Tube Equipment: Is a D/A converter really required?

Valveglow

Super Member
Please allow me to preface this question by stating that I am aware of how a variety of factors and equipment could change the outcome of what I am seeking to determine. Yet, I am looking for those who bothered to intently A/B their systems to determine what's best. Any and all opinions are appreciated. Thank you.

My question involves the necessity of using a D/A converter to receive inputs from a CD player and a computer. Of three computer set ups I own, one is connected to a fully solid state audio system, while two are connected to fully tubed systems. I own one good, inexpensive D/A converter, a Maverick D2, and it is in circuit on one of the fully tubed systems. Is this really necessary? It's not as though I am listening through headphones and trying to get rid of transistor hardness. Listening is done almost exclusively through speakers. Also, I am definitely not inclined (nor do I have the ability) to spend real big money on a D/A converter.

Would it be better to use analog outputs from a computer or player and run them directly into a tubed preamp? The system sounds great as it is, but I am wondering whether the D/A converter is smoothing digital hardness or is in fact acting as an additional and unnecessary step in the "straight wire with gain" approach.
 
Analog form computer are mostly of poor quality.

CD players sometimes are good, i use analog outputs on good quality ones.

I use optical from computer and i realyze my TubeDAC-11 runs much cooler than when i used the Coax.

Edit:

I will add that a not really optimized DAC can be worse, i optimized my TubeDAC-11 to get rid of the harsh treble and over brightness.

http://audiokarma.org/forums/index.php?threads/grant-fidelity-tubedac-11-capacitors.731802/

Every 6DJ8 i use now sounds closer to each other, but all sounds better than before.
 
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Well, by definition, if you are going to listen to digital sources (CDs or whatnot), then you have to use a DAC *somewhere*. I mean, it's not like your tube amp can directly play audio encoded as 16-bit linear PCM. Your CD player has one built in, and it's just fine. As far as the computer-as-a-source goes, if you have a "Line Out" port, then that should be just fine, as the on-board audio hardware on practically every modern computer made these days is pretty good (and practically everyone uses the one that Intel provides in their I/O controller chip). It's a slightly different story if all you have is a headphone output, because there is going to be a small power amplifier there to drive headphones, which may add some noise. All an external DAC does for you in that case is give you a different path to a line out; they typically present themselves as standard USB audio-class devices, and advertise a set of encodings they support to the host computer, although I would say that most of the time, the host computer is going to transcode from whatever format the audio file is in to 48KHz 16-bit linear PCM, so your super-special 96KHz DAC isn't going to really buy you much except some silk screened numbers.
 
I am wondering whether the D/A converter is smoothing digital hardness

Oh, actually, I want to touch on this, too. "Yes, that's exactly what DACs do." It takes the binary data (square waves, more or less) that represent the audio signal and decode it, producing an analog signal that can be amplified and played through a loudspeaker. But it's not like you can skip this step... the digitally-encoded audio is not directly playable, which is what I assume you mean by "straight wire with gain".
 
Some CD players (and “universal players”) have “audiophile grade” DACS built-in. The just-released Oppo UDP-205 is an example. (Mine will be delivered in a few days.) I currently own the earlier Oppo BDP-105, BDP-95, and DV-980H models.

The Oppo UDP-205 and BDP-105 can function as a stand-alone DAC via its digital audio inputs, in addition to playing FLAC audio files, and Blu-ray discs, DVDs, SACDs, CDs, etc. Moreover, these Oppo units can function in a limited sense as a preamp, by virtue of their volume control, their built-in subwoofer crossover, and ability to set trim levels as high as +10dB. (No phono preamp, however.) I can drive a power amp (and powered subwoofer) directly from any of the Oppo players – if I don’t need tone controls.

So, to answer your question directly, an outboard DAC is almost never needed. People usually buy outboard DACs because they think it sounds better than the DAC in their CD player, or PC, or Chromecast Audio, etc. Whether or not an external DAC sounds better is up to each user to decide. Several years ago, I bought a modestly priced MUSIC Streamer II DAC for my PC and I still use it. However, I haven’t A/B tested it with the analog output from my new Windows 10 laptop. I use the external DAC with my laptop because … well … I already own it …

I briefly compared the analog output from one of my Chromecast Audio gizmos with the TosLink connection into my Oppo BDP-105’s DAC, and the Oppo’s DAC sounded better to me. My only cost was to buy the mini-TosLink-to-TosLink optical cable for less than $10, so it was a no-brainer decision.

