2. amps-preamps
  3. 128361-4692

Straightening Bent Fins

I purchased a huge Krell amp that arrived yesterday! (Used) It all seems OK, but it shifted in the box, and one of the fins was bent. You may as well know it was the one in the front! This is a 130 pound amp, so it's got a pretty good curve in the fin. I know this is a fairly common thing to happen during shipping. It's not severe enough that I don't want the amp, I'm not gojng to send it back over one bent fin. But I ask everyone out there, has anyone ever had any luck straightening a fin? Any advice on the best way to go about it? I don't want to break it off, or scratch it up. Any experiences good or bad, let me know what you think. 
alpha_gt
yioryos's avatar
yioryos
723 posts
 
Hi Alpha_gt
Ok,first I want to say your writing style is very funny ,and yes I mean it in a good way. You think positive and that’s good.
In regards to the bend fin, because I work with aluminum material and know how it behaves. Understand that the fin on your Krell amp is made of aluminum and then black anodized. The anodizing process makes the aluminum harder but also brittle. So even if you succeed in bending it back to straight ,I am afraid the anodize will be affected and will show discoloration at the very least,most likely a white shade where the metal got stressed.Have you ever seen pictures of big Krell class A amps with blue fins from the heat discoloration?
If it was me and I cherished the amp I would go straight into ordering a new fin. By the way my dream amp is a Krell FPB-600 but out of my price range in my area.
Thanks
George
jetter
2,971 posts
 
I assume that to buy a new heatsink, if you find one, you will need to replace the whole side as it is one piece per side.  If so, you may want to replace both sides in case there has been fading over the years. 

Alternatively, if possible, if you move the left heatsink to the right, and vice versa, the bent heatsink will be on the back?
jetter
2,971 posts
 
Meant to say bent heatsink fin will be on the back.
gdnrbob
4,417 posts
 
You could try to buy a non functional FBP-600 and use it for parts, if Krell is unable to source the fins.
alpha_gt OP
155 posts
 
After I have lived with the amp for over a week now, I am not quite as upset about the fin as I once was. But I'd still like to fix it, to maintain the value of the piece. And there are 3 heat sink plates per side Jetter, the 300's have 3 per side and the 600's have 4 per side. 

Im not sure, but the heat sinks on the later FPB models may be the same? On the C and Cx models? So perhaps Krell will still have them in stock? Anyway, I've sent an email to Tech Support at Krell to inquire about a new heat sink, I suppose it's a holiday weekend for them, so hoping to hear from them later this week. I was an electronic tech in a previous life, so am confident I can make the swap. 

More to discover