Lamm LL2.1 Deluxe "DC Offset"?

In addition to the previous post about problem with the Lamm LL2.1, It's a brand new preamp, running hour at about 30-40 hour when the problem started occured.

When paired it with McCormack DNA 0.5 deluxe and Totem Model 1 speakers. The Lamm+McCormack Combo produces an unexpected and intermitten movement of the totem woofer cone back and forth. But when the Lamm replaced by other preamps (SFL-1 or Graaf or Mark Levinson 380 preamp), the system going fine.

In the other case, when the Lamm paired with a tube power amp, things also doing fine.

Perhaps, because The DNA power amp is a Direct Coupled design, it passing whatever signals, good or bad, coming from the Lamm directly to the speakers, which then produce a sporadic woofer movement. In the case of highly fluctuated DC offset in the Lamm, this then create problem to the system.

Anybody can help?

If it's brand new, why don't you call the dealer?

I own Lamm LL2.1 (and owned LL2, L2R) and tried all of them with a lot of different amps. I never had or had such a woofer movement. You can get in contact with the manufacturer, probably there is something with it, who knows...but it is not common imo.

Dear Chayro and Syntax,

Many thanks for your advice.

I did contact the dealer as well as the manufacturer. It seem they in difficulties to find out what is realy happen to the unit itself.

I onced sent it to the dealer, they hooked it to their hybrid Audio Research amp and found that things seem just fine. But when I brought it back home, the problem remain occurs. Then I brought the unit again to the dealer when we finally confirmed that there is a Highly fluctuated DC Offset. Not as high as in my home AC, but that might be caused of their using power conditioner in their system.

They suspecting a leakage in the output capacitors, but considering of its sensitifity to the AC fluctuation I suspect a more serious problem in the upstream side of the circuitry, could be in the power system.

The manufacturer strongly suggested me to manage it through the dealer. While I am away, I did text the dealer to check the progress of their observation but no reply. I am affraid they in trouble of finding the real caused of the problem.

Perhaps I need to find the way to manage and repair it by myself, but need in advance advices before start working on it.