New BHK Pre Owner and Having Issues

Hello All,

I’m in need of some assistance. I’m a new and first time owner of a PS Audio device. In May of 2020 I purchased the BHK PreAmp for my two channel listening. I’ve been listening almost every day to music or movies for about 2-4 hours at a time and I love the unit. However I just started experiencing an issue with the device.

When listening to any source whether it is Music or BD Movie the Left Channel loses mids and highs. Its most clear when listening to Music. The center stage shifts to the right and all I hear is low end from the left speaker. If I turn the BHK Pre up or down one volume level it comes right back. Sometimes that fixes it and it stays; but sometimes I have to do this a dozen times during one record.

Also I have removed the BHK completely and listened to Music and movies over my Marantz as the Pre and the issue has never happened. All two channel equipment has been swapped out for newer and different units for troubleshooting and nothing has ridden me of this issue. So I’m now asking for assistance. Thanks in advance.

Please advise on where I should start with troubleshooting the BHK?

System Setup is as follows.

Sources:

VPI Prime with AT-ART9XA to Gold Note PH-10 PhonoStage
Mac Mini to Chord Qutest for Streaming
Xbox One X for BlueRay
Apple 4k TV

AV PreAmplifier:

Marantz AV7703

Amplifier:

McIntosh MC452 for Fronts

Speakers:

Martin Logan Renaissance ESL 15A’s

Cables:

AudioQuest Water XLR’s and Leopard ToneArm Cable for TT
Nordost Blue Heaven for Streaming setup
Nordost Red Dawn Speaker Cables

Again thanks for any assistance. Wanted to ask before I started replacing Tubes or even taking the cover off.

Did you try to switch left and right tube to see if that’s it?

If you do, let them cool down before touching them. Not because of your fingers, but because tubes are sensible when still warm.

1 Like

I would do nothing until you speak to PSA.

3 Likes

No I haven’t done anything yet since this is my fist piece of tube gear and my first PSA. From what I have read and seen on YouTube it can’t hurt to move them right?

If you’re totally new to tubes take care to just slightly tilt them while pulling, so that no pins break. Better then as RonP said, wait for PSA assistance. I don’t want to make you damage your unit, but I’m quite confident you just need new tubes.

If you feel like walking on the wild side, unplug the preamp, wait 10 minutes, and switch tubes left for right. A slight, gentle but firm rocking motion to facilitate them coming out. Then carefully line up the pins and again, slightly rock them back home.
If your problem shifts to the other channel, then it’s a tube. BTW, if tubes develop a white, milky looking coating inside, the tube has a vacuum leak and it’s toast.

2 Likes

So I have 4 extra tubes that came with it from Upscale Audio. I’ve watched the tube rolling video on YouTube also. So when you state “slightly tilt while pulling them” you mean not to just pull them straight up and out?

Wait until tomorrow to speak with PSA.
The extra tubes are likely 7 volt, not 12 volt as originally installed. If that’s the case, you need to move some jumpers.

So according to Upscale Audio they are 2 pairs of the BHK Select tubes. They say on the side of the boxes Tungsram PCC88/7DJ8.

Usually tubes have quite some friction within the socket, so if you just pull, you could end up suddenly throwing it behind you :wink:

That’s why slightly! moving them forth and back while pulling a bit usually helps.

Take care to use matched pairs if indicated.

Take care what RonP said then, my Info is just general, not BHK specific.

Hey JLasher22443…

Please contact PS Audio support…

In your new BHK pre you should have Psvane branded tubes…
Have you switched them out for the Tungsram or are the Psvanes still in your new BHK pre?

For the time being keep the Psvanes in your new BHK pre…they are better quality than the tungsram.
My .02

In a totally different piece A classic 60’s Mcintosh tubed tuner preamp I have used Tungsram tubes
that did exactly what you are describing…
Tungsram tubes proved to be short lived in my gear whie other major NOS brands are very long
lived…

Best wishes …

I’m not sure what is in the BHK right now because I haven’t opened it yet. My assumption is Upscale Audio swapped them out for the Tungsram’s but not sure.

So by matched pair how do I know? Here is a photo of the spare tubes still in the boxes sent with the BHK.

1 Like

So you are correct I opened it up and they are the Psvane branded tubes. Is V1 left channel and V2 right channel?

1 Like

A deviation up to 10% is ok between the two values among each tube, so I’d combine the first with the last and the two middle ones.

1 Like

Thank you for sharing your findings…

Since I don’t own a BHK pre I cannot comment if v1 is lt and v2 right…could well be that way…

I encourage you to pm jamesh tech support par excellence…address your BHK pre issues
with him he is most outstanding and helpful…

Best wishes

1 Like

I use white gloves that have a slightly grippy surface. Grip the tube by pinching it between thumb and index finger. Pull gently up. I find the gloves help. I never rock tubes. The tubes are the logical place to start.

from Brent Jessee highly regarded tube supplier

http://www.audiotubes.com/6dj8.htm

Ok so once everyone gets to know me and reads my posts they will find I’m very impatient. LOL. Not in a mean way but in a way I either impulse buy or screw something up royally by not waiting. LOL. In this case neither happened, But once I had one person here respond to make the swap; it gave me enough confidence to do so. LMAO!

So with that being said I unplugged the unit and let sit for about 15 minutes. Opened her up and took a look. The tube in V2 was not all the way down and leaning a little to the right; not sure if that matters. Also read here about checking the boards right behind the tubes. Both were a little wiggly when I touched them so I pushed down a little and they tightened up. Next I went ahead and removed the leaning tube to see it in my hand. Used white gloves supplied. Was very easy to remove with the tilting method explained by some of you. Got the tube out and was like “that was easy”. So I decided to swap V1 with V2 and see if the issue happened again in the right speaker this time.

I’m happy to say I am almost done with Side A on the first album and no loss of mids and highs yet.

Thanks everyone for the wonderful support. I’ll keep you posted if things change. I’m only about 80-100 hours into the unit and loving it!

7 Likes