mark-d said What is the amount of gain in db's and the type of tubes used in the pre?I believe the preamp has 12dB of gain and the tubes we use are the 12AU7
Too many variables. This is supposed to be easy and fun.
Streets Still Works saidAdd a third option (user selectable from the front panel) to either 1), no mute, 2) permanently mute or lower the output level to a user-defined level, or 3) mute/lower level for a few seconds, then go back to the before-jack-removed setting.
That way the user has full control over what happens.
–SSW
I was going to suggest exactly the same thing!
-Pb
Paul McGowan said Too many variables. This is supposed to be easy and fun.My thinking too.
Let me begin by saying I used to be in the high end audio business at the retail level and also as a manufacturer, so I have had exposure to a great deal of gear over the years. My current reference system consists of a pair of BHK Mono amps, each one receiving power from its own P10, then a Direct Stream DAC and Perfect Wave Transport, both plugged into a P5, and all controlled by my new BHK preamp, also plugged into the P5. Analog front end is a Walker Audio Proscenium Black Diamond V turntable and phono amp running a Clearaudio Goldfinger Statement cartridge. Speakers are Focal Grande Utopia EMs. Cables are a mix of Silent Source Reference and Nordost Valhalla.
The new BHK preamp sounds great right out of the box but it rises to a completely different level of performance after many hours of burn in time. In fact, it is now the finest sounding preamp I have ever heard under controlled conditions. While I listen to a wide variety of music, I find it most enlightening to evaluate new components by using acoustic instruments as a reference, therefor I will refer to my experience with classical music for this report. With the BHK in my system, air and space around instruments is now palpable which adds significantly to the impression of hearing music being performed in a real space. Within that space, individual instruments are rendered with astonishing clarity and precision. While some components attempt to recreate this sense of presence by adding an etched quality to the performers, the BHK preamp instead adds a believable third dimension to the presentation which results in near holographic imaging. There are no bandwidth limitations that I can hear with truly extended highs floating off into the ether and well-defined bass extension down to the subterranean level. At the same time, extremely complex music is handled with an ease that I have never experienced in a home system before. Playing a large orchestral piece at realistic volume level offers a perfect example of this quality with no perceived strain and rock steady separation of each instrument involved. This is the first time I have ever felt I was close to recreating the weight and dynamic range of a full orchestra in my own home. Easily one of the most impressive aspects of the preamp's performance is the speed with which it delivers transient information, best described as startlingly realistic. From sparkling high frequencies to literal body blows from low ones, the sharp delivery of leading edge transient information adds greatly to the music's impact and drive. Low level detail retrieval is also a revelation as, for example, it now provides a wealth of those subtle cues which inform your brain about the construction of the instruments being played. A perfect example is the sound of tympani drums, which, on a good system, are not hard to distinguish from other types of drums. Now, however, with the BHK preamp handling the signal, I can not only hear the distinctive sound made when the tympani drum is struck, but the fact that it is round in shape, with energy radiating outwards in a circular fashion. Another example would be the newfound ability to not only hear the full impact of a bass drum strike, but also the much lower in level vibrations of the drum's skin which continues to radiate decaying sound waves after the initial strike. I could go on citing examples of the preamp's many strengths, but suffice it to say, all of these factors combine to bring the listening experience up to a level of realism that is quite breathtaking.
What I really want to convey to those considering the BHK preamp is that once you get over the excitement of hearing the improvements it makes to your sound system, you will be treated to its greatest contribution, which is to make your listening experience more about enjoying the music than listening for audiophile highlights. Whether it's human voice, acoustic instruments, or the bombast of rock and roll, you will find yourself getting caught up in the spirit of the music as the analytical portion of your brain relaxes and your pleasure center takes over. It's just so deliciously musical!
