Search found 6509 matches

by daverj
Wed May 11, 2016 1:24 pm
Forum: Eurorack Modules
Topic: Announcement: ** Jones O'Tool Plus **
Replies: 201
Views: 23681

Some differences from the original O'Tool: - temperature stable tuner and frequency meter - extremely accurate (the frequency meter tracks my professional freq meter from 1/10Hz to 100KHz) - voltage scales are now +/-6v and +/-12v instead of +/-5v and +/-10v, so signals have some headroom in the dis...
by daverj
Wed May 11, 2016 1:11 pm
Forum: Eurorack Modules
Topic: Announcement: ** Jones O'Tool Plus **
Replies: 201
Views: 23681

The following dealers will be carrying the O'Tool Plus. There are a couple of more that I am waiting to hear back from. Not all dealers will have the same quantities, and the total quantities are limited in the initial run. So many smaller dealers might sell out very quickly. (and one dealer asked n...
by daverj
Wed May 11, 2016 1:10 pm
Forum: Eurorack Modules
Topic: Announcement: ** Jones O'Tool Plus **
Replies: 201
Views: 23681

Announcement: ** Jones O'Tool Plus **

I know you guys have been waiting for a long time for this, and you'll have to wait just a little bit longer..... About two more weeks. Shipping around the end of May 2016, the new O'Tool Plus oscilloscope and audio tools module. It looks a lot like the old one, but it's a whole lot more. https://ww...
by daverj
Tue Jan 05, 2016 2:07 pm
Forum: Eurorack Modules
Topic: Coming in 2016?
Replies: 94
Views: 12133

Desperately hoping that the Dave Jone's O'Tool+ comes out early in 2016. It will. I just finished tweaking the frequency meter/tuner section so that it now tracks my precision 8 digit frequency meter within +/-0.0002% all the way from 1/2 Hz to 100KHz (with no temperature drift). Still have lots mo...
by daverj
Fri Sep 25, 2015 10:09 pm
Forum: Video Synthesis
Topic: Experimental TV Center show in NYC
Replies: 7
Views: 681

The show is up September 25–November 21, 2015 There's two sections on the main floor (ground floor and a mezzanine), and more up on the 2nd floor. (elevator from the mezzanine) It was good meeting you Matt. The opening was amazing. There was kind of two openings. From 5-7 was a walk through for patr...
by daverj
Sun Sep 20, 2015 12:18 am
Forum: Video Synthesis
Topic: Visualist - Build startet, some question
Replies: 10
Views: 1656

Aaha. Something I did not know about :) And I cant really find them also. But: if I look at the Schematics, it is supposed to be IC Pin 17 -> 4,43Mhz Crystal -> 30p vari cap -> GND. But if I look at the layout, it goes Pin 17 -> 4,43Mhz Crystal -> GND. The vari cap has a place, but its second leg g...
by daverj
Fri Sep 18, 2015 3:03 pm
Forum: Video Synthesis
Topic: Experimental TV Center show in NYC
Replies: 7
Views: 681

Experimental TV Center show in NYC

Hi folks. I've been away from here all summer, and will still be here rarely in the next couple of months. Hopefully life calms down a bit after that. For those of you in and around New York City, there is a show opening next week at Hunter Galleries, 205 Hudson St. (entrance is on Canal). It is up ...
by daverj
Sat Jun 13, 2015 3:38 pm
Forum: Video Synthesis
Topic: Sharp QC-54 (1985)
Replies: 1
Views: 594

I used black and white cameras with Newvicons back then. Not color. The Newvicon was designed for low light indoor use, so not too surprising that the colors were off a bit outdoors. Plus single tube cameras got their color by placing a striped filter in front of the tube and using electronics to ex...
by daverj
Sat Jun 13, 2015 3:07 pm
Forum: Video Synthesis
Topic: What video camera to buy? - ipad isn't doing it for me
Replies: 5
Views: 762

Generally the cheap stuff doesn't have external audio inputs. The higher priced stuff does, but is past your budget.

Maybe find a higher end one used?
by daverj
Sat Jun 13, 2015 2:02 pm
Forum: Eurorack Modules
Topic: post-oscillator PWM
Replies: 15
Views: 925

A comparator with two inputs lets you feed in a triangle or ramp on one and a voltage to do the modulation into the other. For a comparator with only one signal in and a knob, you would need to mix the ramp/tri first with the modulation voltage before going into the comparator. That's assuming you w...
by daverj
Sat Jun 13, 2015 1:56 pm
Forum: Eurorack Modules
Topic: how to stop the bleeding
Replies: 4
Views: 464

Are you testing it with just the knobs, or with a CV and the knobs? Does your CV go all the way to -5v?

