BHK Pre - some pre-buy questions

For a long time I have just connected my DSD Jr dac directly to my mono blocks. Never had a reason to argue with myself about that, and with streaming, the need for multiple inputs are very limited.

Now, with all forum threads (and even Paul changing his mind ) I have considered to try a BHK Pre out in my system. Before that however I have some questions I have not managed to get answered anywhere else in the forum, but bear with me if I have missed them out anyway…

I have never been a tube fan, and I know almost nothing about the topic, and I am not really looking forward to the BHK tubes as such - even though I understand that they might have the most substantial impact on SQ. But, why is there such lengthy discussions about replacing the tubes? Are the ones delivered not good? If so, why would PSAudio put anything less than optimal in their product?

2nd question is about noise. Those of you using the DSD+BHK pre combo, are you using the output from DSD with our without the attenuator? Without it there is this small background noise, and with the BHK pre added, is that also amplified to an irritating level? Or how does that work? What would be the best combination to minimise background noise and still getting the best S/N ratio? (And the best ooommpph)

Hope someone clever can clear out my questions, and make me hit the buy button later this Summer.

I’ll give my perspective to your first question. I’ve owned my BHK pre for 1 month but it was a substantial upgrade in all areas for me (I’ve owned a dozen or so SS, Tube and hybrid preamps in the past that we’re all in the $1k-2.5k price point used). I think the OEM tubes are really good and fit the sound that the majority of owners will find enjoyable in their system. A few (it is a small percentage of you look at total ownership) will roll tubes because all of us have slightly different tastes and there are ways to “tune the engine” to get extra out of it. If you visualize the OEM Tube putting you center stage and row 8-12 of 20, some folks want to be in row 15 or further back, others in row 1-5. There are warmer tubes, cooler tubes, etc… all tastes vary.

I’m a middle of the road guy and love the sound of the OEM tubes that are a quick replacement every couple years for me. I will confess that I will also more than likely take a listen to other tubes in the future to compare and look for even better synergy in my system.

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As to why people can’t seem to quit talking about replacing tubes, the answer is simple: this site is populated by obsessive audiophiles who are hoping that there’s always another tube that’s better than the ones they’ve already tried. Same way some car owners are always hoping another set of tires will give them better handling than the set their Porsche 911 came with from the factory. :smile: I know, I’m one of those guys. There is nothing “wrong” with the tubes the BHK’s ship with. That said, the tube manufacturing business isn’t capable of the consistently high quality standards it was in the days before transistors replaced vacuum tubes. Vacuum tube demand today is infinitely small compared to what it was in the past and manufacturing expertise, capacity, and personnel skill levels are more difficult to maintain. The reason manufacturers don’t use old tubes made in the past is because there aren’t enough of them to supply manufacturer demand for consistent supply and they cost so much the benefit to a manufacturer would be negligible. If PS Audio installed a $600 set of Siemens CCA tubes instead of the $60 Genalex’s they use, you can be sure few would want to pay the additional price because most listeners either wouldn’t care about the incremental improvement or they’d immediately want to replace the tubes with something they were convinced would be better. Similar to the reason few manufacturers supply expensive aftermarket AC cables for their products.

Hi Senna 1a

Please shed some light as to which preamps you have had in your system…
your previous one you used…

How your new BHK pre has changed your sq…and what it is you like about
this change…

Your sharing would be very helpful for me to better gauge where I may go next
due to a very constrained budget as of the moment.

Thank you for helping

So that’s makes sense. Reassuring to my ears also, thanks!

Wow, I didn’t even know that a couple of tubes could even cost as much as hundreds of dollars… Gosh. Then I also fully understand the vintage aspect of tube rolling, quality! THanks!

Over the years I have tube rolled for my mid 60’s Mcintosh MX110z all tube tuner preamp…

Tube rolling very quickly becomes a very expensive rabbit hole. The strong innate desire to learn of the audible differences between tube brands and within a brand
whether a triple mica variety yields a quieter more detailed over a simpler double mica
design…
Examples: the ecc 801s Telefunken or the dual mica more common 12at7 Telefunken.
or the Sylvania Gold Brand 6201 12at7 variants and there are many more…

In my system the Tele 801s yields more detailed refined sound over the more full bodied Tele dual mica 12atz …while the Sylvania 6201was darker less detailed.

Once in a while these become available at less stratospheric prices…
over time have spent $$$$ just to satisfy the want to know …

For this reason I have been leaning more toward all ss gear…

Therefore my question for senna 1a…

Yes tubes are amazing…

Note this is about a 25-30 year journey, but here you go.

I’ve had several SS pre: Parasound, Bryston, Adcom, B&K, Hafler - all of various models - some I’ve tried stock vs modded with updated caps/power supplies (look at musical concepts for some of his work). AVA, modded eastern electric were full tube and quickly moved away from that camp. Most of the SS mods moved the soundstage out of my lap (row 1) and back a bit, provided a bit more laid back and refined top end, but still had an upper range edginess in my system. All the full tube preamps took the edge off, but I lost too much resolution. Note I’ve run similar SS amps until I moved to Pass Labs 18 months ago.

