Computerized Audio Project.

Started by Ken S. Tucker in sci.electronics.design9 years ago 34 replies

We using the printer cable to send 8 bit waveforms to a speaker. I figure using a DAC-08 (D to A converter) will create any sound we want, in...

We using the printer cable to send 8 bit waveforms to a speaker. I figure using a DAC-08 (D to A converter) will create any sound we want, in 0-255 amplitudes. Essentially were making a speech synthesizer. Ken


THD and DC performance

Started by Vladimir Vassilevsky in sci.electronics.design9 years ago 30 replies
DAC

Is there such DAC in the world, that would allow for: * pure THD ~ 0.0001%, SNR is not very critical. * frequency response up to several...

Is there such DAC in the world, that would allow for: * pure THD ~ 0.0001%, SNR is not very critical. * frequency response up to several kHz * DC accuracy in 10mV range Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com


Your Favorite ARM?

Started by Martin Riddle in sci.electronics.design8 years ago 31 replies
DAC

Which Mfg has the best options for their ARM processors? I've never worked with a ARM, and I was going to play with a Atmel AVR32, but the ARM...

Which Mfg has the best options for their ARM processors? I've never worked with a ARM, and I was going to play with a Atmel AVR32, but the ARM seems to have more features for a buck or two more. Preferable package is LQFP. And not so pricey tools. 12 bit DAC and ADC a plus. Cheers


TI DAC2904 dual DAC

Started by John Larkin in sci.electronics.design2 years ago 3 replies
DAC

Has anyone used the DAC2904? We don't entirely understand the timing. We asked TI for help, and thay said "Oh, that's an old Burr-Brown part,...

Has anyone used the DAC2904? We don't entirely understand the timing. We asked TI for help, and thay said "Oh, that's an old Burr-Brown part, nobody knows much about that." -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com


Where to get high speed ADC's and DACs

Started by RobertMacy in sci.electronics.design6 years ago 48 replies
DAC

Where do I get 24 bit high speed ADC and DAC systems out to 10MHz? Or, turn around how much digitization can I get out to 100MHz today? 20 ...

Where do I get 24 bit high speed ADC and DAC systems out to 10MHz? Or, turn around how much digitization can I get out to 100MHz today? 20 bits?


Photonic ADC and DAC-good books

Started by AntonF in sci.electronics.design2 years ago
DAC

Hi! Could you recommend good books/materials on: - photonic ADCs and DACs - radio-photonics thanks!

Hi! Could you recommend good books/materials on: - photonic ADCs and DACs - radio-photonics thanks!


The Anything Transmitter - progress report..... Update

Started by Jan Panteltje in sci.electronics.design6 years ago

I wrote (not the 'I' for 'I' and 'Q'): > It Works! > > The I (and Q) signal at the modulator looks almost digital.. recorded that way with...

I wrote (not the 'I' for 'I' and 'Q'): > It Works! > > The I (and Q) signal at the modulator looks almost digital.. recorded that way with rtl_sdr: > http://panteltje.com/pub/rtl_sdr_recorded_I_signal_at_QAM_modulator_IMG_3857.GIF > Funny, it occurred to me I am likely sending signed 8 bits into that DAC.. > (rtl_sdr recording format). No I did it right, rtl_sdr records unsigned!


The Anything Transmitter - progress report..... Update

Started by Jan Panteltje in sci.electronics.design6 years ago
DAC

I wrote (not the 'I' for 'I' and 'Q'): > It Works! > > The I (and Q) signal at the modulator looks almost digital.. recorded that way with...

I wrote (not the 'I' for 'I' and 'Q'): > It Works! > > The I (and Q) signal at the modulator looks almost digital.. recorded that way with rtl_sdr: > http://panteltje.com/pub/rtl_sdr_recorded_I_signal_at_QAM_modulator_IMG_3857.GIF Funny, it occurred to me I am likely sending signed 8 bits into that DAC.. (rtl_sdr recording format). So the signal, even for small amplitudes flips betw


Re: Adjustable current mirror

Started by John Larkin in sci.electronics.design9 years ago

On Fri, 19 Feb 2010 18:29:25 -0600, "Tim Williams" wrote: > "John Larkin" wrote in message >...

On Fri, 19 Feb 2010 18:29:25 -0600, "Tim Williams" wrote: > "John Larkin" wrote in message > news:6a6un59g6aag0i95l8hco6p34ng0t7j3og@4ax.com... > > We are today trying to modify an existing board that has an LC filter > > after a DDS DAC. The Ls are all 1206s, and we want a 100 KHz lowpass. > > It looks very nasty, as we need


Good hardware, poor software

Started by bitrex in sci.electronics.design2 years ago 68 replies
DAC

The graveyard of audio production equipment is littered with the corpses of products that had rock-solid hardware designed by professionals, but...

The graveyard of audio production equipment is littered with the corpses of products that had rock-solid hardware designed by professionals, but firmware written by nincompoops. It's really frustrating when you buy a blinky-light box that some engineers somewhere likely spent thousands of man-hours on designing the best sounding DAC structure they could for the budget, but then the OS ...


Current mirror with gain?

Started by Jan Panteltje in sci.electronics.design8 years ago 49 replies

For some application I need a constant current drive of a few mA, but I only can supply some uA from the opposite rail from a high impedance DAC...

