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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: poorlyconditioned on January 31, 2006, 10:37:07 PM
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Hi there. I've been doing a lot (too much!) hacking on UA5's lately.
I fixed a failed digimod unit.
Then I played with all kinds of opamps in my own unit. I finally settled on an AD712 input stage followed by a pair of AD8620's for the ADC driver stage. I would have went with all AD8620's except that I only had two of each type (samples from Analog Devices :)). The chips are real expensive to buy as well. (AD8620 is something like $10-15!, AD712 is $5-10 I think.)
OK, I'm thinking, how about putting a pair of INA217 opamps in there (samples from Texas Instruments this time :)). They are 8pin DIP, so they would need a small board added in there, but it seems like it should be possible. There is a +/-5V power supply. And the INA217 chips each take only 10mA each. So either disconnect the some of the other opamps, or just load another 20mA, which is not too much IMO.
Hey, I think what I'm going to do is leave my unit the way it is and put a switch to swap out an INA stage for the existing AD stage.
I can't keep my hands off of this puppy!!!
Richard
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Is there anything special you have to tell them to get samples. I've filled out the web form in the past and never gotten anything. I'd love to try a TI DAC or ADC in a project one of these days.
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The INA217 is a single channel op amp so you would need a daughter board with two of these to replace each op amp already there. There are good dual op amps that work well.
The AD8620 is a nice sounding op amp I like that one but it is expensive to buy.
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The INA217 is a single channel op amp so you would need a daughter board with two of these to replace each op amp already there. There are good dual op amps that work well.
The AD8620 is a nice sounding op amp I like that one but it is expensive to buy.
Hey, thanks for the info Chris. I'm thinking exactly what you say, "daughterboard". I don't think that would be hard, at least with my "heatshink-hotmeltglue" approach! I'm just tempted because: 1) the UA5 already has +/-5V supplies, 2) it has all the XLR input stuff (caps, etc), 3) and well, because I can do it!
I think new trim pots are needed though. Something like 10K or even 5K (log taper).
Anyway, I'll certainly post here if I have any luck with it!
Richard
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Is there anything special you have to tell them to get samples. I've filled out the web form in the past and never gotten anything. I'd love to try a TI DAC or ADC in a project one of these days.
I was able to get samples by using my business name. I also added that I was in the research phase of my project.
I got some AD8620's for a headphone amp project.
They are nice op-amps IMO.