PS Audio BHK lacking..

I bought a used PS Audio BHK preamp to replace my Rotel.  It sounds thin with no depth & bass compared to my Rotel so I let it run for over an hour with no change. I'm new to tubes so I'm looking for ideas. New tubes or what?
Something definitely sounds off with that particular unit's performance, and I suppose it could just be worn out tubes or poor tube choice.  I ran one for ~3 years with much satisfaction.  It replaced a VAC Ren Sig II convincingly in my system, and I only moved on for an AR Ref 40, which does offer more, but doesn't exactly embarrass the BHK pre.  I found soundstage depth and bass to be strengths of the preamp, not weaknesses.

Trying a new set of tubes is a good place to start.  Check out the PS Audio website forum for some detailed discussion threads about the many varieties that are possible, with a nice number of sonic impressions reported.  After comparing 10 different varieties, I was smitten with Amperex 7308's in the unit, because it offered the right balance of fullness in mid-bass through low mids that my system needs, while not sacrificing the highs.

Since you have a used unit, I'm assuming it is well broken in.  Several have reported some big changes in their first 100 hours (wasn't a big event for me when I broke in a new one).
I have tubes ordered from PS but I've read on here that others are better & I can't remember their name.

If the sound doesn't change for the better you should call PS Audio and see how they suggest you proceed.
Tunsgrams are the way to go though anything is better than the stock PS Vanes. Upscale audio has the specific Tunsgrams and it is a different tube type so you have to change a jumper on the amp when you swap the tubes. 

I had serious buyers remorse until I rolled in different tubes.  With the better tubes, it is a very nice unit.   
As tubes age they at the 'end of their lives' sound pretty lackluster.The gold lion tubes that PS Audio recommends are fine tubes but emphasize the mids and bass.A faster sounding lively tube is the JAN Phillips 12AU7.It's one to put on your list to try.
Hi fertguy

If you try some high quality nos tubes in the BHK Signature preamp it will transform that preamp into a very good sounding preamp. Either a 12 volt 12au7 from either Telefunken, Mullard, Amperex or Siemens from the 50’s or the 60’s should sound great. If you change the two jumpers to the 6 volt settings and the 5 milliamperes bias settings then either a pair of 6922’s, 7308’s or 7dj8’s will sound great as well. BHK’s favorite tubes are the Tungsram 7dj8’s from the 60’s. Any of these nos older tubes will elevate that preamp to a whole new level. Best of luck.

if $10k worth of gear cant beat < $1k step #1 is to measure and baseline that it is working even remotely properly.  Both performance and settings (eg..; Bias)
The day I bought the BHK here on the Gon I ordered a new set of stock tubes from PS Audio.  They showed up a little while ago. I have them in now & they made a big big difference. It's starting to happen. I'm looking forward to trying some of the tubes you guys mentioned.
Next is what should I expect to pay. There is a set of Telefunken 12au7 on line, new for $400.
What kind of qualities do you enjoy most in your music and what music do you play most often?  Easier to recommend tubes knowing what you like....warmth, speed, soundstage, strong bass, lots of air, treble sparkle, etc...
I’d go with strong bass, soundstage & air.  Mostly old rock, country, & now classical because it is well recorded.
It should be better than a Rotel, I had the 250 for about 2 days and returned it.  In all fairness, I did purchase it used from The Music Room.  No problems returning.  It just is underpowered.  I had sold an old Adcom 555ii which would beat it hands down, no tubes too, and sounded sweeter.  I like PS Audio's marketing and return policy and the people - but the stuff is not high end in my opinion - right in there with MAC and Rotel.
@plaw - was that the BHK250? I don't have any comment in regards to their power, efficiency of your speakers, size of your room or the listening levels you enjoy..

I do know that a BHK250 does sound markedly better with the BHK Pre, honestly I can't speak as to why it's the case. But it is just so.
Contact PS Audio and explain your situation. They have some pretty decent tech people that can make the right suggestions. 
Even though they are "factory direct" now they have a good team of engineers. 
Next is what should I expect to pay. There is a set of Telefunken 12au7 on line, new for $400.

That’s high for experimenting. If you were sure that Telefunken was your favorite tube and that was a superb pair, maybe. You should be able to buy some nice tubes from a reputable dealer for $200 or less.

Here are a few good dealers. You can google them.

Andy Bouwman at Vintage Tube Services (he can be slow but many people swear by him)

Brent Jessee

Kevin Deal at Upscale Audio (some people find his personality abrasive)

Jim McShane

I hope others will chime in with those I’ve forgotten.

They will all talk to you about what tubes might work for you and they are probably all familiar with your pre.  I’ve read that Brent Jessee allows returns if you don’t like the tubes. Check that with him before buying.

Take your time shopping for tubes and listen to the stock tubes for a while to get familiar with the baseline sound of your pre. Then decide what you might like to change with new tubes.

