BHK Preamp tube rolling

No worries brett66 the fame of the teles precede them …the secret was let out of the bag decades ago… :grinning: yet even the old ones with who knows how many hours of old equipment being left on by mistake
for who knows how long…the teles just keep playing on and on. May
just well bury new gear purchased today…and keep on singing…not bad for 55 + year old tubes still singing away…

Just my own experience with them…
Never mind me though, I just excited happy when vintage gear struts
its stuff…

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I am not debating with any of the experienced veterans here. This is just my own little experience. I got my new BHK Pre in Nov. 2019 to replace Stellar Gain Pre. After all the burn-in things sounded a bit better and by comparison with GainCell, a tad more natural though timbre and body were not what I expected. Also, the sound stage was 2D without height or depth. I was suspecting my cables, room acoustics, speaker placement, etc. BHK reached 1000 hours early Sep. 2020. People say pre-amp tubes can last longer than 1000 hours, but I went ahead and replaced the factory installed PSVanes with a matched pair of 12AU7 Genalex. Within the space of an hour, I felt like I have just bought a new system! Not only did I get a 3D sound stage, but timbre, bass definition, instrument placement, realism of instruments and vocals took a on whole new benchmark that I have never experienced with my gear or with my Naim Audio system. Someone said it could be a psycho-acoustic illusion. So, in a few days, I went back to the PSVanes, and that reconfirmed my findings. I am sticking with the Genalex matched pair.

Be safe, healthy and happy
Serhan

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Thank you Serhan for sharing your experience…
You have experienced the wonderful way tubes of different
brands and sub types within the brand can improve the 3D audio
soundstage…

Yes and yes you have experienced a new and wonderful
benchmark… Congratulations!!

Small signal tubes should last 5000 hours or so…the nos
50s - early70s tubes are known to go 10000 hours.

From the very little I know of the BHK preamp…I am thinking
that they are gentle on the tubes…as opposed to my old
1960s classic tube Fisher receivers…where apparently
they were hard on tubes…from what I have read …yet
my old Telefunkens soldier on as if they were new out
of the box.

Power tubes 1800 hours or there abouts.

Thanks again for sharing

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Thank you David.

That is very helpful, and encouraging. In the 90s, I owned F22 Musical Fidelity tube line stage preamp with f15 hybrid pure class A power amp. Eventually, I replaced the F22 with the newer F25 for its impressive phono stage. The FCD was tube based as well, but had serious mechanical issues. I still recall how good that system sounded especially with Apogee Duetta and Martin Logan SL3. That was my first love affair with tube based, and hybrid systems.

Kind regards

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Hey Serhan…

Apogee Duettas that would be a tough act to follow even by ML…
Are you currently using ML speakers?

Hi David,
Apologies to participants, I am deviating from the topic of tube rolling.
You could use the F15 for cooking, but at 100W per channel that amp blew me away with it ability to drive ribbons and electro-stats. All were gone in 2006 as I relocated. Living in apartments, and relocating frequently, I chose Dynaudio Contour 20. Probably, I should have gone for Confidence 20 instead.
Kind regards

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Ah Serhan the price to pay for class A …room heater cooker for sure.

Years ago I had an amazing experience auditioning Acoustat Spectra 2
( foggy memory here ) driven by Nakamichi Stasis PA 7 ( under licensce
from Threshold).Just like yourself was quite taken by this set up.

Years later I walked into a shop where a pair of ML CLS speakers
had just been set up with Threshold amp and preamp. What an amazing experience…the see through the speakers soundstage
was amazing…I wish I could have brought that home with me…
The tech doing the set up said they were not at their best as this
setup had yet to be burned in…

Yet still the sound was very captivating!!

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I think these are the best budget NOS period.

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Just installed my first set of “Baldwin” 1950’s black plate 12AU7 in the BHK preamp purchased from Brent Jesse. These must be the bargain of the century. Sublime sound, perfect matching (no audible clicks during volume adjustment) and a price that’s very reasonable ($40 for a matched pair; gain on all four triodes = 2000). Will definitely buy some backups for the future.

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Which ones sorry?

