Nobsound E6 Preamp Uses Directly Heated Tubes
- Thread starter FlaCharlie
- Start date
Maybe another AIYIMA A07 too 
I got my E6 a few days ago ang got around to listening to it today. Boy what ringing. At first I had it placed where it was in front of my speakers and such a ringing, oy-vey! I moved it across the room away from the speakers and it was much better. No serious listening yet but first observation is it's nice. Russian tubes are on order.
Pike72
New Member
You know what you guys are? A bunch of enablers. That's_ what_ you are. A bunch of enablersI was perfectly happy with my AIYIMA Audio 6J1 version of the tube 03. It would be easy to resist if this bit of kit was expensive but at this price I can't resist.
fjdds
Active Member
Tried it today.
After quite a bit of messing with positioning was able to reduce ringing quite a bit. Just don't breathe on it.
Sounds pretty good, but a little thin on the bottom and harsh on top. (Prefer the Tube 03, perhaps because of the tone controls.)
Will see how it compares whith the Russian tubes when they arrive.
After quite a bit of messing with positioning was able to reduce ringing quite a bit. Just don't breathe on it.
Sounds pretty good, but a little thin on the bottom and harsh on top. (Prefer the Tube 03, perhaps because of the tone controls.)
Will see how it compares whith the Russian tubes when they arrive.
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I have been pretty pleased with mine so far and noticed the sound really smoothed out after about ten to twenty hours of use. I only have a little bit of ringing just after turning it on, and it settles down after about five to ten seconds. But yeah, don’t breathe on it. I am hoping the matched quad of Russian tubes I ordered will be better than the stock tubes. The seller claims no microphonics. I’ll find out shortly because they should arrive next week. I currently have two E6 in use and really like the overall sound.
How long have you been using your E6?
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drjohnnyfeva
Well-Known Member
I only had the ringing issue with the Chinese tubes, but that was because I bumped it while in use. I have not had the issue with the Russian tubes, but due to the the experience with the Chinese tubes, I've basically not touched the unit since putting the Russian tubes in. Since they were replaced, the unit has been on constantly. Somewhere I read that the chain of turning things off was farthest from the source to the source itself. Or the other advice was to just leave tube preamps on. I think it was in the $31 Wonder thread. I just leave the two tube units I have in the chain on always. For me this works and it's always ready to go and I've read the tubes break in that way almost as quickly as playing for several hours.
We've got a lot of people who are awaiting units and/or Russian tubes. I'm looking forward to what everyone thinks once those are installed and have seasoned a bit. I'm a happy guy with mine and don't mind the lack of tone controls at all - which is near heresy for me to say.
..I only had the ringing issue with the Chinese tubes, but that was because I bumped it while in use. I have not had the issue with the Russian tubes, but due to the the experience with the Chinese tubes, I've basically not touched the unit since putting the Russian tubes in. Since they were replaced, the unit has been on constantly. Somewhere I read that the chain of turning things off was farthest from the source to the source itself. Or the other advice was to just leave tube preamps on. I think it was in the $31 Wonder thread. I just leave the two tube units I have in the chain on always. For me this works and it's always ready to go and I've read the tubes break in that way almost as quickly as playing for several hours.
We've got a lot of people who are awaiting units and/or Russian tubes. I'm looking forward to what everyone thinks once those are installed and have seasoned a bit. I'm a happy guy with mine and don't mind the lack of tone controls at all - which is near heresy for me to say.
Good stuff. My procedure for turning things on is preamp first then power amp, and the reverse when shutting down. I will notice a bit of ringing as I begin to slowly raise the volume of the power amp, but as mentioned, it settles quickly. I’ve already got my tube cutter and am ready for a bit of Russian tube rolling
Thanks
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fjdds
Active Member
Just for a few days.
In use..
The Russian tubes came today so I marked the pins, cut the cans off, and rolled ‘em in. Immediately noticed an improvement over the Chinese tubes. Warmer, richer, fuller. Wow. And quiet too. No singin’ and a ringin’.
So a huge thanks to FlaCharlie and the rest of you guys. The little E6 is terrific.