Bottom line, I’m a fan of “universal players” like the Oppo high-end units. IMO most people want to watch movies, and listen to music, and one machine can do it all, and support any format, and serve as a DAC for a computer or other device. Setting aside LPs and an all-analog audio chain (including the recording and mastering), IMO a “minimalist system” (i.e., fewest components to “muck up” the sound) for digital recordings is a universal player directly connected to a power amp. IMO, in a digital world, this is as close as you can get to a “straight wire with gain”. My Oppo BDP-105 directly connected to a pair of 1950s era McIntosh MC30 tube power amps sound fabulous, and will play any digital audio or video format (except UHD video – and the new UDP-205 is in the mail). Similarly, I achieve excellent results with an Oppo player directly connected to a single-ended-pentode power amp (i.e., no preamp). When an amp/speaker combination sounds too “bright”, or too “thin”, then I’ll introduce a pre-amp with tone controls. And to listen to LPs I need a pre-amp. Otherwise, an Oppo universal player is the centerpiece, and a tube power amp is the “straight wire with gain”. (Some of my McIntosh tube power amps don’t even have a power switch.)

I’ll report on the Oppo UDP-205 in a week or so. Based on my experience with Oppo’s earlier units, I’m confident that I can connect it directly to a tube power amp (whether SEP or push/pull) and achieve excellent audio quality.

That’s my 2 cents.
 
That Maverick D2 you have is reported to be a great sounding DAC. Running the line output of that DAC into tube amps should sound great.

My experience with good external DAC's is they do indeed reveal small details in digital audio files that you may not have noticed before.

They also can help make digital audio file playback sound more natural, less harsh and with less listener fatigue.

And no, generally speaking computer motherboard audio line outs don't sound nearly as good as a decent external DAC.

As mentioned, some CD and universal players have audiophile quality DACs built in with great sounding line output, but some CD players sound terrible.

When using an external DAC with a computer, just be certain you are bitstreaming the raw file data via USB using WASAPI or ASIO drivers so the computer does not resample or downconvert your audio files.

So if you usually listen to digital audio files from your computer rather than CD's from a dedicated player, an external DAC can definitely help with the sound quality.
 
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WOW!! What a wealth of information!! Thanks to all!! Part of my confusion came from the fact that some CD players offer both analog and digital outputs, while others like the Sonic Frontiers Player only offers analog outputs. On my main tubed system, I have a USB connecting a computer and a digital COAX cable connecting a Sonic Frontiers Transport to the Maverick D2. On a secondary tubed system, I have a mini jack adapter (green colored output) from the sound card to a set of RCA cables to the preamp's input. They both sound good with no hardness whatsoever. I was just wondering how improvements could be made.
 
When using an external DAC with a computer, just be certain you are bitstreaming the raw file data via USB using WASAPI or ASIO drivers so the computer does not resample or downconvert your audio files.

I'm not a PC expert. I waited to buy a Windows 10 PC because my (admittedly vague) understanding is that Windows 10 improved native audio quality (compared with earlier Windows OS). And Windows 10 added native support for FLAC.

Are there any configurations where add-on WASAPI or ASIO drivers (or other drivers) are needed with Windows 10 in order to achieve good quality audio when listening to music (vs. recording or editing music)? Do some DACs require WASAPI or ASIO drivers because they're not fully compatible with Windows 10? Do some DACs use WASAPI or ASIO drivers because they can achieve better sound quality with Windows 10?

FWIW, I found the following via an internet search: https://www.reddit.com/r/headphones/comments/3fehls/asio_wasapi_windows10/ I don't know if this is accurate. Here's another discussion: http://forums.stevehoffman.tv/threa...ng-they-dont-bypass-the-windows-mixer.643282/

Because I'm not a PC expert, I'd be leery of any DAC that required software installation (or modification) if it is complicated. I don't use my PC for critical listening, but I've perceived no problems with audio quality with my Windows 10 laptop and my Music Streamer II DAC. IIRC, I made a simple change in Windows 10 "Sound" settings so that the OS doesn't play noises through the speakers. Other than that, IIRC it was plug-and-play. (OTOH, I had problems with my old Windows XP PC and the Music Streamer II DAC, such as "skipping".)

