As for the question of longer lifetime, they write: "You can replace any 300B with this tube. Just plug it into any 300B amplifier, and the tube will set itself exactly to the original 300B working point. The EML 300B-XLS is is a very strong tube, and it will develop the output power with more ease. Specially for amplifiers that let the 300B tubes work very hard, the EML 300B-XLS is the right product to choose. Any amplifier that is trying to get as much as possible power out of a normal 300B, will benefit from the 300B-XLS. Improved sound and longer lifetime will be the result." Of course, it remains to be seen if this claim will hold true. I have put 1,670 hours on them today (yes, I keep a log ), and they still sound great.
Their website is *so* terrible! Two links on the Conditions webpage are defective, reason being the person who did it didn't even link to the actual hosted page but rather from items on his hard drive so the routing doesn't even work! Anyway, in case anybody cares and does want to have access, copy the link and remove everything prior to the "/html" portion, then paste the domain before that bit. So instead of ; file:///Z:/DATA/emissionlabs%20-%20Kopie/html/guarantee/boxes.jpg It should actually be this ; http://www.emissionlabs.com/html/guarantee/boxes.jpg Here are the links for the white spark issue ; Application Note 05. The white spark problem. Here's the pic, by the way.
Like @Seafinch predicted back on page 19, almost 4 months ago, I did not have to wait 1-2 years to get this amp. In fact, I bought his yesterday! He's a baaaaad influence. lol! It should be shipped tomorrow. Had to do some serious creative financial juggling to make it happen and it'll definitely take quite some time to recover but I think it's worth giving this amp a shot to knock my socks off. Bought unseen and unheard. I'm anxious and excited at the same time. Let's see what you got, Line Magnetic!
Hello, I am new here and a beginner in tube world. I have to say that english is not my native language, so please be merciful. I have recently bought a LM 508ia. Few days ago. I have listen maybe 8 hours now. I like very much the sound but I have some issues/problems. The big one is a BUZZ. It seems to come from the transformers but I am not sure. There is however a noise floor (I think I can live with it) for about 4-5 seconds and then this buzz for about 11s and then this sequence repeats: 4-5 s some noise/11s buzz and so on. The buzz is extremly disturbing. This buzz is not related with volume (minimum or maximum the same intesity of the buzz) or source cables. I disconected all interconects and the same buzz with same intensity. Music covers this buzz but al low levels with quiet music I can hear it. What can be the cause? Secondly, I have noticed that one 300B tube is a bit taller and when I checked I found that has some free movement in its plate. I mean it moves a bit or a lot (I dont know how it should be normal) in its support. The other one is stable, well introduced. Is this normal? I also noticed that the are some brown stains around the area between glass part and white part for both 300B tubes. Normal or not? One more thing about this 300B tubes. The one which is not stable in its plate (moves) has much more burned glass (the glass tube is black) in its lower part than the other one. Is this normal? However the amp is new and with warranty. I like the tube soud but this issues bother me. Has anyone any ideea if the amp is OK or it has some big problems?
Hi Sandu. Congrats on the new amp. I hope you work through the initial difficulties and get to enjoy everything the amp brings to the table. Regarding the buzzing sound, the first thing I will investigate is whether there is an ethernet router, cell phone, or anything that creates RFI around the amp. I use an Orbi mesh router and the satellite sits near my amp for internet streaming, and sometimes when I move it slightly away or closer to the amp I get a humming sound. Also, have you biased the amp yet - that should be the first thing you do after connecting and powering it up. Thirdly, there are hum balance pots near the bias pots that you can play with to attempt to reduce the hum. Hope this helps.
Sorry, I don't have an answer to any of your questions. Hopefully someone with experience can chip in.
Thank you for your answers . I did the bias and I have tried to adjust the hum. For the bias seems to be OK, I checked and is quite steady. When I turned on the amp for the second time I needed to adjust a bit the V2. For the hum, I tried and I think I have the best I can now. But the noise is not a hum in speakers is a buzz coming from I think transformers. I cant say if the buzz is transmitted in speakers or what I can hear in the speakers is just a hum. As adamaley said I have also considered the RFI around my amp. The character of this noise makes me think it can be a RFI problems. As I was previously said I am new/novice in tube world am I am don't know if such things are normal and I am afraid that my amp having a serious problem. But I unplugged all other sources and is still there. what I have noticed is that I cant use my laptop plugged to play music because there is a huge buzz. When I unplug the laptop I have only the buzz I was taking about. I don't have any radio, router or TV in that room. Just hifi equipment - amps, a tube phono preamp, players, laptop and another pair of speakers. I have no radio in the house. The closer neighbor is 30 m away. I also noticed some interference with my phone from time to time. One interesting thing is that a few months ago when I have received my tube phono preamp (an Unison Research Phono One) and I plugged the RCA cable while introducing the second connector someone started to speak through my speakers. I was receiving a radio station from somewhere outside my house. Very strange. I have pictures and a movie with the buzz (I have them on my computer) but I can't figure out how to attach them. It seems using an URL path but I don't know how to do that.
can you clarify your question? i was using the RCA 5691 (6sl7) along with the sylvania 6sn7gt 1950's brown base.
