How many use the DSJ as their preamp vs DSJ into a dedicted Preamp?


#1

Interested in knowing how many use the DSJ as their preamp vs DSJ into a dedicted Preamp? I believe Dennis has stated that using the DSJ without a seperate preamp is the “prefered” option.


#2

I ran my DSJ in for 200 hours prior to doing any serious listening. The plan was to run it direct into my Pass Labs X150.5. A simple elegant solution to be sure. Anyway, I listened on the high gain setting first - lots of hiss - so I had to turn it down to the low output (defeat?) setting. I noticed this same issue with a Gain Cell DAC that I auditioned here in Australia not long after it was released. In that setup, feeding an Auralic Aries into the Gain Cell DAC then into some of the S300 Gain Cell amp’s on the high gain setting was very hissy. A bit of shock since at the time I was still listening to a Devialet Le 120 - deathly silence at all volumes. Back to my setup - on high gain settings, the DSJ was able to get the Pass Lab’s dial bouncing around the the right but at low levels, the hiss was distracting.

So low gain it was. And this then brought on a new problem. Not enough gain. I set the Pass Labs to it’s highest gain setting (there are jumpers internally to raise the input sensitivity by 6dB). I also made sure that I used XLR cables to get another 6dB over RCA interconnects. At 100% volume it was not enough to get anywhere near enough power out of the Pass Labs. I was barely jumping out of Class-A (anyone who is familiar with or has owned Pass Labs gear will understand what that means).

So I got hold of a Xindak preamp. It is fully Class-A running FETS and is really nicely designed. It has an implementation of Nelson Pass’ now out-of-patent super-symmetry circuitry in it. On the practical side it also has 10V output and has enough juice to get the Pass Labs all the way around to the right hand side of the dial (loud!). So on a purely objective point view, the introduction of a pre-amp with gain (not a passive one) will get you out of trouble if the DSJ can’t get your power amp into clipping at full volume.

On a subjective level, the introduction of the Class-A pre-amp brought a slight smoothing of the sound, more relaxing and no obvious lose of detail. Is this an improvement? Well, that’s where we slip into the realm of subjectivity, taste, system balancing and all that. Personally, with the Xindak between the DSJ and my Pass Labs, I’m getting back to the sound that I love. A few years ago I had a pure class-A First Watt F6 fed by a Bride of Zen pre-amp. It was under-powered as a system but the sound was glorious, effortless, beguiling. Perhaps something that even a tube lower would love. With the Xindak pre-amp I’m back at that sound. In purely objective terms, the pre-amp has to be adding or subtracting something but that is an entirely satisfying thing. I may try other pre-amps if I can find anyone who is willing to give me a short term loan of one.

I know Paul has mentioned that SOME pre-amps really work well with the DSJ/ or Seniors. The one he recommends is not cheap though. It would be useful if we could get some feedback from other users about what setups they’ve managed to get to sound good with their DSJ / Senior when using other pre-amps. At the lower end of the price range there will always be some compromise but it would be useful to know what matching have worked so that people can audition gear in a more focused way. My Xindak was bought quite cheap as a 2nd hand unit - it’s the old model now. New they are about $900US so they’re not the cheapest units out there but they are not venturing into the super expensive end of town either.


#3

I don’t have a DSJ but I have a DS Sr. Before I had it converted to a DS Sr it was a PWD Mk 2, and that I ran straight into the power amp. It’s interesting to note that the PWD had a stronger voltage output via single-ended and balanced than the DS Sr. When I first received the DS Sr I compared it directly via the single-ended outputs into my power amp (a tube amp–a Decware Torii Mk III with Jupiter beeswax cap and stepped attenuator options) and through my preamp into my power amp (a Decware CSP2+ tube preamp with Jupiter beeswax cap and stepped attenuator options). I preferred the sound directly into the amp by a smidgeon, I was getting great sound either way but did not have two of my very best interconnects and felt that was making a slightly negative impact on the sound. Also my lowest source into the DS Sr, the DVR, sometimes was just a bit too quiet for my wife and so she would rather hear the compressed sound of the TV.

Around this time Decware introduced their ZBIT, a fully-adjustable balanced-to-single-ended transformer that I added to the system which allowed me to use the balanced outputs of the DS Sr into the power amp and gave me more voltage and allowed that one lower output input to be quite loud. Overall the sound had just a bit more body and density, which I liked. I used this set up for a year.

