BHK Beta Tester Reports

Audio Components Amplifiers
61

First of all, I would like to commend the beta-testers that have posted their comprehensive and insightful comments on the BHK 250 set forth above. I have now had about 10 days with my unit and would like to offer a few of my impressions.

I should add that I don’t consider myself a “golden ear” nor do I have any experience in articulating on paper what I am hearing from my system. However I am an avid, if not obsessive, music lover (aren’t we all?) and I am absolutely delighted when I can gain improvements in the reproduction of music through my system.

Therefore, as I unboxed the BHK250 and installed it in my system I couldn’t help but wonder if I would even notice any differences in the music. What gave me encouragement to even take on the responsibility of a Beta Tester was the fact that I did notice improvements in the sound quality when I replaced my PS Perfect Wave DAC with the Direct Stream DAC, and installed the two firmware upgrades in the DS DAC, which improvements are well documented in the PS Forums.

Set up

The packaging was more than adequate but my initial impression was that it was somewhat flimsy with a lot of loose cardboard until I saw the double foam setup (I may be spoiled with the packaging of the DS DAC which, of course, weighed a lot less).

The speaker outlet terminals also confused me until I realized that their nuts had to be unscrewed to accept a banana plug and then tightened to secure the plug. It turns out that they are by far the best terminals I have encountered in many years of experience.

Associated Equipment

If you are an electron passing through my system you will become well acquainted with PS audio gear, since you will be passing from a dedicated AC line through a Soloist wall outlet, into the P10 Power Unit and, from there, to the BHK 250 and to a DS DAC, with all power connections being made by AC 12 cables. I use an Olive 06hd media server as my program source and each of my two speakers (BSI Model 4) include a Scanspeak Illuminater tweeter flanked by two Scanspeak Revelator mid-bass 6.5 inch drivers. (Each speaker also includes two Scanspeak 10 inch woofers but the BHK was disappointed to learn that it will not get a chance at the woofers since each pair is driven by its own built-in Hypex amp.) I adjusted the subwoofer outputs so that the BHK was in charge of everything above 70 hz.

Comparsion

The BHK 250 is replacing a 80 watt per channel REX Power amp, an all tube design made by Balanced Audio technology, which retails for twice that of the BHK. In my opinion, the REX is an excellent all-tube amplifier.

The Sound

I heard several areas of improvement in the sound of my music using the BHK 250 when compared to the REX.

  1. There is a lower noise floor resulting in notes appearing in a background completely void of noise and artifacts, resulting in more clarity in the overall sound.

  2. The sound is more delicate yet crisp (this may be related to No. 1, above).

  3. The depth of the soundstage, as well as the clarity of the music across the soundstage is improved to the extent that in certain recordings I could actually “hear the room” where the recording was made.

  4. The transient response, notably in the lower midrange - upper bass (70-100 hz?) is improved.

  5. The music is more forceful, with more body, This is especially true with respect to solo vocals.

Since this is all about the music, I used several CDs to ferret out these improvements:

The song “Hotel California (Live) from the Album “Hell Freezes Over” by the Eagles. Soundstage, clarity, transiant response, warmth - you name it.

The album “Complete Greatest Hits” by the group America (especially the songs “Sandman” and “Lonely People”). Nearly all of the improvements noted above can be discerned in this album. It is a masterpiece from a recording engineering standpoint (listen to the shifting of the guitar(s) sound around the soundstage in the introduction to “Sandman”). Incidentally, this was one of Harry Persons favorite albums (so I hear).

The song “Pipeline” by Bill Frisell from the album “Guitar in the Space Age”. Check all the boxes on this one. This is my favorite “single”. [Caution - very mood inducing].

The song “Navajo Rug” from the album “Live at Longview” by Ian Tyson. The most accurate rendition of acoustic guitar I have every heard. Also, the fullness of Ian’s voice and the subtle changes in his voice is palpable as he varies his position relative to the microphone. The vocal harmonies are also right on.

The song “Just a Little Loving” from the album of the same name by Shelby Lynn. We all know about this one especially the title song. Also check out “You Don’t Have to Say You Love Me”.

Any classical recording by Reference Recordings. For example, the albums “Tutti” and “Reveries” by the Minnesota Orchestra set standards of delicacy and clarity without any trace of noise, artifacts or digital glare.

Any song from the album “From the Golden age of Swing” by Dick Hyman. I’m not that big on swing music but this album is also on theReference Recordings label (the reason I bought it), and the BHK revealed a large recording venue which permits significant soundstage depth, something I didn’t notice with the REX.

Finally, I have to include the song “I’m Through with Love” from the Diana Krall album “All for You”. The accurate reproduction of sibilents in this recording is putting it mildly (how about “saliva management”?) Anyway Diana’s vocal is reproduced with stunning clarity.

