Search found 663 matches

by davebr
Mon Jun 22, 2020 12:39 am
Forum: Music Tech DIY
Topic: 208p build thread (papz's PCBs)
Replies: 802
Views: 56740

Re: 208p build thread (papz's PCBs)

Rats, I read the board backwards. I only have a image of a EMS board and There is a trace similarly placed under the waveshape pot. However, when I wiggled the MO pot, I might have moved the motherboard and gotten the CO to touch. I guess I'll pull it again and raise that pot just in case.

Dave
by davebr
Sat Jun 20, 2020 9:21 pm
Forum: Music Tech DIY
Topic: 208p build thread (papz's PCBs)
Replies: 802
Views: 56740

Re: 208p build thread (papz's PCBs)

Maybe this will help a builder someday. There was a hard to find short between quiet ground and -15V on the motherboard of a 208 I'm currently building. It was caused by a metal tab below the CO fine tuning pot touching the -15V trace of its CW terminal. I didn't recognize this tab from the photo b...
by davebr
Thu Jun 04, 2020 8:55 pm
Forum: 5U Format Modules
Topic: Pony-Tails and Moog (MU/5U) modulars
Replies: 45
Views: 1859

Re: Pony-Tails and Moog (MU/5U) modulars

I just couldn't resist. I will say I've never seen anyone with a ponytail play a Moog. I would expect that of some other unnamed format. I haven't had a ponytail since college when I couldn't afford a haircut, and that was 46 years ago. However, after trimming my beard for 34 years in the workplace,...
by davebr
Thu May 21, 2020 11:42 pm
Forum: Buchla, EMS & Serge
Topic: Program Card for V1 Easel Clone
Replies: 16
Views: 580

Re: Program Card for V1 Easel Clone

papz wrote:
Wed May 20, 2020 10:18 am
Thanks for the feedback.

The rev1 calibration procedure is on http://emcloned.com/viewtopic.php?f=17&t=244#p3752
Registration is needed.
I also have a page with some tips and mods on the 208 V1 module.

Dave
by davebr
Sat May 09, 2020 2:05 am
Forum: Buchla, EMS & Serge
Topic: 281 R Gate Light?
Replies: 9
Views: 302

Re: 281 R Gate Light?

I can never remember so I finally put a description and scope images on my 281 Quad Function Generator page.

Dave
281_quadrature_quad_pan1.jpg
by davebr
Sat Apr 11, 2020 5:30 pm
Forum: 5U Format Modules
Topic: New Moog module photos
Replies: 8
Views: 1370

Re: New Moog module photos

I just added a number of new internal photos of the Timing Clock courtesy of the owner on the CEMS Clock page.

Dave
by davebr
Mon Apr 06, 2020 8:34 pm
Forum: Eurorack Modules
Topic: Plan B Model 13 Dual Timbral Gate - Setup/uses
Replies: 45
Views: 5279

Re: Plan B Model 13 Dual Timbral Gate - Setup/uses

I'm wondering what people use their Model 13 for... the filter doesn't do much and the VCAs don't totally close (they leak a little in Amp mode and a lot in Filter + Amp mode.) It also "rings" for so long that I can't really do anything percussive with it - if I want it to close in any reasonable a...
by davebr
Tue Mar 31, 2020 12:53 am
Forum: Buchla, EMS & Serge
Topic: Roman 245 / 246 CV pot "dead zone" fix
Replies: 7
Views: 1147

Re: Roman 245 / 246 CV pot "dead zone" fix

Old news but my fix for completeness of this thread is on my 245 Sequential Voltage Source module and the 246 Sequential Voltage Source page.

Dave
by davebr
Sat Mar 28, 2020 11:53 am
Forum: 5U Format Modules
Topic: Dotcom Bat Meter is back
Replies: 25
Views: 1432

Re: Dotcom Bat Meter is back

I bought one and my system is mostly MOTM so I need to make a power adapter cable. I emailed them and they confirmed the power is +/-15V for the LEDS only. No +5V is used. The meter works unpowered.

Dave
by davebr
Wed Mar 11, 2020 6:11 pm
Forum: Buchla, EMS & Serge
Topic: BENJOLIN 4U
Replies: 73
Views: 9179

Re: BENJOLIN 4U

He sent me a PCB and panel set for my help so I built it. I have a few pictures on my Buchla format Benjolin page. I didn't add any operational information since I have that on my 5U Bejjolin page.

Dave
by davebr
Tue Mar 10, 2020 1:46 am
Forum: Music Tech DIY
Topic: Oxidized CMOS chips from Mouser
Replies: 18
Views: 1616

Re: Oxidized CMOS chips from Mouser

I just opened a shipment from Mouser. All the TL072, TL074, and a CD4021 parts were tarnished so I had to clean them before installing. Is the CD4021 date code really 1993? What is the top date code - 1998, 2008?

Dave
Mouser ICs.jpg
by davebr
Tue Mar 10, 2020 1:37 am
Forum: Buchla, EMS & Serge
Topic: Easel program card and MO range
Replies: 5
Views: 341

Re: Easel program card and MO range

I am wondering if I couldn’t use a program card, a switch and two resistors to be able to switch the MO between Lo and High range. Is this possible? This is exactly what I did although I used trimmers so I could trim them exactly The switch is 3 position so +1 oct, 0, +2 oct. It's at the bottom of ...
by davebr
Tue Mar 03, 2020 12:26 pm
Forum: Fractional Rack Modules
Topic: Frac-format Serge WAD
Replies: 4
Views: 996

Frac-format Serge WAD

I just built a Serge WAD in a Frac-format for a customer. It uses the CGS-208 PCB so it is a deep module. Photos and such on my Frac WAD page.

