Search found 672 matches

by davebr
Tue Jan 05, 2021 8:29 pm
Forum: Music Tech DIY
Topic: a440 mixer schematic advise
Replies: 7
Views: 246

Re: a440 mixer schematic advise

Email me and I'll walk you through some stuff.

Dave
by davebr
Tue Dec 22, 2020 11:49 pm
Forum: 5U Format Modules
Topic: Do 5U modules come with power cables?
Replies: 9
Views: 307

Re: Do 5U modules come with power cables?

I also solder all my MTA cables. For the MOTM power cables I use 20 AWG wire and I made myself a punchdown tool out of a screwdriver. I always put the connector in my vice sideways and solder it from the "side". I had one where the solder wicked down and I couldn't insert it so switched to the horiz...
by davebr
Thu Nov 05, 2020 3:07 pm
Forum: Buchla, EMS & Serge
Topic: Buchla 244 mods: CGS ASR and Pulse circuitry
Replies: 15
Views: 2414

Re: Buchla 244 mods: CGS ASR and Pulse circuitry

The CGS-34 V2 is so much better that I decided to remove the ASR components from the 244 and piggyback the CGS on the rear. You can make all the connections to PCB2. I used the trigger and counter circuitry on the 244 and the input and shift registers on the CGS. I put instructions for both mods on ...
by davebr
Wed Nov 04, 2020 4:37 pm
Forum: Buchla, EMS & Serge
Topic: Buchla 244 mods: CGS ASR and Pulse circuitry
Replies: 15
Views: 2414

Re: Buchla 244 mods: CGS ASR and Pulse circuitry

I have been doing some experiments with the 244 ASR trying to improve it. The circuit topology of the S&H has several issues. A CD4052 powered from +15V is used as the multiplexer to the S&H cells and the demultiplexer for the outputs. That means to have a wide +/- signal range, the input has to be ...
by davebr
Fri Oct 16, 2020 8:42 pm
Forum: 5U Format Modules
Topic: 'Scope for inclusion in 5U rack?
Replies: 7
Views: 401

Re: 'Scope for inclusion in 5U rack?

It's dated but here is my 5U 5U module . https://modularsynthesis.com/modules/DJB-019/djb-019.jpg Later I used these for a PAiA module . It's color and probably a better solution although by now there are probably even better LCD scopes. https://modularsynthesis.com/paia/4700/scope/scope.jpg Dave
by davebr
Tue Sep 29, 2020 2:46 pm
Forum: Music Tech DIY
Topic: BMC016. Dual Nice Quantizer
Replies: 84
Views: 12270

Re:

TL074 P ... ? What in blazes is the "P" suffix for? I cannot seem to locate it anywhere within the Texas Instruments datasheets, Mouser gives me the finger when I search for it there, so does Small Bear. The Dual Nice Quantizer v1.2 has "TL074P" silk screened on the PCB. Is this something extraordi...
by davebr
Tue Sep 15, 2020 8:45 pm
Forum: Modular Synth General Discussion
Topic: What Amp / Monitors do you use in your home for Synth?
Replies: 28
Views: 866

Re: What Amp / Monitors do you use in your home for Synth?

Old school here. Custom output module to a Carver PM-600 to JBL L100S speakers. I have two other synth setups in the room, both with Carver PM-600s. One driving JBL 4311 Control Monitors and the other driving JBL L80S. I like Carvers and JBL.
by davebr
Tue Sep 15, 2020 8:08 pm
Forum: Buchla, EMS & Serge
Topic: MARF 248r source code available
Replies: 245
Views: 19892

Re: MARF 248r source code available

Per above There are also good operational descriptions for the new firmware features there. Dave Brown's 248 V2 page Programmed Pulse out LED Swapping. You no longer have to do the resistor swapping mod. We now handle that in firmware with a interface on the panel. Since I was running on a board whe...
by davebr
Thu Sep 03, 2020 12:09 am
Forum: Buchla, EMS & Serge
Topic: Help me understand the QRV outputs on my 266r
Replies: 12
Views: 1111

Re: Help me understand the QRV outputs on my 266r

When I took all those scope images and really understood the 266 I did so on my 5U version which had my custom panel so everything matched. My Buchla V2 matches the panel. I don't have a V3 to verify but as you've noted it is pretty easy to tell. At N=1 both outputs have just two values as seen in t...
by davebr
Mon Jun 22, 2020 12:39 am
Forum: Music Tech DIY
Topic: 208p build thread (papz's PCBs)
Replies: 856
Views: 70832

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: 856
Views: 70832

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: 50
Views: 3238

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: 908

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: 518

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: 1599

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: 5774

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: 1309

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: 1950

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: 74
Views: 10842

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: 1938

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
Mouser ICs.jpg (58.58 KiB) Viewed 85 times
by davebr
Tue Mar 10, 2020 1:37 am
Forum: Buchla, EMS & Serge
Topic: Easel program card and MO range
Replies: 5
Views: 465

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: 1254

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
serge_wad_frac_panel.jpg (91.14 KiB) Viewed 429 times
by davebr
Fri Feb 28, 2020 2:31 am
Forum: Music Tech DIY
Topic: Oxidized CMOS chips from Mouser
Replies: 18
Views: 1938

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: 1712

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: 1599

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...

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