The tubes would need to be on for at least 20 min before you start adjusting bias. Don't adjust when you first turn it on. It needs to be adjusted to 120 on the meters. It is normal for the transformers to make a small buzzing/humming sound. If you turn the volume at zero, you will hear it when you are near to the amp. Add the videos on a YouTube channel and paste the URLs to the videos here.
Oops. Confused the 6SN7 and 6SL7. What I meant was whether anybody has used the RCA 5691s with a Sylvania 6SN7 Bad Boys. If so, what were your findings?
It sounds to me like you have a ground loop in your chain. If you can ascertain that, a device like Hum-X will help to eliminate it; it's worked for me in the past. Edit - In hindsight, if the sound isn't coming out of the speakers, but rather from the transformers, it may not be a ground loop. I'll contact your dealer regarding this. Unfortunately, I remember reading something somewhere about someone having a similar issue with this amp.
i feel the RCA 5691 is a very good tube and also a good value, haven't tried the bad boys. i'm currently using the MULLARD ECC35 and the HYTRON JAN CHY 6SN7GT which are great value 6sn7 in my opinion. i find the combination of mullard+hytron to be less edgy and yet very musical and detailed without the super expensive price.
I have 1952 Sylvania 6SN7 3 hole bad boys running right now with a Mullard ECC35 (European nomanclature for a 6SL7). The combination is fantastic. I think the bad boy tubes gives more air and 3D imaging than any other tube I've used. It's something that is immediately apparent upon installation. They did not require burn in. Only a good first time warm up of a solid hour before I really stared to critically listen. I haven't tried the RCA 6SL7 but I have one from the 1940's showing up next week. I am looking forward to trying it out.
I did the bias after 10 minutes the tubes are on as it was written in LM booklet, but I shall do it after at least 20 min (tomorrow because now is almost midnight here). Also tomorrow I will try to load on YouTube a video with that buzz. Unfortunately I can here the buzz from 3 meters away and during listening sesions at low level volume and with more quiet musical passages and that upsets me. With higher volumes of course I hear only the music. The buzz of my LM 508IA is coming from inside the unit I am sure and the culprits I think are the transformers. This buzz is not transmited to the speakers, however these have a slight hum. I read somwhere that this buzz may come from pollution of AC line with DC and a Humbuster 3 from PS audio can solve the problem. Unfortunately nobody in my country is selling this device. Anyway I will call the dealear as you suggested and have a talk. Any opinions about my tube issues?
Finally here are path to listen the noises I was taking about from LM 508IA: noise in speaker using CDplayer line connected for LM 508IA noise phonoline LM 508IA
Transformers *will* make noise but some will make less noise than others. Transformers will normally buzz slightly. But the whirring sound you're hearing is cause for concern. If the YouTube video you posted is showing the noise without any volume to the speakers, I believe you should contact your dealer as that is not normal. Using the hum calibration screws won't change that noise as it's designed to change the amount of noise heard through the speakers. I don't believe this is power-related so please don't waste your time or money buying power cords or power conditioners. It's all a waste of money. Contact your dealer while your amp is under warranty and have them exchange or repair this problem. The only other possibilities is you are encountering RFI. To test it out, if you are in a house, turn off every breaker except for the one where the 508IA is plugged in. Does it still make the noise? Plug it into another outlet where nothing else is connected in the circuit. No power bars, extenders, splitters, etc. Does it still make the noise? When you bring it to the dealer, plug it in over there. Does it still make the noise? As for the tube issue, if you're talking about one or two power tubes not keeping their bias, it happened to the previous owner of my 508IA amp. He needed to buy a new set of tubes. If your tubes are still under warranty, you could exchange them. If they're the ones that came with your amp, talk to your dealer to have an exchange made.
Thank you for advices. In fact I am sure the noise is from the transformers. The recording was done with microphone very near to transformers to catch the noise (I didnt know how will sound on YouTube and I was afraid not to recorded it well). At the listening site I can still hear it, not much, but today with the music at low levels that buzz was very well coverd. Also today I succeded in lowering the hum into the speakers using that hum adjustem system. I don't know how I wasn't able to do it before. Now is really alright about the hum-barely audible in the speakers. As for noise with my phono preamplif I am sure is a problem with it. I will send it to be fixed. The sound is very pleasant. I am listening with volume at around 8-8.30 . At 10-11 oclock I hear some distortion, but anyway I cant listen at this level because is too loud for me. I don't know if this is normal. At 10 oçlock is realy loud for me. Due to the fact that it sounds alright do you think is a problems with tubes? I dissused with my dealer (explained all and discussed about 1.5 hours - my dealer is in other town at about 500 km away) and he assured me that there is nothing wrong with the tubes and the transformers are indeed buzzing. However he proposed me to send the amplifier back if I am not pleased (on their spent) and they will refund me all the money. They offer to find a solution to lower the transformers noise. Now what to do? RFI problem? Possible. I will do what you suggested and see what happens. I have a solid state and there is not a problem with it. Dead silent. About the bias. When I said they don't keep it , yes indeed but I was refeering that is not perfect. I wanted and I thought that once you did the bias at 120, the needles must stay there at 120 sharp. The deviation I encountered was at 122-123 twice. My dealer said that is normal. Do you think?
