Hi Tom,
Your Benchmark DAC thread was very informative and a pleasure to learn from, even if headphones aren't my thing. https://www.whatsbestforum.com/threads/benchmark-dac3-dx.23831/
For my bedroom TV system, while surely waiting in vain for some LED/OLED brand to issue a ~48" 4:3 panel, I enjoy using my lovely old Toshiba 32" CRT to play vintage 1.33:1 (and widescreen) content, fed by my Oppo BDP-95 BD player. The Oppo's unbalanced stereo outputs directly feed my First Watt F4 power amp which drives my DIY floorstanding speakers. The sealed 4-way speakers with 15" woofers are ~ 84 db/w/m. The input impedance of the F4 amp is 47K ohm but being a source follower amp the voltage gain is -0.3db. This Class A amp runs quite warm but I don't feel too guilty as I only use it for a couple hours or so for a nightly movie.
With ~ 9v input the F4 will output 25wpc into 8 ohms, but even 7 watts would likely blast me out of the ~ 15 x 12 bedroom, and I sit ~ 10.5 ft from the speakers. Even so, depending on BD/DVD audio quality I sometimes have to crank up the Oppo remote's analog output volume, so for this and other reasons I'm hoping this Benchmark DAC will deliver ample output voltage to the F4 amp's unbalanced inputs.
Presumably however, since both the Oppo's and Benchmark's unbalanced outputs are ~ 2 volts RMS, would not output impedance vs. frequency determine the loading effects on the F4 amp's inputs, and thereby it's output power?
https://www.stereophile.com/content/bryston-bda-3-da-processor-measurements
Luckily, Atkinson also ran measurements on the DAC3 HGC which remained at 30 ohms across the audible range. https://www.stereophile.com/content...preamplifier-headphone-amplifier-measurements
However, I would still like to know why the Bryston's output impedance, however much audibly relevant, varied so much with frequency, while the Benchmark's didn't.
But it certainly does look like the DAC3 might drive my F4 amp every bit as well as a Pass Labs preamp or line stage.
Connectivity wise, I do hate the fact that the DAC3 (and virtually all DAC brands) still include a TOSlink input, or more so that they don't add an extra SPDIF coax input, even if they couldn't be used simultaneously. I have no optical cable and I've heard horror stories where if you bend the cable however much the signal craps out. So, I'll have no choice but to use TOSlink as I want to use both my Oppo and Pioneer LX500 BD players.
A recommended optical cable makes/models least susceptible to signal loss?
My other A/V source will be my pc's BD drive. The video card will output HDMI video to a Black Box composite video converter for the old CRT, while the pc outputs audio via USB to the DAC3. JRiver and VLC handles transport functionality, menus, et al.
Any issues with using the DAC3's USB audio input this way?
My only other concern is that the audio quality of most DVD/BD movies in my collection range from good to very good to excellent. But however the Oppo's ESS and Pioneer's AKM DAC chips and output stages have characterized what I've long been hearing, how likely will I be dismayed by what the DAC3 may reveal about my sources?
I'd gladly spend ~ $2.5K more than the DAC3's price for a DAC that was clearly better across all performance parameters, but I doubt that would be too easy. And the DAC3 also clobbers intersample overs distortion natively, rather than having to do so via your software player.
https://benchmarkmedia.com/blogs/ap...-in-cd-recordings?_pos=1&_sid=0eeb1f150&_ss=r
https://gearspace.com/board/mastering-forum/1401406-intersample-clipping-audible.html
OTOH, some user comparisons of the Bryston vs. DAC3 had the former sounding "relaxed" and the latter sounding "thin".
https://www.stereophile.com/content/benchmark-dac3-hgc-da-preamplifier-headphone-amplifier
And while the DAC3 won praise for its sound stage size and dimensionality, users here found the Exasound-using the same ESS DAC chip-did that better, and with more "detailed treble". https://audiophilestyle.com/forums/topic/61748-benchmark-dac3-vs-‘higher-end’-dacs/
Perhaps splitting hairs here, if over "subjective" comparisons, but please share experiences and suggestions.
