Wyred 4 Sound or PS Audio

Hello, My name is Mark and I am a hifiaholic. It has been 5.5 hours since my last purchase: W4S mAmp mono blocks with the wiring/post upgrades - these will replace a Pro-Ject Amp Box RS, my gateway drug and a well-loved member of the family; I'm still a bit unsettled about the separation.

I am also experiencing cravings to replace the preamp, also a Pro-Ject (Pre Box RS Dig) with something with HT bypass to once again make use of the extra speakers and (really good)HT receiver on hand. My dilemma is this: I have the good fortune of two great deals: a new PS Audio BHK Signature Preamp at 50% off retail, or a new W4S STP-SE Stage 2 modified Preamp for $1k less than the PS Audio. I know, such a sad story.

I have recently lucked into used PS Audio PWD MkII and PWT, and have a PS Audio NuWave Phono Converter. Seems like I'm chasing the PS Audio dragon, and my pupils do dilate when I see the BHK, but I have read such amazing things about the W4S STP - and this passive/active preamp idea is super intriguing - that it is making the decision a tough one. Would the amps have better synergy with a pre of their own kind, or would the tubes in the PS balance perfectly with the D-Class W4S? Is the PS deal just too damn good to pass up and everything else be damned, or is the W4S really the sleeper deal of century? Does anyone have any firsthand knowledge or wisdom to impart. Shouldn't there be coffee and cookies around here...


hah, you could not have picked two preamps that are more different than those!

I do not have direct experience with either of these, but the W4S STP looks like it is going to be very much like a passive preamp, but with gain applied to the voltage so that it can drive the demanding impedance of amps. This means that the STP is going to be the most transparent to the incoming sound waveforms.

The PS Audio BHK, on the other hand, has a 12AU7 tube gain stage and a Class A discrete output stage. These two stages are going to soften the "square wave" nature of the waveforms coming from the DAC. Since your PWD DAC already has a Class A output stage (and it is written that this DAC will have a slight high-frequency rolloff), pairing with the BHK might put too much of a "laid back" character on the sound (losing even more high frequency detail and clarity/punch).

I experimented for a little while with Class D amps, but discarded them when I figured out that they just did not have enough current to drive certain speakers. I don’t know your synergy, but my experience with Class D seemed like a very nice tube amp. It had a nice full midrange, but lost bass/midbass punch and high frequency excitement.

Not knowing your system or how things sound, I would probably pick the STP with your combination of equipment so that I could keep the most amount of resolution of the sound.

Thanks, Auxinput. Very informative. I decided on the mAmps because I put a class D - Peachtree SonaAmp - in my bedroom system and have been really happy with the sound. In the main system, everything ends up in Klipsch towers, so a little softening is not a bad thing there (I do love the speakers, but that horn can stand out at times). It's a tough choice, and it's easy to get lost in all the specs...and opinions. Thanks for your input!
I have I have both the P.S. Audio BHK Preamp and a W4S STI 1000 integrated. The W4S has a similar preamp to the separate unit, but not exactly the same. Do yourself a Big favor and get the P.S.Audio BHK preamp, I cannot recommend it highly enough.

 I am now retired and because time is limited I have purchased some equipment in the last few years that I felt would make my life complete before it's to late. Several purchases have been off the charts, Pass Labs xa160.5 mono blocks, BSG QOL and now the BHK preamp. WOW!

I have the good fortune to have two major systems with my other system centered around Tannoy Westminster Royals with tube electronics but if I only had one system it would have the P.S. audio BHK preamp in it.

Hope this helps.


@markkelly70 - I have had Klipsch speakers before.  I don't know if this is possible with your model, but see if you can take out the horn and apply dynamat to the backside of the horn material/plastic.  This will calm down the resonance/vibration of the horn plastic and will calm down the effect of the horn itself.
@tubeking1 That's great information, thank you! I definitely get the 'end game' feeling from the PS Audio components I have - they are 'lifers,' and I imagine the preamp would be the same. The scale is leaning! 

@auxinpput The horn on my speakers sits in a rubber enclosure, a feature that I think is new to this series. It's only an issue on certain recordings, and not enough of one for me to start pulling the things apart since I've no experience in that! Still, both the speakers and my ear are amenable to upchain contributions of warmth.
Mark, while I don't have either a PS Audio or W4S component in my system, I do have a preamp that is a Grounded Grid kit from Transcendent Sound, that has some key upgrades, such as caps, tubes, attenuator and switching, but the main point is that it uses 12AU7 tubes.

I would in no way call it laid back, or smoothed over or rolled off in high frequencies. It replaced a very good passive line stage, and I feel there is no loss of transparency with the change.

I drive either a Class D (500 Wpc) or an SET 300B for my 12" Tannoy HPD's, and each sounds very special in their own way. I'm leaning towards the BHK pre being the best choice, it sounds like a great deal.


I have the W4S STP SE, and was immediately struck with how transparent it sounds. I originally paired it with a Musical Design D-140 and Maggie MG-12's. I now have it paired with a Son of Ampzilla II and Maggie 1.7i's. The combination is the best system I've ever had.

The STP is a VERY nice preamp that reminds me of the best qualities of a tube pre with great bass handling. It may lack slightly in high end extension, but that could be the Audioquest Type 4 speaker cables.

I have no problems with enough gain, and it's nice to finally have a remote volume control that is actually usable for a change! 

I’ve done a lot of experimentation with Class A circuits. Class A is an excellent way to smooth the "square waves" from DAC and translate more bass and a more natural sound.  I have found that the best number of Class A circuits in an entire audio path is two (meaning from source CD/file all the way to speakers).  There was still an excellent amount of quickness, attack, punch and clarity.  However, once the audio path contained 3 Class A circuits, I started experiencing the slow down or laid back affect where I would lose resolution/punch in the bass/midbass and the high frequencies definitely started rolling off. Essentially, the sound started becoming a lot warmer/softer/slower. This was not an issue with power supply, as the problem still occurred if I split the Class A circuits between devices (i.e. one Class A in DAC and two in preamp).

If you combine the PS Audio PWD with a BHK, I see three potential circuits that would affect this. One Class A circuit in the DAC, and one Class A circuit + tube gain in the preamp. I suspect the 12AU7 tube stage is going to do something very similar to a Class A stage. This may or may not push your music into the "laid back" area, it highly depends on amplifier, cables, speakers, etc. I can only speak from my personal experience with pieces of equipment.

Thanks guys. You've given me lots to chew on. As always, there are good arguments for both. Given what I've read about the W4S, it seems that it adds some tube-like feeling despite its lack thereof. And one would imagine that the PWD and BHK were designed to work together without coloring the source excessively, or even markedly - one would imagine. I'm gonna mull it over a few days and see if there is somewhere nearby I can hear each. Then, given my experience thus far with PS kit, the reviews, and the facts that I'm a Colorado native and have a screaming deal available, I'll likely pull the trigger on the BHK, hoping it's a lifer. If not, there's always Audiogon...:)