Small clone for 1590a in SMD

[Scruffie]

It's been a while since I played with the Vgg pin but I don't think it has much effect on gain or much of anything really, it's more just good practice for optimal operation but seeing as it was already tied to ground in the original... The source resistor on the small clone is only 39k anyway, if there was any drop in gain from it you could easily compensate by increasing that.

You'll be fine having the clock and BBD on the same power rail (they were in the original after all) but you'll have to be careful with grounds.

As for how to do the grounds, you'll do better learning from experience than me telling you what to do it's a rite of passage to have a bum PCB and work out where you went wrong anyway.

[brejna]

Thanks Brejna! Everything that works satisfactory will be put on sale. When the time is ripe. I wasn't really planning to do a CE-2/3 as there are already a number of others (Pork Barrel, Ensemble King and derivates, etc.) and I have got a Pork Barrel already. Yes, it's a bit big to my liking 

The resistors are all 0603 as are most capacitors. Some caps are 0805, mainly the larger values. This way I can get a better voltage rating and usually a better capacitance/voltage behaviour (bigger ceramics seem to be better at that). Tantalums are either 3216 or 6032.

That is great, I thought you would do ce2 too..
Anyway I am interested in this project, but I hope I will find dealer for the 0603 components

[Rootz]

Thanks. I'll leave the Vgg supply as it is at the moment. It should work as intended.

I did take a look at the Celeste. Very interesting and I took notice about the separated supplies in that design.

I started reading more about grounding (TI papers on that matter for example). It is much more complicated than bypassing. I usually place bypass caps as close as possible to the ic needing them, thus hopefully taking out switching from the power supply at the source of the problem.

It looks like in the original SC all grounds are shared too. As far as I can see a very simplistic design, pcb wise. I designed the VDD supply very close to the clock and BBD. Not separated. Not the best solution, but the return paths are short and the ground planes petty solid. For 30 bucks I can take the gamble and see if it works. I hope I have better luck than I usually do in a casino.


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[Rootz]

Thanks Brejna! Everything that works satisfactory will be put on sale. When the time is ripe. I wasn't really planning to do a CE-2/3 as there are already a number of others (Pork Barrel, Ensemble King and derivates, etc.) and I have got a Pork Barrel already. Yes, it's a bit big to my liking 

The resistors are all 0603 as are most capacitors. Some caps are 0805, mainly the larger values. This way I can get a better voltage rating and usually a better capacitance/voltage behaviour (bigger ceramics seem to be better at that). Tantalums are either 3216 or 6032.

That is great, I thought you would do ce2 too..
Anyway I am interested in this project, but I hope I will find dealer for the 0603 components

Let me begin with your last sentence: you can get 0603 part from virtually anywhere. If I'm not mistaken, 0805, 0604 and 0402 are the most common and cheap SmD parts you'll find. No, not at Tayda or Smallbear, but anywhere from Aliexpress to Mouser.

I am working on a small CE-2. It is using a double decker pcb (clock, BBD and power supply on a small board on top of the main board), but it's a lot of work and time is scarce... I've made a start designing it, but no idea when I'll finish it. Eventually I will.


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[pickdropper]

You can do a CE-2 with 0603 without any issues.  I did a 1590a layout with 0603 for the caps and resistors and through-hole ICs and Transistors and it fit fine.

[Rootz]

Of a CE-2 you mean?


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[pickdropper]

Of a CE-2 you mean?


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Yep, the CE-2

[Rootz]

Good lord that's gorgeous! Definitely my benchmark for clean work. Just everything looks shiny. How do you get that board so clean? Isopropanol?

Could you please share the layout for that board with me? Not for copying as I will mount all pots (depth, rate, mix), jumper blocks, switch (chorus/vib) and jacks on the same pcb. The way you made your layout would sure give me some clues how I should or could do mine.


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[Rootz]

Got some more work done on the Small Clone; added a charge pump board to it. It accepts a wide variety of it's and offers options for boost (solder jumper) and clock speed cap. Nothing new for the rest, just a digital test fit. It should fit, albeit some small margins.

I get the ic's for the Triple Wreck tomorrow, so this on is on the verge of being fabbed at OSHPark.

[sturgeo]

Those 3D models look the mutts nuts, looks like i'll have to learn yet another bit of CAD software!

[m-Kresol]

wow, looks very good! And I agree, those 3D renderings are great. Would be more than awesome if you ever find the time to do a little tutorial about that part.

[Rootz]

Haha thanks guys. I think making these 3D models works great as a tool to see if everything is going to fit like I want (and it looks cool). I just found out that the MN3007 socket is fine and doesn't touch the underside of the jack. The jumper block on the other hand... I'll have to move that one around a little.

The biggest drawback of Sketchup is that the models that you can download are not very accurate most of the times. I used a 9mm pot from the 3D Warehouse (where you get the models), but it was pretty different from the metal shaft 9mm Alpha's I made. The last ones are very specific to the models of pots I use though. It always a good habit to check the models against the data sheets and real life components.

Sketchup has got a bit of a learning curve, but it's very intuitive. Good thing is there are countless tutorials online. I'm a bit short on time lately, so I might take me a while to write a tutorial. That's less than awesome . If you want to read into some of the existing guides, search for EagleUp on the internet. That will get you started and there are great tutorials for installing Sketchup and EagleUp. I'm on a Mac and installing was far less easy than it is on Windows. Installing on Windows should be very convenient.

You could always try an online 3D (Eagle) board viewer (search for it). It's nowhere as extensive in the possibilities as Sketchup, but very good for a quick mockup.

[wgc]

I think Diptrace has a 3D library too, which you can export into a 3D cad program and do some nice renders with. Gotta mess with that soon.

[Rootz]

So, it's finally going to happen: I ordered the boards for the SC, foot switch and the charge pump. Let's hope it works right away. Fingers crossed...

[Rootz]

Boards are in! But guess what: I'm on a vacation coming week, so soldering time starts first week of December...




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