I’m not saying that these improvements were dramatic, nor am I saying that all five improvements above were discerned with each song. In fact, an average or casual music listener may not be all that impressed, and fans of all-tube amps may disagree with my conclusions or take the position that the improvements are not major enough to justify changing amps.

But to me the cumulative effect of the improvements result in an amplifier sound that has all the warmth of a tube amp with the delicacy and clarity of a great transistor amp, and they were significant enough to take my music enjoyment to another level. During periods of this evaluation not only was I tapping my feet but I found myself waving my arms to conduct a rock group. To me, that is what high end audio is all about.

I should add that those that are inserting their BHK into systems with top-notch electronics and speakers should find it constructive, and maybe even fun, to mix and match the five above improvements with the songs. Try it - it may lead to a new parlor game!

I plan to update this in a week or so with answers to the various questions Paul set forth in this emails, and a response to the questions raised in the demo disc.

62

Welcome to the forum! Well written! Kudos!

63
woot said Via the XP-20
Ever tried without? Just curious... Unlike the PWD, the DS likes to be connected directly. And from what I understand, the BHK amps were designed with the direct connectivity in mind.
64

@wbk: Was your amp constantly playing all these 10 days? What do you think about the break-in time? Is the sound “stable” now?

As an experiment, for the first time in my “audio-life” I decided to break-in first, then carefully compare the BHK with my current amp to minimize the “memory distortion”. 1 hour audio-memory should be better, than, say 10-day one. And switching between the two is too difficult because of the size/weight/cabling, etc.

65

wbk- First, let me say that is an incredibly well-written review! I sense a kindred spirit music-wise and to that end I’d like to make a recommendation if I may. Yours is not the first mention of Shelby Lynne’s songs I’ve seen here and specifically the two songs you mentioned. Without intending to trample your post or this thread I wonder how many here have heard those songs and many others Shelby has done recently that were recorded almost 50 years ago by Dusty Springfield. Specifically the “Dusty in Memphis” album? Recorded in 1969 in Memphis by the A-Team at Atlantic records, ie; Wexler, Dowd & Mardin with back-up vocals by Sweet Inspirations and the instrumental band Memphis Cats. The preceding years had found Dusty being the team of Bacharach-David’s go-to girl. Think “The Look of Love” from Casino Royale. Incredibly sultry, evocative and lustful voice. For those that like Shelby give “Dusty in Memphis” a spin. Available at all the usual suspect’s streaming services. Definitely in my top 3 all-time easy-listening and soulful albums. Esp the also Shelby done Randy Neuman written; “I don’t wanna hear it any more.”

Now back to your regularly scheduled programming…

66

Great review wbk. And welcome to the forum indeed.

67
Alekz said
woot said Via the XP-20

Ever tried without? Just curious… Unlike the PWD, the DS likes to be connected directly. And from what I understand, the BHK amps were designed with the direct connectivity in mind.


No. To many gizmos.

68

About 22 hours on mine so far, so still breaking in. And no, I can’t run continuously to break in because my wife works at home during the days so the stereo has to be off.

At 17 hours I played Elton John’s “Can’t Wait to Be King” from the Lion King album. A few minutes into the track he pounds on the honky-tonk piano. The attacks on the piano seemed a little subdued, it seemed it should have been more snappy. This may be because the unit and its XLR cable may still be breaking in. Of I’m playing it on a DirectStream via Bridge II beta and that hasn’t been optimized yet for sonics.

Just putting it out there. Hopefully it will ‘open up’ as it breaks in more.

More later.

–SSW

69

According to the manual, just leaving it in standby helps to break-in the output section as there is always some current running through the MOSFETs. They suggest leaving it on (full on) for the first 24 hours even if no music is playing to break-in the input section. I had more than 24 hours actual playing time before I got the manual so I did not do that.

The amp has opened up some as it has broken in, particularly the bass. Also, I have gotten more used to its sound (may be a bigger effect than break-in). It does sound different from my other amps. For one thing, it is so much quieter and cleaner. I think wbk nailed it in his point #1 above–the lower noise floor makes everything stand out against the background (or, more accurately, the absence of the usual background noise), revealing more low level detail than other amps. For TV sound, I listen with my preamp set at the same level as my PSA Classic 250, suggesting that the gain is quite similar. For music, though, I find myself turning it up a bit higher because the detail just sucks me in. In a sense it doesn’t sound like it is playing louder than I usually played music on the Classic 250, but it is (I can tell because my old ears can only take so much loud music at a time; it’s not “listener fatigue” caused by the equipment as I react the same way to all prolonged loud sounds (and is why, for example, I wear earplugs on the subway); it’s just me getting old). Turning up the volume on the BHK did not seem to increase the background noise the way my other amps do (I’m sure it does but I still don’t notice it; I didn’t really notice it in my Classic 250 until the noise was gone). I thought at first that the amp was a bit subdued at times too. But, the more music I played (and it didn’t take long), the more obvious it was that it was just playing the way the music was recorded. My other amps were just emphasizing different parts of the audio spectrum. Now, everything just sounds right to me through the BHK 250.

