Hi all.
What i have done to Dr Boogey is that i have replaced regular fet gain stages with SRPP. Which is not only self basing but also noiseless and more high gain.
Also I and most of the users on this forum experienced that tonestack of Dr Boogey is useless. So i decided remove that passive marshall/fender/mesa tonestack and replace that with an active one. A good one is ROG's Tone Mender.
Here with new mesa without Tonestack.
(http://img269.imageshack.us/img269/1598/mesanew.th.png) (http://img269.imageshack.us/i/mesanew.png/)
(It is copy of gaussmarkov/Electric labs schematic. But this is new version with SRPP)
I need your comments, suggestions and advice for this.
Could you show the part values ?
Sounds very interesting. I did the Dr Boogey and replace the complete tonesatck with a few filters.
Alf
of tonemender?
(http://www.runoffgroove.com/tonemender.png)
Output from mesa will be its input. This will give you complete preamp.
(http://img9.imageshack.us/img9/4027/setupe.png)
(from runoffgroove)
http://www.runoffgroove.com/tonemender.html
@OP:
You have weird / bad connections in your schematic: Q3, C8 --> R10, R11
Thanks you :) I corrected it : :icon_exclaim:
(http://img23.imageshack.us/img23/1598/mesanew.th.png) (http://img23.imageshack.us/i/mesanew.png/)
if youre using the tone mender, you don´t need the last fet buffer..the tone mender has its own buffer
Quoteif youre using the tone mender, you don´t need the last fet buffer..the tone mender has its own buffer
Thanks daniel. 8)
Anymore error or suggestion please!!!
Would anyone be so kind to make a perfboard version?
I would like to build one, but I'm a complete newbie. I'll start a topic about my build.
Jeroen
Quote from: jerrepain on November 08, 2009, 11:25:00 AM
Would anyone be so kind to make a perfboard version?
I would like to build one, but I'm a complete newbie. I'll start a topic about my build.
Jeroen
Then you have to wait. because this is not tested yet. If you still want a Dr boogey you can make gaussmarkov's version.
Schematic Revised.
(http://img687.imageshack.us/img687/6647/mesarevised.th.png) (http://img687.imageshack.us/i/mesarevised.png/)
just curious, but why did you remove the source follower (last fet)? It's not a part of tone stack and if it's anything like the real tube circuit, a follower will have a great impact on the tone. Another bonus is lower output impedance. I'd leave it in.
i suggested to eliminate the source follower since the tonemender already has one..
Interested to hear how it works. The DB has a little too much gain anyway.
With the added gain of the SRPP I wonder if it will be even more prone to oscillate?
John
TOO MUCH GAIN?!
huh. Interesting concept.
:)
I am thinking of adding a switch to simulate orange and red channel. Orange will use 3stages and Red will use 4 stages like a hell :icon_evil:.
yes, i think 4 srpp on cascade is playing with disaster on gain. an input attenuator and regulating the gain between stages may be a solution for that..
bsiab has 2 muamps and its quite high gain..imagine 4..it´s like 2 bsiab on series.. i don´t get this pushing and pushing to improve dr boogie, it sounds pretty good as it is..some people don´t get that fets are fets, and tubes are tubes, and doesn´t matter how much you tweak, you´ll NEVER make it sound exactly like a dual rectifier.. there are so many other different, easier, and efficient ways to design and build great distortion pedals that don´t need gazzillions fets and eternal tweaking..cmos, opamps, diodes, etc. If you know what youré doing, you can get a better sounding distortion with half of the parts..
Quote from: dschwartz on November 08, 2009, 07:05:53 PM
i suggested to eliminate the source follower since the tonemender already has one..
it's not only about buffer, it's probably contributing to overdrive. Tonemender has IC buffer which wont clip the same way.
Quote from: bancika on November 09, 2009, 04:58:01 AM
Quote from: dschwartz on November 08, 2009, 07:05:53 PM
i suggested to eliminate the source follower since the tonemender already has one..
it's not only about buffer, it's probably contributing to overdrive. Tonemender has IC buffer which wont clip the same way.
I will try both.
Anyway thanks for suggestion.
This is design not final. So I only want improvements and suggestions of expert. Any thing else you may wan to point you will be more than welcome.
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.
That's a good point. I don't like BMT tone stack too much on my boogey either because it's not flexible enough...but I don't see how I can be much happier with Tonemender either because it's similar. Maybe a graphic EQ is what you need..I ordered mxr 6 band eq recently, can't wait to try it.
Quote from: anchovie on November 09, 2009, 06:41:54 AM
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.
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.
Quote from: ubaid88 on November 09, 2009, 07:24:56 AM
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.
Quote from: anchovie on November 09, 2009, 08:03:47 AM
Quote from: ubaid88 on November 09, 2009, 07:24:56 AM
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.
(http://img408.imageshack.us/img408/1705/mesafethn5mod.th.jpg) (http://img408.imageshack.us/i/mesafethn5mod.jpg/)
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. :icon_rolleyes: 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 (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 (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=78782.msg649726#msg649726)
http://www.diystompboxes.com/smfforum/index.php?topic=75716.0 (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 (http://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...
Thanks Liquids.
You gave lots interesting suggestion and most are them very helpful to me. Specially your Tonestack one.
I can't see the schematic at work, but IIRC it did not use Noiseless Biasing on the Mu amps. :icon_cool:
Ok here 2 type Baxandall Tone Controls from carvin amps.
Passive one
(http://img517.imageshack.us/img517/3282/carvintonestack.png)
Active one
(http://img262.imageshack.us/img262/3676/carvin2.png)
Check them, if there is anything wrong or missing in them. I will use active.
And If we use a presence control like the AMZ presence control?
http://www.muzique.com/lab/tone3.htm
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..
Hi ubaid88, were you able to build a proto of this build? Guys? Anyone? Thanks. :)