There might be a difference between using only the knob vs a combination of CV and various knob settings. (I don't have one, so just guessing)
by daverj
Sat Jun 13, 2015 12:38 pm
Forum: Eurorack Modules
Topic: Power supplies, Analogue Systems and such
Replies: 12
Views: 653

Part of the reason that costs what it does is because it's sold for industrial use, and is fully tested and certified internationally. But another part is that it has 3 outputs. That 5 volt output in addition to the +/-12v adds to the cost. Do another search for the HAA15 and you'll see the savings ...
by daverj
Fri Jun 12, 2015 2:09 pm
Forum: Video Synthesis
Topic: PBB high-pitched tone and possible repair, super confused
Replies: 12
Views: 651

Can you tell where the sound is coming from? Is it coming from the brick/wall wart? Or is it coming from one or both of the power boards? (or even from a module plugged into one? If it's hard to judge direction of the sound, then maybe holding some bubblewrap over each object one after the other wil...
by daverj
Tue Jun 09, 2015 1:34 pm
Forum: Music Tech DIY
Topic: schematic feedback please
Replies: 14
Views: 576

These days people should be trying to move away from 5% resistors and stock up on 1%. The prices are not far apart. 30.1K is the standard value for anything tighter than 5%. On the other hand I don't know where the 61.1K comes from. That's not a standard value at any tolerance. 61.9K is standard at ...
by daverj
Tue Jun 09, 2015 1:02 pm
Forum: Eurorack Modules
Topic: uZeus limits/power concerns
Replies: 16
Views: 1021

Be sure to double check all of the power needs of the modules with the manufacturers sites. The numbers on ModularGrid are not always accurate (if you find discrepancies, fix them on ModularGrid) Don't add the +12 to the -12. They are independent totals that you need to be aware of. And the uZeus ha...
by daverj
Mon Jun 08, 2015 3:11 pm
Forum: Music Tech DIY
Topic: Laser cut wood faceplate?
Replies: 11
Views: 852

I use two pieces of Baltic Birch plywood. Each about 1/16" (1.6mm) thick. The top one has the mounting holes for the panel parts plus the labels. I glue a second piece behind it with different shaped holes that go around the panel parts, but reinforces the wood panel since a single sheet is not very...
by daverj
Mon Jun 08, 2015 3:01 pm
Forum: Music Tech DIY
Topic: Lightpipes for SMD leds
Replies: 4
Views: 377

Assuming that you have other through hole parts on the board, such as jacks, switches, pots, etc... then another approach is to use a simple LED spacer with a through hole LED. They come in lots of lengths, are very cheap, and hold the LED the right distance off of the board during soldering. If you...
by daverj
Sun Jun 07, 2015 3:06 pm
Forum: Music Tech DIY
Topic: Whats the difference between -12V and Ground?
Replies: 48
Views: 1991

If I were designing a brainwave to audio modular system, here is what I would probably do: I would want the part connected to the head to be powered by a battery. And signals that I want to extract would go though some type of electrical isolation circuit to get to the modular with no direct power/g...
by daverj
Sun Jun 07, 2015 2:27 pm
Forum: Modular Synth General Discussion
Topic: Lineal VS Switching Power Supply Sound Quality
Replies: 19
Views: 4715

There's no simple answer to your question. Are switching supplies noisier than linear supplies? Generally yes. Is that a problem? Sometimes. A good circuit designer takes into account the entire system, including the power source, when designing a circuit. If a designer assumes that the power source...
by daverj
Fri Jun 05, 2015 1:11 pm
Forum: Video Synthesis
Topic: PXL-2000
Replies: 8
Views: 859

The Pixelvision sensor and recorder are only 120x90 pixels at 15 frames per second. It uses a memory chip to act almost like a TBC to bring that up to the normal 30 frame (60 fields) rate of NTSC. It uses a Chromium Dioxide (high magnetic permeability) audio tape running at about 9-10 times normal s...
by daverj
Fri Jun 05, 2015 12:30 pm
Forum: Music Tech DIY
Topic: Looking for passive wave rectifier schemo
Replies: 4
Views: 331

The simplest circuit is to feed a signal into one end of a diode and connect the other end to a resistor going to ground. The output is at the resistor. This is a half wave rectifier. The output contains the portion of the input signal that is above or below ground, depending on the direction the di...
by daverj
Fri Jun 05, 2015 12:18 pm
Forum: Music Tech DIY
Topic: Whats the difference between -12V and Ground?
Replies: 48
Views: 1991

Just to add to the confusion, lets clear up a couple of terms being thrown around. A "ground" or "zero volt" point in a unipolar power supply driven circuit that is artificially created between the two power supply voltages of the unipolar supply (ie: the ends of a 9 volt battery) is usually called ...
by daverj
Thu Jun 04, 2015 11:29 am
Forum: Video Synthesis
Topic: PXL-2000
Replies: 8
Views: 859

Video artists discovered those almost as soon as they came out. Within a couple of years of being discontinued they were widely sought out by film and video students, some of whom were willing to pay a lot of money for them. Then bigger artists and filmmakers discovered them as an "effect" and the p...
by daverj
Thu Jun 04, 2015 11:14 am
Forum: Music Tech DIY
Topic: Voltage References - How and when?
Replies: 4
Views: 330

You could use the voltage references to power the Tune pot and trimpot, which would isolate them from the power rails. The C922 doesn't use much power. You can probably power it off of the 4040 also (adjusting the resistor as needed). That won't make it any more accurate, but it will isolate it from...
by daverj
Thu Jun 04, 2015 10:49 am
Forum: Music Tech DIY
Topic: Linear Power Supplies - Fuses blowing on Powerup?
Replies: 11
Views: 503

Hi Dave, I'm in the UK so 1A is the stated value. Over there the slow-blow fuses should typically have a "T" marking on them (for Time lag). Like "1A T" It's odd that you would have the same issue with two separate units in two separate cases. You've double checked the wiring to the primary? If it ...

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