Metrum Pavane NOS DAC

I built an AD1955 dac based on AD Evaluation Board, and they are made very nice. here is a pic of the one I made up years ago. So the AD5791 should be just as well made.

http://www.diyaudio.com/forums/digital-source/227677-using-ad844-i-v-34.html#post3672888

Cheers George

I looked at my AD account and AD has an AD5791 Evaluation Board complete up and ready to go, available for around $150usd all you need is power and a chassis and be an account holder and you have your own dac.

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCkQFjAAahUKEwjQ6M_VwrPHAhXlrKYKHR8XAX4&url=http%3A%2F%2Fwww.analog.com%2Fmedia%2Fen%2Ftechnical-documentation%2Fuser-guides%2FUG-185.pdf&ei=PJzTVdDaBeXZmgWfroTwBw&usg=AFQjCNENr4SFOC4ZcTxbgqOUNF9bb7CIXw

Cheers George

A few of the "gurus" say it has a problem with dynamic accuracy?

http://www.diyaudio.com/forums/digital-line-level/275444-most-accurate-r2r-nos-dac.html#post4350335

http://www.diyaudio.com/forums/digital-line-level/275444-most-accurate-r2r-nos-dac-2.html#post4369948

Cheers George

I think I see now, this may have been done before on other dac chips, I think with those who understand it, say it's a hybrid? Part low res R2R ladder Multibit, part Delta Sigma? Would this dac then do you think be tarred with the same brush?
If this is the case "those that say it's a hybrid" say it's still not as good as real R2R Ladder Multibit? But it's easier/cheaper to manufacture than true R2R Multibit.

Cheers George

Sorry Al Separate Buffer? or separate I/V then buffer??
Correct me if I'm wrong.
As from what I saw there were no current (mA) output figures given for it's output, which all manufactures give for current output dacs. Also Look at page 26 Positive input to the opamp, and no grounding of the negative.

Now look at the page 9 of the PCM1704 I/V stage neg input with grounding of the positive for low impedance input. Same for what I've seen for most current output dacs on data sheets.
http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CCQQFjABahUKEwiixfXOwqzHAhWlqqYKHRcmAYI&url=http%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Fpcm1704.pdf&ei=p_DPVeLVNKXVmgWXzISQCA&usg=AFQjCNEK5ScUy3tujTC6njrwwvKnluukTg&bvm=bv.99804247,d.dGY

Cheers George

Yes, sorry you are right, back on topic.
Sometimes we can get off on the tech side of things just as much as the final sound of them.
Then the embryo of the final sound is the tech side.?
Oh dear now I've got a headache.

Cheers George

So are you saying Al that this dac is a real R2R Ladder Multibit dac, that can output volts even though it's high impedance (rather than being current output) with no I/V stage involved?

Cheers George

Sorry Al, I misunderstood your post. As to no experimentation with any I/V stages, as I originally posted with this dac.
As great leaps have been made with I/V stages (away from the norm) and this dac doesn't allow this.
As it would have standard text book I/V embedded within the dac itself which looks to be A1 on the data sheet, but with high output impedance.
That's all Cheers George

From what I quickly saw on the data sheet of the ad5791 it has voltage outputs, not current, which usually means it has it's own I/V stage built in.

Cheers George

Pity it uses the Analog Devices AD5791 dac as it looks like has it's own I/V stage built into it, leaving no room for I/V experimentation, and there a lot of good work being done in this area by some heavy hitters.

Cheers George

PS: the Totaldac is also R2R Ladder Multibit.

Cheers George

Coli hi, the Metrum Pavane has old school R2R Ladder Multibit dacs, to my ear I believe R2R Multibit to have it all over the current new Delta Sigma, Bitstream, ESS type d/a convertors when playing Redbook CD's. This is why they are very hard to get and expensive, about 10 x the price.

Cheers George