It is normal. Don't worry about it. Bias should only be done once every few months. Not once a day. Which phono preamp do you have? Which cart? My guess is you're using too much gain. That's why it distorts and is too loud. I agree with the dealer. Perform the tests I suggested first, in case it is RFI. if it's not, it could be one transformer is defective.
My phono preamp is Unison Research Phono One (has a gain of 54db) and I am using an Ortofon Quintet Black which is only 0.3mV output. Indeed I have to rise the volume pretty much to listen. For the same level the knob volume is at 8.30 CDplayer line and for phono line somewhere between 10-11.00 o'clock. About buzzing do you think that the amplifier should be dead silent? I don't have experience but I've read and my dealler said that tube amplif may have some noises. There is some other things. I think I have to use better interconect. At this moment I have the most basic cables from Atlas and Audioquest (was't very important to me for solid state). I am leaning towards some Neotech Iris cables. I think I must use only copper cables and not some silver-copper cables because the heights are still to strong for me. I must say that I have filter plug and power chords from Isotek-Polaris and Premium.
Remove ALL filters, power bars, splitter, etc. Plug directly into the power outlet into the wall. Use the power cord that came with the 508IA. does it still make noise? It's normal for this amp to make a little bit of noise. It's the transformers making the noise. But it shouldn't be sounding like your recording and not that loud. Do the tests I asked you to do in the previous message (and this one) and let us know the results for each test.
I did what you asked for. Removed everything, used the power cord that came with the 508ia, plugged directly into the outlet wall. SAME NOISE! NO CHANGE! SO...
With troubleshooting, the goal is to eliminate possibilities. We've eliminated a few with that test... which is a good thing. 1. Do you live in a house? If so, go to your electrical breaker box and turn *everything* off except the breaker needed to be on to have your 508IA working. Also remove everything else on that circuit. If there are lights, turn them off. If there are TVs still working or appliances, etc. Unplug them. Try the 508IA again. Do you still have the noise? If not, something on your circuit path is creating interference and you can find out what by plugging things back in, one at a time. 2. Did you ever power the 508IA without speakers plugged into it? Doing that would damage the transformers and might explain why you have that problem, now. 3. Plug the 508IA in a different environment. Your friend's place or the dealer's. Do you still have the noise? If so, the transformers are probably defective.
Take the dealer up on having your money returned. I have had several tube amps and CD players come through and never had noises or anything - the amp clearly has something wrong if the amp is making the noise internally. The tubes don't have to operate exactly at their ideal area - generally if you run them outside their best range the tubes will simply die faster. I have an AN M3 preamp, OTO integrated, DAC 0.1x and Kingko KA 101 integrated - all use tubes and all have transformers and all are absolutely dead quiet. My CD 215 has a slight hum as did the the 219IA - to be fair the 219IA uses a big output power tubes while these other amps are small output tubes. I also had no noise with my Audio Space Integrated amp (EL34) Interestingly - over the years I have had more noise and hum issues with Solid State amplifiers. Nothing is perfect - Way back in the day I bought a top of the line Pioneer Elite receiver - got it home and it was DOA. No sound - nothing - they replaced it and the next one was perfect. No company is immune from problems. Some shipper drops the box 8 feet and a solder joint comes loose and the amp is screwed. Even big companies like a Rega had trouble - they buy a given laser reader from a well regarded supplier and they screw up - it's not Rega's fault but they are stuck with all the complaints. Who knows maybe they put the European/Asia transformer in your US/Canada voltage amp. Good luck with it but either way I suspect you will have to return it.
All of my gear with unshielded transformers hums to some degree, sometimes. With the Oto, sometimes you'd have to press your ear to the case to hear it, other times its faint. It's the input transformer, so the fact it varies probably has something to do with power quality. When the hum becomes more of a buzz is when it's problematic.
1. NO CHANGE. I live in a house. 2. NO WAY. NEVER. 3. A bit difficult. Music covers that noise but during silent passages I can hear it. I love the sound. But it seems that this amplif has a problem. I will re-discuss with my dealer. I launched previously in a post some questions about tubes 300B - are different in shape and height, has some brown deposit at the junction of the glass with the white area, and moves a lot in the grip base. Is this normal? Any opinions on these?
Let us know what your dealer says. Worst-case scenario, exchange it for another 508IA. About the tubes, they shouldn't be rocking in the socket. Are you sure you pushed them down completely? No great force is needed so be careful not to press hard. Once they are fully inserted, there should be very little wiggle for each tube. Again, if possible, I'd ask the dealer to look at the tubes' integrity.
