USED D/A - worth the effort?

My digital source is currently a CAL Icon MKII (NO HDCD/Powerboss). I have been looking at upgrading, but am not ready to spend big bucks for a new one box player. There is a proliferation of used D/As in the $300-$600 price range. Will an older Theta II or III sound any better than my Icon? How do these processors compare to current bargian processors like the MSB Link III (no upgrades)? I would plan on continuing to use the Icon as a transport. When I get past the other upgrades that need done first, I'll go for a new digital setup. ANY advise is appreciated!!!
Interesting question. Not only for you, but also for those of us that have higher quality DAC's with mileage on them. I wonder what something like the PT1/3 combination sounds like in comparison to high end DAC's that are 5+ years old. Also, does it make more sense to adds upsampling devices to older 20bit DAC's?
I am currently in the same bind. I just wrote the thread on digital or analog d/a convertors. Basically the price on high end processors is dropping like a Led Zepplin. I saw a Proceed PDP-3 which is a $2495 processor 6 years ago selling for >$400 and not going. That's just an example there is a lot of great prices on the older (non-upsampling) d/a convertors out there. The new generation of Per. Tech., MSB and Bel Canto must be great. I'm concerned that at the prices some of them sell (under $1k) that all the money is spent on the digital section, with a mass market analog section. Do these sound better than a Sonic Frontiers SFD-1 mk II convertor? I 've seen these for about $700 and would think the tube analog output with balanced outputs would sound better than the new digital with cheaper analog section. I haven't heard one of the new generation dacs yet. Are they that good? Or is it just the latest digital hype?
IMHO, I wouldn't recommend spending the money on upgrading the DAC. I recently acquired a new MSB Link DAC III, with upsampling upgrade to 96mmz, and the upgraded Monolithic Power Supply. I'm using a Pioneer Elite DV09 as a Transport. I have not been able to identify any difference between listening to the DVD player direct and switching to the MSB output. Perhaps it's just that the Pioneer DACs are really good? Not sure. I've really tried to discern a difference, using my Sennhesier 600s and Musical Fidelity xCans v2 - couldn't find any difference though. Cabling between the Pioneer and my Preamp (Bryston BP20) is relatively cheap Monster cable RCA (551 I think, which is about $50). Cabling between the Pioneer and the MSB is a DH Labs DH60 Digital Cable (about $60), and cabling between the MSB and the preamp is .06Meter Cardas Golden Cross RCA ($460). Before I got the MSB I had a Bel Canto DAC 1. Here, I did notice a difference but it was so subtle, and not necessarily better - more polite and refined, but less dynamic/exciting. I'm happier without it. Overall, I'd recommend spending money elsewhere on your system - that's what I'll be doing from now on anyway. Let me know if you can think of anything I can do to get some more juice out of the MSB :-) I'm personally baffled at how these DACs, and high price CD players in general get recommended so ardently by mags like Stereophile. All my other analog stereo component upgrades have been easily noticeable and satisfying, but from my experience so far it will be really difficult to justify any new digital upgrades - perhaps something like a Naim CDX or BAT VK5 would do the trick, but I don't want to take the gamble. Anyway, let me know if you've any advice. Best of luck with your upgrade choices!
I added a Bel Canto DAC to a CAL Icon MKII (same as yours) and am happy with the upgrade. The stand alone CAL is my favorite sounding inexpensive player (which is why I have it) but the Bel Canto adds a sense of refinement and "realism" that I feel is worth the asking price of a used unit. To A/B the Icon with and without the DAC is to easily hear the benefits added and though both suit my personal taste and sound musical to me I do get added enjoyment with the DAC. However, I have found that both the CAL and the Bel Canto need better power cords to perform "as stated" in my system. I am just using HT Pro 11's which sell for approx. $125 used and perhaps just a good Belden design such as those sold by Kevperro would work as well, (what's up with yours David99?) I don't know. Either of the units with their stock cords do not do it for me musically and in my situation (power supply and corresponding gear) the upgraded cords are not an option but a necessity. I was very disappointed with the sound of the Bel Canto when I first installed it with its stock cord. Perhaps others will not find the same to be true with their systems and this is just my experience with the two units which both sound less dynamic and dull without the PC upgrades. Sorry to continue rambling, but I also liked the sound of the Homegrown Super Silver IC's with the stock CAL (prior to adding the DAC) as they added further detail and made the sound more in your face, which is quite and accomplishment with the CAL, without sounding bright. Anyway, this might be something to look into on the cheap as well as some footers such as Vibrapods if you haven't already.
PS: As much as we both apparently like the CAL, it is not the best transport by any means. A friend recently purchased an old Meridien player (for not a lot of money) that had better bass than the CAL, IMO, when I tried it as a transport. I would eventually like to replace the CAL, perhaps with an SACD model that would hopefully better it as a transport.