BHK Signature preamp Review coming to TAS

It is simply Goldmund’s marketing terminology for building vibration isolation/control into its products. Thus, mechanical (physical) “grounding.”

It has nothing to do with star grounding or any other type of electgrical ground.

Ahhh. Thanks Elk. There’s been a lot of talk lately about ground sinks and electrical grounding solution to reduce noise. I have an idea of what’s going on but want to learn more.

Me, too. Electrical grounding without access to an earth ground intrigues me.

I assume the grounding sinks on the market have a low potential so that stray voltage is discharged into the unit - like carrying a static charge from walking on wool carpeting in the winter and touching someone else and the resulting static spark.

I prefer the idea of improving the system earth ground with a better grounding rod installed with conductive chemicals to reduce impedance, but perhaps the sinks have an even lower impedance.

It might be that the idea is to try to make a common groundplane with a rather large area in order to minimize differences in ground potential. For this to work however the common groundplane has to be returned to ground. What I struggle to understand though is that it seems that the cables might be of different lenght and AWG. This is the recipie for mV (or mOhm) potential difference (i.e. hum exposure).

I am with you Frode. A lot of these ground products focus much on improving conductivity and, as Elk said, that’s important when you’re burying a ground rod - because what you want to do is get as close to the lowest potential you can. But how to do that in a box, when the box must somehow be tied to ground?

The only reasonable explanation I have yet heard is the use of high frequency absorptive materials/products in the ground chain - which is something I think Shunyata does in their power products that seems to work.

A good friend of ours uses a heavy choke in the star ground path which is something we’ll likely try at one point.

The boxes are indirectly tied to ground; they are attached to equipment chassis with their proprietary cabling, and most equipment’s chassis is tied to ground. But this seems far less than an optimal path and relies on how good the conventional earth ground works in any event.

Star grounding makes good sense. I have seen studios where the entire studio is star grounded, piece by piece. A great deal of work. Not a hum to be found.

I retrofitted some tube amps giving the vibration a better path to exit and found considerable benefits.

Yes, many have found mechanical vibration “grounding” effective.

tony22 said +1 in spades. I've had gear in my system that arguably wasn't as good in some terms as maybe other more expensive alternatives, but "clicked" just right with the rest of my gear. I suspect as with everything else I've heard so far from PS Audio, the preamp will be better than the industry expects. But as with everything else it'll be what it brings to someone's own system that counts.

I would love to hear those speakers.

Hi Paul,.

Any idea on ballpark of pricing? One question (based on my current set up), I currently bi-amp in my system with a pair of Bryston monoblocks for the base and matched (to the brystons for input sensitivity and gain) Sonic Frontiers Power 1 SE (upgraded to use KT120s) for the mids/top. I run balanced front to back, I noticed that the BHK only has one set of balanced outputs. From a functionality perspective, one pair of balanced pre-outs would likely be one thing that would hold me back from purchasing.

Can the single-ended outputs be run along with balanced outs?

Thanks

Lou.

$5,999 US retail. It has one set of balanced and one set of RCA outputs.

Yes, these can be used at the same time feeding two separate amps. You can also use an XLR splitter if you need.

You can see a picture of the back panel here:

http://www.psaudio.com/products/bhk-signature-preamplifier/

Thanks Paul,

Would the XLR splitter cut the output voltage in half? So each would be 2 VRMS?

Looking forward to reading the Absolute Sound review laugh. Wouldn’t mind comparing one to my much older Sonic Frontiers Line 2 SE++ (which has had numerous upgrades and mods).

Nope - voltage remains identical - two for the price of one!

I believe that what Paul means is that the BHK Preamp has a very low output impedance and sufficient drive that using a Y adapter on the output to feed to two separate components is a non-issue. This makes me happy, as I have long been of the opinion that the lower the output impedance and greater output current drive capability the better.

J.P.

Yes, that is exactly what I meant. Thanks JP

Any updates on when the TAS review is expected to be published?

With the BHK pre-amp announcement today in the PS Audio newsletter.

I’m undecided whether to buy one. I have my DSJ connected directly to the amplifiers, and vol=100 gives me the desired listening volume. I don’t need to go louder, sometimes I might crank it down to vol=90, but not very often.

I take it vol=100 is a “pass-through” level? If so, which leads to my next question, with the BHK pre-amp between the DSJ and amplifiers, presumably it would also be at unity gain to achieve the same volume level as I’m currently getting with the DSJ direct connection?

If unity gain of the BHK pre-amp gets me the desired listening level, what’s the purpose of introducing the BHK pre-amp to the signal path (apart from the occasional cranking down the volume to 90)?

You may have no need for a preamp.

  1. Some of us, like me, still have multiple sources (phono stage, FM tuner, SACD player, DAC) so we need ability to choose among them.

  2. In some people’s systems, adding a preamp improves the sound. This sounds illogical but is true, as has been discussed in multiple threads here.

  1. is clearcut, 2) is not; you have to try in your own system (get it from a place where you can return the preamp if it doesn’t improve the SQ).

It sounds better, and not just by a little. I clung on to the mistaken belief that the DAC straight into the amps was the best and cleanest path possible.

Inserting most preamplifiers between the DAC and the amp proves me right. But then…

When preamps get to a certain level of sound quality there’s a magic that takes place, a magic I cannot technically explain, yet cannot ignore either.

I often make the quick A/B comparison for people in Music Room One, between the DS directly into the amps and then insert the BHK preamp. Jaws drop at the improvements in sound. It is truly stunning.

Paul McGowan said

I often make the quick A/B comparison for people in Music Room One, between the DS directly into the amps and then insert the BHK preamp. Jaws drop at the improvements in sound. It is truly stunning.

In short, which parameters improves the most in your opinion?

When will the ‘beta’ spec sheet be available for view or download on your web page?