I'm not happy with the UI of Window 10's standard Groove Music audio player - which appears to be primarily a platform for advertising fee based services - but that's another story. (I seldom listen to my digital audio files directly from my laptop. I copy the files onto a USB drive and plug the USB drive into one of my Oppo machines, which works great for me.)

Can anyone shed light on Windows 10 and DACs?
 
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I'm not a PC expert. I waited to buy a Windows 10 PC because my (admittedly vague) understanding is that Windows 10 improved native audio quality (compared with earlier Windows OS). And Windows 10 added native support for FLAC.

Are there any configurations where add-on WASAPI or ASIO drivers (or other drivers) are needed with Windows 10 in order to achieve good quality audio when listening to music (vs. recording or editing music)? Do some DACs require WASAPI or ASIO drivers because they're not fully compatible with Windows 10? Do some DACs use WASAPI or ASIO drivers because they can achieve better sound quality with Windows 10?

FWIW, I found the following via an internet search: https://www.reddit.com/r/headphones/comments/3fehls/asio_wasapi_windows10/ I don't know if this is accurate. Here's another discussion: http://forums.stevehoffman.tv/threa...ng-they-dont-bypass-the-windows-mixer.643282/

Because I'm not a PC expert, I'd be leery of any DAC that required software installation (or modification) if it is complicated. I don't use my PC for critical listening, but I've perceived no problems with audio quality with my Windows 10 laptop and my Music Streamer II DAC. IIRC, I made a simple change in Windows 10 "Sound" settings so that the OS doesn't play noises through the speakers. Other than that, IIRC it was plug-and-play. (OTOH, I had problems with my old Windows XP PC and the Music Streamer II DAC, such as "skipping".)

I'm not happy with the UI of Window 10's standard Groove Music audio player - which appears to be primarily a platform for advertising fee based services - but that's another story. (I seldom listen to my digital audio files directly from my laptop. I copy the files onto a USB drive and plug the USB drive into one of my Oppo machines, which works great for me.)

Can anyone shed light on Windows 10 and DACs?

I should have been more clear in regards to WASAPI or ASIO support, sorry... these are components you install in the Foobar media player that allow for direct bitstreaming out of the PC (regardless of what version of Windows you are running)

The JRiver media player (which is not free like Foobar) is easier to set up direct bitstreaming output from the PC... you just have to change a few settings.

I don't know if the media players that come with Windows 10 allow for raw bitstreaming (disabling all internal processing or resampling of audio files by Windows)

Sometimes certain external DACs will need a driver installed to be seen by the PC and Windows software (some are plug and play, though)
 
Some computers and digital music players just have crap sounding analog output. The basic big-box store PC's with onboard sound cards are generally in that group. An external card of some fashion will often give better performance. My favorite cheap computer sound artifact is the buzzing through speakers when you move the mouse or the vague chirping sounds when the hard drive accesses files. In the dawn of forever ago when I actually built computers, I had much better luck using a proper sound card of decent quality vs the onboard sound. Anymore I've been using cast-offs from work of ~4 year old business models that put absolutely no effort into the sound. If it goes "ding" for email, its good enough.

My ipod's headphone output is also entirely mediocre sounding. With the DAC base I used to use, it sounded a fair bit better even when using compressed files. I changed the OS on it though, and the DAC doesn't play nice anymore.
 
I used to have music servers (Mctintosh, Olive) and got rid of them.
I build my own Linux real time fanless server with Music Player Deamon (MPD) and 2 big SSDs storage, to feed an external DAC/tube Preamp (McIntosh C2500) via coaxial digital.

This solution is very versatile, and can do pretty much anything, as I can control my music server from my PC, my tablet or my phone.

I store my own flac library myself (don't pay external music provider or rely "on the cloud"), and I can still play specific Internet radio with the mpd process.


I tried to play the RCA output from my expensive sound card in my Linux server but the sound wasn't even close to the McIntosh DAC output.

