I just got a Audible Illusions L1 preamp to replace my Rotel RC 1070. Gte357s (Threads | Answers)Have you given time to allow the unit and associated cables, all which had to be moved around, to settle in? It could be that with 24 hour a day play for a few days that the preamp and cables will settle in and the harshness could mellow out. How long has the preamp been up and running in your system untouched? If that isn't it, maybe a tube change is necessary, or maybe the L1 could be a poor match in your system.
The pre-amp has been running for an hour. I am not sure if I use the right term. Maybe that's what people called CD glare? I am listening to a female singer pop song, where it is medium to high treble. I tried using the CD input of the L1 where there is a circuit to remove CD glare, and it is a bit improved. And I also tried connecting the L1 to Rotel through a RCA-XLR cable. In Rotel, the balance input gone through an opt-amp, and the glare is removed, but then it sounds very Rotel, sounds very similar using the Rotel 1070 preamp. It seems I either have this glare, or some less musical, "filter-out" sound.
The pre-amp has been running for an hour
1 hour is not enough time to start doing critical listening. Your preamp and cables need more time than that to settle in before you make judgements. Give it at least a couple days then if still necessary start thinking about tweaking things.
Everyone forgot one thing. Turn off your preamp and clean the pins of the tubes. Use an exacto knife and then clean with a contact enhancer or alcohol. Shake dry then re-insert tubes. Turn the unit on and let it sit for about 15 to 30 minutes. Test tubes! Try some different ECC88 / E88CC / 6DJ8 / 6922 / E188CC / 7308 / CCa / E288CC / 8223 tubes. You may want to check your music store(s) for some of these tubes so you won't have to wait for them to arrive.
Last, check to see if the unit has been modified, etc. There are some parts swappers out there that will make changes and won't tell you. One other thing. . . take it to a local dealer for audiophile friend that has some tubes and listen to it there.
The preamp should not have any brightness or extra sibilance in it's sound. That's not an Audible Illusions trademark. If all fails that unit is defective!!!!
In the past, I've thought something was wrong when I installed a new, higher quality component and then later came to realize it's greater transparency was revealing flaws elsewhere in my system. To solicit better informed opinions and suggestions, how about telling us something about your system's sources and speakers. Also, what about the room? Is it bright sounding with bare walls and flooring or is it well damped? None of this may be a factor, but it could be.
Quote from Joe's Tube Lore.
"Special warning to Audible Illusions preamp users:
The one thing you can say for the Sovtek is that you can run it hard and it can take it - and apparently thats exactly what AI does. Unfortunately the classic NOS tubes in this family just cant take this kind of treatment and will rapidly fail when used in these units (and some of you guys have the fried tubes to prove it!). So you AI users are probably best off limiting yourselves to the Sovtek, the Russian 6H23N & 6N1P, the 7DJ8 and the E288CC. There may be others the range of tube types and variations is quite literally bewildering but these are the ones Im aware of that should be able to handle the higher stresses of this brand of preamps. I review the Edicron, Siemens E288CC and 6H23N here but there are other brands for some of these. Ive seen Phillips E288CCs & Amperex 7DJ8s advertised on some web sites in the past and there are probably others. It might be worth your while chasing them down & evaluating them for yourself to increase the number of alternatives for use in your AI."
I would think EH tubes would hold up just as well in the AI....
Thank you very much for all the reply. I tried other better audiophile test disc, it doesn't have this problem. So, I think it is that particular CD's problem. Although the Rotel RC1070 don't have that problem, but then when I listen to other discs, it is not as good as the AI. The tubes are 6h23n-eb, and the seller said there are less than 50 hrs on it.
The rest of my system:
Sony BDP350 Blu-ray player
Maverick Audio tube magic DAC
AI L1 preamp
Rotel RB1080 poewr amp
B&W CDM9NT speakers
cheapy power cord and interconnects
However, I have 2 PS audio statement SC power cord, and a soundsilver interconnect coming.
I would buy a matched set of 6h23neb tubes from the Tube Store and let them burn in for a day or so. I am using those tubes in my Modulus 3A preamp and it has been a revelation. The Sovtek 6922 tubes that Art Ferris previously used in your preamp are no longer of the same quality and can sound harsh and shrill.
Stereo5, I am a bit confused. I didn't buy it from Art Ferris, and it is already a 6h23neb per the seller. But I may still buy another pair and try. Because last night, I tried another CD, it is the same thing. It is quite bad that I have to use the RCA-XLR cable to use the Rotel internal op-amp "smooth" things out. Let me also try connecting my Blu-ray player directly to the preamp, but I don't think it will solve the problem.
BTW, what do you set for the left and right knob? The manual said I should start by setting it at 12:00. But then if I set it to 12, my main volume know needs to be very low, around 6:30. It seems if I set the left and right know at around 6:00, and the main knob around 8:00, then it is smoother. Is the left and right knob do the same thing as the main knob? It seems it isn't. Thanks.
They are for setting a reference level for each channel. You then use the volume control knob. If your getting too much output with them set at 12, set them at an appropriate level to allow the greatest range for the volume control.
Do you have your CD player connected to the CD input? Try connecting it to one of the aux inputs. You may like the sound better. Also, connect your amp to the Main 2 output and see if you prefer the sound to the Main 1 output.
One thing about Audible Illusions is that they don't use tube rectification but rather solid state rectification. This can and does introduce some grain in the highs. On revealing speakers this can sound somewhat harsh with some music. If I go tube I would insist on an all tube design for a pristine sound. Sometimes a high quality amp can carry a mediocre preamp or vice a versa and smooth things out. Definately try a fresh set of tubes as mentioned above also try different interconnects because that is someting you can do to greatly reduce any harshness.
