Lamm LL2.1 Deluxe "DC Offset"?

I would go with option 1 and have the dealer replace the caps. That way you will have shown Lamm a good-faith effort on your part to see if that was the problem.

And who knows, maybe that will fix things. If not, then it's time for either a full replacement or your full money back.

Am very very surprised by LAMM's lack of effective response to resolve the issue. And this, coming from such a reputable company, can only augur bad things for the company.

I was seriously considering buying a Lamm pre but after reading this, no way... not with such mentality....

Just to put things into perspective here, I have owned a few Lamm components over the years and still cherish my ML2 power amps. I also owned the L2 line stage for a number of years. On occasion, the line stage and amps needed attention. Since I live in the NY area, I was able to deliver the equipment directly to Lamm. It was repaired quickly and inexpensively, and each time, the units were checked, cleaned and on occasion re-tubed (with my prior approval).
The chief difficulty with a company like Lamm is that it is a small operation. This has benefits, in that you can get Vlad on the phone but drawbacks if he is occupied. (I guess I like gear from small 'one man' companies, because I own a phono stage from Allnic, which is similarly the product of one man).
I understand working through a dealer if you are not in the immediate area and don't want to get involved in the cost and risk of shipping. (Although the Lamm stuff is packed in serious wooden crates).
I can't directly troubleshoot your problem, since I was using the Lamm linestage with Lamm amps. But, I generally trust Vlad to do the right thing-
and, also understand why, given the size of the company, he prefers that customers work with his dealers.

Whart,
I can appreciate your positive experience with Lamm products. Doesn't it seem in this particular case Gr-gin's concerns are being brushed off to some degree given the time that's elapsed?
Regards,

Charles- I am not defending Vlad, but put it into context. I assume the OP is overseas, I may be wrong. As far as I know in the US, Vlad has no authorized repair centers; apart from tubes, in my experience the gear goes back to Lamm Industries in Brooklyn for any repair. It seems there are two alternatives here: one, to see if the dealer can sort the problem (my experience with dealers has varied widely over the years, from ones who I would trust with my life and others who are so horrible I wouldn't go public only because it would probably be defamatory). I have no idea how effective the dealer can be in the circumstance, giving him every benefit of the doubt.
The other alternative is to ship the unit to Vlad after making arrangements to do so, with a rough idea of what expected turnaround time would be. Since Vlad builds the darn things, he can get to the bottom of any issue quickly. The biggest obstacle is shipping and delays associated with that. (Although, FWIW, I got stuff shipped from Allnic in days- Korea to NY. Crazy). If it were me, I'd probably opt to have the unit looked over by Vlad.
As to whether this particular preamp doesn't work well with some power amps, I haven't a clue. It does sound like that was one of the messages given to the OP, either by Lamm or the dealer (i'll have to go back and re-read the various excerpts that were posted).
The point of my earlier post was to address the practical exigencies- Lamm is a small operation without the kind of 'customer service' staff you often find at larger manufacturers. (Vlad's wife handles part of the intake and she is charming and usually pretty good about responding to emails). And, I get why, in the first instance, Lamm would urge the dealer to try to sort the problem, particularly if the dealer is close by- the dealer can go to the customer's house, can try and troubleshoot the unit, rather than figure it out over the phone, etc. For that reason, I don't think Lamm is giving the OP the 'brush off.' That said, I still think the best option is to send the unit back to the factory. If it turns out that there is some fundamental incompatibility in how the unit works with certain kinds of amps, and nothing is wrong with the preamp, that's a different issue. But, to definitely determine whether something is wrong, I'd arrange to have the dealer send it back, as described above. Worst case, presumably, if the OP bought it from that dealer, is that he works something out for a different product, assuming the unit checks OK .