amp clipping or low freq causing pumping speakers

thanks for the insight

that's along the two ends of the spectrum I was looking at

The cartridge/table is a very good synergy
Gavia Galibrier / Tripaner / ZYX Universe
many Galibier owners have this combo and it is stellar
and has always been great synergy with my more 'lower end rolled off" ARC LS5 and Dodd preamp

The Doshi plays fabulously at modest to mid high volumes and just glorious on cds. It is a step attenuator so it takes a while for the volume to ramp up on analog

I like to hear subtle things and therefore play analog at louder volumes from time to time getting the speaker cone movement

my previous preamp didn't go that low frequency wise
and a second preamp with very low frequency did the same thing

so yes sounds like subsonic problems

rumble or clipping
could be some of both

not sure I want to filter it - and if the amp which only balks at higher volumes is clipping, I can try more power with a different amp

unfortunately my second amp a Bat vk600se is at a friends 1200 miles away. Perhaps Richard Gray, our local superman electronics guy in New Orleans can lend me something for a while

You're a little unclear, but it sounds like your turntable is not sufficiently isolated.

Your TT looks to be pretty well isolated using the SRA platform. You rack looks OK too.
All-the-same, like Rodman99999, I believe that you have acoustic feedback when you play LPs. It could very well be the speaker design. It could also be a subsonic resonance w/ your tonearm.
If you can get your hands on the HiFi News & Record test LP you might be able to test @ what freq your tonearm-cartridge is resonant. Confirm that it is indeed resonant @ the freq you expect it to be.

It sounds like you have 2 problems...

1- not enough gain just for the system with that cartridge if you crank and don't get the volumes you want, but ....

2- You need to read this thread below and it will solve the woofers pumping basically guaranteed with no sonic effect, but again will not solve problem #1, your other preamp has a subsonic filter most likely, and the other does not, its basically just capacitors in a certain value directly connected at the phono input RCA's in most preamps with built in active phono statges that gets rid of the surface noise off an LP pumping the woofers, take it from experience.

Not sure but possibly the good outboard subsonic filters can add a tad of gain due to most of them are active designs, being it will need to be plugged into the wall I believe. If your really concerned I would call KAB acoustics U.S.A and see if they will let you try one, might be a restocking fee however. Its possible Mr. Doshi since being a custom preamp most likely hand built can put the cutoff Capacitors in the preamp for you on the phono inputs. But the value would have to be determined in order to get the right cutoff... Fact is most of this noise is likely down around 10 to 3 hz.. Were taking its the Wind blowing effect with the groove going thru your cart puffing away, the preamp is just amplifying it, no sonic benefit, nor is it a benefit to your woofers working out on a daily basis for nothing! And of course this is an in-efficient power loss too, so might up your dynamics in the real music eliminating it.

By the way your speakers obviously don't play that low, but this energy goes somewhere and its in a pulse effect causing your speakers to act this way, I have first hand experience and solution on this.See thread

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1267683244&openusid&zzUndertow&4&5#Undertow

thanks guys

seems the record with the most trouble was a slightly warped one. I went back and lowered the volume a little and haven't had the pumping effect. It's mostly very demanding passages - doesn't get overloaded on jazz like it does on some rock records

I have a ZYX Artisian outboard phono pre and will try that in one of the line imputs on the doshi - perhaps there is a roll off in the low freq end of the phono stage

it doesn't do this with cds

I'll touch base with Nic Doshi and get his comments on gain and low end frequency

I believe I do have that test record

thanks

Tom