I’m interested to hear how your impressions change over time.

70
stevem2 said According to the manual, just leaving it in standby helps to break-in the output section as there is always some current running through the MOSFETs. They suggest leaving it on (full on) for the first 24 hours even if no music is playing to break-in the input section. I had more than 24 hours actual playing time before I got the manual so I did not do that.
There are capacitors in the signal path, so there must be a signal to break them in. See this thread: http://www.psaudio.com/forum/bhk-power-and-pre-amp-forum/what-would-you-ask-bhk/#p42983
71
Streets Still Works said About 22 hours on mine so far, so still breaking in. And no, I can't run continuously to break in because my wife works at home during the days so the stereo has to be off.
You can use resistors. 50cents
72

Ah, those smiles…

73

They show you really mean it.

[Discussion of Dusty in Memphis moved to here.]

74
Alekz said @wbk: Was your amp constantly playing all these 10 days? What do you think about the break-in time? Is the sound "stable" now?

As an experiment, for the first time in my “audio-life” I decided to break-in first, then carefully compare the BHK with my current amp to minimize the “memory distortion”. 1 hour audio-memory should be better, than, say 10-day one. And switching between the two is too difficult because of the size/weight/cabling, etc.

Alekz, The quick answer to your first question is no. I was so anxious to hear the BHK 250, compare it to the REX, and write the review in a timely fashion that I neglected (overlooked) any break-in considerations. I estimate that the amp had about 10-20 hours on it during my critical evaluation and I noticed no changes in sound quality during this period. But I have just started a continual playing of internet radio through the system 24/7, and I will report on any break-in considerations in a few days.
75

HERE ARE MY ANSWERS TO THE QUESTIONS SET FORTH IN PAUL’S EMAIL OF MAY 11TH

How has the BHK changed your listening experience?

it has made it more pleasurable

Do you find music-listening to be more involving with the BHK?

Yes

• Compared to your previous amp (and please tell us what that amp was), do you find music through the BHK to have a more realistic tonal balance?

I’m not sure exactly what “more realistic tonal balance” means, but maybe it is covered, in at least some respects, in my posting of May 18th. I will say that I did not notice a great deal of difference, if any, between the tonal balance (as I understand it) of the BHK 250 and my Rex amp

• In our experience more details of soundstage and musical nuances are brought forward with the BHK. Has that been your experience as well?

Yes

• We find the tube in the front end engenders a quality of music not found in solid state amplifiers. Has that been your experience as well?

I can’t compare the BH 250 with any solid state amplifier, since I haven’t owned one in quite some time

Have you ever owned a product with a vacuum tube inside?

Yes, see my posting of May 18th.

• Would you recommend the BHK Signature to anyone/everyone thinking of getting more out of their system?

Yes

76

Only 31 hours into the break-in so far, but I have to tell you guys that listening to the BHK has been a lot of fun, even now. Listening to some 2Cellos albums is a GREAT way to pick up higher order harmonics on each note. Yes, the Streets 950 played them, but as I mentioned before the attack and clarity of each note is much more pronounced with the BHK than with the Streets. The clearer tonal textures presented by the BHK pull my head back into the music if I look away even for a brief moment, as if my head was on a spring and it snaps back so as not to miss a note.

So, YES, the experience is more involving than the Streets. It has added textures and clarity on each note I hadn’t heard before. I did buy a tube preamp 8 years ago, so it helped with the tube-solid state presentation. As a matter of fact, it took me 6 months to train my ear to enjoy everything new that I hadn’t heard with my solid-state preamp. Replacing the BHK was not as significant a jump in tonal quality, however, as mentioned before each note played by the BHK has more clarity than the Streets did, so this may very well have been a result of the input stage tube. Or the back end. I don’t know. I don’t care. What’s being presented on the BHK soundstage are the same notes I got with the Streets, in the same place, but each has a crispness that the Streets just couldn’t duplicate, even though the Streets had regulated power supplies and I had replaced all the fuses in it with HiFi Tuning units that did improve things a bit, but nowhere close to what the BHK can do even at 30 hours of break-in.

I’ve never heard live cellos playing 4 feet in front of me. But between the resin on the bows to the attack and clarity of each note, it sure as hell sounds like it’s right there in the living room where nothing gets in the way of each note.