Hi Gazjam, He meant “The pair of Baldwin 12au7s”

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Thanks!

Welcome to the forum Delphi.

Hi all, well this BHK tube rolling has certainly been interesting reading so far… I have learnt a lot about tube rolling from all the experiments and trials so many of you have been doing, and perhaps also as much about the different effects on various systems and personal tastes!

I’m from Perth Australia (Yep, G’day mate… no bloody shrimps on this barbie) …had my BHK pre for about a year. I couldn’t be more more pleased with my purchase, in my book a master class of a pre amplifier design and build. A keeper. Hats off to you mr King, and PSA.

I was told on purchase that the BHK pre was originally voiced on the Tungsram PCC88 / 7DJ8 NOS tubes and to acquire some asap once the unit burnt in, so I bought two sets of balanced and cryo’d tubes from Tube monger.

This was my experience, on my system in my listening room;
As with everything in life, striking a balance is a trade off… some recordings are dark, some are bright. What I found is that the stock Psvane 12AU7’s seemed to handle just about anything I threw at it with control and poise. As many observe the top end is a little rolled off, however with good interconnects I found it presents fine high frequency detail…albeit in a supple manner.

After a few month of sleep deprivation due to being drawn in to long listening sessions, yes hard to walk away from my system… I decided to install the Tungsram’s Id purchased.

Anticipating a more open top end, that is exactly what I got, wow… almost crystalline and incredible spacious mid and top end… 50 hrs later after minimum burn in it was time to really delve in and see where it was at now;

As reported on this forum by some before It didn’t take me long to notice on the downside that the mid range and upper bass had been somewhat stripped of its body, or if you like; had become leaner and of a seemingly smaller scale.
I also noticed the bottom end was not as as authoritative and controlled as the stock PSvanes, although still delving very deep. Perhaps more off putting for me on my system was the fact that any thin or slightly bright recording sounded fatiguing, but in essence the overall effect for me was to not go on listening, sleep restored :wink:

Remember folks for all the recommendations out there, tube selection is mostly taste and system dependent.
For me in my current system the stock tubes are working their magic and I’m very happy… but perhaps with different speakers in future I may need to refer back to this informative forum!

Enjoy the music …

System;
PSA P3 - isotek premier leads
PSA - DSD with Bridge 2
PSA - BHK pre
PSA - M700 monoblocks
Modified Technics 1200mk2 - Ortofon MC20 cart
Dynavector P75 mk4 Phono line stage
All on Isoaccoustic isolation pucks
Analysis plus silver apex interconnects
Analysis plus Oval 9 mesh speaker cables
Rhythmic audio 12SE sub
Axis voiceboxes - stand-mount speakers
Treated room

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Welcome Nicolas…to PS Audio forum…lots’a goodies
here…

Well if no shrimps on the barbie…hmm Manley amps have a
“shrimp” just for you all tubes… :innocent:

Just a tease…
Happy trails listening

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Can I get confirmation on WE396A/2C51 tubes compatibility with BHK Pre. I really like these tubes and have the adapter for them, just wanted to ask if there’s any follow up to BHK comment here? I tried searching and this is the best I got, sorry if I missed anything.

One word of warning. The BHK Pre should in theory use 6SN7 and other variants. I tried a VT99. It sounded glorious. However after a while you could smell something overheating. I pulled the tubes and went back to my Telefunken 6DJ8’s. My warning is to be cautious.

Thanks for the warning… that’s why I asked here to be sure. I thought I read some where that WE396A is compatible, but that the only comment I found. Maybe @BHK can confirm. I’m not sure what load line considerations is… is this a no-go or it won’t sound best, but is safe to try.

Thanks for info James. I have not been following up on this tread and did not see this until now. I have 200 hours on my BHK pre using PSVANE CV181 T2 6SN7. I guess they have to come out. I absolutely love the way it sounds with these tubes.
Does anyone know if 6SL7 which have a heater current of 300mA will work ok in the BHK pre?

Thank you

Yes, from a heater current perspective they will work. The larger issue is that the 6SL7 has more than twice the gain and it will make the Pre crazy loud and therefore much noisier. I probably wouldn’t use them.

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