Steiner Microcon Project

dingebre · Posted: Thu Nov 24, 2011 2:40 am Post subject: Difficult to find parts

I thought I'd give those interested in this a little heads up if you haven't already checked the parts. There are a couple of parts which may or may not give you problems in this project.

First, there is a 74C14 HEX SCHMITT INVERTER. The original part seems to be discontinued, but NTE makes a replacement. I will try this in the prototype to make sure it works. This seems to be in stock at Mouser, but only about 700 (as of today) in stock.

The 2N5172 and PN5138 are apparently at their end of life. Mouser still has a pretty good stock. I don't think these aren't really critical. Any decent small signal NPN or PNP should work.

There is a matched pair in the VCO or course. This can be a hand matched pair, or any of the usual monolithic pairs. The pinout will most easily fit an EBC type pinout, so a typical monolithic pair like SSM2210, LS318, MAT-12 should work great. You can shoe horn the 2N5172s, but you will have to pretzel the leads to fit since the 5172 is an ECB pinout.

The JFET is a 2N5246. Still out there, but at its end of life. Again Mouser has a bunch, but not really huge numbers.

If anyone can find a 2 Meg pot, please tell me. You will need to substitute 1 Meg for these two pots in the EG.

Last, these aren't gone, but might be problematic depending on where you are. It takes two Vactrols, VTL5C3/2. I've seen them in a couple of places.

Anyway, just a quick heads up to make sure you can source the parts you want to use if you are going to build this.

I'm attaching a very PRELIMINARY BOM. This will almost certainly change, so don't buy off this. I offer it for information only.

Microcon PRELIMINARY BOM.txt

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Dave Kendall · Posted: Thu Nov 24, 2011 8:26 pm Post subject:

Hi.

The 74C14 should be replaceable with a common 40106. The motorola ICs I have are marked with both MM74C14N and CD40106BCN.

cheers,
Dave

dingebre · Posted: Thu Nov 24, 2011 11:00 pm Post subject:

jnuaury · Posted: Sun Nov 27, 2011 12:03 pm Post subject:

Very cool!

dingebre · Posted: Mon Dec 12, 2011 12:12 am Post subject:

A little more progress. the prototype PCBs came in this last week. I have already made changes/corrections to the layout, but I can still stuff these to verify the basic function. I'll post progress when I've got something to share.

David

dingebre · Posted: Sat May 05, 2012 8:48 am Post subject:

Sorry to seem dormant. I've pretty much finished the Steiner Duophonic keyboard stuff and can make more time for the Microcon. I will have the version 1.1 prototype PCB next week and will post results after I get one built.

David

dingebre · Posted: Thu Aug 23, 2012 12:41 am Post subject:

Brief update. The prototype is stuffed and I passed it off to Nyle today. I thought it best to let him put it through its paces because he knows much better than I how it should work. I'll let you know how it goes.

mig27 · Joined: Mar 09, 2011 Posts: 21 Location: Berlin

Cool project, keep it coming!

dingebre · Posted: Fri Aug 24, 2012 9:36 pm Post subject:

dingebre · Posted: Sat Aug 25, 2012 8:22 pm Post subject:

So, here are the current PCB layout and Schematic. The PCB is 4 inches by 3.9 inches. I added connectors for either Doepfer or MOTM style. It calls for +/- 12 volts, but should be fine on +/- 15.

Unless someone raises a very compelling argument, this will probably be the production PCB.

SP_Microcon_Names_1.2.pdf

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SP_Microcon_Values_1.2.pdf

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SP_Microcon_Schematic_1.2.pdf

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dingebre · Posted: Mon Aug 27, 2012 12:17 pm Post subject:

Quick update, again. I spoke to Nyle and two things:

1. He has some notes he made "in the day" regarding a mod to make it more compatible with his EVI wind controller and asked me to hold off on the PCBs until he had a chance in the next couple of days to look into it. Something about the sustain in the EG section.