For some application I need a constant current drive of a few mA, but I only can supply some uA from the opposite rail from a high impedance DAC output. A single transistor would do, with a base resistor as drive, but the gain depends on beta, and that drifts with temperature, and from part to part. Any ideas?


Where do you buy instruments, and who makes 'em?

Started by Tim Wescott in sci.electronics.design8 years ago 20 replies

I need to get a nice audio signal generator. Something that refers back to a crystal, instead of a function generator chip. Preferably...

I need to get a nice audio signal generator. Something that refers back to a crystal, instead of a function generator chip. Preferably something with a DDS and a nice high-accuracy DAC. I have something hacked together on proto board that worked astonishingly well, all things considered -- but it's still hacked together on protoboard, and only changes frequency with a change of a crys...


semiconductor drift

Started by John Larkin in sci.electronics.design5 years ago 52 replies

We have two 8-channel waveform generators that were shipped 4 months ago, and came back because the customer ordered too many or something. We...

We have two 8-channel waveform generators that were shipped 4 months ago, and came back because the customer ordered too many or something. We routinely test anything that comes back, before returning them or returning to stock. What's interesting is that all 16 channels have a negative DC offset. Each channel is a diff-current-output cmos DAC, an opamp diffamp, a passive LC filter, and ...


Delta Sigma DAC article

Started by Charlie E. in sci.electronics.design7 years ago 9 replies

Hi All, Ok, going crazy (short trip, I know...) A few months ago, I saw an article that included information on delta sigma DACs, inlcuding...

Hi All, Ok, going crazy (short trip, I know...) A few months ago, I saw an article that included information on delta sigma DACs, inlcuding some code the author had written, I belive for an 8051, to implement one in software. So, now that I finally want to try it out, I can't find it anywhere. Anyone know what magazine or have a link to that article? I thought it was in EDN, but can't f...


Multiplexer sample and hold

Started by bitrex in sci.electronics.design3 years ago 37 replies

In some old schematics for analog music synthesizers, where the analog signal path is under microprocessor control, I see that they use a...

In some old schematics for analog music synthesizers, where the analog signal path is under microprocessor control, I see that they use a multiplexer arrangement to route control voltages around being driven from a single DAC, usually like a DAC08 or something. They feed it into something like a 4051 multiplexer, followed up with a JFET input amp like a TL084 configured as a buffer, ...


continuous-play DAC

Started by John Larkin in sci.electronics.design7 years ago 8 replies

Hi, We have a customer who has a mess of digitized data from some sort of aircraft system, and wants to play it back into some box for...

Hi, We have a customer who has a mess of digitized data from some sort of aircraft system, and wants to play it back into some box for testing. It will be 2 channels of 16-bit data originally sampled at about 500 KHz, several hours worth. They want us to design a VME module with dacs and a huge amount of DRAM to store the data. We don't really want to do it - they only need a couple o...


High res PWMs

Started by Phil Hobbs in sci.electronics.design6 years ago 33 replies
DAC

Hi, all, I've been working on an automatically-tweaked noise canceller design with my trusty code and layout Sherpas-in-training (my son and...

Hi, all, I've been working on an automatically-tweaked noise canceller design with my trusty code and layout Sherpas-in-training (my son and my younger daughter). I need about 10 slow but high resolution DAC outputs for the tweaks, and I was thinking about using PWMs run from the LPC1769 processor. I can close the loop on them with an on-board delta-sigma ADC (the AD7708 or maybe ...


High resolution PWM for fake DACs

Started by Phil Hobbs in sci.electronics.design6 years ago 4 replies

Hi, all, I've been working on an automatically-tweaked noise canceller design with my trusty code and layout Sherpas-in-training (my son and...

Hi, all, I've been working on an automatically-tweaked noise canceller design with my trusty code and layout Sherpas-in-training (my son and my younger daughter). I need about 10 slow but high resolution DAC outputs for the tweaks, and I was thinking about using PWMs run from the LPC1769 processor for at least some of them. I can close the loop on them with an on-board delta-sigma...


Re: wrapper around Spice

Started by Phil Hobbs in sci.electronics.design10 years ago 16 replies

John Larkin wrote: > Suppose I have a fairly complex circuit that includes, say, 10 or 20 > DACs to set up some parameters. I can simulate...

John Larkin wrote: > Suppose I have a fairly complex circuit that includes, say, 10 or 20 > DACs to set up some parameters. I can simulate each DAC with a fixed > voltage source. > > If I create an LT Spice model, I'd like to write a top-level program > that tweaks the DACs and evaluates the circuit output for some sort of > goodness, using some algorithm. So, how do I essentially use LT S


Using Analog to Digital Converter for modulation

Started by chess in sci.electronics.design4 years ago 5 replies

Hi I have written Matlab script for BPSK modulation. The way my code works is as follow: series of 0 and 1----> NRZ data (continuous...

Hi I have written Matlab script for BPSK modulation. The way my code works is as follow: series of 0 and 1----> NRZ data (continuous rectangular pulses with amplitude -1 and 1)---> multiply by carrier----> add noise--> multiply by carrier---> integration---> detection---> Bit Error collection? I would like to know can anyone tell me where I should apply DAC and ADC ? I am wondering should it