SE'ed LP125M are back

[Puma Cat]

Originally Posted by bgiliberti

If it were a tube, I would not expect that on/off quality.

So, I am beginning to wonder the same thing about my KT120s....night before last, when I shut off the amp after a first evening of listening to them with real music for the first time, they sounded great. Last night they didn't sound good after all....as if they were distorting on louder passages, notably piano, etc and with dark quality....wondering if this is tube burn-in thing, as they sound good, then bad, then good, etc. until they start to actually sound good, or if I am indeed crazy. Nice thing is it's easy to swap out to the original 6550s to check.

[bgiliberti]

Originally Posted by Puma Cat

So, I am beginning to wonder the same thing about my KT120s....night before last, when I shut off the amp after a first evening of listening to them with real music for the first time, they sounded great. Last night they didn't sound good after all....as if they were distorting on louder passages, notably piano, etc and with dark quality....wondering if this is tube burn-in thing, as they sound good, then bad, then good, etc. until they start to actually sound good, or if I am indeed crazy. Nice thing is it's easy to swap out to the original 6550s to check.

Given that the LP125S has Teflon caps, wouldn't you need to swap out the KT120s to isolate the issue? I think that maybe you are having the same issues with the Teflon Caps that I am. It may be the Teflon plus some "other" as yet unknown factor, like AC power condition, that makes it more acute in one system or another. I hate to be posting so negatively here, because I am sure that for some people, the Teflons are not problematic, and in fact are wonderful. At times, they are for me too.

[Puma Cat]

Originally Posted by bgiliberti

Given that the LP125S has Teflon caps, wouldn't you need to swap out the KT120s to isolate the issue? I think that maybe you are having the same issues with the Teflon Caps that I am. It may be the Teflon plus some "other" as yet unknown factor, like AC power condition, that makes it more acute in one system or another. I hate to be posting so negatively here, because I am sure that for some people, the Teflons are not problematic, and in fact are wonderful. At times, they are for me too.

No, the what I am noticing is specifically related to a tube swap night before last. I am using a LP70S....the caps are well-burned in and the sound has been exemplary and stable for almost two years now.

[jimtranr]

Originally Posted by bgiliberti

One weird thing is that when it sounds right, the preamp is noticeably warmer to the touch near the face plate, and also, my adcom power conditioner seems warmer. This could mean nothing, it could suggest an issue with the AC power I'm getting from Pepco, or just a mere coincidence.

On the face of it, sounds like an AC issue. Does the warm faceplate/warm ACE-515 phenomenon occur only when you're playing punchy, dynamic program material or is it present with tamer stuff as well?

[bgiliberti]

Originally Posted by jimtranr

On the face of it, sounds like an AC issue. Does the warm faceplate/warm ACE-515 phenomenon occur only when you're playing punchy, dynamic program material or is it present with tamer stuff as well?

I would say punchy/dynamic. What does that indicate? Probably just that it's drawing more juice? I don't play too loud normally, but I have been burning in with power amp off and the volume a bit past my normal highest listening level, mindful of the advice to avoid clipping the preamp (which I had never thought was possible, but why take a chance?). That procedure does seem to warm the preamp and Adcom faceplates up more, and I do think it has helped with burn in.

[ronenash]

I don't know if it is an AC issue or some other issue but it sure ain't the teflons. The Classic SE uses teflons to bypass ploypropelene caps as opposed to the higher end models which use pure teflons throughout the signal pass. They should not had that huge of an impact on the sound quality. In this configuration the teflons bring more air in the highs and tigher bass but the mids are usually not effected that much.

My LP125M SE has 300 hours on it and it sounds absolutly amazing with no regression in sound since about 200 hours. I will write a more complete impression/review in another post.

[Rayooo]

Originally Posted by Puma Cat

So, I am beginning to wonder the same thing about my KT120s....night before last, when I shut off the amp after a first evening of listening to them with real music for the first time, they sounded great. Last night they didn't sound good after all....as if they were distorting on louder passages, notably piano, etc and with dark quality....wondering if this is tube burn-in thing, as they sound good, then bad, then good, etc. until they start to actually sound good, or if I am indeed crazy. Nice thing is it's easy to swap out to the original 6550s to check.

I've been reading these recent comments, with great interest.
As an example I would swear that the ET-5 sounds better when played every day...as opposed to when several days go by without it being on. Almost as if it in fact "falls back" a bit. I would also swear that my Classic SE did NOT do this.

In truth I've wondered this for years, with different gear etc. Why a given system would sound spectacular one day, and far less so another.

AC Power? Relative Humidity? Phase of the moon? Position of Earth in relation to other planets? Pretty scary starting down that path.

Getting back to reality, (as not much I can do about Earth's position in space anyway) I've accepted (kicking and screaming) that Teflon Caps need to break-in. Do they fall back after a few days of non-use?

What about "human factors" ? One of these is when I switch from enjoying the music/system , to evaluating the music/system. I'm always fascinated how I can switch my system from sounding warm, liquid and engaging to dry, flat and lifeless when I start trying to determine for example if power cord A sounds better than power cord B.

I don't mean to vector this discussion off track..but this has been a fascinating interest of mine for years now and I had to put my 2cents in! Who remembers the Tice Clock?

[bgiliberti]

Originally Posted by ronenash

I don't know if it is an AC issue or some other issue but it sure ain't the teflons. The Classic SE uses teflons to bypass ploypropelene caps as opposed to the higher end models which use pure teflons throughout the signal pass. They should not had that huge of an impact on the sound quality. In this configuration the teflons bring more air in the highs and tigher bass but the mids are usually not effected that much.

My LP125M SE has 300 hours on it and it sounds absolutly amazing with no regression in sound since about 200 hours. I will write a more complete impression/review in another post.

Thanks for the info. I'm thinking more and more that is is not the Teflon, because the highs and transients are amazing. Most likely, it is that my PV-7 was "filtering" out the midrange edginess I am hearing now on the more detailed Classic SE. Harbeth 30s are unusually articulate in the midrange and will pick that up. Given that I am using a good, but not great Denon universal player, I'm thinking of trading it in on a Rega Apollo or a Marantz SA8004, which have warm midranges and offer more musicality. I also do think the power I get from Pepco is pretty nasty, and that my Adcom power conditioner is not really able to do the job. At some point, I will upgrade that too.