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In the Forum: Melquiades Amplifier
In the Thread: Valve Preamplifier for Macondo/DSET
Post Subject: A long story about Phasure and the PlacettePosted by anthony on: 4/27/2019
Romy, I will attempt to fill you in on some backstory.

My Placette was purchased from a guy in France.  My dac is made in the Netherlands.  To an Australian that is just like next door.  I have a good and strong relationship with Peter Stordiau who makes the Phasure stuff and at the time he was looking at releasing a SS preamplifer himself.  Maybe.  Peter has a strong set against preamps because they "ruin the sound" and I thought that this would be a good opportunity for Peter to play with the Placette so I had the Frenchman send it to Phasure instead of to me.  The first thing that Peter did before listening was measure the linestage and its volume control in various positions and it does measure very, very well.  But as we all know THD does not count for much of the listening experience and he put it in his system and really did not like it..."just like all preamps the Placette also ruins the sound" and then "you should send it back".  Peter is a busy guy and I did not want him to lose too much time with this project but I did ask him to pull off the lid and see if there was anything obviously wrong and perhaps to give his opinion on how to modify the buffer.  Well, everything is glued down inside and it is difficult to get a look underneath the circuit boards but all the caps and wires looked fine, the unit measured well and operated properly in its own idiosyncratic way.  

When I received the unit in Australia I put it straight into play and was immediately disappointed.  Of course I had more time to experiment than Peter so I raised the mains voltage to 120V which helped things a little and then eventually I tried -6dB attenuation through the dac (Peter and I had been running zero attenuation...why attenuate at both in software and the linestage?) which for some reason improved things a lot.  And so it has been running ever since.  I have not experimented with different attenuations but on my previous system I have experimented with putting the Placette between the NOS1a G3 and without, and there was still an audible but subtle degradation.

Since getting Macondo hobbling along I have not repeated the experiments but I should.  After listening to Macondo my old system sounds compressed and incompetent and it may be possible that the effect of the Phasure/Placette on Macondo could be amplified, but alas that is something that I will try down the track when I have Macondo up and running in full.

Peter never released a Phasure preamp.  I don't think he ever strongly felt the need for one in the Phasure community and perhaps he was never really satisfied with his attempts.

I have recently talked to Peter about beefing up the output stage of the NOS1a and I know that during development of the latest IV stage (the G3 in NOS1a G3) that Peter was experimenting with stacking the modules for more voltage output but Peters seems to think that I would be best off getting a preamp with some amplification so that it can push 4V from modern low output sources.  He has no suggestions...does not like preamps, haha.

So the modern standard is 2VRMS output which pretty much everything these days adheres to.  Peter chose less output (1.25VRMS) for a number of reasons including "it sounds better" (was able to eliminate one regulation stage in the dac) and because most modern amps have too much gain and thus less source output equals better overall gain structure.  It harms me especially because I run at -6dB into the Placette which is half the rated output (0.6VRMS).

Hopefully that explains which I run things as I do right now.

  
 Romy the Cat wrote:

Since I do not feel it is possible I preams there are 3 factors that might be in pay. 
 
1)      Your Placette is misfunctioning
2)      Your admiration with “expedited” sound somehow find a pass in your mind to this decolorization
3)      I am clueless with my assessment and somehow Phasure found a new “golden middle” at the level I am not familiar. 
 
All of the options above sound reasonable to me. 


I am pretty sure my Placette is functioning correctly.  At least there were no THD remnants when Peter looked at the unit in the Netherlands.  It did come halfway around the world to me afterwards, but I am currently operating on the premise that it is fully functioning.

So, Mani's comments of the NOS1/PM2 in 2011 are before my time:  I purchased my NOS1a (notice the "a") in 2013.  Phasure's business model is not really a business model per se, more an enthusiasts model.  Peter is forever experimenting in software, connections or hardware and when he finds something with sonic merit he releases it to the group as an upgrade rather than as a new dac.  So that NOS1 of Mani's in 2011 has had three major upgrades since then for it to become the NOS1a G3, the G3 being the new current amplification output stage (1.25VRMS), the "a" was new power supplies and somewhere along the way there was a new improved USB interface.  Along with changes in the software that drives the dac, the current NOS1a G3 is a higher functioning, better sounding dac than the early model that Mani had to compare to the PM2.  I've never seen a PM2 so cannot comment on its harmonic content et cetera, but I have directly head-to-headed it in my home system with some very good dacs (MSB/Playback Designs/Killerdac/AMR/Weiss) to name a few, so I can comment on what the Phasure dac brings when compared to those dacs and what it gives away.

The biggest surprise to me as far as performance goes was a dac produced by the local cult of the Killerdac.  It is a simple redbook only, TDA1741a dac with a valve output stage.  In its home environment, listening to simple music (girl and guitar, Frank Sinatra, Ella Fitzgerald) this dac slays everything, even the Phasure dac with its harmonic content and pure engagement.  It is beautiful to listen to.  But as soon as there is any sort of complexity to the music, think rock or heavens forbid orchestral, it just falls in a congealed heap and is beaten by pretty much every dac out there.  A one trick pony.

I had a top level MSB Analog dac here for several weeks and I can say that this is a good example of "expedited sound", or should I say what I think you mean by that phrase.  Some would call it clinical, but I would call it bleach white and dry.  By contrast the NOS1a (it was 2013, so not the modern incarnation of the Phasure dac) had more body and flesh, definitely more sustain and more engagement.    

One dac that I listened to that I liked was the Playback Designs MDP-8 (not the MPD-5, that was ordinary).  In direct comparison in a better system than mine both the Phasure NOS1a (not current version) and MPD-8 were reasonably similar in many ways with similar dynamic swings and harmonic tails.  They were more similar than dissimilar.  Where the Phasure stood out was not at the beginning or end of the strokes, the attack and release, but in the middle of the note, the decay and sustain.  This is I think where the "clarity" as Mani's calls it really comes from with the Phasure...the in-between.  There is a resolution here, particularly noticeable with male voice and with piano, where the Phasure just has more texture.  I love it.  As soon as I realised that extra resolution is there I listen more carefully to it in other sources.  


Other dacs that I have compared to the Phasure dac have all been different in various ways, but I seem to notice a few "constants" of the Phasure dac that other dacs I have tried have not been able to replicate.
I can see how some people may be underwhelmed by the Phasure dac when they listen to it for the first time.  There are no "oh wow" sound effects and everything just seems normal and balanced and capable.  There is the obvious "clarity" that Mani talks about, but I would call that something else..."uncluttered".  The harmonic decay is all there, the resolution is all there, tone is probably a little darker than most dacs because of its uncommon resolution in the bass frequencies.  After using it for a while many get to appreciate what it does not do:  stumble, exaggerate, clutter, colour.  I think that it is a great source for a SET amp...apart from the dismal voltage output.


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