Turkey Day SHOOTOUT Competition

[digi2t]

One thing you can do to connect the ground plane to the box is to use a thin gauge wire from the ground plane and tuck it under the bypass switch and tighten it down to hold the wire to the enclosure

You could use metal stand-offs directly to the boards ground plane, and attach the board to the enclosure cover. Support and ground in one swoop.

[deadastronaut]

cool tremolo john, nice build and theme ..goes well with distortion too..

now you can relax and get some kip...

its been great to see so many of you guys pushing the boat out and coming up with new ideas, and improving on others too.. ....its been a great competition in the true 'spirit of diysb'

now who's going to win that sausage pic?...


good luck all you guys....

[Jdansti]

Thanks for the complements guys. 

Also, thanks for the advice on grounding the enclosure.  I thought about the other options, but decided to make a little spring because I could.  

[samhay]

And it looks like I will just squeeze in before the bell too. Many thanks to the organisers and other contestants/forum regulars. There have been a lot of neat new circuits described over the last month or so.

I will keep it short, because it is now 2am. My entry is tentatively called the 'Double Up': two precision full wave rectifiers (so gating is not really a problem) in series to create 1 and then 2 octaves up with some  filtering to try to make the waveforms more symmetrical and to keep the high frequency fizz under control - it's not super clean, but it's not really a fuzz either.
The two octaves can be mixed together and then this can then be mixed with the dry signal. Because there are 6 op-amps involved (it started to feel like a 'fun with op-amps' project), I figured it might as well have buffered bypass too so long as it still passes signal without power (which it does).
To make this more interesting, and because nobody has entered one yet, I decided to cram all this into a 1590A-size enclosure - if you can't make it better, then make it smaller. This was my first 1590A build - which may explain why I thought this would be a good idea. I will be doing others, but will be buying some smaller jacks and pots first

Many rectifier circuits have been built over the years and although I designed this from scratch, i would imagine something very similar has been done before. The precision rectifiers started out on my breadboard looking like Rod Elliott's (ESP) textbook example. I also spent some time playing with the octave stage of John Hollis' Omnidrive. The filters are nothing special (but the frequencies are tuned more to smooth the rectified signal than to filter a specific frequency) and the mixing is done passively to keep the number of knobs down. An old post http://www.diystompboxes.com/smfforum/index.php?topic=76327.0 was quite helpful and gave me the idea of sharing a circuit simulation, which you can play with here: http://tinyurl.com/cxwt398.


Schematic:

It is roughly unity gain, but if you have the space, it might be nice to replace the 220k resistor in the feedback loop of the output op-amp with an e.g. 1M gain pot.

Layout - It's on vero and is a bit of a tight fit, so the pull down resistors were moved to the jacks. A 1590BB version could be a lot cleaner (the wires in the middle of the board really bug me). However, I do feel quite smug that I managed to keep all the resistors lying down - you win some, you lose some.


Build photos:

The board:


The gut shots (halfway there and complete). You might notice I had to trim both the in/out jacks and the pots - fun times:




And the finished product:

A chronic lack of time left me with little option but a naked enclosure. I did sand and polish it up a bit, but ultimately it is a little bit of an ugly duckling in this competition. To try to hide this, I have used an ultra-bright blue LED so you can never look directly at it.

And finally, some uninspiring 'evidence' captured on a stills camera in between my sons crying. This was all played on the neck pickup of a telecaster. That said, it works reasonably well with a bridge humbucker too. What it sucks badly at is playing more than one note at a time. This is a general problem with rectifiers I believe.

[midwayfair]

Holy crap! Two octaves up in a 1590A!

<3

It's got some interesting ring mod-like stuff going on. Is it sensitive to where you set the guitar's tone control and so forth?

Nice job on your first 1590A. It's difficult even for veteran squeezers to get something that size into a 1590A and you did it on your first try.

---
Also, John, very cool tremolo. I haven't messed with the 555 much at all. I need to fix that.

[digi2t]

To try to hide this, I have used an ultra-bright blue LED so you can never look directly at it.

We have a saying at work, when faced with a difficult job, or situation, "We won't let ourselves die out in the field".

Those ultra-blues are like lasers, so BRAVO! 

[samhay]

Jon - thanks and I should have mentioned that a photo of your large family of your 1590As got me thinking about this in the first place.
I am still trying to get my head around the pedal as I had my first proper play with it about 2 hours ago. Like other similar circuits, it is quite sensitive to the tone pot - I will try and do some better sound samples at some stage if anyone is interested.

digi2t - I have some diode lasers at work, and yeah, the ultra-brights aren't far off them.

[haveyouseenhim]

One thing you can do to connect the ground plane to the box is to use a thin gauge wire from the ground plane and tuck it under the bypass switch and tighten it down to hold the wire to the enclosure

You could use metal stand-offs directly to the boards ground plane, and attach the board to the enclosure cover. Support and ground in one swoop.

common sense strikes again

[digi2t]

One thing you can do to connect the ground plane to the box is to use a thin gauge wire from the ground plane and tuck it under the bypass switch and tighten it down to hold the wire to the enclosure

You could use metal stand-offs directly to the boards ground plane, and attach the board to the enclosure cover. Support and ground in one swoop.

common sense strikes again

http://www.radioshack.com/product/index.jsp?productId=2102848

[haveyouseenhim]

lol   you don't have to tell me. The manager of radioshack pays me to organize the parts section because all of the employees are tards.

