Adjust according to your personal preference as well as the matching of your speakers. Mine is at 3 most of the time.
I'm my system I prefer it set in 4. If the Ken Rad 6C8G is the same valve (as I believe) as the Amerty Mullard 6C8G I have, wich I will know in two or three weeks (I just bought one Ken Rad and it's coming), I found it more dinamic, 3D and detailed than the Mullard ECC35. If the Ken Rad is the same as Amerty, I think the ECC35 will be even mellower.
Perhaps that might be the reason you are losing details on the ECC35. Compare ECC35 at NFB 3 and Amerty Mullard 6C8G at 4 again, and let us know. In my setup, ECC35 at NFB 3 sounds the most balanced. BTW, if anyone wanted to know, my pair of ACME 805 has passed the 4,000 hours mark on LM508IA, and still going strong with no sign of drifting. Now, I am thinking of ACME 300B instead of WE300B from Psvane... Has anyone compared these two, especially on LM508 / LM805?
@AP1 had a very good post a ways back including many detailed measurements that suggested that NFB2 provided the best balance, followed by NFB1. I find that NFB2 is the best compromise and NFB3 sucks too much life out of things. This is with an ECC35 and a pair of TS RGBP’s. (I moved my ECC32’s to my Lampizator Baltic 3). @tlowe I am using ACME 300b’s and they have been rock solid since day 1. But the only point of comparison I had were the stock tubes and that was well over a year ago. That said, I do think there are QC issues at Psvane - I had to exchange my first ACME805’s after initial purchase because one didn’t work out of the box. The replacement has worked fine.
On another note, after brushing aside my skepticism, I bought some used Auditorium A23 speaker cables and for whatever reason they have made a marked improvement to my LM805. They just have the right electrical joo joo for SET amps it seems. I recommend trying them out. They are fairly easy to find used and can be resold for the same.
I forgot to try changing the NFB setting. Nevertheless, I think they have less impact in sound that rolling tubes. With different valves, in different occasions, I always found NFB 4 more suit to my taste, with better 3D and body, considering my system and room. It takes a lot of time, effort and money to find a very good valve combination because it so dependant on synergy with the tubes themselves and with the rest of the system. For instance, I like a lot RCA 6CG7 clear tops because the are warm, full bodied and 3D, but they are better combined with the more lively Amerty 6C8G than the more polite ECC35. Maybe I can try the ECC35 with more dry and analytical tubes on the 6SN7 slot, like the Sylvanias 6F8G I have. I will do it some day.
I have the same issue, but the seller changed it right away. I haven't had any issue since then. My ACMEs 805 are working fine for almost two years.
I didn't get to spend much time with it at the #3 option before leaving for France. Won't be home for another week or so but looking forward to spending more time figuring it out. I did notice an ability to listen at higher levels without the fatigue but seemed a bit less dynamic and detailed but need more time.
Hello guys I've just received a new preamp to try with my LM508. I've beeen using an Audio-GD Master 1 preamp before, with good results, but not meaning a big difference vs the LM-508 as integrated, maybe getting a little more refined and 3D sound with the M1 in line, but not night and day. On the other hand, I have a dedicated AC line for the system + a Holton DC Blocker + an Audioquest Niagara 1200 + some decent power cords, so the AC feeding my system is not bad at all. Regarding all that I mentioned, and considering that some of you haven't found also big differences using good preamps with the LM-508, I was not expecting a big difference when I bought the Audio-GD HE-1 Mii preamp (with AC regeneration inside). I bought it just in case I wanted to upgrade to monoblocks in the future. I really really was not expecting a big difference replacing the M1 for the HE-1..... ....boy, I was wrong. The M1 is a great preamp for the money, maybe one of the best at it's price point, but man, the HE-1 Mkii is incredible. I would summarize it as BRUTAL REALISM. HE-1's resolution is unbelievable. Bass is utterly controled, mids are smooth as heaven and highs are incredible silky, but it's biggest strength is soundstage, without words to describe it. I agree with everything Glenn Young mentions in his review of the orginal HE-1 in here: AUDIO-gd HE-1 STEREO PREAMPLIFIER REVIEW - HomeTheaterHifi.com and this new model is said to be considerably better. I will try latter on the LM-508 as integrated and as power amp with the HE-1 to confirm my thoughts, but I'm pretty sure about it regarding my experience with the M1 preamp before. I post this because I believe a very very good preamp can make a difference with the LM-508. Maybe it's about sinergy, I don't know. Any other similar experiences?
[QUOTE="Pedro Guillemain, post: 29331860, member: 85446",,,,] I post this because I believe a very very good preamp can make a difference with the LM-508. Maybe it's about sinergy, I don't know. Any other similar experiences?[/QUOTE] Very good preamp will not make a difference unless you use advanced functions like balance or tone control. Circuit of LM-508 does NOT change when you switch from integrated to power amp mode. All switch does - it adds resistive divider to reduce sensitivity. Thus all can happen - slight increase of noise level. Nothing more, nothing less.