Now for the practical feedback. The preamp is solidly built and the interior layout is beautifully done. Top quality parts everywhere you look. On my unit, the top plate did rattle a bit if you tapped on the top of the chassis. I solved this with a thin gasket around the perimeter of the tube access plate without losing its connection to the ground plane. The hand-held remote is the best I have ever used and a major improvement over previous units supplied with PS Audio gear. Brilliant in its layout, granting full control over all important functions for a wide variety of components, and it even anticipates some products PS Audio hasn't released yet. At first I thought it would be nice to be able to lower the light level of the volume readout so it wasn't as noticeable on the preamp's display but soon discovered that the technique recommended by PS Audio was even better. With a push of one button on the remote, you can simultaneously turn off the displays of all front end PS Audio units. Then, when you want to make a change to some setting, you just press the appropriate control button and that unit will light back up to allow you to see the results of your input, then go back to sleep after a short period. The preamp does emit a slight clicking sound when the volume level is raised or lowered. I don't find this annoying in the least but would suggest a mention in the owner's manual so people understand this is considered normal behavior. Tube rolling has been made very convenient with easy access and adjustments available to accommodate a variety of different operating parameters, although I suspect only a few hardy souls will ever take advantage of the flexibility they have built in. Still, kudos for accommodating the lunatic fringe. The head phone jack is conveniently located on the front panel and while I didn't have time to do much listening with cans, the automatic muting of your speakers when a headphone jack is inserted is a very nice feature. However, on my system, I had to increase the preamp's volume level considerably to listen with headphones and it would be very nice to have the volume level default to some low level when you remove the jack so you don't overdrive your speakers by accident. I have already substituted cones for the supplied feet, installed tube dampers, swapped the power cord, and changed the fuse to a higher quality one. Small improvements to a great sounding preamp.
My congratulations to all involved in this project. You have crafted a very special piece of gear and I am thrilled to be an owner!
I received my BHK Beta sample and installed it this weekend. Before getting into my impressions, I probably should describe my system and room to give a bit of context to my remarks.
My listening room is used both for listening to 2 channel stereo as well as a 7.2 channel home theater and measures 27’ by 17’ with 10’ ceilings. All of the speakers are manufactured by Wilson Audio (Maxx Series 2 for the mains) with the exception of the subwoofers in which I use 4 JL Audio F113’s. The two channel system is designed primarily for digital audio and uses PS Audio’s Directstream DAC and Perfectwave transport as the main source components. They feed a Pass Labs X-O.2 3 chassis preamp which are connected to Bryston 28B SST2 1KW mono block amps. Everything is cabled with Transparent Audio Reference cables. Power is provided by 2 PS Audio P10 regenerators. IMO, the result is a very neutral sounding system that is exceptionally musical and can reproduce virtually any type of sound exceptionally well at whatever volume the program material calls for. One invited guest who came over to listen to my system (a nationally known proponent of vinyl) after listening to several of his favorite tracks was impressed with the sound enough to wonder out loud how he would ever be able to get his all of his LP’s replaced with digital. I’m not saying this to boast, only to point out that the system that the BHK Preamp has been inserted into is one where significant improvements are relatively difficult to achieve.
So how did it sound? After about 3 hours of burn in (that’s all I could wait before sneaking a listen), I can sum up all of my impressions with one word - Better. The dynamics are better. The imaging better. The soundstage depth and width are better. Virtually any desirable characteristic you would want to consider was better with the BHK vs. the Pass Labs Preamp. Not by huge amounts, but they are better. And thats saying a lot given that the Pass Labs was considered a “statement” piece when it was introduced and originally sold for nearly twice the amount of the BHK.
I am pleasantly surprised by just how good this preamp is now and am looking forward to hearing how the sound evolves as it continues to go through the burn-in process.
There are 2 comments that I do have regarding the BHK design. First, the headphone amp (which I have not had the opportunity to listen to) does not accommodate balanced connectors. Most audiophiles I am aware of using headphones at this level use balanced connections to drive their cans. Not a huge issue, but it should be noted.
