[twsmith]

I just received a GS-X (fantastic amp) and am presently using the XLR output from my DAC1 USB for balanced operation.   I would like to know how best to configure the DAC1 XLR output to match the GS-X.   Presently I'm using the DAC1 factory settings with XLR output jumpers set to -20 db attenuation in "calibrated" mode and the GS-X set to "medium" gain.   I find that this sounds very nice but I'm not having good control over the volume with too large a jump between levels on the DACT volume control.   I tried using the "low" gain setting on the GSX, which gives better control over the volume (more steps) but now the sound seems not quite as full-bodied and detailed.   I've read that changing the DAC1 XLR jumpers to O db (no attenuation) results in much better sound from the DAC.   My question then is how this would affect the GS-X -- will the increased XLR output overload the amp, or will the "low" gain setting offset the higher output and still give me both good control over the volume and optimal sound quality?  
 
This is not a trivial question since I will need to open the DAC1 chassis (makes me a little nervous) to change the XLR output attenuation jumpers.   Any recommendations from other DAC1 USB / GS-X users would be most appreciated.
 
thanks

 

[Michgelsen]

Quote:

Originally Posted by twsmith /img/forum/go_quote.gif
I tried using the "low" gain setting on the GSX, which gives better control over the volume (more steps) but now the sound seems not quite as full-bodied and detailed.

Are you sure about the bold part..? This is not expected behaviour of the amp. Be aware of the fact that music typically sounds more 'full-bodied' and 'detailed' when it's simply louder.
Anyway, if you were to open your DAC1 and make it 20 dB louder, know well that 20 dB is a LOT, so you will have even less useful steps on the attenuator. The best idea is probably to have the internal jumpers at -20 dB and use the low gain setting, which should not harm the sound quality.
 
Another option is to buy an in-line attenuator: just a plug that attenuates the signal by 10 or 20 dB or another value. This is an example of what I mean: http://www.rothwellaudioproducts.co.uk/html/attenuators.html . I'm sure there are more.

 

[twsmith]

 
Quote:

Quote:

Originally Posted by twsmith /img/forum/go_quote.gif
I tried using the "low" gain setting on the GSX, which gives better control over the volume (more steps) but now the sound seems not quite as full-bodied and detailed.

Are you sure about the bold part..? This is not expected behaviour of the amp. Be aware of the fact that music typically sounds more 'full-bodied' and 'detailed' when it's simply louder.
Anyway, if you were to open your DAC1 and make it 20 dB louder, know well that 20 dB is a LOT, so you will have even less useful steps on the attenuator. The best idea is probably to have the internal jumpers at -20 dB and use the low gain setting, which should not harm the sound quality.
 
Another option is to buy an in-line attenuator: just a plug that attenuates the signal by 10 or 20 dB or another value. This is an example of what I mean: http://www.rothwellaudioproducts.co.uk/html/attenuators.html . I'm sure there are more.

 
In retrospect, you may be right -- increasing DAC1 output to 0 dB, even at low gain setting on GS-X would probably be too much.  Having listened now for a week or so, I've decided I really like the medium gain setting keeping DAC output at -20 dB.   I doubt now I will fool with output jumpers.  Perhaps the recommendations to change jumpers were related more to amps with no gain control and/or low input sensitivity.   The GS-X definitely does not have that problem. 

 

 

[schaqfu]

twsmith,
 
Not to go off topic, but I think this question is highly related: Like you I have a DAC1-USB and am strongly considering getting either the GS-X or HeadRoom BUDA to allow me to go balanced with my HD800s and HD650s.  I see you are enjoying the first combination, and I also note from your posts in another thread that you have (or had?) the BUDA and Ultra DAC stack combination.  Which combination do you prefer?  I'm going to stick with the DAC1, but do you think I would be better served by pairing it with the GS-X or the BUDA?  And I'll be very curious to hear if your thoughts evolve at all on your OP in this thread as to the proper output settings for the DAC1 into the GS-X.  I would have thought that 0dB output would have been fine into an amp as robust as the GS-X and that it would be better to control the volume attenuation range with the amp's gain control rather than with the DAC's jumpers, but I don't know enough to judge.
 
Thanks!

 

[twsmith]

 
Quote:

twsmith,
 
Not to go off topic, but I think this question is highly related: Like you I have a DAC1-USB and am strongly considering getting either the GS-X or HeadRoom BUDA to allow me to go balanced with my HD800s and HD650s.  I see you are enjoying the first combination, and I also note from your posts in another thread that you have (or had?) the BUDA and Ultra DAC stack combination.  Which combination do you prefer?  I'm going to stick with the DAC1, but do you think I would be better served by pairing it with the GS-X or the BUDA?  And I'll be very curious to hear if your thoughts evolve at all on your OP in this thread as to the proper output settings for the DAC1 into the GS-X.  I would have thought that 0dB output would have been fine into an amp as robust as the GS-X and that it would be better to control the volume attenuation range with the amp's gain control rather than with the DAC's jumpers, but I don't know enough to judge.
 
Thanks!

There is no question in my own mind that the DAC1 USB and GS-X are superior in every way to the UDAC-BUDA combination that I had earlier.  Unfortunately I sold both before acquiring the DAC1 and GS-X.  However I still have an older Headroom Ultra Desktop (2006) which apparently has the same amp modules as the BUDA (but not balanced), and I did try this with the DAC1.  I still thought that the DAC1's headroom amp was a little better, although the DAC1-Ultra Desktop/DAC1 wasn't bad -- but clearly not in the same league as the GS-X.  
 