There are good sellers on ebay, but it’s not where I would start my tube journey, especially if you don’t have a tube tester.
In my experience, the stock tubes are better than any of the 6volt tubes I tried including the Tungsrams, and better than Radiotechniques 12au7. The Psvanes have a cleaner midrange that is more balanced with with the highs.
Interesting on your experience on the Psvane tubes.  Just goes to show how system synergy and personal preferences are so important.  Most folks on the PS Audio forum have preferred alternatives, as have I, but that certainly doesn't invalidate yours or anyone else's experience.
Don’t lump McIntosh in the same group as Rotel.  Rotel is a joke compared to McIntosh. Back in the 70’s, the only stores that sold Rotel were those that couldn’t get credit from any of the other companies. Shame on you!
I was thinking to replace my parasound jc2 with BHK preamp for the last couple of months, but looks like other experiences and opinions r so controversial. Now what I have is big big doubts. Should I do it and will SQ get benefited from it !!!???
fertguy-Is it possible that your speakers are out of phase? That could cause what you are describing.
No, I’ve solved the problem. It was old tubes. I’m new to tubes so I spoke too soon. surfmuz, don’t hesitate because of my screw up. Mine is sounding much better w/new tubes.
@surfmuz   It's a worthy preamp.  I ditched a VAC Ren Sig II for it, as it quite convincingly sounded truer to the music in my system.  For the money, especially used, it's a good value in sound and function.
Another big question...- is hybrid preamps like BHK much better in bass aspect then full tube units like Modwright or VAC ? Did anybody compared same price range preamps with hybrid and full tube circuitry?
Well, the BHK's bass certainly bested my VAC Ren Sig II, which retailed at a distinctly higher price range in its day.  Haven't heard a Modwright preamp.  I'm guessing the BHK's MOSFET output gives it bass authority, but you can play with tonal character with tube choices, so.....
There may be something wrong with your preamp outside of tubes-There is no way it should sound as poorly as described if all is well. What kind of amp are you pairing with? Have you played around with the current jumpers? If it is a tube issue, there are plenty of options out there ranging from the inexpensive to more pricier options. I have played around with a number tubes, including 6sn7 tubes w converter. I am currently using Siemens CCA that sound incredible, granted they cost quite a bit. My runners up are Telefunken 6922 and the Tungsrams as suggested by BHK. just be sure to get tubes that are tightly matched otherwise you will suffer from volume pops. Best of luck and hop it works out!


I owned a Parasound JC2 for several months. I kept it long enough to make sure it was completely broken in. I couldn’t wait to terget rid of it. I found it to be just mediocre at best. Very polite and very boring. 

With regard to your question about a hybrid design, the reason BHK designed it like that is it’s quieter. You still get the tonal color and accurate timbre from a tube design but because it only uses 2 tubes, there is much less noise (tube rush). Best of both worlds. You have to remember, BHK has been designing preamps for 50 years!

I bought the BHK preamp and it just blew away the JC2 even with the factory tubes. After about six months I decided to try some nos Telefunkens 12au7’s from the early 1960’s and those tubes elevated it to a whole new level. Those vintage tubes made a world of difference to the point of it was almost unrecognizable. I’ve had the BHK for over two years now and the more I improve my system, the more I appreciate how good that preamp is. For $5995.00, I don’t know what would beat it. They come up on Audiogon every once in a while for $3000 - $3500.00. Get one and get some old nos tubes from Mullard, Telefunken, Amperex, Siemens, just make sure the tubes are from the 1950’s to the 1960’s and you will be amazed. Good luck.


I catch a little heck because I’m using a TFM 45 Carver. I bought the amp new in the 80s. About a year ago it was completely updated with new & better everything. Long list. It is dead quiet, runs cool & is rated at 375 WPC. They told me when they rebuilt it it would be tube like. I'd never had tubes so how would I know. I used to have it on a set of Kappa 8s & it was wonderful.

Great choice on the Telefunkens from 1958. Those tubes should sound fantastic. I’ll bet those weren’t cheap. My Telefunkens were date coded from 1962 and they were just amazing. It took that BHK preamp to a whole new level. Let us know what they sound like after you’ve had a chance to listen to them for a month or two, I think you’re in for a real surprise. Enjoy.

Telefunkens are great on rock  and most jazz .
Often to harsh in treble for  classical .
My BHK suddenly sounded horrible.  I reseated the tubes and all was right in the world.

I wonder if the tubes might be on the way out so ordered a variety of tubes yo tey out. Each really changed the sound but did settle on a pair that sounded much nicer than the original factory tubes.

My advice is to roll the existing tubes left to right , etc and then repower. 
I really like them. Everything is smoothing out with more depth.  Worth the money.
These Kantas can be a little bright on some tunes but the tubes helped. I'm thinking tube amps next.  On we go..
Also check the tube voltage thing switch inside (see owners manual). Make sure they match the voltage of the tube that's is installed.
Check and make sure the amp you are using input impedance is a good match for the PS Audio preamp. If that is not a good match you will find the bass is rolled off big time. 
Hi fertguy

I want to start by saying something is very wrong. I’m not going to list all the preamps I’ve owned in the last five years but I can honestly tell you that in my opinion, my BHK preamp is a tremendous value and just a killer performer. After about six months of using it and making sure it was completely broken in, I bought a pair of nos vintage (1960’s)  Telefunken 12au7’s and you would think it was a different preamp. Those tubes transformed that preamp like you wouldn’t believe. I’ve owned it for about two years now and I realized that I like the 6 volt tubes you are able to use in it better than the 12 volt tubes. (there are two jumpers inside that have to be changed, one for the voltage and one for the bias).This 6 volt family of tubes consists of 6dj8, 6922, 7308,  or cca’s. 

If if you try a pair of vintage nos tubes and it doesn’t sound much better, then something is wrong with yours. I have had preamps that cost three times what the BHK costs and I like the BHK better. IMHO dollar for dollar, it’s one of the best sounding most musical preamps out there with the right tubes in it. 

If you put in a pair of good nos vintage tubes in it and it doesn’t blow you away, then I would send it back to PS Audio and have them figure out what’s wrong with it. Good luck.

scothurwitz,We're on the same page. I'm using Tele 12s from 1958 now. Sounds great.