Elists: synth-diy

Re: [sdiy] What to do with XC4003A's

2001-06-09 15:43:44

The XC4003 is very small, 3000 gates, 200 flip flops. I have thought about what you are talking about. I have expermented with the Altera tools and their APEX parts (100,000 gates), and yep, you can do some pretty cool things in those. Time is the major killer of big projects like that at the moment. -Jim Grant Richter wrote: > Hi Jim, > > I don't know what the gate count is for that part. But if it is high enough > you can implement a full multi-timbral multi voice synth engine including > keyboard encoder. > > My best friend is the Chicago area Xilinx field application

Fw: [sdiy] Digitally controlled VCO core

2001-06-09 14:47:01

----- Original Message ----- From: Paul Maddox To: Sent: Saturday, June 09, 2001 10:46 PM Subject: Re: [sdiy] Digitally controlled VCO core > Mikko, > > Get hold of a copy of the ROLAND JX8p/3p manual, > it in there, Its also in the JUNO range aswell... > > The amplitude thing is easily done by one of two methods.. > one icreasing the VCA level as you move up the scale > and/or, > Haveing ranges and different capacitor chargeing currents for each range. > > An easier solution would be to use a micro to generate the sawtooth > useing phase accumulator techniques... you can have a reso

Re: [sdiy] Synthfool is back in town...

2001-06-09 14:56:11

From: Richard Subject: Re: [sdiy] Synthfool is back in town... Date: Sat, 9 Jun 2001 21:12:37 +0100 > In message , Magnus Danielson > writes > >Maybe some of you would like to see this... > > > >http://www.sonicstate.com/synthfool/ > > > >I guess Kevin could not hold his horses... I knew something was > >cooking in the behind... > > > >Cheers, > >Magnus > > > > > All I get is a page not found message.... It did work for me... I can find several pages, but it seems like the site is flakey or on a low bandwidth. Don't kill the messenger... I only report the news! ;-P Cheers, Magnus

Re: [sdiy] What to do with XC4003A's

2001-06-09 14:42:47

From: patchell Subject: Re: [sdiy] What to do with XC4003A's Date: Sat, 09 Jun 2001 12:37:31 -0700 > > > Magnus Danielson wrote: > > > > > Yeah... if you do the phase accumulator you got the frequency > > divisions for free. Toss it through waveshaping and spurt out tones > > and you could even build yourself a Hammond organ equalent... ;O) > > > > Cheers, > > Magnus > > Now, this is a subject I am pretty ignorant on (Hammond organ tone > generators). I guess I have no excuse for being ignorant on this subject > (My father repairs old Hammond organs as a quasi hobby/business),

Re: [sdiy] 1S2473 vs. 1N4148 diode specs

2001-06-09 14:15:12

Hi, Ok, for a moment let's forget about the 0.7V drop theory and have a look at some practical values: I got my DMM hooked up to my Polysix and I measured a voltage drop of 0.4V across the diode (D19) that runs from the 5V power supply rail to the RAM memory. And the most interesting part: the 1N4148 diode, in between the Lithium battery and the RAM power line, gives a 0.25V voltage drop when the synth is turned off. Yes, of course the circuit could've designed better from the start in Japanese and other equipment, but in practice the voltage drop isn't as large as one would expect from

Re: [sdiy] What to do with XC4003A's

2001-06-09 13:40:51

Message text written by patchell > Now, this is a subject I am pretty ignorant on (Hammond organ tone generators). I guess I have no excuse for being ignorant on this subject (My father repairs old Hammond organs as a quasi hobby/business), but I am. Are there any good descriptions on the internet that explain the operation of a Hammond tone generator/organ. Did they all use drawbars? -- -Jim< Hi Jim: Check out this web site, it has many Hammond organ and Leslie speaker related links, including some that describe the design and operation of the Hammond tone generator. http://cc.

Re: [sdiy] Synthfool is back in town...

2001-06-09 13:12:37

In message , Magnus Danielson writes >Maybe some of you would like to see this... > >http://www.sonicstate.com/synthfool/ > >I guess Kevin could not hold his horses... I knew something was >cooking in the behind... > >Cheers, >Magnus > > All I get is a page not found message.... -- Richard

Re: [sdiy] What to do with XC4003A's

2001-06-09 12:37:31

Magnus Danielson wrote: > > Yeah... if you do the phase accumulator you got the frequency > divisions for free. Toss it through waveshaping and spurt out tones > and you could even build yourself a Hammond organ equalent... ;O) > > Cheers, > Magnus Now, this is a subject I am pretty ignorant on (Hammond organ tone generators). I guess I have no excuse for being ignorant on this subject (My father repairs old Hammond organs as a quasi hobby/business), but I am. Are there any good descriptions on the internet that explain the operation of a Hammond tone generator/organ. Did they a

Re: [sdiy] What to do with XC4003A's

2001-06-09 12:41:10

Hi Jim, I don't know what the gate count is for that part. But if it is high enough you can implement a full multi-timbral multi voice synth engine including keyboard encoder. My best friend is the Chicago area Xilinx field applications engineer. We have spent much time discussing the possibilities of big FPGAs as the new hobbiest/hacker/midnight engineering hardware platform of choice. With a sufficient gate count, you can "hardware code" complex functions that would otherwise take a microprocessor and software. Since one of the graphical interfaces is schematic based, it allows hardw

[sdiy] Synthfool is back in town...

2001-06-09 12:47:57

Maybe some of you would like to see this... http://www.sonicstate.com/synthfool/ I guess Kevin could not hold his horses... I knew something was cooking in the behind... Cheers, Magnus