Thank you so much!
You might want to use the low output setting on your dac, and, turn the volume to 106. I hear no SQ degradation in that setting.
Yes I’ve tried it. Not sure if it is just me imagining it but it sounds sl. worse to me so I just manually lowered the volume.
Sweet, whatever works best for you, is , best for you! Enjoy the music!
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I’m sorry to say, but hiss is unacceptable to me. If I upgrade my amp/preamp, it will likely not be a BHK.
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If hiss with your ear right up against the speaker is an issue to you then you will need to avoid tube gear altogether and not just BHK.
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Any amp will produce hiss at loud volumes if you put your ear against the speaker. The threshold will just be slightly higher for solid state amps.
His right up against the speaker, that I’ve had before and is ok if it’s only when it’s REALLY soft.
There seems to be more than that though I’m the BHKs. I supposed the only want to know is to test one out.
So an update: I put the Psvane 12AU7s back into the BHK Preamp. It’s not silent, but the level is much lower than with the Tungsrams. I can hear some faint noise at 4-5 ft, but by 10ft I hear nothing. Adding the DS into the input raises the noise very slightly.
I’m in my 30s, still have pretty good hearing and have a fairly close listening position, so I think with the stock tubes most people won’t hear any hiss. Esp if you have lower sensitivity speakers.
Another tricky thing in the comparison is when I un-mute the preamp the noise floor temporally jumps up for a few seconds (similar to when crossing certain settings on the volume control). Once it settles, it is pretty quiet.
The Tungsram tubes do sound a bit more musical and 3D, if less accurate on top, but they really add some noise.
Edit: Having run it for over an hour with the stock tubes the noise is essentially inaudible at most prime volume settings. (20-24, 40-52, and 65+ are audible, though) I have to put my ear right up to the tweeter. I guess these things need time to stabilize.
tensor9
The hiss from the BHK is no different from any other tube gear that I have owned including six different tube preamps. The primary factors determining how much hiss you will or won’t hear are the combination of the gain of the preamp, the input sensitivity of the amp and the efficiency of the speaker. These factors need to be taken into consideration with all tube gear relative to the speaker you are using or planning to use. Unlike with most SS gear the matching of the gain of a tube preamp to the amp it is to be used with is critical and why you can’t just buy any old tube preamp no matter how highly reviewed it is and stick it in your system if it doesn’t match up to the amp. The higher the sensitivity of the speakers the more critical this matching becomes. I used Vandersteen speakers for over twenty years and with their mid-80’s sensitivity I never noticed tube hiss even if the gear match was not optimal. However when I switched to the 91 db Nola KO’s the hiss became readily apparent and resulted in me swapping out several pieces of gear. So if your preferred speakers are inefficient you won’t notice any noise if they are efficient you may.
The Tungsram tubes do sound a bit more musical and 3D, if less accurate on top, but they really add some noise.
Could this be due to age related deterioration of the tubes? Most of my experience (especially with headphone amps) has been with newer production tubes and they have tended to be very quiet. Ditto for the stock tubes in the BHKs (which I believe are also current production). Is this an issue that affects NOS more, or is it purely down to the tube type?
I think it could be the lower voltage, the tube design, but before I put them back in I’m going to use some contact cleaner on those pins. I have noticed certain types of preamp tubes have lower noise, like EF86, which is a pentode, but they are also prone to microphonics.
Almost all the NOS tubes I’ve used are a little noisier than good new ones, even Telefunken, so noise isn’t really their main benefit. Also, the reality is that we are scrapping the bottom of the barrel and the best tubes were sold and used 60+ years ago. I’ve never heard the REALLY good ones.
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Can you please explain why, if tube designs are inherently noisy (to whatever degree), why are there tube based headphone amplifiers? I would have thought any hiss would be more noticeable in a headphone. Why I ask is, I have a pair of headphones coming soon (world first with graphene drivers), and I’m contemplating whether to use them with my Halcro pre-amp, or buy a dedicated headphone pre-amp.
I never described them as being inherently noisy. I said any amp will make hiss if you put your ear next to the speaker drivers and turn the volume up far enough.
The issue is that if you are listening to your headphones at those kind of volumes then hiss is the least of your problems - I would be more concerned about permanent hearing loss.
So to put it another way I would presume the reason it is less of a problem with headphones is because the you don’t play them as loud as you play your speakers.
I never said you did describe them that way, but somebody else did.
Yet your question with that statement was to me.
If you have your headphone amp turned up enough to hear significant noise, you are in hearing loss territory. My solid state Lehmann Audio headphone amp has a SNR of 75db, while the BHK is supposed to be around 90db through XLR. I can’t hear any noise with it, even on sensitive headphones.
Because you said you have experience with headphone amplifiers.
The safest bet for you might be something like the Pass HPA-1 unless your dealers will let you test out the ones they carry with you headphones.
OK it just seemed weird like you were asking me to justify a statement I didn’t make. Anyway I think the simple issue is that of how much you are amplifying the signal to play through headphones as I stated.
I’m curious about these graphene headphones and would love to hear more about them - are they electrostatic?
Most of my experience is with electrostatics like STAX but although they sound fantastic they have a tendency to fall apart (the build quality has always been flimsy). I’ve tried planar magnetic too (Oppo, HifiMan, Audeze) but find the sound kind of midway between regular dynamic headphones (with weaker bass) and ES (midrange is better than dynamics but worse than ES).