[NagysAudio]

BobM, actually the spike is better than the footer. A single spike near the center of the amp acts as a vibration drainage. I think in the DNA 500, the transformer(s) is towards the front, so I would place the spike/cone in the middle closer to the front.

The drainage of the vibrations makes a significantly bigger difference than damping the heatsinks, or top cover. Although, the amp might sound better with the heatsinks damped as well...

If you put the rubbers on each fin individually, it's going to be very ineffective as a damper. They won't ring as much, but will vibrate just the same, only at a different frequency.

To do it right, you need a brass metal bar, maybe 1/2" in diameter and as long as the amp/heatsinks. Glue a piece of rubber along it and bolt it to the heatsinks. The rubber side of the bar has to apply pressure across all of the fins. This is a lot of work and if you decide to sell the amp, it will be modified at that point. So not worth it in my opinion and I would just recommend using the single cone/spike.

[avahifi]

Actually, the best way to "damp" a heat sink is wrap wet washclothes around them.  That will get them good and damp.

Of course that would be contrary to our famous old damping factor specification:

Damping factor: the unit should not get wet. 

Regards,

Frank Van Alstine

[gerald porzio]

With all this drainage, an outsider might conclude that this is a sewer forum.

[TONEPUB]

Man, even I have to agree with Gerald on this one.

I would think that there are so many OTHER ways you could improve the sound of
your system before worrying about damping the heat sinks....

[jules]

Bob,

how about using a silicon gun to create some silicon drops/blobs of a size that would wedge lightly between the fins. You could make up a heap of them on a non-stick surface [lightly oiled perhaps?], leave them to cure for a week or so and then put them wherever you want them. It wouldn't matter if half the blobs you make aren't the right size but I'm sure it's one of those things that pratice would make perfect.

It's much the same as your earlier scheme but replaceable.

jules

[BobM]

Wow. I guess nobody reads the earlier posts. This is an experiment. OK, I'll say it again. THIS IS AN EXPERIMENT.  I never said it was an important tweak or mod. I never said it would have an audible effect. There is substantial ring from a heatsink and I want to find out what daming might do. THIS IS AN EXPERIMENT.  That being said (and sincerely hoping Gerald will go away) - Steve, no luck at Ace last night. They don't even know what an ACE Superstore is and have no clue what I'm asking for. Are you sure it's an actual ACE hardware store you're finding this in?   Thanks for all those who have contributed in a positive light.

[turkey]

Gerald, if you don't have anything positive to contribute then please go haunt someone else's thread.

He makes a very valid point though.

[ohenry]

Wow. I guess nobody reads the earlier posts. This is an experiment. OK, I'll say it again. THIS IS AN EXPERIMENT.  I never said it was an important tweak or mod. I never said it would have an audible effect. There is substantial ring from a heatsink and I want to find out what daming might do. THIS IS AN EXPERIMENT.  That being said (and sincerely hoping Gerald will go away) - Steve, no luck at Ace last night. They don't even know what an ACE Superstore is and have no clue what I'm asking for. Are you sure it's an actual ACE hardware store you're finding this in?   Thanks for all those who have contributed in a positive light.

Isn't fun to accept "encouragement" from folks that have never experimented?  This reminds me of the guys on diyaudio that blather on incessantly, but never build a f-ing thing.   

Lord help you if you are brave enough to post your perceptions.   

[rollo]

Bob I feel your pain. This is a hobby I believe. So you want to experiment. Experiment. I have witnessed and heard some of your tinkering and your efforts have had interesting results. Some good some not. That ART DI/O was a winner, your TT another as well as your rack.  However we learned something every time and had FUN doing so.
   So keep on trucking Bob, your system is proof as to what can be obtained with some experimentation.



charles

[BobM]

Thanks Charles. Just picked up this tidbit on another forum, so I'm going to give it a try. Again, my amp runs cool so no worries about heat melting it.

"Charles Hansen of Ayre made a recommendation here a while back regarding dampening fins. Simply use a strip of clear packing tape and place it in the center of the fins, front to back. The tape should be in contact with each fin. I tried this tweak about a year ago and it really helped in reducing the ringing. One of the cheapest tweaks ever! I would suggesting searching for Charles' posts for more details."

[avahifi]

I suggest a easy to do "double blind" experiment you can try with heat fin damping.

Simply first listen carefully to a stereo amp with mono sources (or simply with your preamp set to mono), switching back and forth between the channels with the preamp balance control to make sure there are no audible differences between the channels to start with.

Then do whatever damping you wish with one channel only.

Then have a friend randomize all the connections in the system, left to right - - - from the source to the preamp, from the preamp to the power amp, and from the power amp to the speakers.

Have the friend leave the room before you re-enter and have him stay gone while you repeat all the A-B tests between the two channels over as much time as you want.

Write down your choices as to which channel is damped and which is not with each listening test.

Then check your results with reality and see if you really did hear any real differences.

Of course you can do this testing with speaker cables and interconnect cables too.  It is an easy way to see what is real and what is sugar pills.

Best regards,

Frank Van Alstine

[BobM]

Well the packing tape did in fact provide an inexpensive, removeable, non-damaging solution to the damping. It does damp the fin edges sufficiently to reduce the ringing in a satisfactory manner without blocking air circulation. We'll see how long it can adhere without coming loose, in time.

I'm not making any claims as to audibility, since that would seem to strain everyone's mind just a bit too much, but I have accomplished my initial goal. And if you want to try it for yourself you now have a solution that almost everyone can afford with materials that are probably at hand. So try the experiment and come to your own conclusions.

Thanks for participating.

[rollo]

Bob hopefully your avatar looks that way becauce you hit the piss out of it and not because it dosn't like water.


charles

[BobM]

It's what my ball looks like as it's about to hit a tree