For the last +10 years I’ve used a ModWright SWL 9.0 SE. - it’s what I consider a hybrid with a 5687 tube front end only. It provided the soundstage with middle row seating I like, a nice resolved sound without upper edginess on most recordings. It’s been my goto pre for the last decade.

What the BHK has offered me - it’s provided a similar experience, but with greater resolution, deeper soundstage, and a more refined top end. The fact it is fully balanced, also gave me the flexibility to run XLR from DAC / Pre / Amp. Just to share rest of my system, I’m running an Esoteric SA50 SACD/DAC > BHK Pre > Pass Labs XA60.5 > NHT 3.3

While my system is no where near what others have created, it’s given me enjoyment and the BHK helped tremendously given my budget constrains. I’ve been blessed to have a hi end shop nearby that would let me listen to $100k+ systems on a regular basis when I was younger for hours and hours; unfortunately they closed (like many others). While a blessing to have that luxury, it also amplified my own system shortcomings, so chase the better system, albeit on a modest budget.

As a stand-alone piece of kit, I know my Esoteric is a bit too analytical for my tastes. My XA60.5s are missing the absolute refined bass under 100Hz, and my NHTs medal dome tweeter can sound like someone running their nails down a chalk board depending on the recording. But with the BHK, it’s added a bit of warm ness to offset the DAC, a bit of tightness down low, and helped tame the edge up top. True synergy that’s helped with shortcomings of others parts of my system.

At least that’s what I’m hearing/experience. YMMV.

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Senna 1a …thank you for taking the time sharing background of gear you have owned.
I home demoed a Parasound P7 preamp which placed me at about where the conductor stands yielding a very unrealistic soundstage for me …My McIntosh MX 110z places me around row 14…giving me a more panoramic acoustical view point

My Wyred4Sound STPse stage 2 around same row 14… more body less detail than
MX110z

Enter my Emotiva XSP1 Gen 2…same row 14…more dynamic and more detailed than my W4S stage 2. Depth breadth scope of soundstage detail is quite breathtaking.

After reading the numerous owners very positive experiences with their BHK preamps
it is all too tempting…

Thank you Senna 1a for sharing your experiences
it is appreciated.

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PerL:

With a preamp driving your DAC, you can set the volume of the DAC in order to “attenuate” the sound the way you like. You could, but wouldn’t necessarily need to use the built-in attenuator. Start by setting your DACs volume at 100, and then you can dial it in to your own liking. Some people on this forum have said they prefer to set their DS to “80.” Obviously, there’s a wide range of options . . . . . 0 - 100!!

I have my DS Sr. set to 90 “high”. If I keep it at 100, it sounds like the pre is being stressed once in a blue moon. Set to 90, that is never the case, so I just keep it there.

As to the stock tubes, they are good, it’s just that you can find even better NOS (new old stock) tubes. The great thing about tubes is that it allows you to tailor the pre to fit your system and your sound preferences .

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“90” sounds about right audiojan. I’ve had DS set at 100 all week since I received the BHK (on the fourth of July), and it does seem a little “hot.”

I’m definitely going to try some NOS tubes for the fun of it, but I have no idea yet which ones to buy. It seems like the 6DJ8 style give people the most grief (“noisy”) even though they seem to receive the most hype . . . . . I am curious if anyone has found a worthy upgrade with 12AU7’s.

Hi Timequest…not sure what you maybe looking for in 12au7 upgrades whether
warmer, or more detail or more zing…

There is a lower mu or gain tube…the 12bh7 a quieter tube but may have more ma
current draw than 12au7…in my Mcintosh MX110z yields a beautiful detailed non tizzy
soundstage…but overall volume level will be lower given the lower mu gain of this tube type. Can the BHK pre safely run this tube? I don’t know…

I had posed a question along this line regarding 12x allowable variants for the BHK pre
but it went unaswered…

Hopefully some one more knowledgeable of the BHK’s power supply range of allowable current draw for this particular application will chime in…

Maybe Elk or Ted Smith

I would check out the BHK tube rolling thread for some good ideas:

The 6sn7 tube is a 6 volt variant that is not compatible with BHK pre
or even the 6922, 7308, 6dj8,7dj8 types variants that can be used in the
BHK power amps…

The 6sn7 form factor wouldn’t fit in the space given the 6922s

hope this helps

Several are running 6SN7, one needs to use risers and an adapter. Be mindful of the heater current required though…BHK says it’s OK but close to the limit

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Thanks Brett66 didn’t think an 6sn7 could be adapted…I have read elswhere
that 6sn7s are more desireable than the 6922 variants …

I’ve read the same but wary of a bad one pulling too much and killing the circuit. 2.5 years of rolling 12AU7 and 6/7DJ8 bliss for me, why risk it

Maybe you could answer this one for me…

The 12bh7 tube is a quieter lower gain mu tube than 12au7…could it be used in the
BHK preamp…how about 12at7s which are higher gain than 12au7s…will the BHK preamp power supply while being designed for the 12au7 …could it be called upon to deliver with these other 12a variants?

Thanks Brett66

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