Holy mother of .... BHK Signature Preamp

Well this is officially my first piece of PS Audio gear. Nice to be back into tubes again.
2 hours in and WOW, this piece is special. Dead quiet. Well built and modern but understated. Much better in person.
If this is just the beginning, we are in for a long term relationship!!
Coming still is the BHK 300’s and Directstream DAC.



@RsZk - I just hooked up mine this afternoon; 2hrs in and it’s pretty nice… needs a lot of burn-in… The soundstage opened right up, already had very low noise floor… we’ll see over the next couple of months. I have the stock tubes and will be adding the “special BHK tubes” w/ Rx-9 tube dampener in the next week or two when the functionality is wrung out. What you will notice with all nice gear is if you like it now, you will love it in a few months (500hrs). Got to let things settle in. Also, make sure you plug in your head phones and let them run all night to burn-in the headphone section.

Also, keep the DAC on all the time and after about 6 months it will really show it’s true colors. The pre and amp go to standby at the end of the evening and ON the first thing in the morning. Anything solid state needs to be on all the time.

Also, the PSA P20 is unbelievable and worth every penny… Great power and interconnects are so important!

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Good call on the headphones, I will do that. I have been burning in my new planar headphones on my living room system lately on my new Hegel amplifier. It’s been a very fortunate year!

Cheers and congrats as well.
Happy listening

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@RsZk - I have a set of Focal Utopia HP with Nordost cable (3m) so my plan is to plug in the HP in the evening and let it rip, then let the mains run all day. You may think about the special tubes w/ dampeners… You are going to love the PSA DS DAC. My system sounded amazing with just the DAC to BHK250 and now it sounds more open and better. A little harsh; however, too early to judge. You need at least 500hrs before you sit down and really judge the preamp… for now, it is a little more open…

Where are you getting your tubes and dampeners from?
I shopped at tube depot in the past online.
I’m from Canada


@RsZk - I got my Preamp from Upscale and it comes with 2 sets of BHK select tubes. Kevin Deal takes care of his PSA clients.

Dampeners from Herbies Audio Lab. I got SS-9 dampeners for my BHK250 when going select tubes a few weeks ago and Rx-9 ready for this Preamp. The amp is a little more room constrained.

My mom is from Keybeck… speaks fluent French… what part of Canada?

From Alberta.
Hmm I wonder if can purchase the tubes from Upscale? I did see his videos on them.

@RsZk - Yeah, that’s an approach. I would look around and get some prices. I love that shop and have been treated very well by Kevin. Any issues I have with anything, they take care of me very quickly. I have had good luck there. However, I live in western AZ and only about 300mi from Upscale. In addition, I drive to LA every 6 weeks to touch base with the team I manage for a few days. So, I am pretty close.

I’m just getting into the whole tube rolling and find it fun. You can change the characteristics of the pre/amp for a few hundred dollars as opposed to buying a new pre/amp… I waited for about 2,000 hrs before I changed my BHK250 tubes to the “select” tubes and the sound was definitely better. I look at this hobby as long term investing of time and resources… having a plan is important; however, all the cool stuff seems to fall in place by happenstance…

Also, you picked the right place for some dialog. There are a lot of amazing people on this forum with a very deep and wide breath of knowledge. Just ask away and the fun begins…

Typically you can buy any tube from Upscale they have in stock. Occasionally they limit sales of limited availability tubes to those who have purchases equipment from them.

Cardri - did you notice any benefit from using the ss-9 dampers in the BHK amps?

hey RsZk, i’m in eastern Canada. in NB. Check out Vintage Tubes. Andy is a cool guy to talk to - straight up, and he knows his tubes. congrats on the BHK. I just bought my first piece of PSA electronics last week - the Perfect Wave DAC. switched out my Bryston BDA2. good luck! TJ

@emailists - I changed the BHK250 factory to “select” tube & SS-9 dampener at the same time. I posted the installation pics on the forum. A pretty tight volume. A very big difference SQ; however, did them both at the same time so I assume most of the SQ benefit is from the select tubes.

My next step is to isolate all the components using Isoacoustic pucks (Bronze & Bordeaux). To assist in isolation, I just received a custom bamboo cutting board (20in X 16in X 1.5in) using it as a plinth for my Nucleus+ & (2) SBOOSTER LPSs. I finished staining the bamboo ebony last week, waiting for the pucks.


The DS will change your life.


The thing about the PSA DS DAC is that it sounds good right from the jump and then in a month you do a double take one evening and it has you re-listening to the day one source material. Then some months later it is so smooth, open, lower noise floor because you will be hearing stuff you swear was not there. Just remember you only turn it on once. Do not turn it off or in standby and the reward is amazing. Just be patient.

All very true, except in my experience when I first turned mine on I though about crying as I sold my VPI TT and a Quicksilver Pre when I ordered the DAC…it sounded very mediocre, I was soooo bummed.

BUT every 24 hours it got better and better and better. After about a week of running music in to it 24 hours a day, my jaw fell to the floor.

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Oh boy. I can’t wait for my amps, but the way you talk about the DAC, I wish I had it now.
One thing for sure it’s great to hear the improvements in stages as well.
Thanks all! It is a great community for sure.


Hi Tj Sully. Thanks for the recommendation on tube vendor. I am changing from a BDP-2 and BDA-2 myself. Hopefully there is a substantial improvement to the DS DAC with Bridge II option.

Just changed the stock BHK Preamp tubes to “select” tubes. When changing to “BHK select” tubes, Bascom mentions going from 4mA to 5mA bias (current), in addition to going from 12V to 6V. The bias selection is implemented using 2 stakes; connector is only on one stake (4mA). Connecting the 2 stakes with the connector changes the bias current from 4mA to 5mA. Current stakes are near the tube on the right. Below is a pic of the preamp and amp tube rolling process. In addition you can see how the Rx-9 dampener fits nicely. Below the preamp pic is the BHK250 amplifier pics. The Rx-9 dampener is a little wider than the SS-9 dampener and would have a tough time fitting; reason I went to the SS-9 dampener on the BHK250 Amplifier.

BHK Preamp:

BHK250 Amplifier



I’m not gonna lie @cardri I love your illustrations, I’m am consultant so a big fan of great detailed Visio and other diagrams!

@Veneet - Yeah, that is the trouble with being an engineer for 40 years… I started as a test technician and wrote my first test plan & procedure at 21. Then wrote my first product user guide after my first product line design - spectroscopy amplifier in my 20s… at 60 years old, been documenting my whole life. Before I think of anything I open VISIO and start thinking. If I can’t ask 20 questions, I need to think more…

As an aside. I designed my 2nd home in VISIO back in the 80s. 12 “E” sized drawings I got through planning & zoning as the architect… been using VISIO for a long time…

This VISIO drawings help. The preamp and amp are separated by the P20. Since the drawing is scaled I know the distance the XLR cables need to be. I bought those cables (Nordost Valhalla 2) months ago. I also followed up to make sure they were 0.6m at the beginning of the legitimate bend radius to make sure I would not have to go out and buy the cables again… :slight_smile: Come to find out the cable is 30in end to end and a very comfortable 0.6m after the proper bend. This is why I use VISIO. I have made so many bone headed decisions without thinking things through… after your 100th stupid mistake you realize VISIO is free (work) and so is my SAT afternoon… so why not think it through…

As another aside about documenting. Usually some illustrator redoes your patent diagrams. I just got another patent last summer and all the diagrams I did in VISIO and they were used. So cool looking at the patent and seeing my drawings…

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