Beta testing the new BHK Preamp

I received my BHK preamp last night and have only several hours of listening on it. I will post more stuff in a few days, but as I saw folks were already posting, I decided to jump in now.

I’m keeping it!

The BHK replaces a VanAlstine Fetvalve CF preamp, DeHavilland UltraVerve preamp and tubes4hifi SP-14 preamp. (John Broskie design) The Sanders electrostatic speakers are biamped, using BHK 300 amps to drive the electrostatic tops. With the exception of tape and phono (who has tape?) the system is now fully balanced.

It is very dynamic, reaches into the music and has great extension and control into the bottom octaves. But that description is not adequate. There is a “rightness” to the sound that makes me want to keep listening and smiling. It has “soul.”

Looking under the hood, there is no evidence this is a beta piece…no pc trace cuts or parts tacked in to stop oscillations that had to be debugged. And the ability to use 6 and 12 volt tubes, as well as the ability to bias the tubes 25% hotter (a jumper move) really appeals to the experimenter (nerd) in me. The quality, physical heft, fit and finish is awesome. I like the blue and simple display.

I wish that gain control didn’t tick when I used it.

No regrets in getting this, after a few hours, it is clearly a much better preamp than anything I have owned!

I’ll post more early next week.

Paul McGowan said We do, yes. We have a fellow that moves all our trade ins - and he does a great job. If you'd like the name of his company, let me know.
I'm sure that I am not the only one who looks for a good bargain on used equipment when I am in the market, so let us know who sells your trade ins. I assume that you do a functional test before passing these on to be sold.

Great reports, everyone.

This is almost asking the impossible, but can anyone quantify how loud the volume change ticks are? I doubt they would bother me, but I suspect people will want to know.

If no mention is made of the ticks in the manual I suggest doing so. It would never occur to most that they are normal.

Anybody would be able to compare the BHK Pre with a Cary SLP-05 preamp ?

Another question - Does the BHK Pre has a HT (Home Theater) by pass ?

Elk said Great reports, everyone.

This is almost asking the impossible, but can anyone quantify how loud the volume change ticks are? I doubt they would bother me, but I suspect people will want to know.

If no mention is made of the ticks in the manual I suggest doing so. It would never occur to most that they are normal.


I’d say they’re comparable to light to medium surface noise on an LP - not really that obtrusive at all. I agree with mentioning it in the manual and I’d do it like this, “Behind that elegantly understated volume knob on your BHK Signature Pre-amplifier is groundbreaking technology that not only adjusts output without impacting the quality of the sound but changes the actual gain of the tubes. When you adjust volume you may hear a ticking sound - this is normal! It is the telltale evidence of Mr. King’s engineering wizardry answering your request and then stepping out of the way of the signal.”

-Pb

Dev said

Another question - Does the BHK Pre has a HT (Home Theater) by pass ?

Yes, though I haven't played with it yet.

According to the manual, “The BHK Preamplifier features the ability to assign any of the 5 inputs as a Home Theater Bypass. The purpose of this function is to enable surround sound users a fixed volume level when playing movies or when the input volume level is controlled outside the BHK Preamplifier.”

The manual then explains how to enter setup mode for a selected input, access the HT bypass function, and set the desired level.

-Pb

Elk said, If no mention is made of the ticks in the manual I suggest doing so. It would never occur to most that they are normal.
Those who, like me, have been using a preamp that clicks whenever you change the volume find them perfectly normal. But better to mention them, and I like PB's suggested phrasing!
Peanut Butter said
Dev said

Another question - Does the BHK Pre has a HT (Home Theater) by pass ?

Yes, though I haven’t played with it yet.

According to the manual, “The BHK Preamplifier features the ability to assign any of the 5 inputs as a Home Theater Bypass. The purpose of this function is to enable surround sound users a fixed volume level when playing movies or when the input volume level is controlled outside the BHK Preamplifier.”

The manual then explains how to enter setup mode for a selected input, access the HT bypass function, and set the desired level.

-Pb


Thanks. I haven’t taken a look at the manual. I am assuming, unlike the Cary (as a true h/t bypass) that the pre has to be kept on when in this mode ?