So to answer your question, a good external DAC or DAC/Preamp combo is a good solution if you want options.
 
I'm in the process of finishing a room that I want to become a media room. I'll probably be looking into some sort of digital music server rig once I get that done. Does your machine already come with the digital out capability, or did you have to get that via a sound card?
 
I used to have music servers (Mctintosh, Olive) and got rid of them.
I build my own Linux real time fanless server with Music Player Deamon (MPD) and 2 big SSDs storage, to feed an external DAC/tube Preamp (McIntosh C2500) via coaxial digital.

This solution is very versatile, and can do pretty much anything, as I can control my music server from my PC, my tablet or my phone.

I store my own flac library myself (don't pay external music provider or rely "on the cloud"), and I can still play specific Internet radio with the mpd process.


I tried to play the RCA output from my expensive sound card in my Linux server but the sound wasn't even close to the McIntosh DAC output.

So to answer your question, a good external DAC or DAC/Preamp combo is a good solution if you want options.
I do something similar. Computer into a tube DAC into a tube preamp into a tube headphone amp for late night listening sessions when my wife is asleep.
 
I used to have music servers (Mctintosh, Olive) and got rid of them.
I build my own Linux real time fanless server with Music Player Deamon (MPD) and 2 big SSDs storage, to feed an external DAC/tube Preamp (McIntosh C2500) via coaxial digital.

This solution is very versatile, and can do pretty much anything, as I can control my music server from my PC, my tablet or my phone.

I store my own flac library myself (don't pay external music provider or rely "on the cloud"), and I can still play specific Internet radio with the mpd process.


I tried to play the RCA output from my expensive sound card in my Linux server but the sound wasn't even close to the McIntosh DAC output.

So to answer your question, a good external DAC or DAC/Preamp combo is a good solution if you want options.

Interesting comments Brice. I have a computer with fans providing the service, but it is closed behind thick solid wood doors, so the fan is completely inaudible. Interestingly, the wireless controls all work perfectly with the door fully closed. Two of my sets ups include a Sonic Frontiers Line 2 Preamp (which I find extraordinary) and an excellent Audio Research SP-16, neither with any DAC capability and both near the limits of what I am willing to spend on a preamplifier. The system with the Maverick tube DAC has the Sonic Frontoers pre and also their SFM-160 monoblocks, so the system itself presents no hardness whatsoever. I just wondered if a tube DAC was needed given the associated components. I can't spend $4-6K on something like the McIntosh.




I do something similar. Computer into a tube DAC into a tube preamp into a tube headphone amp for late night listening sessions when my wife is asleep.

Leftside, which tube DAC do you have? Is a tube headphone amp necessary when one has a tube DAC and a tube preamplifier? This situation is not very dissimilar from my own in that I wanted to minimize the number of components in the signal path.
 
Again thanks to all who posted such excellent commentary, though some of it was "over my head". Nevertheless, i would welcome additional comments and personal experience; the more the merrier. Thanks again.
 
"basic big-box store PC" kind of specifically excludes Mac. Mine are hum drum Dell business model machines. They aren't terribly noisy but the sound is just very blah despite any tweaks and settings. There is some amount of hiss though. Also not surround sound capable. The goal for one of these machines is to be the heart of an HTPC setup and I want surround capability.

So my statement still stands, the onboard cards were intended to go "ding" for email and not much else. I suspect you'll find this to be true on many business model computers.
 
Gadget,

I tried the native computer out and as many found it thin and bla.
So I added a real good sound card in that Linux box and use it for all music related stuff.

Also many app "manipulates" the bit stream, for example for music leveling, re-sampling to higher resolution for no reason, etc...
I configured my mpd to do bit perfect streaming, meaning bit in bit out without alteration from the flac media.

Most of the product out there do change the original bit stream.
 
I tried the native computer out and as many found it thin and bla.
So I added a real good sound card in that Linux box and use it for all music related stuff.

Cool, kinda what I was thinking to do as well. There are cards now that have optical and coax digital out, as well as the individual channels for surround sound use. I was thinking that one of those would probably get the job done. Still a project for later, need to get the walls closed and a ceiling in before I get too worried about electronics.
 
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