During that year I slowly started to gain extra listening time by using headphones and bought a great used headphone amplifier and ran my Cambridge Audio CXU’s output into that. I later bought the latest version of the headphone amp and realized that the CSP2+ preamp I had used before had two stereo outputs and would allow me to run one to both the power amp and the headphone amp and the sound from the DS Sr into the headphone amp was better than the sound from the CXU. So I reinstalled the CSP2+ . . . and over a year later, with a great set of tubes and now with two pairs of my best interconnect. . . I preferred the sound to either the DS Sr directly into the power amp OR the DS Sr using the ZBIT. The latter two were very close in sound, but there was a touch more dynamic contrast with the CSP2+ and a more solid instrumental image. So now I am enjoying the CSP2+ preamp in between the DS Sr and both the headphone amp and power amp. I am getting sound that just floors me. I get out of bed wanting to turn on the system.

I can heartily recommend this preamp, which is now in an updated version, the Decware CSP3. This preamp is an OTL design, that is it does not have output transformers, and it offers a lot of voltage out to an amplifier and the voltage is adjustable at both the input and the output. By playing with the output voltage one can tailor the sound. This is a very transparent and dynamic preamp and also serves as a headphone amplifier very admirably. (The other headphone amp in my system, the Decware Taboo Mk IV, is designed to power planar magnetic headphones, my favorite type, and I use it with Oppo PM-1 and Audeze LCD-2 headphones–it drives these phones wonderfully).

Hope that isn’t too confusing. So. . . I have used the DS Sr. three ways and I think with the right preamp it gives its best sound. . . . Just my two cents.


#4

If you only play digital music, and the digital volume control of the DSJ will suffice, it’s hard to make the case for adding a separate linestage preamplifier. Gainstaging is important though to make sure you get enough volume without hiss. With my speakers (89db efficient) and amplifiers (27dB gain), the low gain setting on the DSJ is just about perfect. I need to employ the high gain setting about 1% of the time or less (in which case there is noticeable hiss, but this would be for high volumes anyway when it is less noticeable.

I find controlling volume with the DSJ through the volume knob, or remote, or within Roon all quite nice. Adding a great preamp like the BHK would be thousands more. YMMV


#5

I don’t know if this applies to the DS Jr, but I’ve found that connecting my DS Sr directly to the inputs of a power amp can have highly variable results. In my own experience, it has ranged from sounding fine (Air Tight ATM-1s) to being kind of flat and lacking in dynamics, particularly in the low end (Hypex NC400 monoblocks, Benchmark AHB2). Even in the “sounding fine” case, the introduction of a high-quality preamp seemed to clear up some minor phase distortion/smearing that I wasn’t even aware of until it was gone. The preamps I use with the DS Sr are the Spectral DMC-30SV, or this DIY preamp, depending on where I have the DS in my apartment. Both are very high-measuring solid state preamps that, for whatever reason, sound more transparent to me than a straight cable from DS to amp.


#6

Thanks all… very good conversation… I have experimented and liked the sound better with my AE3-DJH preamp in the loop. Also found that the extra gain was very helpful. I just changed amps to Primaluna Dialogue HP’S (single ended input only) and currently running direct… With all that extra power, I am getting plenty of volume, but not nearly what I expected… I will try the Pre-amp again once I get used to the sound of the new amps…


#7

I will never connect a network enabled DAC directly to power amps, due to risk of a volume runaway to the high side and blowing up my speakers. Which happened to me with DS Snr. I know they’ve put a volume limiter function in it now, but in any event, setting the PS DAC vol = 100 and using a dedicated preamp sounds better in my installation.


#8

Is your concern with connecting a DAC directly limited to network enabled DACs, or is this a broader concern?


#9

I’m running DS directly into a pair of JC-1 amps via balanced cables. Zero hiss with gain set to high, and with Huron, it sounds amazing.


#10

It would interesting to get an EE’s input here into why some power amplifers show excessive hiss when used on the high-gain setting and other don’t. I personally would have liked to be able to use the DSJ straight into my Pass Labs as that’s a simpler and cheaper solution. The Pass Labs X150.5 specifications state 26dB gain, full power at 1.73V. The JC1 spec’s state 1 V for 28.28 V. I’m not sure how to read these two sets of figures as I don’t know the maths to work out the differences between them.

Also there might be some factor with the input impedance on the amplfier. Parasound states that the XLR inputs are 100kV, unbalanced (as usual) is half that at 50kV. On the Pass Labs the figures seem to be the same so I assume that is not a factor.

I’m showing my lack of electronics understanding here no doubt.It would be useful to know whether the input sensitivity differs greatly between the 2 amplifiers and whether a higher or lower input sensitivity leads to less hiss or whether there are other factors.


#11

The input impedance, which you have listed as 100kv (you meant 100kΩ) is perfect (as is the 50kΩ for single ended) but has nothing to do with hiss levels. Hiss levels have everything to do with sensitivity. How much signal is needed to get the amplifier moving. I am a bit surprised that the Pass, with a gain of 26dB (less than BHK), has hiss. In that case, it would seem your speakers are likely very sensitive.