I checked Fed Ex tracking page (preamp not delivered yet) and came home early from work so wife could go out with girls. I recheck tracking page and it says delivery attempted no one home. There was sticker on front door. Wife did not hear the bell. Now I have to wait till tomorrow. Darn it. The reports above just make the wait worse.

Dave said I checked Fed Ex tracking page (preamp not delivered yet) and came home early from work so wife could go out with girls. I recheck tracking page and it says delivery attempted no one home. There was sticker on front door. Wife did not hear the bell. Now I have to wait till tomorrow. Darn it. The reports above just make the wait worse.
I always reroute delivery to Fedex office for pickup to mitigate this risk. I need just a few more positive reviews and I'll pull the trigger and put in an order myself.
Paul McGowan said There are small clicks to be heard when ramping the volume up and down - and a small jump between several major points along the way you might have noticed too.
I expect clicks with the big volume changes made by the stepped attenuator, but do the tube gain changes also result in clicks?

What is the resolution of the changes, o.5dB?

Peanut Butter said ... While this doesn't really bother me, I notice that the PS Audio logo buttons on my PWT (early model), my DS (PWD kit rebuild), and now the BHK SP all have different brightness levels. I've chosen to stack them in descending order of brightness. Be prepared for complaints or to offer button upgrades.
I like the logo buttons to be the same colour, and brightness. I used to have a stack of Parasound gear and the logo buttons of the different components in the stack had a slightly different hue of blue, and different brightness. It used to annoy me.
Paul McGowan said ...There are small clicks to be heard when ramping the volume up and down - and a small jump between several major points along the way you might have noticed too. This is the only "downside" to this amazing engineering feat of a volume control.
To me the volume ramping clicks are an upside...I like to hear a click, confirmation to me the machine is responding to command inputs. My (4 times more expensive than BHK pre-amp) Halcro pre-amp clicks with every volume and source change. The absence of a click when I expect to hear a click flags to me that something is wrong. Which is why I like the clicking to be heard when expected.
Elk said
Paul McGowan said There are small clicks to be heard when ramping the volume up and down - and a small jump between several major points along the way you might have noticed too.

I expect clicks with the big volume changes made by the stepped attenuator, but do the tube gain changes also result in clicks?

What is the resolution of the changes, o.5dB?


Yes, 0.5dB on average. Of course, it follows the standard logarithmic curve all volume controls do, big jumps at first, fewer as it gets louder.

brodricj said I like the logo buttons to be the same colour, and brightness. I used to have a stack of Parasound gear and the logo buttons of the different components in the stack had a slightly different hue of blue, and different brightness. It used to annoy me.
In many ways audio attracts OCD sufferers as a moth to flame.

Discipline and uniformity appeals to me…when logo buttons have different hues and brightness just screams at me that some discipline in design or uniformity in manufacture is lacking. From this you can probably tell I am ex-military.

I can’t stand discipline and uniformity and was delcared unfit for military service (in the Netherlands which had mandatory service at the time) on psychological grounds. Yet we both love music, and hardware produced by Paul & Co. to render it realistically. Such is the beauty and unifying power of music.

edorr said I can't stand discipline and uniformity and was delcared unfit for military service (in the Netherlands which had mandatory service at the time) on psychological grounds.
Somehow these feels as if congratulations are in order. :)

On the topic of logo buttons, I would prefer they not light up at all - uniform or not.

At a minimum, it should be possible to toggle all lights on a unit off. I am clever enough to know if they are on, and if I forget it is my fault.

I’m assuming that if I want to measure tube hours I’ll have to rig up a separate hour meter like I did with my BHK 250 to run when the trigger output is active, but is there really no way to use the on-board processor and display screen to display hours of operation on the front panel display using a remote button and some firmware that counts cycles while the tube is on and increments a counter once an hour? You already have the capability of storing the user-defined inputs in EEPROM or flash, so the data can be stored from one power cycle to the next. I just wonder if there’s an accurate enough timebase in the microcontroller somewhere so that while the unit is operating it can just figure out a reasonably accurate “hour.”

Or do I ask for too much?

–SSW

Dev said Anybody would be able to compare the BHK Pre with a Cary SLP-05 preamp ?

Another question - Does the BHK Pre has a HT (Home Theater) by pass ?


Yep. You can assign any input as a HT bypass - and set the level of the bypass wherever you like.