2. amps-preamps
  3. 1442207121

Lamm 1.2 tubes, power cable and slight one channel

Hi All. Well I have just (last week) had my Lamm 1.2s arrive (second hand via the local dealer) and they are ohhhh so nice to listen to. Fantastic detail and sound stage, I have an Antipodes DX into a Meitner MA1 Dac into the latest Concert Fidelity pre into the Lamms. For cables - mostly Antipodes Komako (IC) and am trialing Townshend SC into Harbeth Super 5s.

My tube questions are:
- Has anyone tried EAT (new - which appeals but are they any good) valves or CCA Philips yellow lables?
- What tubes would go best with these (2 or 3 choices in case I have avail. /cost issues)? What are the best few i should be saving/waiting for?
- Who are the most trusted tube sellers? i just hear so many bad stories.
- What should I be looking out for/asking when buying tubes?

Also should I be using any special power cables and/or a conditioner with the Lamms - and if so any recommendations?

Finally (sorry for all of the questions) I am using them unbalanced with the shorting cap on. However I get a very low level hum (audible from more than a few feet away) on one channel. That channel had no issues when running my Airtight previously. This is even when all of the local RF generating items are off and the pre is unplugged from the Lamm - and also when the pre is muted (but plugged in). I have tried swapping out the power cable with the other amp (which has no such noise), changing speaker cables, making sure power and sp cables are well seperated, changing where it is plugged in to (wall socket) but still... The tubes are a few months and 40 (or so) hours old. I am thinking of next swapping the two amps over to see if it's a very very localised RF issue - and then swapping the tubes over to see if one tube got damaged on the amps being delivered. Could a tube be creating a very low level hum? And is there anything else I should be thinking about or trying?

Thanks in advance - any and all thoughts and help really appreciated. Kind regards
Stu from NZ
colville12

Showing 1 response by hotjacket

hotjacket
1 posts
 
I understand this is a very old post, I just spotted it now ... but I also have a pair of Lamm M1.2 Reference amps, which have always made a humming / buzzing noise (not through the outputs, but a physical noise emanating from both amps). What I find interesting, is that I also live in New Zealand... so I wonder if that is a contributing factor.

The only way I got rid of the noise was by running through a PS Audio PowerPlant 10 power regenerator... which is unfortunate, since Lamm recommend in the manual not to use such devices. I emailed Lamm but never heard back, so they’ve been gathering dust for some years now :-( I'd not thought about using a dedicated circuit though, so might give that a go, they are very musical amps but the buzzing always drove me nuts.
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