Just bumping my earlier post as there as some eyes on this thread at the moment and I might have an opportunity for some reasonably priced ECC32’s ...
Right and thanks but I noticed that you had previously asked someone (LM?) and were told that it ran too hot? Obviously this has not been an issue for you or others so far.
No, I was told flat out not to use them but that's due to warranty concerns. People who aren't affiliated with LM and know electronics confirmed it works and it does... Beautifully.
Are you sure EML 300B-XLS are safe to use with LM? I mean warranty wise and technically wise. I'm a bit concerned when I read on other forums that these tubes draw more current than standard 300B's (even more than mesh plates) and may possibly not survive or cause amp damage when applied to amplifier which is not compatible with them.
@Strat-Mangler I am curious to know why would the EML 300B XLS be safe to use and not the mesh plate (which you earlier said would be incompatible) ?
"Bias and Anode dissipation must be reduced from 22 Watt to absolute maximum 28 Watt." 300B Mesh Emission Labs Data Sheet The 508IA/805IA is 48 WPC.
do you guys connect the LM straight to the wall or through the power conditioner ? if through power conditioner, do you hear the benefit and what do you use ?
I use a PS Audio P12 regenerator and it makes a notable improvement in reduced hum as well as better dynamics.
I use this. It really makes a difference. Bolder, more taut bass. Mids are slightly more dense. Highs are smoother. Overall the vocals have better clarity too. It makes my system sound more ‘energized’. Like it’s on Viagra. FRANK ACOUSTICS: FRANK PB-15000Ws Power Bank Storage
I use Audioquest Niagara 1200 power filter and it works great. I also have a dedicated AC line for the system, wich helps pretty much.
I too use a Niagara 1200. How much it helps SQ is hard to say but I do know that there is zero background noise emanating from amp to speakers.
The HumX indeed solved my hum issues (thanks to @Ontheone) but there is still a catch. I can’t connect everything to the same power conditioner. I use a Puritan psm156 and when the 805IA is connected to it, the Puritan buzzes crazily. I also hear transformer buzz from the LM. I never had ground loop issues before with any of my components and I have had many over the years. The LM seems to be the only one that is prone to this issue. Anyway, for now I connect the LM straight to the duplex where the Puritan is also connected along with the HumX on the preamp. This reduces the hum significantly from the speaker as well as the transformer buzz. I don’t know if there is an easy way to figure out if there is an issue with either the LM or Puritan. Any thoughts ? I am now wondering if there is a better way to feed the LM with clean power, maybe an Isotek evo3 synchro or AQ Niagara or a Shunyata Denali. Anyone experimented with different power cords with LM ? What do you use ? I have a Shunyata Alpha NR v2 connected at the moment.
I was using a Niagara 1200 with my LM and then I stepped up to a PS Audio P12 (bought during a promotion at a deep discount). The regenerator made a huge difference. For whatever reason I get some hum when I use the pre-in connected to my VAC linestage. Using the P12 the noise is almost nil unless my ear is up to the speaker. If I use the LM as an integrated amp I don't get any noise or hum whatsoever. Unfortunately it just sounds way better using the pre-in connected to my VAC. I suppose it makes sense as the VAC costs 2X the LM price so it ought to do something.
I briefly tried the Supratek and do indeed noticed that it sounds just better. I haven't done enough comparison to see how much better but I am still running stock tubes, except a pair of Sylvania Vt-231 in the 6SN7s. When using preamp input, does the LM bypass the internal preamp section completely ?
Does anyone here know why the 508ia would lose most of its high end? This has happened gradually over time to the point where now it is pretty noticeable. I have swapped out all the tubes in various orders, including going back to all stock. Good service techs are hard to come by here in Phoenix, so trying to troubleshoot on my own. Any ideas where to start?
That's what I was afraid of. Guess I'll have to find a tech in Phoenix who can work on this, not an easy task.
This will unlikely happen in both channels at the same time. But if there is any suspicion - need to run bandwidth test. Anyone who works on audio electronics should be able to do that. As a separate task, I would recommend to test hearing.
After battling with the ground loop, I now have another issue with 805IA where the left channel is playing a lot louder than the right channel. It seemed as if someone turned on a balance control on the left side. It is also evident from the meter displacement - the left swings more than the right. But this happens only at NFB setting of 2 (which I like). Other setting seems to give balance sound though there is lot more noise in position 1 and 4. I have swapped tubes (all of them one by one) and also swapped speakers connection just to be sure its not the speaker but nothing works. I just want to make sure the amp is not broken while shipping because the original owner claims it all worked fine. What do you guys think could be an issue ?
If replacing all tubes does not help, it means that you broke something under the hood. You have a choice either to find someone who can fix it, or work with seller on returning the amp. As to the hum, for me the key was to eliminate ground connection in power cable. With that done, only low level hiss can be heard with ear next to speaker.