The Russian tubes came today so I marked the pins, cut the cans off, and rolled ‘em in. Immediately noticed an improvement over the Chinese tubes. Warmer, richer, fuller. Wow. And quiet too. No singin’ and a ringin’.
So a huge thanks to FlaCharlie and the rest of you guys. The little E6 is terrific.
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drjohnnyfeva
Well-Known Member
I think we are pretty close to confirming that the Chinese tubes are the root of the problems people are having with the unit. From ringing to shorts, it's starting to seem as tho the order process should include obtaining the Russian tubes as a matter of necessity to see the real potential of this unit.
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I think you may be right. There are a lot of eBay sellers of this tube. I got a matched quad from a seller in Romania, he goes by tubes_old70. I chose him because of them being matched and he claims they are not microphonic. He wrote down all pertinent test results on the original papers that came with the tubes.
Man, what’s cooler than tubes? There’s just something about them; the flimsy boxes, the way they are packaged inside the box, the smell of that cheesy old Russian paper. Not to mention the glow when you fire ‘em up, though not these particular type of tubes. And of course the sound! The sound, the sound, the sound, I say!
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I got one of the seand it only sounded OK with the stock Chinese tubes. I mean it sounded OK just nothing to write home about even if I let them run a while. After I swapped in some Russian tubes I ordered I liked it a lot better. Also the ringing issue was gone. New problem tho'. After a few days I started getting scratching when I turned the volume knob. Generally a shot of contact cleaner is what's called for but this is a new unit. I'm hesitant to open the unit and give it a spray, it being new, but I may return it before the Amazon 30 days are up. Anyone else experience the same problem with theirs?
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No scratching with the volume knob on the two I have. Yeah, maybe send it back and get another one.
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drjohnnyfeva
Well-Known Member
Yeah, I'd say return too. I think it being the first model year is the biggest problem - quality control seems a little shoddy.
My dad bought a Chevy Citation 4-speed, 4 door hatchback in the first model year in 1980 and, boy, it sucked eggs and was in the shop for constant refitting. I think we might be experiencing some of this kind of thing with this unit. Sad, but one hopes they are improving.
It's good to have more confirmation that the ringing seems to end with NOS Russian tubes. And - - - that it sounds better with them, which is really what matters.
No problem with returning for another go. Just pop the Russians in and evaluate from there. Can't wait to hear. Sad that the units seem so hit or miss.
Just installed my matched Russian tubes from the same ebay seller. Still rings like a bell.
I think part of the issue is that the tubes have a glass "teardrop" in the middle of the pins, and if the teardrop is long enough, it contacts the circuit board. If you're lucky your "teardrop" is short and doesn't contact the chassis.
The circuit board is rigidly held in the metal chassis, but is suspended only by it's long outer edges. So the resonant metal chassis is connected to a fibreglass pcb which is suspended like a trampoline and the tube is in contact with it.
Thinking about cutting a hole through the pcb where the LED is located. This would allow the use of the tube in its metal casing, which has about 1\4" of paper rings inside of it to damp the tube body.....
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We
Well that stinks. I’ve been lucky with mine, no ringing at all. Keep us posted.
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Well that stinks. I’ve been lucky with mine, no ringing at all. Keep us posted.
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FlaCharlie
Super Member
Under what conditions?
I don't consider microphonics to be a problem unless there is ringing present under normal listening conditions. Tapping on the tube itself or on the chassis is not something I do while listening to music.
One way I test is to play music at a level that's considerably louder than I normally listen and then pause the music. If there is no residual ringing I'm happy.
If the chassis is picking up vibrations from the music at normal listening levels you might try putting it on some soft foam to isolate it or move it further from the speakers.
Vibration from the chassis is transferred to the tube through the socket whether the "teardrop" contacts the board or not. So I doubt that's the issue.
The metal casing of the tube will not fit through the hole in the top of the chassis. If you wanted to use the tube with the casing on you would need to put the board in a different chassis and use chassis mount sockets that have enough clearance underneath them for the locator pin, which is considerably longer than the "teardrop".
BTW, the "teardrop" is where they sealed the tube after the process of creating a vacuum inside it was complete.
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