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Linestage types versus soundstage

A little background. I have been cynical about powered linestages in a digital system. If the impedance ratios are okay, what needs any gain or amplification? Isn’t “straight wire with attenuation” the goal? What’s all those components doing in there if it all ends up going through an attenuator anyway? Would such linestages exist if CD’s had been invented before vinyl? As I watched these products climb to $10K, $20K and beyond, it just seemed stranger—likened to a product that makes water wetter. Cynical, rational me.

But I still felt audio was an experiential endeavor, and had a tube integrated because I enjoy music played through it. I got the upgrade bug and bought the newer, bigger, better tube amp from the same great company, thinking I’d stay in budget by running my Benchmark DAC2 HGC straight into it.

So I did. Things are clearer and more extended…and the soundstage moved to the wall behind the rack and went flat. Let me say here that I have complete belief and trust that Benchmark products are at the top of their class. I respect their recommendation to place nothing between their DAC’s with HGC and the amp. Nevertheless, I borrowed back my old Pass Aleph P linestage. This line stage allows me to optionally add gain to each single-Mosfet channel that fronts a high-quality attenuator. I did that and the soundstage seems taller, but not back to the voice hovering-in-space of the tube integrated.

To summarize, I’ve gone from a tube integrated to tube amp driven from a very good DAC, and gone from EL34’s to KT88’s, and gone from single-ended to balanced, but the DAC and speakers are the same. Perhaps I’ve screwed up something else in the signal path. I wasn’t planning on adding another device, but it looks like I’ve crossed the Rubicon on tube-powered linestages, which I’ll judge on experience rather than thought. Still, some questions hover:

1) What creates soundstage and is there something about tubes that gives them this ability?
2) How is the signal leaving a powered linestage better than the incoming signal? I can answer that question for amps, phono stages and MC step-ups, but beyond "attenuated" I'm still conflicted on powered linestages.
3) Is there an argument that a lot of energy behind the signal going into the linestage attenuator can produce better results? If not, why does BAT have all that energy storage?
4) What new or used tubed preamp less than 4k will give me back that compelling 3D soundstage that extends in front of speakers without added bloat and syrup? New Backert, ZOTL or Van Alstine or a used BAT or AR?  I'd like one that doesn't create a lot of heat.
6) Should I leave things as they are and look to speakers to address the soundstage issue?

I’m going to AXPONA to see what’s out there.
Thanks for any advice or education.
electroslacker
9 responses Add your response
1markr
594 posts
 
I can without doubt tell you that the Backert will give you the 3D soundstage and musical bloom you are looking for, but that assumes the rest of your components are up for the task as well. It’s not just preamp / linestage related, but contributions from your front end components, amps, and all your cables will affect a holographic soundstage, and lets not forget the room either! 
charles1dad's avatar
charles1dad
10,250 posts
 
Electroslacker,
In addition to the Backert I’d look into these given the stated price range 4K or less.
Don Sachs Line Stage
Aric Audio to custom build one for you
A used Coincident Statement Line Stage
A used TRL Dude
A used Shindo Aurieges
A used Atma-sphere MP-3
Different topologies, circuits and tube choice but all high quality options.
Compare them to Your Benchmark DAC running direct and just "listen" this is the key point,  trust your ears. 
georgehifi's avatar
georgehifi
10,312 posts
 
Isn’t “straight wire with attenuation” the goal?

Yes I firmly believe this, "if" impedance matching is good and you have enough volume, direct source to amp is the closest to that you’ll find to the above statement, giving the most transparent, dynamic, accurate staging and depth of sound possible from the source.
Anything active in the path can only add noise, distortion/s, and reduce the dynamic range (unless it has a dynamic range enhancer circuit which sound like c**p)

Cheers George
kalali's avatar
kalali
1,977 posts
 
This topic has been discussed ad nuseam and the debate goes on.
My advice is trust your ears and ignore the rest. I have yet to hear a passive linestage that could approach the soundstage and overall musicality that an active linestage, particularly a tube design, could deliver. Call it inaccurate, too tubey, or whatever, but clearly more enjoyable. And that's the ultimate goal.   
atmasphere's avatar
atmasphere
11,794 posts
 
1) What creates soundstage and is there something about tubes that gives them this ability?
2) How is the signal leaving a powered linestage better than the incoming signal? I can answer that question for amps, phono stages and MC step-ups, but beyond "attenuated" I'm still conflicted on powered linestages.
3) Is there an argument that a lot of energy behind the signal going into the linestage attenuator can produce better results? If not, why does BAT have all that energy storage?
4) What new or used tubed preamp less than 4k will give me back that compelling 3D soundstage that extends in front of speakers without added bloat and syrup? New Backert, ZOTL or Van Alstine or a used BAT or AR? I'd like one that doesn't create a lot of heat.
6) Should I leave things as they are and look to speakers to address the soundstage issue?
1) proper phase relationships and bandwidth
2) It isn't. The thing is, what you are not including here is the effect of the interconnect cable. The fact is most cables editorialize- the have colorations of their own. One thing a decent line stage can do is minimize those colorations and so it can appear to sound better, because it does. But there is no question that it degrades the signal! Funny, huh? With regards to cables, it is easier to reduce cable colorations by going balanced. However there is a balanced standard that is not well supported in high end audio, so you will still be auditioning cables if your gear is balanced but doesn't support the standard.
3) No. But you are confusing (or the post is mis-worded) the energy going into the volume control (attenuator) with the energy used to power the circuit. They are not the same. The energy in the power supply of the preamp simply has to be as clean as possible so that the active circuits are not influenced by the power supply. Brute force is one way to do it, good regulation of the supplies is another.
4) If you want to avoid 'syrup', that is an aspect of single-ended operation. But a preamp can be single-ended and have very low distortion, in which case it will not be 'syruppy'. Auditions are important. We avoid syrup (2nd harmonic) by employing differential balanced circuits throughout our balanced preamps.