Now I set the left and right at about 6:00, and the main knob around 8:00. It seems it is better, I don't know why. It seems the harshness becomes more prominent when the main knob is set to very low (close to 6:00).
For another tube, it seems the 6h23neb is agreed as the best choice. So, I will just try another set of 6h23neb?
for the interconnect, any suggestion on the brand, or the material (like copper, silver, copper-silver alloy, cryogenic treated copper, special drawn copper .. etc)?
If I am still not satisfied, I guess I will sell it out and try a all tube, like a Cary SPL-9x
You have a truly great preamp there. It is essentially the line stage version of my Modulus 3A. Do your Energy speakers use metal dome tweeters? I ask because I had speakers with metal domes and the sound could be a little shrill. I now use speakers ( DeVore) with a silk dome and they are much better to my ears. It may be the Rotel amp is of much less quality than your preamp. The preamp can be very revealing. I use MIT cables, the long discontinued Terminator 2 cables.
I would try the preamp with a better power amp and or try different speakers. It definitely isn't the preamp unless there is something wrong with it. As far as the preamp not using all tube rectification, that is total BS, The solid state power supply does not make for grainy highs.
Yes, my B&W has a metal tweeters. It is a bit hard to upgrade or try out different speakers due to its size. The next speaker I want is B&W N802 .. but it is kind of expensive, and I want to pick up, so, I need to wait until it comes up.
As for the amp, I am tempted to get a McCormack DNA-1 or DNA-125. Again, waiting for a Rev A or deluxe version to come up. BTW, is it a good match with the L1? Other models I have been looking are Belles 150A, or Aragon 8008/4004. But from the reviews and comments, it seems the McCormack are better. And I just post another thread asking for the difference between the DNA-1 and DNA-125. But in the mean time, I will try another set of tube first, or some interconnect.
Gte357s, you are on the right track with the McCormacks. In fact I have used the AI L1 with an upgraded McCormack with great success. I have spoken very highly about the L1 in the forums. My reference to a mediocre preamp in comparison to a high quality amp has nothing to do with the L1 but was trying to point out that one quality component can improve the sound of the other. There is no perfect preamp but the L1 gets alot right. However the ultimate tube preamp would be one that has tube rectification (no solid state devices) and ultimately will dispense with even the slightest detectable grain, but may lack the dynamics of the L1. There are some sacrifices with any design.
quite honestly, I don't know if this is a brand new (never used) pre-amp or one that needs new tubes. If brand new, then hook it up, turn it on with a source whenever you get home and leave the room while letting it play. this needs to be burned (broken in). devices will sound extremely harsh until properly broken it. this could take days literally. So, before you spend large sums replacing tubes and other things, just turn on some music, let it play for the recommended burn in period and then come out and play. If it is brand new, I bet it will sound much better in about a week after burning in. If it is used or an older demo unit, then maybe the tubes need replacing. But, it could be your source, cable/equipment interaction, etc. A little bit late but, it is always a good idea to borrow a unit or give the dealer a credit card number and take the unit home for a week to listen before purchasing. I don't deal with dealers that won't let me take the unit home for a week or so first. I give them my credit card information, but with the agreement that if I don't like it, I can bring it back.
I've been using the AI mod3, 3a, and 3b, for some time now and can honestly say it is very revealing and will force you to upgade everything else to max out its potential. I've been there. Unfortunitly IMHO the SS Rotel needs to replaced with tubes... and personally I don't think the Sony BRP is a good cd transport. And forget the "cheapo" cables... buy Crimson CAbles and be done with it.
It might be easyier to get a less revealing preamp...
Actually, I feel my problem is resolve. I set the left and right knob to 6:00, and the main knob to around 8:00. I listen to it all night last night, no harshess, and no "s" sound. It seems the bass doesn't kick in when the main knob is set to very low (close to 6:00). Anyway, I will do more testing.
But still, I am seriously considering upgrading my amp due to the upgrade bug, but my budget is < $1000. I am leaning towards a DNA-1, but also comparing to Belles 150A, or PS Audio HCA-2.
I spot another one, a Mcintosh 2105. I can't really find a review for that probably because of its age. But it is really eye catching. How is 30 yrs old Mcintosh it compared to more recent SS amp like the DNA-1 or Belles 150A?
Oh my god, this preamp is sooo revealing. I am listening Chario audiophile disc, 4th track, Memory, I can hear each breathing of the performer playing flute. I have never heard this before.
Actually, I think it sounds very good now. No harshness. And actually the Rotel RB 1080 sounds pretty good. Do you think I will get much improvement by replacing it with a DNA-1?
Apologies if someone else has mentioned this...
AI notes that the L1 inverts phase and you should swap your + and - cable connections at the speaker.
I have had an L1 for many years; this makes a big difference. If you were nice and smooth with the Rotel preamp (which almost for sure doesn't invert phase) then you would swap + and - to get nice and smooth with the L1.
Because I have no idea how much experience you have with stereo fiddling I'll just say equipment off, unplugged and give it time to discharge before connecting/reconnecting any cables/wires or opening anything up to take tubes out to clean pins/sockets.
FWIW, I used an AI 2C for many years and found the Svetlana 6n1p to be the smoothest (least harsh) tube type of any that I tried. AI warns against using the 6n1p for performance reasons, however, for me, it was consistently the preferred choice in my system. They're relatively cheap and so might be worth a shot... (Note that this tube is listed as a recommended choice in "Joe's Tube Lore" referenced in a post above..).
You said you were playing a CD of a female voice and it sounded shrill in the low treble. That is the sound of female vocals on major label CDs from the 80s and 90s. Female vocals sounded terrible on CD but not on LP because the major companies were using crummy analogue-to-digital converters. Emmylou Harris was poorly served for example. Joni Mitchell's Dog Eat Dog sounded terrible too.
Try a jazz CD.