Something New from Doc Sketchy

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Dr. Sketch-n-Etch
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Thu Apr 01, 2021 10:25 pm

devinw1 wrote:
Thu Apr 01, 2021 9:55 pm
I do reckon that's the Dagwood sandwich of Euro modules! Well done! :sb: :sb:
Well, there's a lot of circuitry in there! Two complete Dome filters (one 12-stage, the other 18-stage), two four-quadrant multipliers and two output amplifiers. And those PCBs are stuffed (although there is a tiny bit of wiggle room on the top PCB). To get the Dome filters to fit onto these euro-sized PCBs, I had to break my own rule and install ICs without any space in between. The 9 TL072s in the 18-stage Dome filter are all smashed together, so that they take up 3.6" of length. This can be done with 8-pin ICs, but not with 14-pin ICs like TL074s. Those must have a 0.1" space between because they are actually the same length as 16-pin packages, so if you try to install them without a space in between, you have to grind a bit of the package down on the edges. I learned that the hard way. But, with 8-pin ICs (and, presumably, 16-pin ones as well) you can put them right together. The challenge then is to fit all of the associated circuitry, and to arrange the necessary traces, into the 0.4" space of each IC. The 18-stage Dome filter is my favorite layout ever.
18DomeLayout.png
18DomeSchematic.png
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Re: Something New from Doc Sketchy

Post by AlanP » Thu Apr 01, 2021 11:21 pm

Doc, how well would 1% caps work with no binning for further accuracy by the builder?

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Re: Something New from Doc Sketchy

Post by devinw1 » Fri Apr 02, 2021 11:03 am

Dr. Sketch-n-Etch wrote:
Thu Apr 01, 2021 10:25 pm
devinw1 wrote:
Thu Apr 01, 2021 9:55 pm
I do reckon that's the Dagwood sandwich of Euro modules! Well done! :sb: :sb:
Well, there's a lot of circuitry in there!
Yes, of course, and I hope you didn't take that as a knock! I always love seeing your creations and have much respect for your artisanal builds!

The dome filter layout is indeed nice. It always feels great to have such a nice symmetry to these things.

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Re: Something New from Doc Sketchy

Post by Dr Gris » Fri Apr 02, 2021 3:12 pm

Wow, impressive!!
I think the now discontinued RS-240 is 122 mm deep.

//M

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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Fri Apr 02, 2021 5:25 pm

AlanP wrote:
Thu Apr 01, 2021 11:21 pm
Doc, how well would 1% caps work with no binning for further accuracy by the builder?
1% caps would probably be OK. On top of the 1% accuracy of the resistors, this would give a maximum 2% error. I just ran this through my simulation (adding and subtracting random numbers bounded to 2% of the target from the RC factors in the filter) and the predicted phase displacement can be quite far off, as much as a 2 degrees off of 90, but is typically within 1 degree.
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Fri Apr 02, 2021 5:28 pm

Dr Gris wrote:
Fri Apr 02, 2021 3:12 pm
Wow, impressive!!
I think the now discontinued RS-240 is 122 mm deep.

//M
You can buy an RS-240 from Big City Music today for $2,199. You could get seven Freak Shifts for that. However, the RS-240 does have a VERY BIG KNOB.
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Fri Apr 02, 2021 5:35 pm

Actually, I came by the thread today to tell you all that I tested the "new and improved" euro Freak Shift this morning with my trusty electric guitar, and it worked perfectly. It's now just waiting for a nicer panel, and it will be shipped to McIntosh.

I actually put a new panel on it as well. The graphics are still a little messed up, but it turns out that I drilled the holes for the jacks slightly too low on that first panel, and it was stressed and slightly curvy. I had another panel which I hadn't drilled yet, so I drilled the holes about half a millimetre further up, and that panel slid onto the panel components with ease. It turns out that the centre of the jack on those damned Thonkiconn jacks is not quite aligned with the 0.1" grid (although the solder tabs are), which makes it a pain to put in my layouts. However, I copied a mechanical drawing of the jack into Excel, resized the drawing until the solder tabs fell on my grid, then put another dot where the centre of the jack actually is, and found it to be about 0.5 mm away from where I had it. I moved the jacks in my FPD panel file, then made a PDF of that and copied it into my Excel layout file, and was able to see that the new jack hole locations on the panel are more or less perfect.
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Re: Something New from Doc Sketchy

Post by Dr Gris » Fri Apr 02, 2021 6:47 pm

Dr. Sketch-n-Etch wrote:
Fri Apr 02, 2021 5:28 pm
Dr Gris wrote:
Fri Apr 02, 2021 3:12 pm
Wow, impressive!!
I think the now discontinued RS-240 is 122 mm deep.

