73-75 Serge panels from Zthee

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seal_cobblr
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Post by seal_cobblr » Tue Aug 28, 2018 1:38 am

@nesto

The 1/4 inch is in the preamp module.
The 3.5mms are passive banana-to-3.5 jack ‘converters’ and may br used however you please as inputs or outputs.

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Nesto
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Post by Nesto » Sat Sep 01, 2018 9:00 am

seal_cobblr wrote:@nesto

The 1/4 inch is in the preamp module.
The 3.5mms are passive banana-to-3.5 jack ‘converters’ and may br used however you please as inputs or outputs.
thanks!
i am moving them to boats today so i will take another look...
must be simple if the middle set is not working.

eveready9v
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Calibrating the Ring Modulator and Envelope.

Post by eveready9v » Tue Sep 04, 2018 9:15 pm

Hey there, so I finished my build a few weeks ago, and I’m finally sitting down to calibrate this unit. I’m having a little difficulty following some of the instructions for calibration, but the one I’m really having difficulty with is the ring modulator, so am I to take a signal from the sawtooth and stack them send one to X and then alligator clip or probe to pad A? I guess what I also don’t understand is Pad A is going to the VC Y banana jack or isn’t it?
Also, with the Envelope, the gate output to plug into the hold, is that the output from the gate module? What should I have that set to? Any help would be amazing. Thanks so much,
Barry[/i]

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tojpeters
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Post by tojpeters » Mon Sep 17, 2018 1:34 pm

The heat sinks in the BOM for the power supply do not fit

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Sammus
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Post by Sammus » Mon Sep 17, 2018 11:18 pm

tojpeters wrote:The heat sinks in the BOM for the power supply do not fit
Hi Tojpeters, what trouble are you having with fitting? I bought the BOM as is for the PSU and mine seemed to fit OK?

Also - I just became aware of the black panels you designed - big fan, and is on my to-do list now :love:

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tojpeters
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Post by tojpeters » Thu Oct 25, 2018 7:07 pm

Calibration information incorrect for ring mod
This is where pad a isImage

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tojpeters
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Post by tojpeters » Fri Oct 26, 2018 9:06 am

So anyone who followed the trim instructions for the ring mod needs to:
Remove all knobs
Remove all the nuts for the pots
Remove panels from boats
Desolder all the jacks
trim the ring mod
Reinstall the panel
Put all the nuts back on
Solder all the jacks
Reinstall into boat
Put on all the knobs
Are you sure you saved a lot of time with ‘no panel wiring ‘?

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lasesentaysiete
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Post by lasesentaysiete » Fri Oct 26, 2018 9:09 am

don't the pcbs have holes in them where the trimmers are installed? That way you can adjust the trimmers without removing the pcbs, no? Just wondering. I don't own this set.

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Post by kroffe » Fri Oct 26, 2018 9:41 am

lasesentaysiete wrote:don't the pcbs have holes in them where the trimmers are installed? That way you can adjust the trimmers without removing the pcbs, no? Just wondering. I don't own this set.
Yes, this correct - holes make the trimpots available from the other side.

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tojpeters
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Post by tojpeters » Fri Oct 26, 2018 10:03 am

There are holes
Still hate the pcb Mount panel components
Way harder to do
And all that work will need done first time you need to replace a pot

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tojpeters
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Post by tojpeters » Fri Oct 26, 2018 10:07 am

And the lack of beta testing drives me nuts
This panel was never built before being released
That is too big a mistake to not notice
I just don’t understand how nobody has reported this major issue
You simply can’t trim the ring mod using the provided instructions

kroffe
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Post by kroffe » Fri Oct 26, 2018 3:06 pm

Strange, built and calibrated mine last winter using that instruction. Works as a charm.

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tojpeters
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Post by tojpeters » Fri Oct 26, 2018 4:01 pm

With an oscilloscope?
Did you use the pad A location I have pointed out?

kroffe
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Post by kroffe » Sat Oct 27, 2018 2:41 am

tojpeters wrote:With an oscilloscope?
Did you use the pad A location I have pointed out?
I’m not sure you’re pointing to the right pad in your picture, but it’s hard to tell. I used a DSO nano scope to calibrate my 73-75 DIY panels but cannot recall any details that stod out as ”wrong instructions”.

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Sammus
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Post by Sammus » Sat Oct 27, 2018 8:52 am

That pad is accessible from the back - you don't have to disassemble it at all to calibrate any of it.

