O2 AMP + ODAC
Jul 15, 2015 at 9:44 PM Post #4,546 of 5,671
@AlanU Having the Creative x-fi connected to the Yamaha through the aux in with RCA cables is how I have it set currently. From what I've been told earlier, plugging the X-fi to the Yamaha through Audio optical would let me use the Yamaha's DAC instead of the DAC from the X-fi ? Could that be interesting to try ??

When I'm not playing music through the Yamaha's speakers I usually plug my headphones in the Creative's headphones out, maybe I should try plugging the headphones in the Yamaha's out to see if I can hear a difference.

I think it could be a good thing to wait, and when I have a nice budget to dedicate to audio I'll take the time to try and compare gear and see what kind of DAC I want to use and see if I want a clean amp or one that adds a colour and everything.. I went with a mini chain for the convenience of having everything in one piece of gear in the first place, and as far as I know the Yamaha I own does a really nice job amongst mini chains and it was the one I preferred over the other ones I tried (some Denon, Pioneer etc).

And same for the Momentum headphones ! Basically I bought the gear I liked the most within the budget I had, and right now I don't have more money to put into and I'm still happy with everything so that should do for a while !

What I was wondering about when I first wrote here was whether the creative x-fi could be a "weak point" in my set up and if an DAC upgrade could improve the result but I think the ODAC wouldn't really represent an upgraded, just something different (and I'm not even sure I'd hear a difference).

BTW, do you know anything about the Apogee Groove ? Does it have the same kind of plain and transparent philosophy as the Objective gear or does it have its own sound features ? Just wondering about it !

 
Sorry I was under the impression that you were using the yamaha headphone out and using the dac to feed the yamaha. 
 
I would hold out as long as you can on any gear purchase. As you go up the ladder in gear you gain refinements and much improved SQ. Enjoy your current gear and build a dedicated headphone rig down the road to max out SQ for headphones.
 
IMO most dac's will sound different from one another even when the same DAC chipset is used. The ESS sabre chipset seems to have a very strong character sound that seems to have a house sound in many dacs.
 
The Dac seems to be the weakest link in most cases. Perhaps it's all about meeting our expectations to make happy subjective ears.  The unfortunate thing is higher end dac's cost alot of $$$$    
 
I've been concerned about my previous comments comparing my Burson Virtuoso and Jds amp.  I did that comparison when my burson was virtually fresh out of the box. I just did an A/B comparison between my objective amp and Burson Virtuoso (now with more hours of breakin' time). Using the Burson internal DAC  via Grant Fidelity vacuum tube processor  feeding the 02 amp I find the JDS amp to sound less refined and edgy/raw. Using the Burson Amplification section while getting conditioned from my Grant fidelity vacuum tube processor the Burson sounds smoother. My previous comments were based on my fresh brand new Burson amp. I'll still comment by saying the 02 amp is a great amp for the inexpensive cost.
 
I'm entertaining the idea of buying an amp from Garage1217 for fun.
 
http://www.garage1217.com/garage1217_diy_tube_headphone_amplifiers_013.htm
 
You can buy an assembled one. So many toys out there :)
 
Jul 17, 2015 at 4:45 PM Post #4,547 of 5,671
  From my experience with my previous O2 (DIY from JDS boards), it does get a bit hot, but nothing too bad. I think it was around 30 - 40 degrees celsius. 

 
But a 3D printed case is still a bad idea since the metal case with the ground wire provides electrical shielding. So unless one can 3D print with a conductive material, it's not such a great idea.
 
Joachim
 
Jul 20, 2015 at 9:37 AM Post #4,548 of 5,671
I agree entirely. The single thing that influences the sound of your system the most is the headphones (or speakers). It goes far beyond the idea that upgrading to a more expensive one will be better; while two expensive (and neutral) amps will sound pretty similar, even two very expensive and "good" "accurate" pairs of headphones will sound quite different; and often even different models by the same company; (and sometimes even different "generations" of the same model). You will also find that certain headphones tend to emphasize the differences in your other electronics, like DACs, while others tend to "gloss over them" or make them less apparent. (And some headphones seem to "work well with anything" while others only seem to work their best with certain other equipment.
 
I would also add that, much like speakers, headphones are one of those places where you really can often get a significant improvement by spending more money (percentage wise). If you have a $50 pair of headphones, and a $50 headphone amp, you'd probably be much better off moving up to a $100 amp and a $300 pair of headphones, than keeping your $50 cans and buying a $350 amp in hopes of some sort of "magical transformation".
 
You should also be aware that, while most neutral amps sound more or less the same (no surprise there), since tube amps are designed to add some coloration, there are often much larger differences between them. Some may in fact sound rather neutral, while others, like the Schiit Lyr, add a more noticeable "tubey" sound signature. Therefore, especially with tube amps, you really should try to listen to one - with your model and brand of headphones - before spending a lot of money. (And also, hyperbole aside, in most cases the differences between different tube amps will be far greater than the differences between different tubes in a given amp.)
 
