proposed dr. boogey layout -- seeking comments

[mr_deadmaxxx]

yeah.. dual opamp IC.

[jplebre]

Guys, question on this, more of a me trying to understand something than anything else but

I understand Q5 is acting as a buffer, as it was explained by John Lyons a couple of pages (way back! I think page 4???) but what about Q3? there's no miller cap there either. Any reason?

[Ajay]

Hey people,

Newbe to this forum and long story short: I made a SMT version of Gaussmarkov's layout, essentially because the J201 seems hard to get and the SMT version is readily available (even in low qunatities at Farnell/Digikey and the likes). The board's just a little over 43 x 49 mm and consists mostly of 0603 components, with the exception of the pots and trimmers (although in my build I bypassed the trimmers by 33k resistors).

I did a quick and dirty build (even using flatcable for pot wiring) and took it straight into band practise (only scope testing it on the work bench) and we were all blown away by the very powerful sound of the box. My fellow bandmate is on his way making one as well

Anyway, if anyone's interested, I could post some pics of the layout and build. Same for the Eagle design files.

[Govmnt_Lacky]

Anyway, if anyone's interested, I could post some pics of the layout and build. Same for the Eagle design files.

Welcome Ajay!!!!

Sounds like a GREAT project and kudos on getting it running and offering to share!!!

By all means.... post it. I am sure there are plenty of people who would be interested in it! 

[Ajay]

Thanks GL,

The first pic is a screen shot of the Eagle layout. It's a two layer board btw, I found a company in China which makes double side 5 pcs of 2" by 2" for less than $10.-, so no stoppers there .


Then there's the initial build of the board (with the trimmers bypassed by fixed resistors):


After that the quick and real dirty flatcable wiring and first bench test:


And the prototype I took to band practise:


The three spare holes are for an MXR noise gate (also in SMT, if anyone's interested, just let me know) and a solo booster in '3D electronics' (without any pcb, just hardwired on the pot).

btw: does anybody know how to post a zip file to this forum?

[madstayen]

Ah, schweeet! nice man! want to build that! dr boogie was my 1st project, yeah i know, anyway, would love to do a good variation. this one seems to cut it. cheers mate!

[Ajay]

Thanks :-)

Actually, the Dr B. got me very excited about doing SMT boards, so tonight I kinda finished the JCM800 Emu. I guess I'll post that in a new post.

Anyway, I'd love to share my design files, but so far I haven't found out how to add them in this forum? Any suggestions?

Okay: sneak of the JCM

[deadastronaut]

hi ajay, welcome aboard..

try 'dropbox', its free and really useful.

[Ajay]

Seems Aron already provided for this:
http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/drboogey_smt.zip.html
If you click on the download archive, you should be able to get the files
(just hoping that I'm not abusing a feature that's intended for other use  )

[deadastronaut]

not at all...

in a few peoples opinion, including mine,  it could do  with a tweak here n there anyway...usually the tone stack comes under fire...

[Ajay]

My starting point was Gauss' layout, which essentially I just converted to SMT without any mods. I had already sent the gerber files away before I became aware of any tone stack discussions

For the SMT version of the JCM800 which I'm currently working on however (I've posted that somewhere else on this forum), i did incorporate some of the tone stack discussions; I've added some resistors and caps there so one can choose between the regular TMB, the Big Muff or the extended Big Muff tone stack. Also in that design I reserved room for more bypass caps, so it allows for more flexibility and room to experiment. Based on my experiences and hopefully comments from others, I will update the SMT Dr. Boogey design (or just hardwire it ).

So if anyone has suggestions/comments on either design, I'm open to it :-)

Cheers,

Ajay.

[Kipper4]

Quick question
how do i set up the trimmers in this build.
I have just recieved a populated board from a buddy and all i had to do was wire up some pots. so not having read alot about it i'm not sure how to bias the jfets. I guess thats what the trimmers are doing.
Thanks
Rich

[bluebunny]

how do i set up the trimmers in this build.
I have just recieved a populated board from a buddy and all i had to do was wire up some pots. so not having read alot about it i'm not sure how to bias the jfets. I guess thats what the trimmers are doing.

Yep: aim for 4.5V on the drains of Q1-4.  According to the madbean build notes, you can get oscillation with everything dimed, so ease back on T1.  If this sucks, put it back, then try backing off T2 instead.  If this sucks, . . .  (You get the picture.)

[Kipper4]

Thanks Mark
I'll give that a go. I'll report back later
despite not being boxed I can tell it's going to sound good already even with unbiased fets. especially with a SS amp, tube amp testing when i get back from work tommorow as its too late to crank that baby up now. I't blow the wife out of bed
Rich

[disabled_shredder]

Kipper looks like that board is already getting better use than on my bench. I hope it fires up no problem. And blue bunny was right its 4.5v do you have a link for the pot wiring?

[chobot123]

ajay, could you please share a link to the chinese company that made the board for you? how much for shipping?
thanks
BTW your layout looks good, I always wanted a Dr. Boogey in a B-sized box, maybe with a 1 knob tone control

[Kipper4]

Yes thanks Dizzy and thanks for the board, superbe qaulity etching btw. nice componants too.
I have the Dr Boo pdf from mr Markov so the pots are all wired up. It's ready for biasing now
Seriously good people here. Amazing generosity and willing ness to share parts and knowledge.
I love it here. Hence how come i have over 1k posts already in a year, admittedly most of its drivell but i'm starting to help a few newbies gain new knowledge too.

[disabled_shredder]

I feel the same way exactly I don't have nearly as many posts but I do read through the forums at least an hr or 2 a day. And I think we formally met when I was helping you get that 45 running. Or that's what stands out. Btw you should be able to match all the fets w that matcher I sent you! Was the pinout description w it? Ok enough of. Do let me know how the pedal sounds.

[Ajay]

ajay, could you please share a link to the chinese company that made the board for you? how much for shipping?
thanks
BTW your layout looks good, I always wanted a Dr. Boogey in a B-sized box, maybe with a 1 knob tone control

Thanks 
The company is Elecrow, http://www.elecrow.com/services-c-73/ Once you'd make a selection of the board size you'd like, there's an option to estimate shipping cost.
For a B size box the Big muff Pi Tone control could be an option. For the Dr. Boogie that would mean changing C17 to 4n7, R13 into 0 Ohm (or just bridging it) C18 should be a 39k _resistor_. Furthermore, add a 22k resistor to ground on pin 3 of the High pot and a 10nF capacitor from pin 1 of the High pot to ground and you should be good to go.
(BTW This mod is also available the tonestack of the JCM800 board I posted, always better to see the picture than just text  ) 

[Ajay]

Quick question
how do i set up the trimmers in this build.

Well, I did it with fixed resistors of 33k which give about 4.5 volt on the drains, except for trim 2. A 12K resistor (equalling to 6.5 or 7. something Volts, can't remember - I'd have to recheck) just sounded better to me.
If you have trimpots, I'd suggest to start with the suggested 4.5V and listen if a change of the trims sounds better or not.