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Post by skunkworks on Feb 7, 2009 14:09:58 GMT
Hi all, my x-can v3 makes a weird boioioiiing sound when I tap on the power connector on the back of the unit. Is this normal or should I start saving money? It's the loudest on the right channel and normal playback is fine.  |
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Vallejos
100+
Roll With the Changes
Posts: 157
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Post by Vallejos on Feb 7, 2009 14:22:48 GMT
Hi,
I tried tapping my V3 on the power connector but could not hear any strange noice, not even when cranking up the volume. So I guess it´s not normal for the unit to make noice when tapping on the power connector...
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Post by PinkFloyd on Feb 7, 2009 15:42:47 GMT
Microphonic valves. If you don't spend all your time tapping the amp when you're listening then not a problem. If you insist in drumming on the amp then change the valves for a less microphonic pair.
Swap the valves around and if the problem migrates to the other channel then you can safely say it's the valves.
Mike.
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Post by skunkworks on Feb 7, 2009 18:38:35 GMT
The v3 still has it's original jan 6922 valves and also make the sound when I close the cd player which the amp is standing on. I'll try swapping the valves when I get back home tonight. btw. what are the best valves to replace them? Thanx for the help.  |
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Post by dejanm on Feb 8, 2009 8:03:14 GMT
For microphonic valves you can use dampers. Some are cheap and others not so cheap. Here is a pic of the dampers I used on my old V3.  mrarroyo, What is your experience with these dumpers ? Any good ? |
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robertkd
Been here a while! 
Electronics Engineer from sunny Queensland
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Post by robertkd on Feb 8, 2009 8:30:35 GMT
here I go again, I think it's good marketing  |
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Deleted
Deleted Member
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Post by Deleted on Feb 8, 2009 8:44:03 GMT
If those valves were in a speaker driving amplifier, they would need to be tossed into the garbage bin.  I have said this before, but ther best place to damp valves is at the base,where the majority of the vibration comes from. Perhaps mounting circuit boards using small rubber grommets may help with valves that are in good condition.Normal anti vibration techniques such as the choice of material that the amplifier stands on, will also help. SandyK P.S. Send them to Rockhampton if you want to dampen them !  |
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Post by PinkFloyd on Feb 8, 2009 9:49:15 GMT
If those valves were in a speaker driving amplifier, they would need to be tossed into the garbage bin. I have said this before, but ther best place to damp valves is at the base,where the majority of the vibration comes from. Perhaps mounting circuit boards using small rubber grommets may help with valves that are in good condition.Normal anti vibration techniques such as the choice of material that the amplifier stands on, will also help. SandyK P.S. Send them to Rockhampton if you want to dampen them ! As it happens..... Sean Redshaw of www.highendaudio.co.uk swears by placing all his valve amps on foam blocks (the kind of stuff you use in furniture) he reckons it is the best possible "stand" for a valve amp..... so there's another thing worth trying...... a lump of foam under the amp. |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Feb 8, 2009 10:26:41 GMT
SandyK P.S. Send them to Rockhampton if you want to dampen them ! sadly we haven't had a lot of rain as yet, not like those areas further north seriously though it might be as simple as a dry joint (sure they smoke the beast  ) but it may not be the tube well possibly not.  |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Feb 8, 2009 10:43:53 GMT
If those valves were in a speaker driving amplifier, they would need to be tossed into the garbage bin. I have said this before, but ther best place to damp valves is at the base,where the majority of the vibration comes from. Perhaps mounting circuit boards using small rubber grommets may help with valves that are in good condition.Normal anti vibration techniques such as the choice of material that the amplifier stands on, will also help. SandyK P.S. Send them to Rockhampton if you want to dampen them ! As it happens..... Sean Redshaw of www.highendaudio.co.uk swears by placing all his valve amps on foam blocks (the kind of stuff you use in furniture) he reckons it is the best possible "stand" for a valve amp..... so there's another thing worth trying...... a lump of foam under the amp. OR a can of ExpandaFoam, yep in through the headphone socket, 1 hour later nothing inside the case moves Seriously don't do it |
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Post by skunkworks on Feb 8, 2009 14:36:40 GMT
I'll fill it up with concrete 100% no more fibrations I switched the valves from left to right and the boioioing sound migrated to the left channel. It doesn't mean that the valves are about to go kaput? |
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Post by dejanm on Feb 8, 2009 17:22:01 GMT
mrarryo, I guess you didn't see my question, therefore I am repeating it: are these dumpers good ? What are your experiences with them ? I am thinking of buying them (for KT88) but I don't have a chance to hear it before ... so probably it will have to be a blind date ... P.S. You can continue though to post pics of these nice babes ... |
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Deleted
Deleted Member
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Post by Deleted on Feb 8, 2009 22:44:49 GMT
I would be reluctant to put any kind of dampening on a valve that is inside a case , where it already runs quite hot, as evidenced by the posted photos of several PCBs with bad heat discolouration. As Mike suggested, sit the unit on a foam block if you are concerned about vibration. Headphone amplifiers should not be critical in this respect, as distinct from valve Power amplifiers that are exposed to vibrations and resonances caused by the loudspeakers.
