Post by thread:Suggestions for a Voltage controlled amplifier of

Hi, Could you nice people suggest a good voltage controlled amp chip (audio) for 4 channels or a matrix switcher with cross point attenuation 9 (chip). This is to be used with a 16f84. I think it is obvious what I am trying to achieve if anyone has another way of attenuating 4 channels of audio (with 2 channels that can be swiched to Mic level) please let me know. Thanks in advance Mathew Cohen

Hi, if you want volume control, could I suggest the MC3340 VCA, which works OK with an RC on the control i/p fed with pulses from the PIC. If you can't tie up the PIC with pulse generation how about using it enable 555 oscillators. For on/off just a fairly simple arrangement of 4066s. Jinx > Could you nice people suggest a good voltage controlled amp chip > (audio) for 4 channels or a matrix switcher with cross point attenuation > 9 (chip). This is to be used with a 16f84.

Mathew, > Could you nice people suggest a good voltage controlled amp chip > (audio) for Some possibilities are: Analog Devices SSM-2018T (single channel VCA) That Corporation 2180 (single channel VCA) Crystal Semiconductor CS3310 (two channel digital volume control) The Crystal part can be interfaced directly to a PIC. The two VCA's have analog control ports and will require some sort of D/A conversion to interface to a PIC. Kelly Kohls, N5TLE Dallas, TX Email: spam_OUTkkohlsTakeThisOuTjuno.com OR .....n5tleKILLspam@spam@qsl.net Homepage: http://www.qsl.net/n5tle/ ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: dl.http://www.juno.com/dynoget/tagj.

Maxim will sample multiplying DAC's in resolutions as high as 14-bit. To use a DAC as a VCA send your signal to the DAC's Vref input. The Vref input will be scaled with the binary word sent by the microcontroller and routed to Vout. External amplification will be needed to drive speakers. National Semiconductor will sample audio amplifier chips with up to 68 watts power handling capability that will probably work fine. The price is right. Good Luck - Keith Causey {Quote hidden}> Mathew, > > > Could you nice people suggest a good voltage controlled amp chip > > (audio) for > > Some possibilities are: > > Analog Devices SSM-2018T (single channel VCA) > > That Corporation 2180 (single channel VCA) > > Crystal Semiconductor CS3310 (two channel digital volume control) > > > The Crystal part can be interfaced directly to a PIC. The two VCA's have > analog control ports and will require some sort of D/A conversion to > interface to a PIC. > > > Kelly Kohls, N5TLE > Dallas, TX > Email: kkohlsKILLspamjuno.com OR .....n5tleKILLspam.....qsl.net > Homepage: http://www.qsl.net/n5tle/ > > ___________________________________________________________________ > Get the Internet just the way you want it. > Free software, free e-mail, and free Internet access for a month! > Try Juno Web: dl.http://www.juno.com/dynoget/tagj.

part 0 3072 bytes Analog Devices do a very nice range of audio mixer ICs, which will handle up to 8 stereo channels, all controlled by a SPI type bus. Have a look at <A HREF="http://products.analog.com/products_html/list_gen_186_2_1.html" TARGET="_blank">products.analog.com/products_html/list_gen_186_2_1.html</A> Hope it works for you, I kept geting an ODBC error, but that may well be my very tired windows installation. Regards Mike Rigby-Jones <UL> {Original Message removed}

<x-flowed>Mathew Cohen wrote: > Could you nice people suggest a good voltage controlled amp chip (audio) for > 4 channels or a matrix switcher with cross point attenuation 9 (chip). This > is to be used with a 16f84. > I think it is obvious what I am trying to achieve if anyone has another way > of attenuating 4 channels of audio (with 2 channels that can be swiched to > Mic level) please let me know. AD have the SSM2163 4/8 way volume control. NS have the LM1971 / LM1972 / LM1973 series. I've used both of these before - SPI interface IIRC. Regards... _______________________________________________________________ Dave Duffy Audio Visual Devices EraseMEAVDspam_OUTTakeThisOuTuq.net.au Unit 8, 9-11 Trade Street, Cleveland, Queensland 4163 Australia Phone: +61 7 38210362 Facsimile: +61 7 38210281 _______________________________________________________________ </x-flowed>

On Mon, 8 Nov 1999, Mathew Cohen wrote: > Could you nice people suggest a good voltage controlled amp chip (audio) for > 4 channels or a matrix switcher with cross point attenuation 9 (chip). This > is to be used with a 16f84. Either 1) buy some CEM3330 dual VCA chips from Paul at http://www.synthtech.com, or go to someplace like http://www.synthfool.com and look at schematics of OTA-based VCAs. --Crow /**/

> Mathew Cohen wrote: > > Could you nice people suggest a good voltage controlled amp chip (audio) fo r > > 4 channels or a matrix switcher with cross point attenuation 9 (chip). This > > is to be used with a 16f84. > > I think it is obvious what I am trying to achieve if anyone has another way > > of attenuating 4 channels of audio (with 2 channels that can be swiched to > > Mic level) please let me know. > I have used the quad VCA made by Analog Devices SM2164 for dynamic audio routing(Dolby Surround), works well. For simple digital volume control I have used the National LM1972, its only dual but the attn steps are known and there is a handy mute command. _____________________________ Lance Allen Technical Officer Uni of Auckland Psych Dept New Zealand http://www.psych.auckland.ac.nz _____________________________