2. amps-preamps
  3. 140146-108796

What will a preamp do for me?

Missing in the chain below is a preamp - I use the DAC to control volume.  This is my only source and will be for some time.  What could I gain by adding a preamp?

I have Thiel CS 2.3s driven by a BAT VK-55, sourced by PS Audio PW DAC, with bridge II, mostly tidal.  The DAC serves as a preamp in terms of volume control.  Mostly Audioquest cables, amp power cord is Cardas Clear m, all fed by PS Audio upc-200.

I am am hoping to improve the highs, which sometimes sound smeared, too much sibilance; would like more air and clarity.  Loud rock sounds flatter, less dynamic than I’d like.  I am not willing to give up the deep detailed and beautifully resonant mids.  Willing to spend up to $3000, used is ok.  Totally balanced is a must.  Not currently willing to entertain the idea of different speakers - my goal is to make the 2.3s sound as good as reasonably possible before moving on to other speakers.  It’s easy to find a really good preamp in this price range, so much so I am almost paralyzed by the choices.  Aesthetix , Ayre, ARC, several BAT, Parasound and more all have apparently excellent models in my price range.  Patience would put Atma-sphere and PS Audio within reach.  Which is best for my situation?  There’s no way to audition all of these, how could I avoid getting on a preamp merry-go-round?  Or should I spend my money elsewhere?
128x128thosb
georgehifi's avatar
georgehifi
4,966 posts
 
thosb
BAT VK-55, sourced by PS Audio PW DAC, with bridge II, mostly tidal. The DAC serves as a preamp in terms of volume control. Mostly Audioquest cables, amp power cord is Cardas Clear m, all fed by PS Audio upc-200. I am am hoping to improve the highs, which sometimes sound smeared, too much sibilance; would like more air and clarity.

thosb Looking at all your specs:
By going direct from PS Audio to Bat 55 and using the Bat’s volume control, specs below shows you have a perfect match with it and the most transparent and dynamic way you will hear your system.
If your getting "smearing of the highs" putting an expensive preamp in the chain will not fix the problem, all it can do is color it more, the problem lays elsewhere.
Specs
"The bat VK55 input impedance is 215kohms"
"PS Direct Stream’s volume control is a no-loss design and may be used at any setting from 1 to 100 without fear of resolution loss.
DirectStream also has two output levels available to users. Go to the setup menu on the front panel touch screen to select the best output level. The maximumoutput voltage at 1kHz was 2.85V balanced and 1.44V"


In the Stereophile review below of your PS dac they said below. This maybe colored by getting the very fine Shiit $149 http://www.schiit.com/products/loki an equalizer that a few here love for what it can do for a problem system, and you can send it back, if it don’t work.
" My first impression was that the PS Audio was rounding off the attack components of notes to the detriment of their sonic physicality, seemed a bit rounded off and lacking the immediacy of, say, Bricasti’s fine M1 DAC"

New firmware seemed to fix some of this, but the way they described it wasn’t convincing, to me at least..

Listening with new firmware
Apparently, my thoughts on the DirectStream’s slightly distant, less-than-fully-textured sound were shared by someone at PS Audio: Unbidden, Paul McGowan contacted me in early June, alerting me to a user-installable firmware update aimed, he said, at "opening up" the sound—and, concomitantly, enabling the DAC to accept PCM files of sampling rates up to 352.8kHz. The new firmware (v.1.1.4) arrived the next day on an SD card; installation was a simple matter of powering down the converter, inserting the card in the rear-panel slot, powering the unit back up with the card in place, and, after reinitialization, removing the card. Anyone could do it. To get a handle on the update, I went back to Beck’s "Lonesome Tears"—and was pleasantly surprised by a very audible increase in texture and touch.

Cheers George


thosb's avatar
thosb OP
76 posts
 
Thanks George!  So far my conclusion re preamps is they can shape the sound (along with source and volume control), sometimes to great affect, but no guarantees that one will provide the specific improvements I am looking for.  I was pretty sure impedance matching in my system was not a problem due to the BAT’s 215kohm input but glad you confirmed this.  Firmware is up to date on the dac.  So I think I need to experiment more with room treatments, especially the sidewalls, before tone control/dsd etc, my thinking is the smear and unwanted sibalance could be those high frequencies bouncing around the room much more than ideal.  Sounds like the start of a new thread!
georgehifi's avatar
georgehifi
4,966 posts
 
thosb OP

Also try a different source, as I’m not convinced about the firmware fixing what the Stereophile reviewer heard because they didn’t do back-flips over it, which is kinda what your hearing too. As what they heard could be  interpreted as "smearing" also.

Cheers George
tomcarr
530 posts
 
Excellent campaign promises OP! And I particularly enjoyed the reference to ABC. Definitely dance-worthy...
audiojan's avatar
audiojan
245 posts
 
The way the volume is dealt with in the PSA PW Dac is pretty good. Upsampling, applying volume, then downsampling to somewhere around 2x DSD (if I remember right). Basically, beyond what you can hear.

It really takes a very special preamp to improve upon it.

I've tried some of the lesser Audio Research and it wasn't until I borrowed a Ref5SE I heard any improvement and it's still fairly small step forward.
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