Hello Sandu, About the 300Bs: last summer I replaced the stock tubes with Psvane WE replicas. After a number of hours of use, one of the tubes shorted. The sound through one speaker was unmistakably loud and startling, almost as if a large body was tumbling down a long flight of stairs. I received a replacement tube that worked normally and has presented no problems. That tube, however, is slightly taller than the tube it replaced. So in my experience there can sometimes be slight variations between these Chinese tubes when it comes to height. But I'm not sure what you are referring to when you mention a difference in shape. (Perhaps you can post a photo?) My sense, though, is that your issue is not tube related. If there was a shorted tube, you'd certainly know about it---and I don't think the sound you are hearing is being caused by the 300B tubes, especially since you have checked the bias. Please note that bias settings can fluctuate--even depending on when you take your reading throughout the day. Sometimes I can even see the needle wobbling slightly. I was initially concerned about this and the tech associated with the shop where I bought the unit told me not to worry about it and told me not to over-check the amp's bias. On another occasion he also confirmed for me that when you set the bias on the 508ia you are actually setting it for the 300B tubes. They in turn control the bias of the 805 tubes. My 300B tubes also have some brown discolorations--but on my tubes this can be seen on the glass nearer the top. Also, it isn't as if the 300B tubes lock or click into place in their sockets. When you say that this tube "moves a lot in the grip base" I take you to mean that the tube can be wiggled around manually fairly easily and not that you can actually see the tube moving on it's own. What I mean is that while my 300Bs are certainly pushed all the way down into the socket, it is still the case that if my hand were to accidentally graze a tube, say when I have the amp off and feel it might be time to try to remove some accumulated dust from the chassis, the tube would move slightly in that direction. This may give the impression that the tube is loose, but it isn't. As long as the 4 pins are inserted completely into the socket, you're good to go. Like the issue of slight differences in height (and perhaps also in shape) this seems to me to have to do with variations in individual sockets and tubes. I hope this helps!
As I said I dont have experience with tube amps but I my impression is the sound is OK (and should improve after some more hours of listening?). So, I don't think is a tube problem. One issue is if at higher volumes 10.30-11.00 I hear some distortions. The vumeters get their maximum and stuck there without moving. Is this normal? I have the amp for one week now. When I explained that the 300B "moves a lot in the grip base" is exactly what you said that the tube "can be wiggled around manually fairly easily" (my bad english-sorry!). The tube locks very well in its socket. About the shape, my impression is the one 300B which is slightly taller (about 4mm) is also a bit thinner, but maybe is just an impression. With the bias probably I don't have to worry about, this is what the tech said to me also. The needle deviates not much, from 120 as is recommended to 123 maybe 125 (once I noticed). But not always. I would like to post some pictures but I dont know how to do it with an URL. Was easyer to download files on YouTube. It seems my problems remains the buzz. I listened more carrefully last night and I am pretty sure the noise came from the right transformer (as you look at the amp) which in the oposite side where power cord is plugged into the amplifier. That buzz as I said is constant now and is not influenced by anything - inputs, volume, and not transmitted into the speakers. The speaker have a very slight hum I was finnaly able to adjust it from the amp at the lower level it was possible. They are not however dead quiet. Probably I can live with it, but my concern is not to have a real issue with that transformer, as Richard Austen said above, which can affect latter the whole amp. The buzz from the amp is there and I know is there even I cant hear it during listening sessions and that bother me. Today is Sunday, so I will have to call the dealer tomorrow.
No. Have you tried other sources like a CD player to see if you can replicate this problem without using your turntable? You need to host the pictures somewhere. Once it's uploaded, you can copy/paste the image in here. Yes, nothing you can do to fix it. Just call the dealer and have them exchange the amp or refund your money and buy something else.
I have some questions about this amp and am wondering if anybody would happen to know the answers. 1. Is there any benefit to lowering the hum screws to the lowest setting, SQ-wise, assuming they were set to the highest setting and there would be no change whatsoever in the amount of hum heard through the speakers? Just wondering. 2. Has anybody experimented with biasing the power tubes at a higher setting? Guitar amps can be biased higher for a warmer sound. Unfortunately, the bias rating of 120 doesn't tell me what that means so there is no way to know what a reasonable level of "overbiasing" (for lack of a better word) would be safe yet beneficial SQ-wise. 3. Wondering which tubes yielded the biggest change in SQ in your systems out of the 805, 300B, 6SN7, and 6SL7. 4. Any reasonably priced 805 tubes offered a huge bump in SQ? Currently am running Psvane 805A-Ts. 5. Any favorite 6SL7s I should be on the lookout for? Currently am using a Mullard.