 
Quote:
   
At this moment the biggest impact in sound would be to buy a different set of headphones. I'm just assuming your Yamaha is feeding your current Momentum headphones with ease since they are more of a mobile headphone (18 ohms) . The resolution of your headphones may not benefit in a large scale if you spend alot of $$$ on a new DAC. Getting different headphones will be a different flavor in sound as long as your pleased with your current dac/amp setup. 
 
If you listen to music at a reasonable volume level and your not surpassing well over 50% on the volume knob and not clipping you may be fine with other headphones that are harder to drive. If your a BASS head into electronica you'll probably hear little difference on certain music genre's. However if your into female jazz vocals, piano, string instruments you will probably be able to pin point the difference alot more as you swap dacs/amp. 
 
Try your yamaha in "aux" mode as you feed it with your dac via RCA cables. Tell us your findings. 
 
On a budget the inexpensive schiit amps or 02 amp will deliver clean power to your headphones. If your wanting more organic natural sound you should be getting the sound signature most from your headphones and DAC. 
 
I do like tubes as it adds harmonics to the music....yes it adds pleasant distortion that most human ears appreciate. Listening to music is subjective and I find tube gear to be much more engaging with realism.  Whichever way you look at audio gear heads there is typically one component that will add colour to the music. This neutral "amp/dac" sounds fantastic but in the end somewhere in the chain is making subjective ears happy. I personally do not know many friends loving dead on "flat" neutral sound using studio monitors (used in mastering) for a chillout session in relaxing.  All headphone companies colour their sound with a signature "house sound" or specific unique sound to the model of the headphone. 
 
I love my tube dac setup and manipulate the source by rolling/changing tubes. In the 2 channel world some use neutral high end dacs and colour the sound with a tube preamp and powerful neutral solid state amp. Some use a neutral DAC and colour the sound with a tube amplifier (customize subjective sound swapping tubes).
 
The beauty of the objective amp/odac is that it's an inexpensive system that delivers neutral sound.  The Odac is doing  a decent job in it's task. If per say you own an objective amp already I'd suggest getting the best dac possible within your budget to maximize sound quality. I'm not into playing with equalizers so I'd resort to finding headphones that works well with the music genre I listen too. 
 
Again... my jds 02 amp really surprised me in how well is performed as I fed it with excellent source. With my tube dac I found the sound to be extremely natural and organic with my hd650 and Hd800. Of course I can step up the sweet mids by using different headphones or buying a tube amp. This stuff never ends. The difference between my Burson Virtuoso and 02 amp using my tube dac is so subtle it's not funny...... source is everything since the 02 amp is very good in performing it's task.

 
Jul 23, 2015 at 5:35 PM Post #4,550 of 5,671
Quick question for those that are running an O2/ODAC (mine is a version 1 ODA made by mayflower) with their HE-400, when I have fubar volume set to 100% and Windows volume set to 100% the amp is set very low ( only at about 15%), is this normal?
 
Jul 27, 2015 at 11:00 AM Post #4,555 of 5,671
   
What about the Lyr gives it a "tubey" sound?  It's claimed to have a flat frequency response and low distortion.

 
(Let me start by saying that I've heard the Lyr "version 1" - and had one to listen to for several weeks - but I've been told that the Lyr 2 sounds "less tubey". I also have no doubt whatsoever that it meets or exceeds the quoted specs.)
 
The difference in sound between tube and solid state equipment is somewhat difficult to quantify. There are some obvious things that affect tube power amps - like lower damping and the phase shift and other phase issues due to the output transformers. There are also the much higher levels of second harmonic distortion, which give much of the distinctive sound to low-feedback triode amps. However, neither of these really applies to the Lyr. And the overload characteristics of tubes are way different - but that shouldn't matter if you aren't overloading them.
 
I've never met anyone who's done an actual study about which aspects of the differences are the ones that are audible, but most people agree that their is a pretty major difference. (For that matter, assuming the product can meet those specs with a variety of tubes, then how can rolling tubes make a difference either?) I've always assumed it is a combination of certain things like distortion spectra being more audible than many people believe, and of (maybe) some time/phase effects of how tubes operate that don't necessarily show up on standard steady-state measurements. Quite possibly it's various combinations of several things.
 
(I have no doubt that, if you were to put the Lyr on our AP tester, you would be able to see obvious differences between it and equivalent solid-state design in terms of distortion and frequency response.  However, I suspect that they would all be at levels that you wouldn't "expect" to be audible.)
 
