[blipblop]

Actually, I did read Tangent's site, perhaps not carefully enough, but after hearing this concept of "unity gain stable" chips like that ad8620 (or is it the ad8610?), I was nervous about sticking in a chip for kicks - although I do remember the distinction appeared to be relevant in the Pimeta and PPA designs. Perhaps, then the relevance exists only when its being used for a seperate ground channel. I'm going to go back and more closely read Tangent's article.

Thanks for the help!

 

[Demolition]

Quote:

Originally posted by blipblop I was nervous about sticking in a chip for kicks

Yeah, I'm not too keen on that kind of experimentation, either. I've blown up a lot of stuff due to being overcome by my sense of adventure.

But, in this case, most of the op-amps seem to be fairly cheap, anywhere from $2 to $10 per piece (except for OPA627/637s). The AD823 is enticing at only $5 each. Almost affordable for "blowing up" purposes.

D.

 

[Pars]

I have tried the AD823 in my Rotel RCD-855 cd player, and I like it alot (that, and the LM6172s, one of which I just tried for the hell of it in the CMoy, but have not yet gotten around to trying in the cd player because I like the AD823s). I have not looked at the datasheet, but will defer to Demolition, who notes that it is not a higher current op-amp, and is probably not a good choice for driving headphones directly. In the cd player, two are used, cascaded (I guess) so essentially the second op amp in the chip is performing the tasks of a buffer (haven't looked at my schematics of the RCD to see exactly how it is configured).

 

[Tomo]

Sorry,

THS4022 isn't "prop"-able solution ... In fact, you will probably have to use SMDs. ... THS4022 power pack is so tiny. I have hard time seeing. (SMDs are hard to see too ... so sorry about the typo so long time ago) But it is a smacking powerful opamp. If you can find THS40XX with unity gain stability, you can probably drive Gradoes with no problem.

Have you guys tried out single-power-opamp designs? Last thing I recall was talking to someone about driving a can with LM3875.

Yeah ... I tend to put priorities on doing weird things over doing the right things. ...

T

 

[blipblop]

Pars, when you say you've tried an opamp in your CD player, are you saying that you are actually replacing opamps inside your player?! That's hardcore....

 

[Pars]

Yeah, I put some good sockets in the cd player and replaced the ne5532s with the ad823s. I also replaced the rectifier diodes with some uf ultra-fast, but I think I may replace these with the Harris (Fairchild, whatever they are these days) ones that Bob Crump on audioasylum (and part of CTC with John Curl) recommends. Those might not be an easy mod tho, with the originals being normal DO35 types (1N1002) versus a TO220 or TO251 style case. Might have to think about that one a bit. Perhaps some schottkys might be a better deal, since they seem to like these for digital (i.e., lower power requirement) stuff.