2. I asked about the 15 volts, and he echoed what I hope I've said here and elsewhere that it should work without a problem, but some of the transistor biasing resistors may need to be changed. Bless him, he doesn't have a 15 volt supply to test the prototype, so I'm going to give him one next week and he'll test in on 15 volts.

I'll make sure I order plenty of PCBs. If I run out, I'll order more, so don't worry.

David

dingebre · Posted: Thu Aug 30, 2012 12:14 am Post subject:

First cut at a panel will all the pots, switches, trimmers on the front panel. I'm sure it could be condensed, but I'm trying to keep the look and feel of the original Synthasystem panels, the resurrected panels I did, and the Microcon panel.

When debugged, I'll post the .FPD file here and on my web site.

Right now, it's 28 HP wide.

David

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dingebre · Posted: Mon Sep 03, 2012 12:24 pm Post subject: PCBs ordered

OK. I've ordered a bunch of PCBs. I am not formally taking orders, I want to build one more and make sure the changes I made didn't screw up anything. I added standard power supply connectors to the PCB, made the pot and switch connectors consistent, and I added a summing resistor and pad if you want to play around with adding a VC pulse width input.

Read the notes on the schematic for some comments about the various switches, pots, and trimmers. I've also redone the panel layout (I'm not posting the FPD file yet until I order a panel and am sure everything fits.)

Right now pricing for the PCBs will be $20.00 for a single PCB with some kind of discount for multiple PCB orders to be determined.

Microcon_1.2.zip

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Microcon 1.2 FPD.pdf

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SP_Microcon_1.2 Layout.pdf

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SP_Microcon_1.2 Values.pdf

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SP_Microcon_1.2 BOM.pdf

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dingebre · Posted: Fri Oct 12, 2012 1:19 am Post subject:

I received what I hope will be the production PCBs for the Microcon. I stuffed one and gave it to Nyle to test. He should be through with it within a week or so. Then, I'll be ready to sell the PCBs, so please stay tuned. The initial tests on the last prototype were great. Nyle found some layout errors and made some suggestions which are reflected in the latest layout.

See below for the documentation packet.

Read the notes because there are choices to be made regarding the trimmers, panel pots, and the Sustain and Resonance (Q) switches.

Don't hesitate to email me with questions or comments

SP_Microcon_1.2.pdf

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dingebre · Posted: Thu Nov 15, 2012 6:10 pm Post subject:

Well, Nyle has approved!

PCBs are available!

I apologize I've been ignoring the list. I'll try to answer questions:

The PCB is 4.0 by 3.9 inches. The panel design I did includes all the options and is generous on space. If you mount the PCBs at a right angle to the panel, don't use all the panel control options, and put panel parts closer together, you could cut the width down. The unit draws -10mA and +20mA

Details:
Price will be $30.00 for a single unit, $20.00 for each additional PCB. I have 50 in stock and if those sell out (probably not), I will simply order more Smile

PayPal is accepted at the email in my signature. Docs are a little "thin" right now, but I'll send what I have and will try to be fast in responding to all questions.

Double check the parts list attached to make sure you can source the parts. nothing too weird other than the Vactrols and 74C14 schmitt trigger and there are some good substitutes.

Check the website under the Synthasystem Price List for shipping costs.-

http://user.xmission.com/~dingebre/Price_List.html

SP_Microcon_1.2.txt

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dingebre · Posted: Wed Nov 21, 2012 8:50 pm Post subject:

Hi everyone. I've received several orders and should have them shipped on Saturday. If you have ordered and haven't had communication from me, please email me or PM me so I can confirm your order.

Thank you everyone.

David

dingebre · Posted: Sat Nov 24, 2012 6:22 pm Post subject:

SHIPPED.

I shipped the order of everyone who has sent money as of today 11/24/2012, (except one who asked me to wait til after Thanksgiving) So, the US orders should be there Monday or Tuesday. The one U.K. order may take a week or so. Please let me know if there are any problems with your order.

David

dingebre · Posted: Sun Dec 09, 2012 7:20 pm Post subject:

There were a couple of "typos" in the schematic vis a vis the notes and BOM. I think this document set corrects it.

David

SP_Microcon_1.2.pdf

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