From an engineering difference, I can even tell you what aspects of the circuitry alter the sound.... for example, choice of grid and plate resistor value and type (carbon or metal film) alter the sound, and the operating points you choose (plate voltage and steady state plate current) make a big difference, as well as the choices you make with some other circuit operating points.
 
From a product engineering point of view, the "situation" is pretty simple. Because of the higher voltages involved, and the need for heater power, and the cost of tubes themselves, it costs more to design and produce a product that uses tubes and, from the perspective of standard specs like frequency response and distortion, tubes don't perform as well as solid state in many ways. Therefore, to put it bluntly, unless you like the pretty glowing lights, you'd be foolish to sell or buy a tube product unless you specifically hear a difference - and find it pleasing. (Which means that, for a company selling a tube product, it makes little sense to try and minimize the things that make it sound different from an easier-to-make solid state equivalent.)
 
In the case of Schiit's products..... if you want tube sound, then buy Lyr..... if you want a similar product, but with a more neutral sound, then you should be looking at Asgard 2.
 
Jul 27, 2015 at 11:19 AM Post #4,556 of 5,671
   
(Let me start by saying that I've heard the Lyr "version 1" - and had one to listen to for several weeks - but I've been told that the Lyr 2 sounds "less tubey". I also have no doubt whatsoever that it meets or exceeds the quoted specs.)
 
The difference in sound between tube and solid state equipment is somewhat difficult to quantify. There are some obvious things that affect tube power amps - like lower damping and the phase shift and other phase issues due to the output transformers. There are also the much higher levels of second harmonic distortion, which give much of the distinctive sound to low-feedback triode amps. However, neither of these really applies to the Lyr. And the overload characteristics of tubes are way different - but that shouldn't matter if you aren't overloading them.
 
I've never met anyone who's done an actual study about which aspects of the differences are the ones that are audible, but most people agree that their is a pretty major difference. (For that matter, assuming the product can meet those specs with a variety of tubes, then how can rolling tubes make a difference either?) I've always assumed it is a combination of certain things like distortion spectra being more audible than many people believe, and of (maybe) some time/phase effects of how tubes operate that don't necessarily show up on standard steady-state measurements. Quite possibly it's various combinations of several things.
 
(I have no doubt that, if you were to put the Lyr on our AP tester, you would be able to see obvious differences between it and equivalent solid-state design in terms of distortion and frequency response.  However, I suspect that they would all be at levels that you wouldn't "expect" to be audible.)
 
From an engineering difference, I can even tell you what aspects of the circuitry alter the sound.... for example, choice of grid and plate resistor value and type (carbon or metal film) alter the sound, and the operating points you choose (plate voltage and steady state plate current) make a big difference, as well as the choices you make with some other circuit operating points.
 
From a product engineering point of view, the "situation" is pretty simple. Because of the higher voltages involved, and the need for heater power, and the cost of tubes themselves, it costs more to design and produce a product that uses tubes and, from the perspective of standard specs like frequency response and distortion, tubes don't perform as well as solid state in many ways. Therefore, to put it bluntly, unless you like the pretty glowing lights, you'd be foolish to sell or buy a tube product unless you specifically hear a difference - and find it pleasing. (Which means that, for a company selling a tube product, it makes little sense to try and minimize the things that make it sound different from an easier-to-make solid state equivalent.)
 
In the case of Schiit's products..... if you want tube sound, then buy Lyr..... if you want a similar product, but with a more neutral sound, then you should be looking at Asgard 2.

 
Thanks for the in-depth response!
 
Assuming both tube and ss amps are under the threshold of "audible" distortions, etc., that we can measure, how do we know which one actually sounds more "neutral?"  Could there be some other characteristic that we're not measuring?  This, of course, assumes that it's not just sighted bias...
 
Jul 27, 2015 at 3:30 PM Post #4,557 of 5,671
   
Thanks for the in-depth response!
 
Assuming both tube and ss amps are under the threshold of "audible" distortions, etc., that we can measure, how do we know which one actually sounds more "neutral?"  Could there be some other characteristic that we're not measuring?  This, of course, assumes that it's not just sighted bias...

 
With devices like DACs this can be quite complicated, however it's pretty simple with an amplifier. A neutral amplifier is simply "a straight wire with gain" - it should take the input signal and do nothing to it other than increase the level. So, if your amplifier has a gain of 20x, and you take it's output and put it through a simple resistor voltage divider that reduces it by 20x, it should sound EXACTLY the same as the input signal. (And you can compare them electrically to confirm this - or you can simply subtract one from the other and see if you end up with silence like you're supposed to...)
 
