solderdude
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Post by solderdude on Jun 28, 2014 6:27:14 GMT
The only reason I could think off with the tube getting hotter may be that the original (ceramic) socket and metal contacts in the Ember do a better job at thermal conduction. The socket saver won't be passing some of that heat, that otherwise is radiated by the PCB, and all of the heat will be dissipated by the tube itself.
It is not of an electrical origin nor bad for the tube or amp.
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Post by whitenoise on Jun 28, 2014 13:19:04 GMT
Okay thanks. I won't trip on it then.
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Post by whitenoise on Jun 29, 2014 4:57:35 GMT
I'm wondering if someone can give me some input. I bought a 12ax7 bugle boy 1965 tube and the seller claims new old stock. Tube sounds fantastic but randomly I get a little burst of static on the right channel. None of my other tubes do this so I'm wondering if this is a sign that the tube is failing? Or something else wrong?
I have the super charger installed on my Ember so I don't think it's caused by a lack of power. I'm a tube rookie so I hope someone here can fill me in.
It's been about 20 minutes since the last static. Could it be that the tube just needs to be on for awhile? I dunno...
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Rabbit
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Post by Rabbit on Jun 29, 2014 7:05:30 GMT
Hi Whitenoise. I don't get noise other than a slightly higher noise floor on noisy tubes. Some are more noisy than others.
I wonder whether there is something near the amp that switches on and off? Some tubes also seem more susceptible to electrical noise - maybe higher gain tubes?
If not external, I think I'd try to send it back. It could be a faulty tube or not NOS. Many EBay sellers sell them as NOS but they are in fact, 'Pulls'. Ie taken out of old equipment; especially if they are only selling singles or small amounts.
I know of one guy who literally buys boxes of NOS since he is very aware of them being pulls, so he goes for large batches.
When tubes start to fail, they can become very noisy and start hissing. I've had one that made shifty noises as well - rustling.
Personally, I'd not use it. If the others are ok, it suggests a tube fault.
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solderdude
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Post by solderdude on Jun 29, 2014 7:32:33 GMT
It may indeed be a tube that is on its way out.
Try tapping it lightly and see if you can evoke the noise.
If it does the tube is definitely faulty.
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Post by whitenoise on Jun 29, 2014 16:09:40 GMT
Thanks Rabbit and solderdude.
Last night I listened to this tube for a couple hours and I noticed that the static would kick in sometimes when I started to use my wireless keyboard. The tube is MUCH higher gain than my other tubes. I mean it's gain is shockingly higher. And I think Rabbit might be correct and it is very sensitive to electrical noise. This amp is sitting on my shelf very close to a 40" LED LCD, a wireless keyboard and 2 powered USB ports. I think it could be due to these electrical gadgets. I would go a half hour with no static and then sometimes the static sound would happen when I was typing, sometimes when I didn't type but was moving my mouse.
I tried tapping it lightly but nothing happens. I'm going to pay very close attention to this for the next couple of day. It's funny because I'm typing on my keyboard now and no static at all but then randomly I will get a little static in the right channel. I don't know.
The seller seems very helpful. They will gladly take the tube back but they claim the tube is awesome. She told me that this was one of her very best tubes that she has been holding for 5 years for an amp project but decided to sell it. She keeps saying how this is a sweet tube and NOS/perfectly balanced.
I can say that this is by far the sweetest tube I have ever heard in my short tube rolling time.
I just want to add that I've been on this forum for a very short time but you guys are super helpful and informative. Thanks a bunch.
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Post by whitenoise on Jun 29, 2014 16:47:56 GMT
Is there anything I can use around the house DIY style to shield the tube? I'm wondering is tin foil or something can be used? Any ideas?
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Rabbit
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Post by Rabbit on Jun 29, 2014 17:02:40 GMT
I get similar problems with all kinds of devices since I use a lot of electrical gear, including wireless senders etc so I know how it feels. Before doing anything drastic, try a tin box. Put the amp in (if you can find one) and switch what you think is the offending device on and off to test for interference. If you can be bothered, you could always wrap it in tin foil like a turkey as well. If the interference goes, then you've hit it.
It could be a case of just moving it somewhere else. I had problems with one of the first Sunrise amps and basically changing room fixed it.
The amp may be more prone to noises given the gain of the tube. You can get tube shields but they do have to be earthed in order to work properly. Distance from the offender will probably work ........ Then you may find something else starts up!!!
Btw - what do you mean by 'static'. Is it a hiss, click, pop or a series of clicks or even hum? I presume it's not static as you get on an amateur radio or cb when there's no signal present?
I got hum and hiss at the same time if I had a certain synthesiser turned on in the house and it only seemed to affect certain plugs as well!!
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solderdude
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Post by solderdude on Jun 29, 2014 18:50:08 GMT
With this extra info it appears as the wireless stuff is interfering with the tube.
things you can do:
Move it away from transmitters (base stations, dongles, wireless equipment) if possible.
Put it in a metal enclosure that is electrically connected to the screen of the input RCA's.