Here's my suggestion -- you already have the DAC1, so it probably wouldn't hurt to first try a BUDA to see if this combination works for you.  Headroom does have a 30 day return policy, I believe, so if you don't like it then you wouldn't lose much (I guess shipping cost mainly; I don't think they charge a restocking fee).   The turnaround time for getting a BUDA is fairly fast too.   The wait time for a GS-X, at least in the past, has been fairly long - many many months, however Justin is now claiming a faster (1-2 month) turnaround for the GS-1 and GS-X.  
 
The GS-X really is a totally transparent amp - it will reproduce exactly what your source is with absolutely no coloration -- so if you really like the sound of the DAC1, then this is the way to go.  The BUDA will slightly color the sound -- it may be a tad "warmer" and more laid back than the GS-X.  People who feel the DAC1 is a little too "upfront" may actually welcome this approach, but not me.   Actually a somewhat cheaper "third" option would be to skip balanced and just get a GS-1, which uses the same modules as the GS-X.  In my opinion you would still get better SQ than going balanced with a BUDA -- it should sound much like your DAC1 headphone amp does now but more transparent, with better control of the highs and lows.  
 
On the other topic, you're right -- the GS-X should most likely be able to handle the O db XLR output from the DAC1.   The question is then is it worth opening up the DAC1 to change the jumpers or not? -- I've found that the -20 db output from the DAC1 with the GS-X gain set to medium sounds just amazing.  I think this is partly related to getting more adept at using the stepped attenuator on the GS-X.   I now doubt that I would hear any "improvement" by changing the output to 0 and using low gain, since the GS-X sound quality to my ears remains the same at all gain settings.   In retrospect, I believe the recommendation to set the DAC1 jumpers to O db probably applied mostly to amps with relatively low gain to begin with, where increasing volume resulted in more noise and diminished sound quality.   The GS-X doesn't have this problem at all.   Benchmark also specifically says that the XLR output attenuation jumpers do not in any way affect the sound quality of the DAC1 -- contrary to what some people have written, I do agree with them.   

 

[schaqfu]

Thanks, twsmith, that's really great perspective and advice.  I suspect I will just bite the bullet--when I have the cash--and purchase the GS-X directly. So much of this hobby is psychological (a fact few want to admit), and I know that even if I'm completely satisfied with the BUDA-DAC1 combo, I'll have a constant nagging desire to know whether it would be even better with the GS-X.
 
Through my own testing of the attenuation jumpers in the DAC1-USB's output, I concur, I haven't been able to hear a sound quality difference.  FYI, though, in case you are inclined to experiment, you should know that opening up the DAC1-USB is not a difficult process at all.  I think it's a total of eight screws, all of which you can see from the outside.  You don't have to remove the face plate or anything, and the outer housing comes off like a shell.  Moving the jumpers themselves is very easy.  The only trouble I ran into was that I accidentally stripped the Phillips screwdriver grooves at the head of one of the screws while unscrewing it.  I just used too much force.  There are seven other screws, though, and this screw is still seated in there fine, I just need to be very delicate with it when I unscrew it in the future.  And this only occurred after I had opened up the chassis a total of perhaps a dozen times during my experimentation.  It's really a very simple endeavor, nothing to worry about even for the non-electromechanically inclined among us.  And unlike some equipment, opening the DAC1's chassis does not void the five year Benchmark warranty.
 
Thanks again for your good info.

 

[schaqfu]

I received my GS-X last week and have had it mated nearly constantly since then with my DAC1-USB and HD800s (with balanced Double Helix Silver Clone cables -- a wonderful new addition to my lineup and noticeable improvement over the stock HD800 cable, imo).  I also have taken some time for extended listening sessions with my HD650s (with balanced APS v3 cable), Shure SE535 IEMs, and Ultimate Ears TripleFi 10vi IEMs.  I'm not prepared to give a full evaluation yet.  However, germane to this thread, I have experimented with the output attenuators on the DAC1-USB's balanced XLR outputs, and while I have not been able to detect any difference whatsoever in sound quality or signature between -20dB and 0dB, I decided to leave the jumpers at the 0dB position if for no other reason than because Benchmark Media (the manufacturer) describes this output level as perfectly calibrated to a standard pro studio level (quite loud, from what it seems).  
 
I do want to share two interesting initial impressions about the performance of the GS-X though:  First, the improvement over the DAC1-USB's built-in single-ended headphone amp (which I consider to be excellent in its own right) is not subtle -- I can clearly detect a lower noise floor and more pronounced and better defined bass, low-mids and low-trebles in both of my Sennheisers.  My second initial impression is surprise at the realization that the HD650 seems to have benefited to a much greater degree from the GS-X than did the HD800s, and, even more surprising, that the Shure SE535 IEMs seem to have benefited as well.  I detect no difference at all with the Ultimate Ears TripleFi 10vi IEMs.  The HD650s and SE535s always seemed to me to have a veil, with pronounced roll-off in treble.  I upgraded the cable on the HD650s and did the "de-foam" mod all in an effort to lift the veil (with some success, actually); none of this was a problem with the HD800, so my HD650s mostly have been gathering dust for a while now.  But all of a sudden through the GS-X for the first time I can hear sweet, well-balanced treble in the HD650s that I would describe as one step short of "sparkly," but without any loss of definition or separation in all the lower ranges.  Total upgrade for the HD650s!  And the veil has been lifted--though to a smaller degree--on the SE535s as well.  Why that would be is confusing to me, and I won't hazard a guess.  But it's a cool bonus.
 
I'm extremely pleased so far!