//M
You can buy an RS-240 from Big City Music today for $2,199. You could get seven Freak Shifts for that. However, the RS-240 does have a VERY BIG KNOB.
The RS-240 sound very good. Your two variants also sound very good.
I’m still saving up for your 5U FS inc VCO but now with the Freak Shift “light” I’m not sure which one to get...

//M

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Re: Something New from Doc Sketchy

Post by Dcramer » Fri Apr 02, 2021 6:58 pm

Dr. Sketch-n-Etch wrote:
Fri Mar 26, 2021 9:04 pm
Dcramer wrote:
Fri Mar 26, 2021 7:11 pm
Hey Doc, yup it fits, of course when you look along the back of my rack it’s the only one sticking out!
Yes, I’ll get a video done, I’m actually several videos behind, so it may take awhile.
I’ve done all kinds of experiments with it, being able to put anything into it makes it so creative 👍🤓
Well, I wouldn't mind just something "quick and dirty" with some of your experiments, not necessarily your usual masterpiece. I'm just really curious to see how a "real" modular musician uses this thing. (If you've seen any of my videos, then you'll know just exactly how low my standards really are.)
Yup, I hope to have something up this weekend :foul:
Of course I goofed around with the thing all night and ended up with over an hour’s worth of footage :hihi:

The new boards look great Doc :tu:
Last edited by Dcramer on Sat Apr 03, 2021 11:50 pm, edited 1 time in total.

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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Sat Apr 03, 2021 12:43 am

I'm really looking forward to seeing (and hearing) some of your footage, Dcramer!
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Re: Something New from Doc Sketchy

Post by Dcramer » Sat Apr 03, 2021 12:47 am

:foul: :foul: :foul:



and the obligatory Euro thread in the hopes that it'll be the next Beads :sstorm:

viewtopic.php?f=16&t=246966
Last edited by Dcramer on Sat Apr 03, 2021 12:59 am, edited 1 time in total.

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Re: Something New from Doc Sketchy

Post by McIntosh » Sat Apr 03, 2021 12:55 am

Brilliant work, its the little details that make the difference. I am so inspired, I decided to build myself a new deeper case so the Freak Shift has plenty of room to freak out, and room for more Future Doc Skectchy lab modules!
:guinness:
Lovely tones, woody and squelchy, brilliant.
Last edited by McIntosh on Sat Apr 03, 2021 1:17 am, edited 1 time in total.
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Sat Apr 03, 2021 1:08 am

Dcramer, that was FREAKIN' AMAZING!!!!!! I think you are now my grandfather!
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Re: Something New from Doc Sketchy

Post by Moog$FooL$ » Sat Apr 03, 2021 4:10 pm

so great!! nicely done Dcramer.... you do a good job of showing some things i definitely wouldn't know of. u seem to know your synthesis quite well.

:tu: :tu:
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Re: Something New from Doc Sketchy

Post by Dr Gris » Sat Apr 03, 2021 6:37 pm

That was truly awesome Dcramer, thank you!

//M

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Re: Something New from Doc Sketchy

Post by zengomi » Sat Apr 03, 2021 8:24 pm

Thank you, Dcramer. Well done!

Ready to freak, Doc.