Second, and more seriously, there are only one set of balanced and one set of single ended outputs on this preamp making it difficult to drive a system that uses subs. Paul McGowan has always professed that any system is better with a pair of properly integrated subwoofers (I agree) but left off the additional set of outputs needed to drive them.
All in all, its the best preamp I have ever heard. I will continue to update as new developments require.
mikeskop saidThis has also been my concern for low level sub inputs.Second, and more seriously, there are only one set of balanced and one set of single ended outputs on this preamp making it difficult to drive a system that uses subs. Paul McGowan has always professed that any system is better with a pair of properly integrated subwoofers (I agree) but left off the additional set of outputs needed to drive them.
Frode saidmikeskop saidSecond, and more seriously, there are only one set of balanced and one set of single ended outputs on this preamp making it difficult to drive a system that uses subs. Paul McGowan has always professed that any system is better with a pair of properly integrated subwoofers (I agree) but left off the additional set of outputs needed to drive them.
This has also been my concern for low level sub inputs.
I’m using a pair of splitters on my RCA outs to run the sub. Kind of ugly but functional and I don’t really have an alternative.
There simply wasn’t room on the rear panel. Many people, myself included, go balanced on the main amplifier and single ended on the sub amp.
I always run my stereo pair of subs speaker level in and much prefer the matched sound this way.
This method picks up sound traits of the amp and does not require additional pre outs.
woot said I always run my stereo pair of subs speaker level in and much prefer the matched sound this way.What does speaker level in mean ?
I think this means hooking up to the output of the Power AMP and attenuating down in the Sub circuits.
I think Rel supports this method, not all brands do.
Anyone with audionote or lampizator preamps able to compare to the BHK?
My velodyne dd10+ also allow for speaker level input. I think they may sound better this way but will try the RCA outs for comparison when I get my BHK preamp in.
Connecting the sub(s) to the amplifier out typically sounds the best and integrates most easily, but it is always worth trying all available options.
Paul McGowan said There simply wasn't room on the rear panel. Many people, myself included, go balanced on the main amplifier and single ended on the sub amp.This doesn't constitute a problem since most sub plate amplifiers take RCA and have a gain adjustment for level compensation, but are you saying that since the preamp does not contain a trafo on its output (like the DS) the RCA connection does not unbalance the XLR when both are connected?
mikeskop saidSo how did it sound? After about 3 hours of burn in (that’s all I could wait before sneaking a listen), I can sum up all of my impressions with one word - Better. The dynamics are better. The imaging better. The soundstage depth and width are better. Virtually any desirable characteristic you would want to consider was better with the BHK vs. the Pass Labs Preamp. Not by huge amounts, but they are better. And thats saying a lot given that the Pass Labs was considered a “statement” piece when it was introduced and originally sold for nearly twice the amount of the BHK.
All in all, its the best preamp I have ever heard. I will continue to update as new developments require.
Thanks mikeskop, really informative commentary.
Out of curiosity, have you ever operated your system without a pre-amp ? If so, any chance you would be kind enough to also indicate how you perceive the improvement with a pre-amp (say the BHK) vs no pre-amp at all ?
Frode saidPaul McGowan said There simply wasn't room on the rear panel. Many people, myself included, go balanced on the main amplifier and single ended on the sub amp.This doesn’t constitute a problem since most sub plate amplifiers take RCA and have a gain adjustment for level compensation, but are you saying that since the preamp does not contain a trafo on its output (like the DS) the RCA connection does not unbalance the XLR when both are connected?
I believe this is true I ask this question earlier and Paul said we could use both outputs with no loading issues
woot said This method picks up sound traits of the amp and does not require additional pre outs.I am with you and that's exactly the right way to go. It's what REL subs do, it's what we'll do in the new PS Audio loudspeaker should that ever come to light. You get much better integration when you take the output of the main power amp and use that as the input source for the subwoofer.