#12

Paul,

Actually they aren’t! 87db/w/m in the midrange and about 88 in the treble region. I heard a similar thing when listening to a demo’ of the gain cell DAC feeding some S700 amplifiers here in Australia. It was on high gain and there was noticeable hiss until I set the gain to low. That was with a pair of Sonus Fabor floor standers (the model escapes me) but the sensitivity of the Sonus floor standards all seem to clock-in at around 87-90db/w/m. The cables I’m using aren’t especially bright either being pure OFC rather than Silver or silver-plated copper which can pick up hiss more than copper cabling.


#13
Elk said

Is your concern with connecting a DAC directly limited to network enabled DACs, or is this a broader concern?


Limited to network enabled DAC. Volume control via network is exposed to latency in the control point and the network.

When I was using eLyric to control DS Snr connected directly to my power amps, on one occasion the Vol+ command wasn’t resulting in any volume change, so I kept giving it some more Vol+. Then all of a sudden the bottleneck in the control link freed up and all those queued Vol+ commands got sent to the DAC. At this stage there was no volume limiter built into the DSD OS and it did what it was told to do and went to full volume. The end result was a very expensive Accuton mid-driver being turned into ceramic dust and splinters. It had to go back to the factory in Germany for damage assessment and repair.

You don’t experience this sort of issue with IR or serial control.


#14

After spending the last few months with my DSJ running directly into a McIntosh MC152 power amp - Today I hooked up a used Aesthetix Calypso line stage and it is the biggest improvement to my system I’ve ever heard! Frankly, I was of the belief that I might see a minor change and was so on the fence about the purchase that I didn’t even bother hooking it up for a few days after receiving the Calypso. The DSJ is my only source so I was thrilled to not need a preamp and I couldn’t believe it would matter much - boy was I wrong!

The changes were so spectacular in my system in every way. The Soundstage expanded by orders of magnitude in every direction, it’s like my DSJ has had the shackles released and I’ve yet to make any adjustments to my system beyond plugging it in and pressing play.

I bought the DSJ with the intention of driving it directly into my amp and never really thought much about getting another preamp until I started reading some of these threads. I know everyones system is different but if you get even a small percentage of the changes I’ve seen with my system, I wholeheartedly recommend trying a preamp and A/B test it before finalizing a setup with the DSJ direct into an amp.


#15

Thats good to know! I’m at a crossroads where I have a great dac, I think a decent preamp in the DSJ and enjoyable speakers but my room isn’t big so it’s not necessary to go huge in size. I really enjoy the Totem Arros, might upgrade but I keep thinking adding a tube pre will sweeten things up and better long-term purchase.

Only funds for one or the other for awhile. And the space isn’t going to change for awhile either.


#16

Did you use high or low gain (defeat) when you were driving it directly? My experience is that I had to use the defeat setting with my Pass Labs to eliminate hiss, even when using balanced interconnects and the DSJ simply didn’t have enough “juice” to power the X150.5 satisfactorily. Adding a Preamp of course increased the gain substantially. The only thing I feel I’m losing is a tiny bit of bass extension but I think I’m gaining in a lot of other areas. And of course, careful selection of interconnects my address the balance a little bit to extend the bass.


#17
LIbrian said

…I wholeheartedly recommend trying a preamp and A/B test it before finalizing a setup with the DSJ direct into an amp.


Paul has written about this in Paul’s Posts and in the forum here. The question how, adding another box in the signal path, improves the sound. Well, it does. You can’t expect the pre-amp in the DAC to be better than a dedicated pre-amp. I also use a dedicated pre-amp with DSJ. I could buy five DSJ for the cost of my pre-amp. Considering what you get in the DSJ for the price it represents great value.

#18

Blang (and others) … I am a true sceptic - from alternative medicines to all kinds of superstitions. Therefore I would never have even tried the BHK (or any other pre) if it wasn’t for the fact that I had one (well, sort of) “lying around” wink

I’m very glad I’ve tried it though - this skeptic is a believer now! I know it defies all logic, but adding a preamp of the BHK calibre just transforms the sound. Without it, soundstage, imaging and instrument decay was greatly reduced.

I had no gain problems in driving the BHK 300’s directly. Furthermore, my second pair of XLR’s is (currently) not even close to the quality of my main pair. Yet, somehow, introducing this second pair of XLR’s plus the BHK just transformed the sound. Why this is so I have no idea. Perhaps Paul is on to something in another thread, where he suggested “isolation” may be the key.

Be it as it may … there’s no ways the BHK pre is leaving my system now. shaking-head-no-smiley-emoticon_gif


#19

Welcome to the forum LIbrian!


#20

I bypass the preamp option on my Headamp GSX Mk2 and go straight to gain stage, which is more than sufficient to drive my Audeze LCD-4’s. I believe that when it comes to putting electronics in between the source and your ears, ‘less is always more’.