Cambridge 840c or Pioneer PD-65/Benchmark DAC 1

Beerad - I was not talking about upsampling but rather downloading rate to DAC. Benchmark is upsampling to equivalent of 1 million times oversampling (equivalent of 44GHz) making mathematical simplifications and taking statistical value of the clock accurate to 5ps. Then it goes thru filtering and is outputed to DAC only at 110KHz for lower THD instead of 192kHz the DAC and upsampler are capable of. It is not a flaw in design - it's conscious decision (read interview with Benchmark's engineer).

At this point it's difficult to say what is right. In general traditional DACs are suffering from accuracy of components and cannot go below 18 bits while sigma-delta type can go down to 24-bits but are loosing it in timing errors. Many people believe that traditional DACs without upsampling give better more organic sound. DCS uses RING DACs where resistor ladder components are shuffled randomly to minimize (after filtering) bit error and get better than 18 bits. No rights or wrongs - just sound that you prefere.

Did I understand ir right that you can connect other digital sources to your CD player - you used term "external DAC". It is very interesting feature - many people were asking about it on the forum.

Mjcmt - when you open your Benchmark check OP-amps manufacturer. If it's Philips than you can possibly change them to a little better (rounder) sounding Texas Instruments. TI symbol on the chip is often shown on the outline/map of Texas while Phillips has either words Phillips or letter "S" for Signetics (part of Phillips). Original amp was designed by Signetics and manufactured to about 2002 (early Benchmarks had them) when their factory burned down and they stopped making them. Texas Instr. bought license, redesigned die (larger) and got a little better sound. Newest DAC1-USB use LM4562 only in output stage to make lower output impedance on XLR outputs (0dB best, -20dB second best, -10dB bad). At the very beggining Benchmark made DAC1s with too high output impedance on RCA outputs.

Fruff1976 - sorry for rambling so much about Benchmark. For you buying newest version might be the safest choice if you decide to go that route. In addition they have free evaluation 30 day loaner program and 5 years warranty.
If you use XLR outputs get newer USB version for $300 more - it has better/stronger output drivers. Also try excellent Bel Canto DAC3 if you can spend $2500 (read on-line Stereophile review and comparison to Benchmark).
I use Benchmark also as a preamp since it has volume control (great simplification and savings on a pair of IC)

Kijanki, I was not refering to a design flaw in benchmarks product, but rather Cambridge. Yes, the 840C does have two inputs that allows you to take advantage of the DACs. The digital to analog conversion of my Sonos signal is all ran through my 840c. They have option for toslink or digital coaxial. Thanks

Kijanki,

My DAC1 is the newest version with the Texas Instument opamps, the 30 ohm optical input, and improved pcbs.

I'm using DAC1 directly to a tube power amp w/ outstanding results. Some say cabling makes a difference but I use only what I had on hand(XLO-ER2 RG6 digital cable, Dynamic Design Platinum interconnects).

The DAC1 is a real shock when you use it. If you have never heard digital playback w/o digititus it is almost impossible to explain. The highs are so detailed, clear and pure it sounds smooth. Not coloration smoothness but lack of harshness smoothness. It's crazy!

The DAC1 does not emphesis one audio frequency or one type of instrument over another. They are all presented fairly and honestly. No coloration that highlights a certain type of music. You can choose what you want to listen to in a recording, it doesn't tell you to listen to this or listen to that. I know why pros like theis piece, it tells it like it is.

This DAC is an eye opener to digital playback. It reminds me of my Consonance CD120 Linear w/ non-oversampling DAC in digital playback, but with added pristine and accurate sound.

For an unfair comparison, my Oppo was crude, closed in, harsh, emphisising dynamics of percusion over sweetness. It was inaccurate and all over the place. I couln't get involved with the sound as a stand alone player but as a transport with the Benchmark DAC 1 doing the duties of convertiong digital to analogue I'm very satisfied now. Especially with the built in preamp/volume control of the Benchmark directly to a tube power amp.

Mjcmt - I also enjoy DAC1 as a preamp but connected to class D amp (Rowland 102). Amp is cleaner (less brassy) than my previous integrated SS but when I connected DAC1 first time I had impression that there are missing instruments on recordings I know very well. Everything is so clean and transparent that it takes time to get used to (learn to listen?). People often perceive sound with a little bit of distortion as more lively (like distorted guitar vs. clean guitar) and call DAC1's sound sterile or uninvolving. I think that sound is very dynamic with great bass control and great transparency/clarity.

Many people don't like well defined bass or even clean sound - they like sound they got used to and there is nothing wrong with it. I even found opinion that instruments should sound together (sound blob) and not separately.

I was a little bit concerned connecting non-forgiving (neutral) DAC to non-forgiving amp (class D) but Rowland while having bright speakers but Rowland tech guy explained that sybillants are more function of distortion than energy in high frequencies (and he was right).

I wondered what makes DAC1 so much better than my old Cambridge CD4SE - one of the better Cambridge CD players.
It could be jitter removal, good components, smart clean design (-140dB S/N) or all of the above.