Your Benchmark DAC thread was very informative and a pleasure to learn from, even if headphones aren't my thing. https://www.whatsbestforum.com/threads/benchmark-dac3-dx.23831/
For my bedroom TV system, while surely waiting in vain for some LED/OLED brand to issue a ~48" 4:3 panel, I enjoy using my lovely old Toshiba 32" CRT to play vintage 1.33:1 (and widescreen) content, fed by my Oppo BDP-95 BD player. The Oppo's unbalanced stereo outputs directly feed my First Watt F4 power amp which drives my DIY floorstanding speakers. The sealed 4-way speakers with 15" woofers are ~ 84 db/w/m. The input impedance of the F4 amp is 47K ohm but being a source follower amp the voltage gain is -0.3db. This Class A amp runs quite warm but I don't feel too guilty as I only use it for a couple hours or so for a nightly movie.
With ~ 9v input the F4 will output 25wpc into 8 ohms, but even 7 watts would likely blast me out of the ~ 15 x 12 bedroom, and I sit ~ 10.5 ft from the speakers. Even so, depending on BD/DVD audio quality I sometimes have to crank up the Oppo remote's analog output volume, so for this and other reasons I'm hoping this Benchmark DAC will deliver ample output voltage to the F4 amp's unbalanced inputs.
Presumably however, since both the Oppo's and Benchmark's unbalanced outputs are ~ 2 volts RMS, would not output impedance vs. frequency determine the loading effects on the F4 amp's inputs, and thereby it's output power?
While the Oppo 95 manual doesn't cite the output impedance, this engineer measures 100 ohms overall. https://www.jensign.com/bdp95/headphones/index.html
Another DAC option is the Bryston BDA-3, but where Atkinson's measurements found the unbalanced output impedance changing considerably with frequency.https://www.stereophile.com/content/bryston-bda-3-da-processor-measurements
Luckily, Atkinson also ran measurements on the DAC3 HGC which remained at 30 ohms across the audible range. https://www.stereophile.com/content...preamplifier-headphone-amplifier-measurements
However, I would still like to know why the Bryston's output impedance, however much audibly relevant, varied so much with frequency, while the Benchmark's didn't.
But it certainly does look like the DAC3 might drive my F4 amp every bit as well as a Pass Labs preamp or line stage.
Connectivity wise, I do hate the fact that the DAC3 (and virtually all DAC brands) still include a TOSlink input, or more so that they don't add an extra SPDIF coax input, even if they couldn't be used simultaneously. I have no optical cable and I've heard horror stories where if you bend the cable however much the signal craps out. So, I'll have no choice but to use TOSlink as I want to use both my Oppo and Pioneer LX500 BD players.
A recommended optical cable makes/models least susceptible to signal loss?
My other A/V source will be my pc's BD drive. The video card will output HDMI video to a Black Box composite video converter for the old CRT, while the pc outputs audio via USB to the DAC3. JRiver and VLC handles transport functionality, menus, et al.
Any issues with using the DAC3's USB audio input this way?
My only other concern is that the audio quality of most DVD/BD movies in my collection range from good to very good to excellent. But however the Oppo's ESS and Pioneer's AKM DAC chips and output stages have characterized what I've long been hearing, how likely will I be dismayed by what the DAC3 may reveal about my sources?
I'd gladly spend ~ $2.5K more than the DAC3's price for a DAC that was clearly better across all performance parameters, but I doubt that would be too easy. And the DAC3 also clobbers intersample overs distortion natively, rather than having to do so via your software player.
https://benchmarkmedia.com/blogs/ap...-in-cd-recordings?_pos=1&_sid=0eeb1f150&_ss=r
https://gearspace.com/board/mastering-forum/1401406-intersample-clipping-audible.html
OTOH, some user comparisons of the Bryston vs. DAC3 had the former sounding "relaxed" and the latter sounding "thin".
https://www.stereophile.com/content/benchmark-dac3-hgc-da-preamplifier-headphone-amplifier
And while the DAC3 won praise for its sound stage size and dimensionality, users here found the Exasound-using the same ESS DAC chip-did that better, and with more "detailed treble". https://audiophilestyle.com/forums/topic/61748-benchmark-dac3-vs-‘higher-end’-dacs/
Perhaps splitting hairs here, if over "subjective" comparisons, but please share experiences and suggestions.