I have asked Jeremy a few times to make a metal enclosure, just for cases like this.
There are 2 types of shields.
A version made of mu-metal (round laminate grey coloured) but this one only does something for magnetic shielding like transformers close by and can be used to eliminate hum (think pre-amps etc. with low signal levels). This doesn't need (and can't be) grounded.
The other version is a metal one or thin copper mesh but this must be grounded to the PCB with a very short wire.
Even with this done it may still pick up RF from close-by transmitters.
It is hard to find stuff that doesn't connect wireless these days but they should not interfere with other equipment.
The amp itself is also open frame and while looking nice it does make them more susceptible to radio frequencies.
As mentioned by Rabbit as well, try moving it away from wireless devices may be the best option.
If that fails we can look at other causes.
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Post by whitenoise on Jun 29, 2014 18:53:26 GMT
It's not a hum or a hiss. It like digital noise. Hard to explain. I'm sitting here right now and the amp is on but I am not playing any music and my right ear cup just started to get that noise again. It sounds like digital noise. static like in a way. Jeez I wish I could describe this better. lol maybe a digital buzzing type sound.
I'm gonna find a tin can to place around it or tinfoil shroud and see what happens.
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Post by whitenoise on Jun 30, 2014 6:17:12 GMT
Okay so about 8 hours ago I removed the Novib socket saver and I have not heard any static noise since. Maybe it's coincidence? I'm not sure but it's been totally clear and clean since taking it out. I'll keep testing this without Novib and see how it goes.
Does this make any sense to you guys? Can socket savers do this? I also noticed that when I removed the Novib that my gain seemed to drop slightly. I don't think this is all in my head but it seemed to anyway.
Also my pc is creating a little noise coming through coax to HK 3490 (preamp) It's slight but there. If I run music from my Rotel cd player to HK to ember the sound is super clean. But through PC I can hear some background noise ever so slightly.
I'm using my PC's onboard sound which is pretty good normally. 24/192 lossless capable. I have a sound card in there too but it doesn't do optical or coax like the onboard.
I purchased earlier a second hand oritek audio omz dac v4.1 that I plan to try out with the PC and bypass my HK 3490. I'm going to run optical out to the oritek dac. I hope this will clean things up from my pc. I also plugged the ember into my power conditioner a few minutes ago. It has a section for a amp.
Things have been interesting for sure. I hope the Novib is to blame for the static as I can go without that easily enough.
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solderdude
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Post by solderdude on Jun 30, 2014 11:21:22 GMT
Okay so about 8 hours ago I removed the Novib socket saver and I have not heard any static noise since. Maybe it's coincidence? I'm not sure but it's been totally clear and clean since taking it out. I'll keep testing this without Novib and see how it goes. Does this make any sense to you guys? Can socket savers do this? I also noticed that when I removed the Novib that my gain seemed to drop slightly. I don't think this is all in my head but it seemed to anyway. It may very well be possible as normally the sensitive gate is screened by the anode. In the socket saver the wires act as little antennae. It should not have any impact on the gain though. Also my pc is creating a little noise coming through coax to HK 3490 (preamp) It's slight but there. If I run music from my Rotel cd player to HK to ember the sound is super clean. But through PC I can hear some background noise ever so slightly. I'm using my PC's onboard sound which is pretty good normally. 24/192 lossless capable. I have a sound card in there too but it doesn't do optical or coax like the onboard. I purchased earlier a second hand oritek audio omz dac v4.1 that I plan to try out with the PC and bypass my HK 3490. I'm going to run optical out to the oritek dac. I hope this will clean things up from my pc. I also plugged the ember into my power conditioner a few minutes ago. It has a section for a amp. Things have been interesting for sure. I hope the Novib is to blame for the static as I can go without that easily enough. It looks like 'common mode' problems due to the presence of 2 or more switch mode power supplies. Solutions can lie in using an USB isolator (for USB DAC) + linear power supply or using a linear power supply for the Ember (is still under construction !) I explained common mode problems here diyaudioheaven.wordpress.com/tutorials/power-supplies/ scroll down to chapter 8 |
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Post by whitenoise on Jun 30, 2014 15:52:31 GMT
Well Rebooting my computer solved that background noise I was getting. (my pc runs 24/7) /facepalm
I ran the ember all of last night and into the morning without experiencing any more static in right channel. So I'm pretty damn positive it was the Novib causing that issue.
I will read that chapter from your link Thanks!
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solderdude
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Post by solderdude on Jun 30, 2014 18:51:15 GMT
Since you liked that tube saver and appears to be the culprit it may be possible to wrap that thing in aluminum foil (only around it) and connect that with a very short wire to ground.
Maybe this way you can still use the socket saver and not be bothered with strange noises.
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Post by whitenoise on Jun 30, 2014 23:49:51 GMT
Well i contacted Tubemonger and they sent another one out. I'm returning the one I have now. If I run into the same issue I will try the foil and ground. Or just go without the socket saver. I only bought it so I wouldn't be rolling tubes in the board socket and wearing it out.
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