Lamm LL2.1 Deluxe "DC Offset"?


Hi there,

Is there anybody who has a deep experiences with high fluctuated "DC offset" in Lamm LL2.1 Deluxe PreAmp?.

My Lamm LL2.1 Deluxe Preamp shows a highly fluctuated DC reading that reaching +-200mV even more. Last night measurement showed a flucuated reading and reached +-300mV.

A three weeks continuous observation shows that the preamp DC fluctuation seems higly affected by the swing/fluctuation of AC Volatage,day time and night time. I can see that even as small as 0.3V AC voltage abrupt swing will directly generate significant DC offset in the LL2.1.

Your sharing experience and advices are higly appreciated.
gr-gin

Showing 4 responses by whart

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.
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 .
Gr-Grin:
1. I'm not going to speculate on the dealer, because that would be unfair,
but I've had such a wide range of experience with dealers, good and bad.
On the 'good' side, I have one dealer who, with a phone call, will show up
at my house (sometimes with the manufacturer in tow), listen, bring over
loaner gear and handle repairs/trade-ins whatever, without my ever having
to lift a box or do more than set up an appointment. In fact, I've never even
been to his facility. On the 'bad' side, I've had dealers who are less
customer oriented, to the point of dropping stuff off on my driveway and
basically acting like it was my problem.
2. No equipment, in my experience, is always trouble-free. That doesn't
excuse defects, bad support or bad customer service, but sometimes the
problem is easy to rectify and other times it isn't; however, my bet is, lot's of
us on this board have had problems in our systems at one point or another,
and trying to sort it out is sometimes frustrating and upsetting, even if no
one is at fault. You should also know that my Lamm amps are very early
ML2 models and the L2 I bought was used and when it needed attention, it
was updated to current spec at what I considered to be a very reasonable
cost.
3. Even with cheap consumer electronics (like a $150 DVD player), I get
very annoyed if I think there is something wrong with the gear, so believe
me, I understand the frustration/upset even more when it is a high end
piece that is costly.
4. My suggestion is to have the dealer talk to Vlad about getting the unit
shipped to Vlad to evaluate- I don't know what that will cost or how long
that will take- assuming that it is an airfreight wooden crate like the Lamm
gear I have owned. I think trying to work with Vlad in a cooperative way
may get you some satisfaction, because in my experience, he has stood
behind his equipment and never charged me a lot when the gear needed
repair. (I assume you are still under warranty).
5. One other possibility- can the dealer come to your home, with his
technical person, and another amp, (and if possible another unit of the
Lamm preamp model you have) just to see what's going on? That may
not solve the problem, but may give you (and the dealer) a better idea of
what is going on. Also, because you said you were dealing with the free-
lance technician for the dealer, have you spoken with the dealer/owner in
addition to the technician?
Perhaps you've already done some of this. But, I never had any dealer
work on any Lamm equipment, and every Lamm dealer in the States
basically sends the gear to him for anything more than tubes.
Where are you located?
Gr- It sounds like the bottleneck is the dealer- I agree that you should not ship the unit to Lamm without a return authorization and some idea of turnaround time. It seems odd to me that the dealer wouldn't handle this, or at least arrange it for you.
Can you tell me what city/country you are in? (I don't necessarily want you to name the dealer here, but perhaps I can help). You can send me a PM or email if you like.