Dr. Boogey clips - here you go

[Bucksears]

Yeah, gain-wise, the 2N5457 is between the MPF102 and J201, but closer to the J. I've heard that the 2N5457 is a little darker-sounding than the J201.
Could try a 2N5457 for both Q1 and Q2?

- Buck

[stumper1]

Bucksears,

Do you have a layout?

Thanks

[Bucksears]

You can download them here:

http://www.4thlevelmedia.com/stompboxes.html

[powerplayj]

Yeah, gain-wise, the 2N5457 is between the MPF102 and J201, but closer to the J. I've heard that the 2N5457 is a little darker-sounding than the J201.
Could try a 2N5457 for both Q1 and Q2?

- Buck

Actually, I stand corrected.  The MPF102 IS the way to go.  I just realized that I not only need to rebias Q1 but the other three transistors as well.  The gain is now equal to the 2N5457 and the circuit is much quieter.  I think I might try the MPF102 for a 2N5457 in the BSIABII and see if it will get rid of the noise that I have always had with that circuit.

[stumper1]

You can download them here:

http://www.4thlevelmedia.com/stompboxes.html

Thank you!!

[stumper1]

Buck'-

I noticed that the PCB and the "Parts Layout" PCB are slightly (after a "quick" look - looked to be the same circuit - didn't trace it ALL the way thru) different.  Any difference? Sugestions, cautions, tips, warnings
Does the Parts Layout still work for "that" PCB Layout?

[Bucksears]

Use the PCB for etching/building the circuit and the Parts Layout for reference.
The differences are that the pads are a little larger on the PCB for some of the off-board connections and the component-to-ground traces across the bottom on the Parts Layout don't connect all the way; it's just because I enlarged the parts layout for easier viewing of the component values. The traces and pads became thinner on the Parts Layout, but the PCB works fine.

- Buck

[kusi]

hi,

do you use 3k9 at the source of the third JFet? in the original Rectifier-circuit, this cathode-resistor have 39k!


best greetings,
markus

[RDV]

hi,

do you use 3k9 at the source of the third JFet? in the original Rectifier-circuit, this cathode-resistor have 39k!


best greetings,
markus

I tried a 39k and it makes it very hard to bias a J201, almost impossible unless you use a larger trimmer there. The Dr. Boogie values are the ones that rock this pedal IMO.

RDV

[mydementia]

Dammit, dammit, dammit...

I just put my second Dr. Boogey together and it squeels like a banshee!!!  I ran wires fairly short and tried an MPF102 in Q1 and then in Q2 - same result.  The tone is EXCELLENT - but when I stop playing, it squeels.  

So...anyone have the magic bullet for this one?  Which wires, specifically, are supposed to be 'short' in high gain circuits?  I get a nice pitch shift in squeel when I turn the treble and mid pots past about 8:00 (6:00 = 0).  When the presence is cranked beyond 12:00 - squeel is worse...when gain is cranked byond 12:00 - squeel is worse.  All the drains biased to 1/2 supply voltatge just fine...I thought I was golden!  I even pulled all the wires away from the board - no change.  I've built a dozen (or more) high gain circuits in my 'career' and have NEVER experienced squeeling like this!

I'm SOOOOO glad I didn't take my first build out of the box to 'finish' it - that one still sounds great...and doesn't squeel!

Any help will be greatly appreciated...
Mike

[RaceDriver205]

I find squeeling can be stopped by keeping the input and output wire as far away from each other as possible. Sheilding them may also stop the squeeling.

[Ardric]

My 2 cents (worth about that much until I build one)...

There's bigger issues than just wiring here.  I'd try these changes...

• Add Miller capacitors on the gates.  Search the forum.  RDV had positive comments on these.
• Filter the power supply.  Look at a real amp schematic for suggestions.  They don't use a single +V for all of the triodes; they use a series of RC (resistor/capacitor) filters.  The ampsim would benefit from the same power scheme.  I'd use smaller value resistors and larger value caps due to the lower voltage... maybe R/10, C*10.  Exact values aren't important.  I bet this would make all the difference.
• Star grounding.

If all that fails, I'd then resort to shielding the offboard wiring and lead dress.  But it shouldn't mattter by then.

[boogietube]

There's a wealth of info here-Thanks guys! I'll try these mods/fixes.  I've got the board done but unpopulated.
My question is what enclosures are you guys putting this in? It doesn't look like it will fit in a 1590bb. Got any pics?
Sean

[markm]

I just gotta say WOW!
This circuit is certainly Very Aggressive.
Nice work guys, not my cup of tea but, I can see why everyone is pumped up about the DB.
Good Job! 

[Bucksears]

FWIW, I'm kinda working on a slightly expanded version of the Dr. Boogey PCB layout. When I was first doing layouts, I was very concerned with getting the whole PCB-as-small-as-possible thing; now, I'm more concerned that the parts are a little too close together and might benefit (noise-wise) from more space.
I'll see if I can add the 'Miller caps' thing as well, if that will help tame it.

It's coming soon, but I have my side-business getting started at the moment.
Thanks,
- Buck

p.s. My Dr. Boogey is in the standard 1590BB, but it's a little tight with 6 controls (2 rows of 3).

[MetalGuy]

I find squeeling can be stopped by keeping the input and output wire as far away from each other as possible.

Same thing here. I'm using taiwanese 1590B and DPDT footswitch. The solder lugs are very close to each other and whenusing the Millenium bypass the Doctor squeals like crazy. My solution: desolder the output lead from the DPDT FS and keep In and Out at least an inch away from each other.

[mydementia]

Still no go...but now I have a new 'feature'... 
When the circuit is bypassed (I always use JD's grounded input switching: http://www.generalguitargadgets.com/diagrams/switch_lo_3pdt_ig_dcjack.gif) I get squeel when I rotate the gain knob past about 8:00 (6:00 = min).  WTF?

I used shielded wire for the I/O (input jack to switch - switch to input - output to switch - switch to output jack) and still have an MPF102 in Q1.  I didn't add the Miller capacitors yet since I didn't add them to my first build (which is permanently in my rig - boogeying right along...NO SQUEELING!!). 

This is absolutely perplexing... When I turn the gain pot to about 8:00 I can use all the controls just fine - and the tone is excellent - just a little less gain than I want.  There's a little background noise - but nothing like the squeeling...

Recommendations?  I'm almost ready to start from scratch using the DIY Layout tool and spacing out the components a little more just to see if it helps... this circuit sounds so good when it works...just irritates the heck out of me that my builds weren't consistent.

Thanks for looking.
Mike