[defaced]

My contest entry is an amalgamation of different ideas I've had for a while.  This worked out to be the perfect time to do this project because I had almost all the skills to do it, and it was an excuse to learn how to do double-sided photo etching.  But before I get into it, I've got some people to thank.  Without their help and sharing of their ideas, I could not have done this:

KMG: sharing your LND150 tube emulation work which is the basis of this project, http://milas.spb.ru/~kmg/jcm800fetLnd150_en.html.  
Nick de Smith, http://www.desmith.net/NMdS/Electronics/NixiePSU.html: who's SMPS was the basis for this SMPS.
Tom Berryhill: your assistance with refining my dry film lamination process allowed me to make this board
R.G: your programmable FX switcher, http://www.geofex.com/article_folders/fxswitchr/fxswitchr.htm, is the basis for the logic switching for the channels
The guys of the world who work on high gain amps, your schematics are the underlying architecture of this project
My girlfriend Christina: your help with the art work, drawing the knife and encouraging this project allowed me to get it done.  
My brother Frank: you gophering for me during the final rush to do wiring was indispensable.  
The guys over at BYOC who pointed me in the direct of the cool knobs and DC jack
Surplus stores around the US for having cool stuff like black momentary switches and tiny PCB turrets.  

I think that's everyone, I hope.  

Cut-Throat is basically a high voltage (+400v) LND150 tube preamp emulation project.  It uses the high voltage depletion mode LND150 MOSFET as the active device.  The project has three channels, two are distortion, one for clean.  The basic idea is you can path into any power amp and have your core sounds in a box.  The high gain channels are a mish mash of the Soldano SLO lead channel and the Fryette Deliverance preamp.  The clean channel is a Fender Twin.  But enough of that, on to the pictures.  

Schematic:


Currently I do not consider the board "verified", so I'm not going to post it.  Also, if someone wants to etch it, they're probably going to need some assistance due to the complexity (dual layer).  If anyone wants it, I'll send it to you, but I'd rather not post it for public consumption at the moment.  

Video, sorry, I blew up the SMPS while testing.  I was getting switching noise in the bypass signal and while the channel switching logic was working, the signal was not being re-routed.  In adjusting the SMPS to reduce switching noise, I made a short with my meter and killed something.  Probably the MOSFET or the MAX1771.  Since I'm at my parent's house 8 hours from my scope, and just finished wiring this an hour ago, troubleshooting will wait.  Anyway, not getting channel switching was probably a relay wiring error (all of that was done as off board wiring because there was no good way to do it because the turrets were so large and restricted the options for making paths).  Such is life.  But on to the pics.

Exterior


Interior


Board with developed dry film resist


Etched board front


Etched board back


Box with exposed film


Box on mill for drilling


Drilling board


Turreted board front


Turreted board back


Completely populated board


Pot point to point wiring of controls

[pakrat]

Ok, here is my second and third entry. This one has 2 boards so as per the rules, counts as 2 entries. It is the ST-9E Super Tube Screamer Executive Edition. I named it the "Executive" edition because it's a step up to the "Professional" version that I built recently. I was originally going to call this the Tube Screamer Ridiculous, but I felt I would need more mods to make it truly ridiculous. Maybe the next competition.....
This project was a leap for me to say the least. I haven't been building for long, but thanks to this forum and all of the great people here, I'm learning. I couldn't find a layout for this so I made one from a collaboration of pictures and a schematic I found on the internet. I've never made a layout before so I wasn't sure it would even work... thankfully, it does. The various mods can be found online but most of them came from Dano at beavisaudio. I'm sure someone here could make a much better layout than this, but it's a good starting point.
At some points in the video, the audio clips a little and doesn't do this pedal justice. My friend Brian, who plays in the vid, absolutely loved this one and I would recommend the stock ST9 to anyone looking for a "better" tube screamer..
The features are covered in this "owner's manual" I made just to be a smart ass.






Some pics:




Gut Shots:






Opamp board:



Here is the layout I made using DIYLC. Thanks Bancika!



The schematic I used:



I copied most of this photo to make the layout:



The opamp board layout:



Steroids mod:


Beavisaudio mods:



Here it is next to my Tube Screamer Professional:



Video:

Happy Thanksgiving Everyone!

[pakrat]

Sorry for posting my entry so close to yours defaced. I was worried time would run out.

[defaced]

No worries at all, I completely understand.  That's a killer build.

[pakrat]

@defaced  Man, you really are a Super Evil Genius, that build looks incredible, and very professional!

[haveyouseenhim]

F*ck my life 

[Ronan]

Wow, two absolutely devastating builds!!!

[haveyouseenhim]

GET TO IT JUDGES!


We don't want a repeat of last time     

[Jdansti]

Sam, Defaced, and Packrat- all three great ideas and builds! Glad you all made it by the deadline! 

[slacker]

Amazing stuff chaps, just logged in over breakfast and I'm blown away by last nights entrys. 3 new designs and an ultra-modded "forgotten gem". Will have to check them out later or I'm going to be late for work