And I think my BHK is idling. Over the last 30 years since I bought the Streets, in retrospect everything I bought was designed to ease the load on the amplifier, both with the subwoofer that was fed one of the outputs of the preamp to the MartinLogan Spire speakers with their built-in woofer amps. So all the BHK has to do at this point is feed the tweeters in the Spires, albeit at about 2 ohms impedance when the signals get upwards of 20,000 Hz.

I always thought the amp was the last thing one should upgrade in a stereo. My priority list, in order, was the preamp, speakers, then the source, then power regenerators/power cables, interconnects and speaker cables. Last was the amp. And the only reason the preamp was in front of the speakers was because the volume control on my old PS Audio IVH was going bad. So I always thought the speakers was the most crucial thing. I may have misjudged that with the BHK, but as I waited over 5 years for it to come out, the wait was worth it if it sounds so much better than a bipolar/op-amp (“conventional”) amp that I was used to.

Would I recommend the BHK? If you can train your ear to hear the differences and improvements that you get with the BHK you will find them in spades. This is the amp to dream about, the Ferrari or Corvette of ampdom. Some folks can’t appreciate it, like the person that drives a Ferrari like it was a Corolla. But if you can appreciate and enjoy the extra performance, then save your pennies and get one of these because you will enjoy it for years to come.

–SSW

Edit: fixed typos in green, just in case someone gets the idea they may want to quote me . . . .

77
Streets Still Works said

I always thought the amp was the last thing one should upgrade in a stereo. My priority list, in order, was the preamp, speakers, then the source, then power regenerators/power cables, interconnects and speaker cables. Las was the amp. And the only reason the preamp was in front of the speakers was because the volume control on my old PS Audio IVH was going bad. So I always thought the speakers was the most crucial thing. I may have misjudged that with the BHK, but as I waited over 5 years for it to come out, the wait was worth it if it sounds so much better than a bipolar/op-amp (“conventional”) amp that I was sued to.

Would I recommend the BHK? If you can train your ear to hear the differences and improvements that you get with the BHK you will find them in spades. This is the amp to dream about, the Ferrari or Corvette of ampdom. Some folks can’t appreciate it, like the person that drives a Ferrari like it was a Corolla. But if you can appreciate and enjoy the extra performance, then save your pennies and get one of these because you will enjoy it for years to come.

–SSW


Wow, what a great review!! That’s the thing, isn’t it? Most of us think the amp is the last thing to upgrade when in reality, its importance simply cannot be understated. Thanks for a great review!

78
Streets Still Works said So I always thought the speakers was the most crucial thing.
I continue to find the most important to be the component that makes a significant change in my current setup. I suspect what happens is I stumble on the current weakest link.

As it happens, the first separate I purchased was a David Hafler amp after I connected it to the preamp out of my receiver. It made a huge improvement. It appears the BHK has accomplished something similar in your system. Very exciting.

79

Well, Bascom and Paul, you’ve put me into this exact quandry. A while back I posted that I was thinking of upgrading my speakers and got some good recommendations from folks here. Recently I learned that there is now a factory upgrade available for my Von Schweikert VRIV-jr speakers. Mine are original and the new ugprade is Mk 4 (I never did the Mk 2 or 3 upgrade). I talked to someone who did this upgrade from an original, like mine, and declared it definitely worth the money, $5000. You get a whole new speaker, except for the cabinets. Not only would I get improved SQ, but my speakers would be good for years to come. They still work fine, but anything that flexes constantly is going to fail sooner or later, and they are now 12 years old.

I had just about decided to get the upgrade later this summer when I started reading all the good things about the BHK Signature. I think my amps may be the part of my system most in need of improvement, so I’m now debating whether to postpone the speakers and go for the amp. It will be some time before I can spend a significant amount of money on components again, so this is a significant choice.

One question: The IV-jr speakers work best when bi-wired (or bi-amped) according to VSA. I have been bi-amping, running a good tube amp (Golden Tube SE-40) on the treble/mid modules and a less expensive but powerful solid-state amp (NAD C275BEE) on the bass units. This has worked well. I’m sure the Signature 250 would be a good match for the bass of my IV-jr’s, but might be overkill for the top half. Any downside to running more power than I need to the treble/mid modules? Also, just to confirm: I think I see two sets of binding posts in the photo of the back of the Signature 250, so bi-wiring would be easy. Is that right?

80

I have VSA VR-5SE’s and they work well bi-wired with my BHK as well as my EDGE 10.1NL.

I have done upgrades with Albert on several speakers in the past and have always been a major improvement.

The BHK is a GREAT amp, so you do have a conundrum!4_gif