Finally I added some pictures. In the first 2-3 pictures - the brown deposit/stains between glass and white area. The second one the difference between 300B tubes. The last two are from today when I noticed that at the jonction of the transformer I suppose is the source of the buzzing, there is this abnormal area. The white zone is in front and right corner of the right transformer, apparently not attached, glued properly (the black paint is missing) as are the rest of the edges of the transformers at the joint area with the chassis. Perhaps this shows that there was and is a problem there.
Audio transformers humming? Pfffft, glad my amp doesn't have them. Tube amplifiers for high-end audio by The David Berning Company
Hello Strat, 1. In my experience, the hum balancers (unlike the biasing screws that clearly move from lowest to highest as you turn clockwise) require an adjustment somewhere between extremes. In other words, the lowest level of hum isn't necessarily commensurate with the screw turned flush left. What I've found is that there is a small range of movement in which the speaker presents the lowest amount of hum and that once I reach that level turning the screw a little more won't matter...until the point, and this comes pretty soon, when moving the screw further reintroduces louder hum. 2. I haven't experimented with over-biasing. From what I understand, this can result in a lower life span for the biased tube (the 300B). When I was doing research about possible preamps to try with the 508, I contacted James at Line Magnetic with a question about which tubes are bypassed when using the "Pre-In."* There was often a lag of a few days between emails but he did answer my questions and I think it might be a good idea to ask him yours about biasing ([email protected]). (*It turns out that both the 6SL7 input tube, which regulates the negative feedback circuit, and the 6SN7 James described as a driver tube (this still confuses me a little since I'd call it a preamp tube) remain in circuit when you attach an external preamp. The only thing bypassed is the volume control. It's my impression, btw, that the 508 uses too many gain stages and that this may be responsible for an occasional harshness or unruliness, perhaps in addition to the fact that the amp runs in class A2, not class A. I've come to understand that additional gain stages may to a certain extent compromise the purity of a source's signal by adding distortion and noise.) 3, 4, 5. All the tube changes I made revealed some differences, but for me the most worthwhile differences came from changing the 6SL7 input tube and the 300Bs. The 5691 RCA Red Base, the Tung Sol 6SU7GTY and the Mullard Ecc35 were all MUCH better than the stock tube. But the Mullard, the one you have now, seemed to me to be the best of the three. The 6SU7GTY is also great---but I believe that it is a somewhat higher gain tube than the Mullard, and the 508ia already has too much gain. I am sure there are more NOS tubes to try though and I look forward to experimenting with others. I've only tried one 300B other than the stock tube: the Psvane WE 300B replicas. What I found most gratifying about these tubes was that they lowered the noise that was audible through the speakers a substantial amount. (My speakers are 15" Tannoys and I can hear stuff through them that I'd never hear using my Dynaudio Focus 160 stand mounted speakers.) If I'm not mistaken, there are posters on this forum who have tried Elrog, EML XL and Takatsuki 300Bs. I would love to hear impressions of what the Elrog 300B in particular sounds like. The first change I made was replacing the stock 6SN7s with Sylvania VT-231s. This made for a very big improvement over the stock tubes, but it's been so long since I've heard any others and there are certainly others I'd like to experiment with in the near future. When it comes to 805s, I'm using the ones you've got in now and they were definitely a good improvement over the stock 805s.
Has anybody thought of using the Psvane 101D tubes in the 300B slots? Psvane Western Electric 101D / 101D-L Replica tubes (pair) | Psvane & Treasure Audio Tubes
Doesn’t the issue just seem to be good old fashioned transformer hum, now resonating more loudly due to a loose or ill-fitting cover? Judd
#1. Thanks. That is useful info I did not have. #2. Thanks for the email address. I might contact him to get some additional info on over-biasing. Wasn't aware there were different categories of Class-A. Why do you say there are too many gain stages in the 508IA? It would be nice to have a description of how all these 300B tubes interacted with the 508IA. Very few users in this thread seem to have experimented with these tubes. This is what @adamaley wrote to me about the Elrogs ; "The Elrogs are better based on the sound I'm going for. They do some things better than the Elrogs. Bass is deeper for one. They also have a sense of being more dynamic, which I am still trying to put my finger on. They move more air towards the listener for sure. The soundstage is also slightly more expansive. The Elrogs are more transparent, and they have a way to bring the soul out of the music - has to do with the way sound grows with air around instruments. They are also better at separating images and making more sense of the musical whole. It was about a 5 month wait for the Elrogs though, so I would jump in line ASAP if you wanted to be included for the next shipment from Germany. Hope all this helps." And in regards to how the Elrogs compare to the EML 300B-XLS... "Definitely more laid back. They have an amazing way of handling loud transients where toy get the sense and feel of loudness, but it doesn't overwhelm you." Hopefully, this will help somebody who is on the fence. Keep in mind that everything I've read about the EMLs states that they're a fantastic tube and certainly a huge upgrade from the stock 300Bs in the 508IA but the Elrogs take it to another level. For almost twice the price, you'd hope that'd be the case!
