How important is the transport when using a DAC?

Yup, I agree the best is MSB and it is linear go figure.

Gummy - this is about di/dt. Batteries have non-zero internal impedance and even with ultracaps they cannot compete with fast low-impedance regulators. The issue is having the same impedance at all frequencies of current.

I have designed and sold both SLA and LI/ultracap supplies in the past.

Steve N.
Emnpirical Audio

But isn't the variance caused by the dynamic nature of the power demand?

I get the transients and "current derivative" or what some in slang call "load backlash," but this is microscopic, no? ...and from what I know, the down-line component would almost have to be "designed" to place the onus on the supply, would it not?

This is the hairy edge of my knowledge and I intend to learn more about it. Answers to the above will help if you have the time.

Coming from a "battery is purity" background...this will be a learning experience.

Gumby - yes, di/dt is the change in current over time. It is the dynamics changing load and resultant current. If the load changes and the regulator cannot respond quickly enough, you get distortion, lack of focus.

This is by no means microscopic. It is a function of the power supply AND the power decoupling at the load and all of the wires and traces bewteen the two.

LI batteries, particularly combined with ultracaps can outperform most regulator designs except the very best.

Its the very best discrete regulator designs that I use. They are faster than the best LI battery supply and very low noise. Critically damped, so no overshoot when responding to transient load changes. These are designs by Paul Hynes that have been optimized by me for digital.

Steve N.
Empirical Audio

OK, this is late in the game for this thread and slightly off topic, but the insights provided here may be helpful to me. I have an Arcam AVR400 receiver and have been trying to set up a modest music and HT system around it and Monitor Audio Apex A40 fronts and Apex A10 rear speakers and B&W PV1D sub. I currently have and old Yamaha CD player but was hoping to be able to use my Blu-Ray player as a transport with the Arcam internal DACs at first and eventually upgrading to an external DAC for two channel.

Multichannel DTS and Dolby Blu-Rays on a Panasonic BDP and CDs played on the Yamaha sounded great through the Arcam, but the Panasonic as a transport for Redbook two channel using either HDMI or Toslink optical cables was not good. Clear but lifeless sound, no swing whatsoever. USB Redbook FLAC files on flash drive plugged directly into the Arcam sounded similarly sterile. I was thinking that the problem was with the Arcam DACs for two channel.

Then my Panasonic BDP quit working reliably, so I replaced it with a new Samsung BD-H6500 which was really well reviewed in Sound and Vision. Using the Samsung as a transport for CDs the sound is completely different, much better, and closer to the Arcam fed by my vinyl analog set up. Good pace and timing, tone, spatial resolution, etc. The Samsung has the ability to feed the Arcam AVR raw bit stream data, and this setting makes a big difference using the Toslink optical cable.

Question for this group, WHY DOES RAW BITSTREAM OF CD DATA FROM SAMSUNG SOUND BETTER ON THE ARCAM THAN THE SAME FILES RIPPED ON FLASH DRIVES PLUGGED DIRECTLY INTO THE ARCAM? AND WHY IS THE SAMSUNG MASS-PRODUCED BLU-RAY SO MUCH BETTER SOUNDING THAN THE SIMILARLY PRICED PANASONIC FOR REDBOOK WHEN THEY ARE VERY SIMILAR SOUNDING FOR DTS OR DOLBY MULTICHANNEL AUDIO?

Thanks in advance for any insights.

kn