Preparing for a BHK 250


#1

I am very close to pulling the trigger on a BHK 250. But first . . .

  1. I want to continue to use my P5. Right now the system is using ~400 watts, less than half of what the P5 can produce. My amps theoretically use 190 WPC, so the BHK might use more, but I think I should be OK. I realize a P10 might sound a little better, but I’ve got the P5 in place. Any problem here?

  2. What do you put under the BHK amps? Twenty years ago I bought a pair of Target amp stands. I have no idea of the model number now; they are a steel frame with an MDF board in the center; the MDF is 18" x 14". (Maybe some of you remember those.) I think the frame would handle the BHK’s weight. But in each corner there is a small triangle of steel, welded (I suppose) to the frame, with a leveling screw poking up to support the board. I am not confident that those triangles would stand up over time. The MDF is already distorting from the weight of a 45lb amp.

I’m thinking maybe of a wooden platform like those from Mapleshade. What else has worked well for folks here, both structurally and sonically?


#2

I’ve had my BHK 250 for about a month and have both it and my Directstream plug into my P5. Haven’t had any trouble and everything sounds great.

As for what I place the BHK, I have a Solid Tech hybrid rack and sit the BHK on the bottom shelf.


#3
  1. You could likely get away with running the BHK 250 on your P5 but I believe it would be somewhat limited in providing ultimate current on dynamic peaks. As an alternative setup you could try running the amp directly from the wall with the rest of your gear on the P5 to determine if you sense any limit on dynamic capability compared to when the amp is being powered by the P5. Then you can decide whether the additional expense of a P10 would be justified.

  2. I have some similarly constructed Target stands to those that you described, and I would not trust those welded corner supports supporting the weight of a BHK amp. If the amp will fit directly on the Target’s frame you could use some appropriate footers to use them that way, or with a wooden platform directly on top of the Target’s frame.

Hope this helps!


#4

Or set up a dedicated separate amp stand. It can be inexpensive butcher block on cones.

I understand there is not always sufficient space or long enough interconnects to do this.


#5
audio.bill said 1. You could likely get away with running the BHK 250 on your P5 but I believe it would be somewhat limited in providing ultimate current on dynamic peaks. As an alternative setup you could try running the amp directly from the wall with the rest of your gear on the P5 to determine if you sense any limit on dynamic capability compared to when the amp is being powered by the P5. Then you can decide whether the additional expense of a P10 would be justified.
Good thinking, thanks. I don't normally run my system at volumes that should put any strain on the BHK, but your suggestion will show whether this is happening or not.
2. I have some similarly constructed Target stands to those that you described, and I would not trust those welded corner supports supporting the weight of a BHK amp.
It's helpful that someone else agrees that those corner supports are suspect -- so I'm not being paranoid. The BHK just fits on the existing shelf. I could get a larger piece of maple to sit on the frame and put some Herbie's dots or similar between the frame and the maple to decouple them.

#6
Elk said Or set up a dedicated separate amp stand. It can be inexpensive butcher block on cones.

I understand there is not always sufficient space or long enough interconnects to do this.


The amp standards are separate from my audio rack; they sit between and slightly behind my speakers. Fortunately, with this setup, I already have appropriate cables and power cords that are long enough to put the BHK centered between the speakers, either with a different top on one of my existing stands or on a different type of platform. At least I don’t have to buy new cables!

#7
Elk said Or set up a dedicated separate amp stand. It can be inexpensive butcher block on cones.

I understand there is not always sufficient space or long enough interconnects to do this.


I just put mine in the rack on some Herbie’s tenderfeet.

Word of caution, though, if you use a rack. When I tried to put my P10 (same size as the BHK) into the rack I sheared off the rubber pad at the bottom of the P10’s built-in footpads as I slid the P10 into the rack (there was only an inch clearance to the shelf above so I couldn’t lift it in.)

For the BHK I had a spare 7/8" (22mm) aluminum dowel that I placed under the back of the chassis near the rear feet. Then the BHK rolled into the rack nicely, and was raised enough to lift it at each corner to put in the Herbie’s feet. The dowel just stays there behind the unit when I need to roll it out to change tubes. You can use a wood dowel if you don’t have aluminum. You just need something to hold the weight of the chassis and get the weight off the built-in feet long enough to slide it back into the rack.

–SSW


#8

Clever, clever. Aside from the expense, the idea of wrestling a P10 into the bottom shelf of my rack was not appealing; this is helpful if I ever do replace the P5. Paul should put this in the manuals for the BHK and P10!


#9
magister said Clever, clever. Aside from the expense, the idea of wrestling a P10 into the bottom shelf of my rack was not appealing; this is helpful if I ever do replace the P5. Paul should put this in the manuals for the BHK and P10!
Great idea why didn't I think of that......103_gif

#10
rogerdn said
magister said Clever, clever. Aside from the expense, the idea of wrestling a P10 into the bottom shelf of my rack was not appealing; this is helpful if I ever do replace the P5. Paul should put this in the manuals for the BHK and P10!

Great idea why didn’t I think of that…103_gif


See? I have a good idea once in a while . . . .

:slight_smile:

–SSW


#11
Streets Still Works said
rogerdn said
magister said Clever, clever. Aside from the expense, the idea of wrestling a P10 into the bottom shelf of my rack was not appealing; this is helpful if I ever do replace the P5. Paul should put this in the manuals for the BHK and P10!
Great idea why didn't I think of that......103_gif
See? I have a good idea once in a while . . . .

:slight_smile:

–SSW

Yes I'm sure that would have avoided a scratch and saved me couple hundred green ones in a resale of my 100# Levinson amp.

#12

Great idea but too late for my beta BHK250. The pads were shredded long ago.


#13
stevem2 said Great idea but too late for my beta BHK250. The pads were shredded long ago.
Keep it in mind when it's time to replace tubes. Sure, the footpads are shredded, but at least with the dowel you can get it in and out of the rack quickly without a struggle . . .

–SSW


#14

Another ez solution is to put pieces of cardboard under the feet.