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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Sat Apr 03, 2021 8:30 pm

Just remember, if you PM me about wanting a module, please tell me:

a) your email address (so I can send a Paypal invoice)
b) your location (so I can calculate the proper shipping cost)

Thanks in advance, bitches!
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Sat Apr 03, 2021 9:18 pm

Dr Gris wrote:
Fri Apr 02, 2021 6:47 pm
The RS-240 sound very good. Your two variants also sound very good.
I’m still saving up for your 5U FS inc VCO but now with the Freak Shift “light” I’m not sure which one to get...
I don't expect to be making any more of the big ones. If you want to buy my existing 5U unit, I'd be happy to sell that to you. However, I think that the Freak Shift is actually quite a bit more versatile than the big unit, because of the ability to use external modulation sources. If I'd have known how good that was going to be, I never would have bothered with the bigger unit, because the quadrature oscillator is about 70% of the circuitry in that unit.
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Sat Apr 03, 2021 10:07 pm

I just wanted to let people know that, if you have ordered or are in the process of ordering a Freak Shift, I probably won't be processing the Paypal invoices for a week or two. I don't like collecting money for stuff long before I can deliver it, and I won't be able to deliver any new Freak Shifts for at least three weeks (shooting for the last week of April) because it is going to take me that long to get the new panels.

At last count, I have 9 people who want Freak Shifts, and that's just from today. I'm writing y'all down in my little black book, and I'll send y'all Paypal invoices later this month. In the meantime, I'm going to start etching and drilling and stuffing and soldering PCB sets, to try to build up a bit of an inventory for when the panels come available.
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Re: Something New from Doc Sketchy

Post by Moog$FooL$ » Sun Apr 04, 2021 2:10 am

i think he may just have some help from a friend..... at least with the stuffing & soldering. :hyper:
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Re: Something New from Doc Sketchy

Post by Huba-Swift » Sun Apr 04, 2021 10:06 pm

I read through the whole thread again today and have a question about your Polaris filter (which looks absolutely mind-blowing btw). You have modes labeled 1-4 and 1-8 on the two scanners, but what are the actual modes it' scanning in-between on each slider? I don't understand how that lines up with the 6 modes and 5 types on the production module.

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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Mon Apr 05, 2021 3:48 pm

Huba-Swift wrote:
Sun Apr 04, 2021 10:06 pm
I read through the whole thread again today and have a question about your Polaris filter (which looks absolutely mind-blowing btw). You have modes labeled 1-4 and 1-8 on the two scanners, but what are the actual modes it' scanning in-between on each slider? I don't understand how that lines up with the 6 modes and 5 types on the production module.
It doesn't. My version has more modes than the production module. There are four banks of 8 modes on mine. This is because I am using a 4-channel scanner and an 8-channel scanner, so I have 32 possible modes. There is, in fact, an almost infinite number of modes possible, but most of them are useless. I identified what I consider the essential modes. I think I put a table in somewhere.

Incidentally, I got rid of that module (I basically gave it to a buddy). If I did that again, I would not use an interpolating scanner, but would instead just switch between modes with analog switches, or even panel switches (or, most likely, the latter sending 5V logic to the former). This would make the module far less complex, and I'm not convinced that the interpolation is useful anyway.
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Re: Something New from Doc Sketchy

Post by Huba-Swift » Mon Apr 05, 2021 5:18 pm

Ahh, I see. I was really curious as to how scanning through various filter modes could be used, and how it would sound, especially when being modulated by CV. Too bad to hear it might not have been worth all the added complication.

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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Tue Apr 06, 2021 1:40 am

Just a reminder: If you send me a PM requesting a module (such as the Freak Shift), please PLEASE give me your email address and TELL ME WHERE YOU LIVE so I can figure out the shipping cost. (I'm looking at you, alanalan, thisoldhouse, and Fayette...)

Incidentally, I'm sitting on 13 Freak Shift orders right now (including 2 orders from one customer). I'm a little nervous about that.... Tonight I finished two sets of boards (all except the Dome filter caps because I'm waiting for a shipment). I'll keep plugging away, making two boards every two or three days, so that I'll have them all built and ready to go by the time I get some panels.
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Re: Something New from Doc Sketchy

Post by Dr. Sketch-n-Etch » Tue Apr 06, 2021 7:13 pm

I've now got 18 orders as of 6 March. I've sent all interested parties a PM informing them that they will soon be receiving Paypal invoices. If you have expressed interest but have not received a PM reply, please let me know. I've got a list with 17 names (somebody wants two units, so he has two positions in the queue), so I know who you are and I think I have all of your email addresses and locations (except maybe one). So yeah, I've started making boards. I've got two sets all made and stuffed (except for some missing film caps for the 180-stage Dome filters and some mounting hardware, all of which is en route from Bangkok as I type this).

Two down, 16 to go....... :omg: :bang:
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