator and play with the resistor/cap/pot values to see how the response changes.

I think this tonestack is not that much successful in fet sim of tube. dschwartz and few more suggested that if this tonestack type is replaced baxandall type with opamp buffer before and after. Then it will works better. Tonemender is an example of that.
Also in my previous version of Dr Boogey i have already used your suggested method see this. But it didn't do much. I not was satisfied by it.

[liquids]

I've never played a Dr boogey, but here is my two cents since I was asked by ubaid88....

1) It may indeed have two much gain.  SRPPs are indeedy high in gain, but controllable. Especially with that many stages and J201s, which is a jfet who's clipping, and tone especially, I personally hate.   I'd start with MPF102s or 2N5459s in all those the SRPP stages, which are a bit 'cleaner' and closer to tubes to my ears in these scenarios.  If you somehow needed more gain after that, upgrade to 2N5058s and then 2N5457s, with progressively more gain.   But you should have plenty.  Likewise, maybe try three stages first...

2) Counterpoint to Daniel (dschwartz), The BSIAB is high gain with 2 mu-amp stages, but it does have 3 stages of gain since the 2nd mu-stage is followed by a trimmer fet gain stage (not cathode bypass).  Still, most people find it has too much gain, keep in mind.   That being said, you may want to start with just 3 SRPP stages and see what gain range that yields you.  Especially comparing what gain ranges you get by using all MPF102s to 2N5057s.  That may make nearly as significant much difference in gain as how many stages you have...but with J201s, I can't imagine 4 stages slamming each other.  There is an awful sound in my head.      Metal indeed, mixed with uncontrollable oscillations, feedback and buzzzzzzzzzzzzz......  

However, if you like the compression and sound of 4 stages, you might simply want to consider adding a second 'gain' pot.  I've cascaded two (heavily modded, lower gain) BSIABs on occasion and it is indeed my 'mesa lead' sound when I want to be cheeky.  But keep in mind that the output of the first is set for unity gain with my clean tone, into the second BSIAB...  so try that too, maybe. A second gain pot between the third and four stage might prove useful.   As would a lot of filtering...

3) All that gain will yield a lot of high end.  JFET stages are nicer when clipped, but still have a lot of buzz.  More tube like when filtered.  Especially J201s.   You probably want some serious high frequency filtering before you even hit an EQ stage, if not inter-stage filtering of high end.  Common would be a single or pair of 10k/2.2n low pass resistors, to start. Change values from there by ear...   It might be wise to place some major low pass filtering before any buffer you use, before going to the true 'tone stack.'   Experiment.

4) The Tonemender is NOT an active tone stack!  Its a buffer, feeding a Fender/Marshall/Vox tonestack with a gain recovery stage. That doesn't make it truly active, it just means it has gain compensation for tone loss.   The focus is mid scoop, and the tone controls are highly interactive.

I think, since you want a mesa sound, you want a way to truly boost lows after all that tight low end.  That is my recent experience, especially for a 'huge rectifier' sound, you may want an ACTIVE bass boost that is not interactive with other frequencies or tone controls, primarily.  Your amp already has a passive EQ undoubetly, and you'll probably need something that can do serious work (like +/- 15db) on the highs and lows EQ to get a clean amp having the EQ curve of a recto, a low volumes.    

Seek out the active Baxandall:
http://sound.westhost.com/dwopa2.htm#baxandall

and the active tone stack in the Boss FA-1 (james/bandall).  http://sound.westhost.com/dwopa2.htm#baxandall


Theres a lot that can be done here.  With the FA-1 variation (looks closer to the passive james tonestack, but is much flat and less interactive)  you can even sculpt it so the frequencies you cut bass are different than the freq you boost bass, likewise with treble...though the FA-1 didn't utilize that in their version, and they use just equal value caps on the pots...

5) Likewise, if you go with a true active tone stack, you may either want at least a simple, passive (or active) way to control/scoop mids.   On that topic, you might find these threads interesting:

http://www.diystompboxes.com/smfforum/index.php?topic=78782.msg649726#msg649726
http://www.diystompboxes.com/smfforum/index.php?topic=75716.0

or this schematic:
freecircuitdiagram.com/wp-content/uploads/2008/11/3-band-graphic-equalizer-circuit.jpg

That's a boatload of information.   But really, you need to experiment with all these and see what sounds best to you...

[ubaid88]

Thanks Liquids.

You gave lots interesting suggestion and most are them very helpful to me. Specially your Tonestack one.

[WGTP]

I can't see the schematic at work, but IIRC it did not use Noiseless Biasing on the Mu amps.   

[ubaid88]

Ok here 2 type Baxandall Tone Controls from carvin amps.

Passive one

Active one

Check them, if there is anything wrong or missing in them. I will use active.

[Vicus]

And If we use a presence control like the AMZ presence control?
http://www.muzique.com/lab/tone3.htm

[dschwartz]

it will work like a tone control more effectivelly, but it will affect the character of the pedal greatly..
IMHO the tonestack defines most of the sound of an amp.
with the BMP tone control, the dr boogie will sound closer to a BMP than a boogie. unless you twak the bmp tone controll ro mimic the freq response of the FMV tonestack on the boogie.
..think scoop around 500hz..

[coolestmaster]

Hi ubaid88, were you able to build a proto of this build? Guys? Anyone? Thanks.