Dave
serge_wad_frac_panel.jpg
by davebr
Fri Feb 28, 2020 2:31 am
Forum: Music Tech DIY
Topic: Oxidized CMOS chips from Mouser
Replies: 18
Views: 1616

Re: Oxidized CMOS chips from Mouser

I get them every couple of orders on older DIP parts. I've had plenty of CD4XXX as well as some of the comparators be tarnished. I have a sharpened pink pearl eraser that I use to polish the inside and outside of the pins. I've never had enough oxidation that I think there would be a problem but I l...
by davebr
Wed Feb 26, 2020 11:54 pm
Forum: 5U Format Modules
Topic: Bass pedals
Replies: 16
Views: 1226

Re: Bass pedals

I built mine 16 years ago with a set of Hammond spinet pedals and a Basic Stamp. I made provisions for CV/Gate/Trigger output but never wired up that portion. I've stayed with MIDI all these years and it works fine. Wow, the videos really look dated on that page with the camera technology back then....
by davebr
Wed Feb 19, 2020 2:31 pm
Forum: 5U Format Modules
Topic: New Moog module photos
Replies: 8
Views: 1370

New Moog module photos

I create web pages with photos of the Moog modular restorations I do. Individuals contact me from time to time with unique modules they have. If they send me photos I create pages for those as well. I just created pages with some of the unique CEMS modules and the 959 XY Controller. Previously I cre...
by davebr
Thu Feb 06, 2020 8:20 pm
Forum: Buchla, EMS & Serge
Topic: Buchla 207r (Clone)
Replies: 6
Views: 592

Re: Buchla 207r (Clone)

I fixed the page and added a reference diagram for V3 from a PCB image I had. He wants to adjust the vactrol gain so A left, A right, F left, and F right match the other channels I believe.

Dave
by davebr
Mon Dec 30, 2019 1:11 pm
Forum: Music Tech DIY
Topic: parts sourcing for Buchla format modules
Replies: 59
Views: 4590

Re: parts sourcing for Buchla format modules

First, on my 204 Quad Spacial Director page I had to replace one of the joysticks that burned out. I found many physically the same but not the correct value. I just chose to use one of a different value. It is simply a voltage divider with a direct output. The issue is if you short the output while...
by davebr
Mon Dec 30, 2019 12:49 pm
Forum: Modular Synth General Discussion
Topic: Static Electricity
Replies: 15
Views: 1539

Re: Static Electricity

I have a banana jack on the front of one of my power panels that is tied to ground. I can use it either with a wrist strap or more often I have just a plate on the desk. I always touch it first.

Dave
by davebr
Thu Dec 26, 2019 8:07 pm
Forum: Fractional Rack Modules
Topic: PAiA V/Hz Interval Scaler
Replies: 1
Views: 1105

PAiA V/Hz Interval Scaler

A customer asked me to make him an interval scaler for a PAiA. PAiA is a V/Hz so you can't just add or subtract voltages from the CV. You can, however, multiply them with scale factors. -1 octave or +1 octave are simply multiplying by 0.5 or 2. He wanted a major and minor third and a major fifth. Th...
by davebr
Thu Dec 12, 2019 1:02 am
Forum: Fractional Rack Modules
Topic: PSIM-1 Club
Replies: 23
Views: 1745

oozitron I hope you post some more this weekend. I need to understand the way the data from IN1,IN2,IN3 could be clocked (perhaps using IN4 as a clock providing the BPM instead of having it as a constant ie get this part 'BPM=300 ' Change this to how ever many Beats Per Minute you want. 'TEMPO=6000...
by davebr
Sat Nov 30, 2019 1:19 am
Forum: Fractional Rack Modules
Topic: PSIM-1 Club
Replies: 23
Views: 1745

Re: PSIM-1 Club

David Brown was an avid developer. I forget his Muffname but I think we are Facebook friends. Cheers! John Mahoney I did a lot of hardware and software development for the PSIM in a 5U format. I added MIDI, SpeakJet and the TTS256 text to speech, and an LCD display. I developed a set of drivers usi...
by davebr
Thu Nov 28, 2019 2:50 pm
Forum: Modular Synth General Discussion
Topic: Tuning VCOs to each other & A440?
Replies: 20
Views: 1644

The second module I made for my system was a final output mixer setup to drive an external amplifier. I incorporated a three channel mixer with clipping detector, spring reverb, and an A-440 sine oscillator which is the fourth input to the mixer. That way I always can generate a tuning reference wit...
by davebr
Thu Nov 07, 2019 3:11 pm
Forum: Music Tech DIY
Topic: How do I connect this board to this faceplate?
Replies: 6
Views: 853

Re: How do I connect this board to this faceplate?

Those pots are mounted on the board so you don't have to hand-wire them. You should not use them to mount the board. The leads aren't designed for that amount of stress, although it will work but won't be robust. What you can't see in that photo is my bracket. The bracket mounts between those two po...
by davebr
Wed Nov 06, 2019 7:27 pm
Forum: Modular Synth General Discussion
Topic: Bringing modular into my STEAM classroom.
Replies: 5
Views: 920

6th Grade Wave Class

I teach a 6th grade wave class on demand as part of our STEM efforts at the vintageTEK museum. I take a lot of gear. Their science book covers waves, typically ocean waves and a slinky. My objective is to give a pretty high level overview of a LOT of material hoping to spark some particular interest...

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