Major Problems with Aleph Ono


I have an Aleph Ono on loan I am considering purchasing. The rest of my set up consists of a Clearaudio Virt. Wood MM, VPI MkIII/PT 6, ARC LS15, ARC VT 200, Vandy 3A Sig's.

The Ono sounds great, much better than the Creek unit I currently use, the problem is, when I turn the volume up to even moderate levels, the woofers in the speakers ossilate and the tonearm starts hopping off the record! I have the jumpers in for the lowest output (60 db) and am using the recommended settings for the cartridge.

I have tried different loading, resistance, cables, balanced and single-ended outputs, I even borrowed a friends pre-amp and took the LS 15 out. Nothing has changed.

Obviously this is not good. I have talked to Pass (not the Ono), the guy selling it (as baffled as I), and someone I consider an experience Vinylphile who told me to move on and buy a different stage (maybe a PH3).

My question is this. Has anyone had the problem and does anyone know how to fix it?
jmcdermott
You're getting subsonic feedback. There is an archived thread with some informative and fun commentary on the subject:

Learn > Forums > Analog > 1033049624 or
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1033049624&openfrom&11&4#11

Best of luck in defeating the wubba-wubbas.
Mike
This precisely why I have my TT and Ono in a separate room from my music system. I run a balanced line to the X1 in the music room. Slightly inconvenient, but enjoyable.
Put the dust cover down and see if the feedback goes away. Then you will know for sure that it is feedback. If it does go away, you will have to mount the turntable in a different location. It can be air borne or vibration borne(through the floor) Isolation is the only answer. It's not your electronics.
I had similar problems way back and ended up moving the t/table further away and settled on mounting it on a turntable wall shelf. This got rid of the floor vibrations.
also try using the proper amount ( by weight ) of "Vibrapods" which work very well for this type of preoblem......Good luck
Well, I got rid of the sorbathane, replaced w/ vibrapods and still had the problem. After moving the table to a kitchen chair placed in front of my rack the problem went away! Now I either need to convince my wife the kitchen chair looks better in the music room or go to a wall shelf I guess.

I'm curious though why the so-called isolation devices didn't work. I even tried stacking the AudioTechnica leveling feet on the Vibrapods and them on top of the Big Feet. It was definately woblly and top heavy but apparently not isolating the table from the correct resonance. Set on the uneven kitchen chair w/ no iso at all solved it! Amazing.

Also, any idea why the lowly Creek MMF8 doesn't present this rpoblem?
It may not be a matter of isolation so much as it is a matter of having the table positioned directly in a low frequency high pressure node. No amount of isolation underneath the table can damp the excitation of the table via air-borne means. Placing the table on the chair in front of the rack probably moved it further away from the wall, which minimizes low frequency reinforcement. Sean
>
I believe the Creek uses a subsonic rolloff filter which would roll the resonant frequency range off therefore eliminating the rumble. A lot of cheaper components do this so the amp(or preamp) is not overloaded by this resonant rumble.
Isolate your turntable on a wall shelf or play it with the top down.
One thing I notice about this phenomenon is that the woofer wobble starts to disappear after the first track of the record has played. I think that as the tone arme moves toward the center of the record, any irregularities are less "dynamic." I wonder if one of those fancy schmancy platter pads'll work?
I'd suggest placing the tt on a solid support, like a granite base. I have my placed on a custom cut base and there's no feedback vibration problems.

If the woofer wobble disappears after the first track, this may mean that the cart is not optimally set. Try checking the alinement.