Downside to R2R Ladder DACs?

A sales person I generally trust told me to steer clear of used R2R DACs, since their reliance on high precision resistors causes them to sound best when new, and degrade fairly quickly.

All I can say is, typical sales persons BS to get a sale on something else.

@abraxalito while your here, been playing around with an old Arcam Alpha Plus, with it’s TDA1541 just using opamp I/V’s for now, what do you think of all the specs on the LME49710 (1.2μs to 0.1% settling time and insane distortion figures also) as one sounded dam good to me when I tried it.

Cheers George

@georgehifi these days I wouldn't use a 'naked' opamp in I/V without prior filtering unless it was a pure video part (AD811 for example).

@abraxalito, think I have some of them laying around, do you know if they're unity gain stable, no mention in the data sheet.

Cheers George
 

@georgehifi Its not a drop-in for normal opamps because its CFB. I get better results using a passive filter before my opamps than I did with AD811 and no filter. AD829 is doing very nicely as I/V for me at present, preceded by a filter.

...steer clear of used R2R DACs, since their reliance on high precision resistors causes them to sound best when new, and degrade fairly quickly...

I think your sales person is trying to sell you a new DAC.

My R2R DAC is a Theta ProBasic III that is more than 20 years old. I love the thing as it does it does not have that treble edge that one hears in so many "modern day" DACs.

Listed new for $2,700 and I bought used about three years ago for $600.

Thanks for listening,

Dsper