That is once again completely wrong. Plenty of people reported massive changes in sound after using a preamp in this thread.
Very good preamp will not make a difference unless you use advanced functions like balance or tone control. Circuit of LM-508 does NOT change when you switch from integrated to power amp mode. All switch does - it adds resistive divider to reduce sensitivity. Thus all can happen - slight increase of noise level. Nothing more, nothing less.[/QUOTE] Well, in the next few weeks I will change the layout of my system and I think I will be able to switch between Pre and Line inputs of the LM-508 easier than now to compare both. I will post my impressions latter on, but regarding my experience with my previous preamp, I'm almost sure that I'm correct. It was noticeably better. If preamp quality didn't matter, it shouldn't make a big difference and it did. I'm not trying to start a technical debate, I just trust my ears.
I had a Niagara 1200. Didn't do anything in my old home. I think it's really overrated for it's current price to be honest. Try a Puritan PSM156 - then you will hear a difference. And it includes a very nice power cord and DC blocking to boot. As @AP1 mentioned, there is no real change to the LM when going from line-in to pre-in, other than a fixed 10db resistor instead of variable pot resistance. But supposedly the ALPS potentiometer in the LM is not that good? Personally, I have had my best results using my tubed DAC straight into the pre-in along with digital volume control in HQ Player.
I believe that is the only difference we hear when using a good external preamp - but I wouldn't dismiss the impact a good volume control can have on sound quality. I listened to my LM805 using a VAC preamp for a year before going back to using it as an integrated but only after settling on a really good tube compliment. The noise is definitely lower without the external preamp but there is definitely something in soundstage and holographic imaging that is slightly better with the VAC in the chain. I had to decide on what was more important to me and I prefer to reduce the noise. By the way, I found that the Equi=Core balanced isolation transformers work far better than the Niagara 1200 in my system.
@Ontheone Agreed. I didn’t mean that pre amps can’t affect the sound. Obviously adding another stage before the amp will have some sonic consequence. i looked into a balanced transformer before settling on the Puritan. One concern was transformer noise/him. Maybe unwarranted.
Dear friends, from experience , is the 230v version LM508ia technically works if I use the two different phase(180degree phase) 110V ac at home to make it 220v ac ( for live and neutral pins) ? I think s-mangler share some experience but need to confirm more before I get one.
I'm unsure what you mean by 180-degree phase but basically any electrician will combine two 120-volt lines to make a single 240-volt line. This is done routinely in North-America. Since I'm not an electrician myself and I'm even less familiar with Taipei electrical current regulations, I can't pronounce myself on whether it would work but an electrician would be able to confirm for you. All I can state is that anyone in North-American can have two 120-volt lines combined to make a single 240-volt line that works perfectly with the 240v version of this amp.
Like in North America , we have two 110Vac going into home besides the neutral and earth ground line. We can think of one is positive 110Vac, the other one is negative 110Vac, combine the two will give a 220Vac. This 220Vac socket can support higher wattage dryer or air condition, while other home sockets will use either one of the 110Vac for other home electrical device ( light, TV, audio,..). And for sure, this need technician to work out.
Technically this will work. But by the code you will need a separate 4 wire connection from distribution panel to outlet, along with two phase breaker.
Hi guys A question for those with more experience and knowledge than me. I'm thinking about experimenting on byamping with the LM-508 and a class D power amp I have. As my speakers have two pairs of binding posts, I was thinking about connecting the LM-508 to the highs binding post and the class D to the lows ones of the speakers. I don't have an active external crossover, so I was suggested on splitting the RCA output of my preamp to both amplifiers and here are some questions: 1- I know that I will probably have problems to match gains of the amps as they are likely different. Does anyone know the gain of the LM-508 when used as power amp with regular 6SN7 and 6SL7 valves? I know the gain also can be modified using different valves like 6C8G, 6CG7, 6F8G, ECC35, etc on the preamp slots. Does anyone know the gain difference between 6C8G vs 6SL7 and 6F8G vs 6SN7? I ask rather than just reading the data sheets of the valves as there are a lot of parameters to understand and I want to be sure. I also believe that changing the NFB selector modifies gain. Am I correct? If so, it will help a lot as it's a lot easier than changing valves. Wich position is the highest, 4 or 1? 2- Am I risking on blowing a tweeter with the LM-508? The speakers manufacturer said I should be careful since the LM-508 will only be running the tweeters and it could "see" a high impedance load at frequencies below the crossover point. On the other hand, people with experience on byamping told me that it's not a risk and I should only have to start with low volume levels and go up carefully. Has anyone experienced something similar? Am I risking the tweeters or anything else? Any thoughts or suggestions are appreciated.