As the simplest example, let's assume your source is a DAC, and you have a preamp with two line level inputs, and you want to make the test with your headphone amp set to a gain of x20. Take the output of your DAC, and run it through a passive stereo splitter. Connect one set of outputs from the splitter directly to one input on your preamp, and the other to the input of your headphone amp. Now, build a passive voltage divider using two very high quality resistors of appropriate values, connect the output of your headphone amplifier to your voltage divider, and connect the output of the voltage divider to the other input on your preamp. You now have one "copy" of your source signal going straight to your preamp, and one copy going through the headphone amp, being boosted by 20x by the headphone amp, then being reduced by 20x by the voltage divider, and finally going to the other input on the preamp. Assuming that the headphone amp is really neutral, then you should hear no difference when you switch between those two inputs on the preamp. (And, even if you didn't get the gain or the voltage divider just right, you should be able to adjust the gain on the headphone amp for "a good null" at some setting.)
 
Note:
 
1) You can use the level control on the headphone amp to adjust the gain very carefully. If it is truly neutral, then you should be able to find a "perfect" setting where it really does sound identical to the wire. (We're confirming that the headphone amp really is "a straight wire with gain" by cancelling out the gain and confirming that it now sounds like "just a straight wire".)
 
2) Even really high quality small signal resistors cost less than $1 each - and you only need four of them - and high quality resistors won't change the sound.
 
3) A passive splitter is simply one input plug connected directly to two output plugs using a piece of wire (avoid fancy ones with transformers), and so won't change the sound either.
 
4) This will work just fine, and it doesn't matter if your preamp, amp, or speakers, have some coloration - as long as they don't have so much coloration that it completely obscures the results - since all you're listening for is a difference of any kind.
 
There are lots of variations on this. If the level control on your headphone amp has sufficient range, and your preamp has a tape monitor loop, you can simply connect the headphone amp in the tape monitor loop. If you set it so its gain is exactly one, you should be able to find a point where you can't hear any difference between when it's "in" and when it's "out"... if it's really neutral. There are also fancier ways in which you can connect the input and output that will allow you to hear the difference between them - in which case, if it's really neutral, you should be able to "null" the difference so there's nothing left.
 
This test will tell you for certain if your amp is not neutral. However, if the output impedance of the headphone amplifier will react with the input impedance of your headphones if it's too high, but won't interact with the high input impedance of a typical preamp, so it's still possible that an amp could "pass" this test, and sound neutral with a preamp, and still NOT be neutral with some headphones. (But, if it isn't neutral when you connect it to the easy load of a preamp input, no way will it be neutral when connected to headphones.)
 
Now, if you don't want to go to all that trouble, there is a slightly less accurate way that is much easier - but depends somewhat more on logic. Since "neutral" is a very specific thing, if you have two or more amps that sound different, then either one of them isn't neutral, or neither of them is neutral. Likewise, if a tube amp sounds different with each of five different brands of tubes in it, then, at the very most, it might actually be neutral with at most one of them. So, if you listen to a dozen amps, and five of them sound pretty much the same, but the other five all sound different, you can guess that there's a pretty good chance that the five that sound similar also sound pretty close to neutral, and that none of the five that sound very different is likely to be the sole one that is neutral.
 
As for "characteristics we're not measuring" - that's also always a possibility - but you can eliminate it by the "difference test". 
 
Jul 27, 2015 at 3:40 PM Post #4,558 of 5,671
i don't have any tube amplifiers on hand or even a soldering iron, but I'm skeptical that they actually DO sound any different, if the following conditions are met:

"There are some obvious things that affect tube power amps - like lower damping and the phase shift and other phase issues due to the output transformers. There are also the much higher levels of second harmonic distortion, which give much of the distinctive sound to low-feedback triode amps. However, neither of these really applies to the Lyr. And the overload characteristics of tubes are way different - but that shouldn't matter if you aren't overloading them."
 
Jul 30, 2015 at 4:43 PM Post #4,559 of 5,671
i don't have any tube amplifiers on hand or even a soldering iron, but I'm skeptical that they actually DO sound any different, if the following conditions are met:

"There are some obvious things that affect tube power amps - like lower damping and the phase shift and other phase issues due to the output transformers. There are also the much higher levels of second harmonic distortion, which give much of the distinctive sound to low-feedback triode amps. However, neither of these really applies to the Lyr. And the overload characteristics of tubes are way different - but that shouldn't matter if you aren't overloading them."

If it uses tubes, it won't be as technically accurate as the best Solid State at that price. Now, it can sound better, or even more natural depending on your headphone, tubes and amp, but won't be as technically accurate.
 
Jul 30, 2015 at 4:52 PM Post #4,560 of 5,671
If it uses tubes, it won't be as technically accurate as the best Solid State at that price. Now, it can sound better, or even more natural depending on your headphone, tubes and amp, but won't be as technically accurate.


My question is whether it's technically "bad" enough to be audibly different. Eg., the Schiit amps have low output impedance, low THD and a flat frequency response, at least into a high impedance load...
 

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