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
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Post by robertkd on Feb 8, 2009 23:44:28 GMT
I'll fill it up with concrete 100% no more fibrations I switched the valves from left to right and the boioioing sound migrated to the left channel. It doesn't mean that the valves are about to go kaput? most likely not, but it does mean that some part of the internal structure is able to move mechanically in response to you tapping the case. Generally if you replace the offending tube obviously the problem will go away, other wise as said before some foam to isolate the amp chassis from vibration. |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
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Post by robertkd on Feb 8, 2009 23:52:18 GMT
You see, this is why I rather post pictures of big breasted women. Those are welcome, but when I post pics of my gear I get criticized and ridicule. Here is what you really want! Oh yeah babes |
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robertkd
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Electronics Engineer from sunny Queensland
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Post by robertkd on Feb 8, 2009 23:53:37 GMT
dejanm, at $15 you can do better. If and only if your KT88 valves will be out of an enclosure go to a hardware store and find a high temperature o-ring that fits over the top of the KT88. That should give you an idea of how the expensive units will or will not perform. Depending on what you hear then you can decide if spending $15 each or more is worth it. do you think that would work on this little guy  |
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Post by dejanm on Feb 9, 2009 9:47:37 GMT
dejanm, at $15 you can do better. If and only if your KT88 valves will be out of an enclosure go to a hardware store and find a high temperature o-ring that fits over the top of the KT88. That should give you an idea of how the expensive units will or will not perform. Depending on what you hear then you can decide if spending $15 each or more is worth it. mrarroyo, I am not sure that this is a viable way to proceed. The guy who is selling these things (I do not know their name) is claiming that they "perform" much better than rings that you are proposing. There is an article on his web site about that. Therefore personal experience is very valuable. I am bit confused though with your answer. It looks like that you are not very much convienced about the effect of these things ... ? |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
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Post by robertkd on Feb 9, 2009 11:11:21 GMT
Alright tube microphonics occur because vibrations are transfered into the internals of the tube and cause internal structures to to physically vibrate, which causes variations in the tubes output voltage thus you hear the effect of this. Okay generally these vibrations are transferred into the tubes internal structure either via the pins and or the base of the tube OR by the direct sound pressure on the tube envelope more likely as a PA amp for band use! Tube manufactures make an effort to minimize this by the method of construction, the device you have seems to be at fault, that is they shouldn't be that supceptable to mechanical vibration. No matter what all tube will suffer from this effect. The use of "Dampening Rings" or devices relies on increasing the mass of the envelope which shifts the resonate frequency of the tube and structures, they are all mechanically connected. This may help in some cases doubtfully yours as in all probability the tube has an fault. Some manufacturers made ruggedised versions which were less prone to microphonics however all tube suffer this to some extent. In other words I don't think any dampening will solve the problem your experiencing. Robert |
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Post by skunkworks on Feb 13, 2009 18:15:34 GMT
EUREKA I fixed the BOIOIOIOIOIONNNNNNGGGG sound and it didn't cost a penny. I pulled my v3 apart today and cleaned the insides and outer surfaces. I figured that when the tubes don't touch the sockets themselves only with the pinns inserted it might work, and it did! I left a 1mm gap between the socket and the valve and no more BOIOIOIOIOIONNNNNNGGGG. Now when I use it next to my lappie on the table and my girl puts something on the table it plays on with no extra sound(or atleast not noticeable. Also the sound became a bit more detailed but that could be a placebo effect.  |
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XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
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Post by XTRProf on Feb 14, 2009 9:36:47 GMT
mrarryo, I guess you didn't see my question, therefore I am repeating it: are these dumpers good ? What are your experiences with them ? I am thinking of buying them (for KT88) but I don't have a chance to hear it before ... so probably it will have to be a blind date ... P.S. You can continue though to post pics of these nice babes ... Just simple, try some cheap o rings or use the cheap water pipe teflon tape for your own experiment. Make sure enough ventilation though by not completely wrapping the tube but allowing some glass space for radiation and conduction. Yes, convection too if thru draft cooling. If good then go for the "real stuffs". MY good guess is that after the teflon tape, you will remain where you r ie Status Quo. Oh, yes, do listen to Status Quo, the rock group. |
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Post by skunkworks on Feb 15, 2009 13:57:13 GMT
CRAP! the boioioionnnnnggg is back and louder than ever. Oh well, as soon as I've got some cash I'll order a pinky and some new valves from Pink floyd, maybe even the v3 upgrade set. |
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