2. amps-preamps
  3. 1273520086

amp clipping or low freq causing pumping speakers

My cd source plays back fine at loud volumes with modest amplfication. My analog MC setup needs much more volume and until I switched out my premap from a Dodd battery powered to my present highly resolving
Doshi Alaap I had little to no pumping / displacement in my bass drivers (Salk HT3's).

Now they noticably vibrate in and out with some breakup distortion. Not as much with jazz but more so with dense rock music. Unfortunately quieter passages are too far in the background when played requiring higher volumes (perhaps I need more preamp gain). CD's with their higher compression sound fabulous on the Doshi and with less volume required

I have seen this once before when at an audiophile meeting a friend brought over an Infinity pre that went down to subsonic frequencies and my speakers were vibrating

my dilema is I need to turn my turntable up louder than my cds(which sound great and don't clip).

Could it be the added dynamic range and more low end of analog sending the speaker into viration mode

Or is the amp clipping not being able to reproduce the load sent to it?

I have a Moscode 401 HR amp, I have a higher powered BAT VK600 with a friend 1200 miles away.

thanks

Tom
128x128audiotomb
bjpd57a1
96 posts
 
Not 100% clear, on the EXACT problem, specifically?

Perhaps some fellow owners will share their experience,

in this area.

Bottom Line: Something is NOT happy, in the loop.

If I had to guess, I would point to the pre-amp.

Power should not be an issue, the pre-amp is failing

to transfer the power cleanly to the speakers.

Elsewhere, there are several other forums about this

awesome pre-amp.

Give the fellow "Guru's" a chance to respond.

Be assured, help is on the way.

I Love My Music!
imhififan's avatar
imhififan
2,186 posts
 
Maybe this can help.
rodman99999
6,132 posts
 
The problems addressed by the site in the previous post are probably the issue, but- a filter such as that is a crutch that will cripple a high-end system(transparency/ambience/harmonics/timbre loss). Much better to actually address things like cartridge/tonearm mismatch(compliance and effective mass), platter rumble, acoustic feedback, possibly warped discs, etc. (http://www.gcaudio.com/resources/howtos/tonearmcartridge.html) (http://www.vinylengine.com/cartridge_database.php) Reproducing low freq rumble DOES use lots of power, and thus can easily cause your system to go into clipping, at any gain stage.
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