BTW, tubes don't have to have syrup, even though they are often know for a lot of 2nd ordered harmonics (example.: SET amplifiers). The harmonic distortions generated by any circuit dictate how that circuit 'sounds', since the are converts all forms of distortion into tonality of some form. So the 2nd contributes to richness and syrup while the higher orders (5th and above) contribute to brightness and harshness (in particular, the 7th contributes to a metallic quality). The reason some circuits have certain distortions and not others is very dependent on the topology of the circuit- for example whether tube or transistor, single-ended circuits will have more 2nd harmonic than a circuit that is fully differential.

Unfortunately the industry does not recognize how the various harmonics influence sound (even though we've known this since the 1930s). So the spec sheets will continue to not be all that helpful- you'll still have to audition the gear to see what works for you.
electroslacker OP
375 posts
 
Thanks to all who suggested  and informed.  A special thanks to Ralph for taking the time to address each of my issues with clarity and insight.

I feel more  empowered and reality-based for my decisions ahead, guided by your experiences and knowing my subjective evaluations have some factual basis.

As an aside, I find it odd that BAT is difficult to get a clear read on.  I was so impressed when I first heard their VK-60 and VK-5 driving Dunlavy SC-4's at their debut.

I know this subject has been discussed alot, but it helped address my specific situation.

Any other guidance appreciated.



raceone
18 posts
 
There's a company in Switzerland - Audio Consulting - that offers a high quality transformer potentiometer call Silver Rock that could be worth consideration. Dick Olsher reviewed it back in 2003 that's worth a read. It's expensive but I've seen a couple used ones here on Audiogon for around $3k.
audioman58's avatar
audioman58
4,134 posts
 
Buy a quality Line stage with very good attenuators, alps sucks ,
a Khozmo shunt with Vishay naked,Takman resistors, 
and great digital remote . Gold point excellent  also. Th3gesta transformer type crazy monies $1500.
i had Vacuum tubeguru Radu Tarta  build me a custom Lundahl transformer based one  for 1/2 of what the Hugh markup charge 
with night and day better quality parts  for $5k range using 
one of the most linear tubes ever made the 4P1L . For 95bd and under sensitivity, or a 2 box unit seperate power supply allways slightly better ,a 300b based preamp . I have a Solid state rectified unit, a bit tighter and faster in the Bass, but tuberectified isplumper
sounding all about preferences . Your soundstage will be Huge ,
great depth of field and lock on imaging . That I can guarantee you.
i have a Pure Audio Project Speakerdual neo 15 inch a Bass drivers and a Voxativ full rangedriver just used from 375 hz and up.
and capacitor,Xover you choose.  My point is you are not limited 
you can have made and voiced to Your preference with much higher quality Premium parts I owned in the U.K until 2007
and know what is inside , it is shocking how many $10k amps,preamps using just average parts , even critical coupling caps , Mccintosh for example great build transformers coupling $6 wima caps ?
why not a Jantzen Audyn Mundorf Clarity a mid grade $20 cap 
so much better you can Clearly hear the difference , you can spend Big $$ on great resistors and capacitors in critical places truly worth the effort. That is why I 
either buy custom . Or buy a solid amp and have it rebuilt,
for 1/2 of what big names want you have a better design better built product.  After 35+ years I have leaned my many trial and errors !! Modwright made a name for himself modding commercial 
products , now he is asking at least 25% more he should andmaking a Huge profits no middle man  like stores at 45% markup.  Buying custom made the majority of cost goes straight 
to the custom case, and parts . About $1k is for the labor and time to design  to yourspecs  . Still far cheaper ,and Better then 90% 
ofthecommercial products at 2-3x the cost .i have owned most brands and my custom better them by a fair distance . It’s your money.  It’s like buying  a Chevy ,or having a custom Bentlet built 
without the $$ amount  . It takes a month to get from  consultation, payment. Just enjoy the quality of your music listening .
electroslacker OP
375 posts
 
In my original post, I said " Perhaps I’ve screwed up something else in the signal path."

Well, time to fess up, man up and eat crow.  I have a sub sitting in the corner, crossed over at 50 hz with a separate set of wires going from the amp taps to it.  As I wrestled to connect the fat speaker wires to the new amp I inadvertently swapped the red/black wires of one channel to the sub.

Now corrected, things have ceased to sound broken, and sound whole even with input coming direct from the DAC.to amp.  But I still want to try a tube pre just to see. 

I just wanted to clear up any suggestion that I besmirched Benchmark Media in any way.  All fault was mine. Curious how that sub mess up affected the sense of soundstage.

Cheers!
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