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the bad producer
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Post by the bad producer » Sat Oct 27, 2018 9:11 am

Tojpeters is correct in that if you calibrate the ring as per docs it will not work correctly, the docs are wrong, pad A is the other one

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Sammus
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Post by Sammus » Sat Oct 27, 2018 9:29 am

Yes, instructions point to the wrong pad. But you don't need to desolder everything and disassemble the front panel to access the pad.

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Post by aabbcc » Thu Nov 08, 2018 4:32 am

Apart from the pad A thingy mentioned above are there any other major bugs/incorrect parts in the BOM etc I should be aware of? A client asked me to built this for him and he has all bom+kit. Plowed through the whole thread but couldn't really find anything obvious.

Flying wired vs mounting pots to pcb? According to Jon and the people in 99musik soldering the pots to the pcb is the way to go?

Also for calibrating I'm going to assume I need a function generator? For example:

START BY SETTING 3 TO CENTER
POSITION, SET 2 TO FULL CCW.
INPUT A 500Hz SAWTOOTH, INTO
X AND PAD A. ADJUST 1 FOR A
SYMMETRICAL OUTPUT.

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Post by ashleym » Thu Nov 08, 2018 12:37 pm

aabbcc wrote: Also for calibrating I'm going to assume I need a function generator? For example:

START BY SETTING 3 TO CENTER
POSITION, SET 2 TO FULL CCW.
INPUT A 500Hz SAWTOOTH, INTO
X AND PAD A. ADJUST 1 FOR A
SYMMETRICAL OUTPUT.
I am sure the B above concert A would do at about 493hz. Any synth should do this

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cygmu
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Post by cygmu » Thu Nov 08, 2018 12:38 pm

You could use the oscillator to generate the input saw for calibration, couldn't you?

Flying wires vs PCB mount must be up to you. That is the beauty of DIY. The boards were designed for PCB mount but IMO that makes servicing difficult and modifications harder. As a general rule I am one of those weirdos who prefers flying wires. That said, I haven't built mine yet, so don't listen to me.

I believe the individual module BOMs in the build guide are wrong in multiple ways but the overall BOM is correct.

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tojpeters
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Post by tojpeters » Thu Nov 08, 2018 1:04 pm

These things are a huge pain in the ass to build
I’d charge twenty five percent more than your price to build a conventional panel
Trying to test all this with alligator clips and bits of wire is ridiculous
I’m guessing most people are just putting them together and if parts don’t work oh well
I mean how many people have used the incorrect calibration information and apparently not noticed or are just pretending that it calibrated just fine

dianusindustrial
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Post by dianusindustrial » Thu Nov 08, 2018 1:54 pm

I calibrated the oscillator first, the used that for calibrating the slews/envelopes etc.

I did my build with pots mounted, the only thing I would caution is if you plan on adding any kind of mods like LED indicators to the slopes, I dont see how that would be possible. Wired pots would make modifications a great deal easier.

I had to desolder the jacks from one panel already (missed a single wire on the power bus whoops) but tbh it is not a big deal. I think you need to carefully consider what the 73-75 synthesizer is, it's not a proper product or kit it's more of a historical recreation of the paper-face system. It's a bit rough around the edges, but to me that's what makes it interesting. For those getting frustrated with Zthee's instructions, I would also suggest reading what Ken Stone has written about the modules. I got lost at times, but figured it all out eventually.

Once tuned it sounds beautiful. Using techniques from this video ( I need to play with it more, but even just simple sequences from my SQ-1 sound amazing.

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cygmu
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Post by cygmu » Thu Nov 08, 2018 2:01 pm

dianusindustrial wrote: I did my build with pots mounted, the only thing I would caution is if you plan on adding any kind of mods like LED indicators to the slopes, I dont see how that would be possible. Wired pots would make modifications a great deal easier.
the bad producer has you covered as far as LEDs go:


Other mods involving adding switches, pot or jacks would be tough.

dianusindustrial
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Post by dianusindustrial » Thu Nov 08, 2018 2:35 pm

Hey that is a nice clean solution. I already ordered a few bezels to experiment with. Putting this on my to-do list!

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zdarma
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Post by zdarma » Sat Dec 22, 2018 11:40 am

I am getting ready to build this and was planning on trying to power this using the R*S PSU or the PSU powering my other panels.
Has anyone else done this?
Can I just build the slim version of the PSU board and run the +/- 12v from the PSU into the V+ and V- on the One Inch Punch PSU board (for the +6v) and not install the converter?
Does someone know how this should be wired up?
Would I run the pin1/black/ground 1 from the psu to the hole marked "COM" on the pcb?

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