What amplifier are you using?
You do realize Iām the original poster, right? I was replying to sixpack1
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I guess I should take my own advice! 
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Would be nice if these forums indicated the OP like many others do
Haha no worries. I should have used the quote feature.
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I feel for you. I went through the same exact thing if you havenāt seen it:
https://forum.psaudio.com/t/bhk-pre-amp-and-speaker-hiss/9838
The most comical part was my dealer sold me the BHK Pre to stop the hiss in my DSD Sr. I ended up moving on to a McIntosh C1100 (and more recently a Levinson No 52.), could never find a solution to make the BHK Pre work in my system without the hiss.
That issue has to be very system dependent. I have 2 BHKās. One in a passive speaker system (DSDjr > BHK pre > M700ās > Tekton Electronās). One active speaker system (DSD > BHK pre > D&D 8cās). Both systems are ādead quietā unless music is playing. I hate gremlins too but never had any trouble. I did lose a tube prematurely in one of them but some help from Richard pointed me in the right direction. I would love for someone to come up with a ātubeyā SS preamp and amplifier that sounded this good.
This is what I donāt get. Some people report dead quiet setups with bhk amps, preamps or a combination of the two, while others are having the issue iām having.
In my opinion there is only so many things from the users end that can cause this.
I literally have a power cord from wall to amp and speaker cables from amp to speakers, and I get very audible noise. Nothing else in the chain.
Tonight Iām going to try swapping power cords, speaker cables, cutting the ground off a power cord etc. but I feel like iām chasing something I canāt actually fix. I even tried other speakers just to make sure.
I had a full tubed integrated previously and never had this problem.
It may be that the speakers and amps simply are not compatible. It is a strange hobby for sure.
You might try the stock PSA power cord if you have not. Also make sure that the AC cable and any signal cables it crosses are at a 90 degree angle and not parallel for any distance.
There may also be another device on the AC line causing the problem. Although it is a PITA you might try and make sure every other device on the circuit is disconnected (unplugged). AC units, heaters, dimmers, computers, other devices can all be problematic.
Or run a heavy extension cord from a different circuit maybe in the garage, basement, or even the neighbors house if its close enough to plug everything into.
One other thing to try is make sure only one input is connected to the preamp. Another Michigan hillbilly trick is to try and cover the top of the preamp in aluminum foil.
Iām just trying to help the cause as these are really good preamps. Best of luck and hope you figure the puzzle out.
I would not be happy with hiss. I have a Cary slp98p direct coupled w a sunfire amp on some Maggieās. No hiss at all. Recently I had a tube go bad and I did get that ārushā sound which was annoying as hell. But I knew it was a tube.
There seem to be multiple reports of this. It would seriously make me hesitate
What amp/amps do you have baldy??
I am pretty certain it has to do with the inherent noise of the BHK Pre and the gain structure of the associated amps (and the sensitivity of the owners hearing). As we all know, amplifiers amplify 
Unfortunately this means the bad stuff (noise) also is subject to amplification.
The data points I have in the same system are:
BHK Pre SNR: 90dB
McIntosh C1100 SNR: 107dB
Mark Levinson No 52. SNR: 120dB
All else equal the BHK Pre was the only pre-amp to cause audible hiss from the listening position in my system. That is part of what makes this hobby intriguing/fun though, it is subjective; there isnāt one solution for everybody.
Cheers,
Tony
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Ok Iāve been at it for a couple hoursā¦ with what appears to be progressā¦ sort ofā¦
I have a dedicated 20amp circuit all my equipment plugs into. I switched the circuit between phases at the panel and it did nothing. I tried a stock power cord, nothing. With the preamp in the mix I tried different interconnects, nothing. Tried regular wall power vs an equitech 2.5kW balanced power supply, same thing.
Then I decided to abandon everything and just plug one of the amps directly into the wall at my dedicated circuit. Just a single amp powered up with speakers connectedā¦ FINALLY the silence others are talking about.
Previously with just amps hooked up BUT other components plugged in, I could hear the hiss 2 feet away, now I literally have to put my ear to the speaker.
HOWEVER, the minute I plug the preamp into the same duplex receptacle the speaker noise jumps back up to that 2 foot spread, and that is with the power switch on the preamp still off, just plugged into the outlet.
I need to get to bed so I couldnāt do any more experimenting, but could this be a ground loop?
Clearly itās something to do with the preamp since as soon as it gets plugged in the noise just jumps.
I was always told with audio gear everything should be kept on the same circuit and you shouldnāt have separate circuits for different pieces of gear since it can cause ground loops, but in this instance something funny seems to be happening.
Please keep the tips/tricks/recommendations/advice/suggestions coming. I will get back to troubleshooting some more tomorrow evening.
I use a Bhk 250. It has the same gain characteristics. I have my whole system powered by a P 10 plugged into a dedicated 30 amp circuit.
Ok, couldnāt sleep just yet.
Plugged in both the amplifiers (only amplifiers) to the dedicated circuit with speakers connected. Very quiet on both.
Next I moved the preamp into the picture.
Before even plugging the preamp in, I decided to hook up only the two output interconnects. So at this point the preamp has nothing but left and right ICās to amp. Hum/hiss instantly jumps to audible level. Next I plug in the power cord without even turning on the rocker switch on, hum/hiss intensifies to the 2+ foot radius. Powering the preamp right up didnāt make much difference.
Soā¦ at this point it looks like it clearly has nothing to do with tubes.
With just the amps on itās very quiet.
And then all the noise comes rushing in from interconnect connection and power cords, before the preamp is even on, so again, nothing to do with those tubes.
So this is starting to look like a ground problem? But from where, the preamp?
Try putting a cheater plug on the preampās power cord especially if you are going back to SE ICās. If this works then put the Equitech back in the equation and see what happens. If this works with everything plugged back in as before then just leave the cheater plug on the preamp as the Equitech will be providing the ground. Fremer had to put a cheater plug on his SE only preamp when he reviewed the 300ās due to noise.
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One system has M700ās and the other uses D&D 8c active speakers.
Do you know who uses D&D 8C active speakers ?
Iād LOVE to hear their impressions as I am considering them as well.
Tom - NJ
Spent more time troubleshooting tonight, this is starting to become very tedious and time consuming.
So, making cheater plugs for the 2 amps and the preamp eliminated the hum.
With everything connected, but only the amps powered up I just get a tiny bit of static if Iām near the speaker, likely from the tubestage in the amps, whereas before with everything connected and preamp off it was humming like crazy.
However now, as soon as the preamp finishes going through itās tube warm up and clicks on, I now have audible static/whitenoise that I can very easily hear from where I sit. The left side is a fluttery kind of static and the right is more consistent sounding, so I swapped all the tubes around (flipped preamp tubes and moved both tubes from one amp into other amp), and the left is still fluttery sounding.
Iām at a bit of a loss as to what I can try next. I feel like itās not the best idea to leave cheater plugs on everything. First itās probably not safe and second it defeats the purpose of having quality power cables. Iām starting to think the majority of the problem, or at least the static and noise iām getting after preamp warmup is clearly from the preamp, but iām not sure where the issues with the grounding lies, Iām starting to think the amps, because I first put only a cheater plug on the preamp and it didnāt help, then put them on everything and it fixed the hum.
Iād LOVE to hear all about your impressions of the D&D 8Cās.
They intrigue me very much and am leaning their way.
Please share your impressions.
Thanks,
Tom - NJ