Thank you for the info about the Elrogs! They certainly seem appealing--especially regarding loud transients, since that overwhelming loudness is sometimes the issue with the 508ia. And I think this may have something to do with the relatively limited useable range of the amp's volume control---which in my mind, perhaps incorrectly, also has something to do with too much gain. I found it difficult to settle on the right volume and often had to make continuous micro-adjustments (sometimes during the same track) with the remote. I did some reading about the issue of extra gain and there are those who opine that modern sources like cd players and DACs don't really need the gain afforded by traditional preamplifiers or the preamplification sections of integrated amplifiers. (This is also true for LP playback when you already have a stand alone phono preamp.) But like everything else in this hobby, the topic is not uncontroversial. I ended up purchasing a passive preamplifier (EMIA remote auto-former) to use with my 508ia and I'm much happier with the more precise control over volume---not to mention the improvements in musical nuance and detail. (I was considering an active preamp with the 508ia until James of LM confirmed that the Pre-In feature does not bypass the preamp tubes.) I've also tried the passive pre with a very low power amplifier consisting of only an input tube and a power tube (no active preamp stage) and was really impressed with how dynamic and vibrant the results were---especially given some comments I'd read about how passive preamps can rob music of these characteristics. This was certainly not what I experienced. And that's what's convinced me about there being too much gain in the 508ia. This isn't to say that the passive pre solves the issue entirely. I still think the amp would be even better if we could bypass at least the 6SN7 tubes. According to James, the 6SL7 can't be bypassed because it's necessary for the NFB loop which all 805 based amps require in order to make the signal more linear. Anyway, I want to underscore the point that I don't really understand all of this and my comments are the byproduct of my limited reading/understanding and my experiences with the amp.
Out of curiosity, do you bias your 508 to 120? You mentioned having not experimented with over biased biasing the amp. I actually met someone who kept their 508 bias to around 135 which at the time, I thought was hot and I didn't know why he did that. It's also not something I know much about though. I'm wondering if there is any good that can come from biasing on the hotter side of 120.
Thank @adamaley ! The Elrogs are marketed as lasting quite a long while but due to the company experiencing reliability issues a couple of years ago, it was sold to a different owner who supposedly got rid of the manufacturing problems. Unfortunately, the 10K hours or more that these are supposed to last will take quite a while to verify, but at least the stream of people experiencing issues after a mere few hundred hours has stopped... which is encouraging. I did find a webpage showing the images of all the versions of the 300B Elrogs over time so they can be identified. I will post these images tonight. Reason being that I already reported one guy on a website selling the old problematic versions as the new problem-free versions. It took a bit of time but his ad was eventually deleted. Considering their costs, nobody should ever be fooled into buying the first few problematic runs. Maybe the issue in regards to the volume adjustments is due to the dynamics. This amp has been marketed and reviewed with tons of references to great dynamics. Perhaps your opinion is that it's *too* dynamic for your tastes which you try to compensate with by making volume adjustments? Just a thought. If you happen to use speakers with very high efficiency, it might worsen this problem by emphasizing microdynamics which, from what I've read, is actually a strength of highly efficient speakers. Could be the case of too much of a good thing, perhaps. Adding a great preamp is supposed to bring the 508IA to another level. I don't have the funds for that but I will eventually try this out for myself. One person I know tried a tube-based high-end preamp but was underwhelmed with the result. Once he tried a couple of SS preamps, the results were fantastic. Also according to him. In case it helps, he stated he tried one from Audio Research and another from Audible Illusions. The former gives a nice tube-like and relaxed presentation whereas the latter has a forward presentation. He preferred the AR and kept that one. Don't know which model but I can ask him if anybody is curious.
