AudioCircle
Other Stuff => Archived Manufacturer Circles => Herbie's Audio Lab => Topic started by: jhrlrd on 29 Mar 2016, 09:14 pm
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So the tubes I'm using are super microphonic. I'm concerned with the transport vibrations getting back to the tubes.
I have Herbies dampers on the tubes, and 4 tenderfeet under the oppo.
This combo barely helps the problem. I've been reluctant to try stillpoints as I like the absorption properties the tenderfeet bring.
Was thinking of adding a fifth tenderfoot in the middle, under the transport, but I don't think that would do it either.
I also tried large fat dots, but they are much stiffer than I thought, hoping for something more compliant.
Is there another Herbies product more suitable for absorbing, damping or draining large quantities of vibration?
thanks
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Perhaps you would be better off looking for ways to dampen the PCBs or panels the tubes are mounted upon. I'm assuming that you are most concerned with mechanical-coupled vibrations from the disk transport rather than airborne vibrations.
If you can isolate whatever the tubes are mounted to, you can isolate the mechanical vibration transfer mechanism. At that point the seemingly ineffective damping efforts you are using on the tube itself may become effective since they will be dealing with a level of vibration that is within their abilities to reduce.
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Agreed, so I tried tiny washers made of Herbies material between the mounting posts and PC board of the tubes. no help.
Also, the transport and chassis are damped heavily with the 3M damping sheet and rope caulk.
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I have the Oppo105/Modrright Truth player (with upgraded tubes) and no problem whatsoever with microphonics. I also have Stillpoints under it. It is superb!!
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There's another topic thread started by the OP in the Modwright forum, I'm not sure why the same topic is now used to start a new thread. Bottom line? You either live with what you have or get new tubes. Stillpoints do help, without a doubt, but they are not a cure.
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I use the Synergistic Research migs under my Oppo Modwright and never had a problem with many brands of tubes.
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I didn't mean to suggest the Stillpoints have any connection to the absence of a microphonics problem; they simply bump up an already great performer.
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I've been interested in this since you started the thread in the Modwright circle.
http://www.audiocircle.com/index.php?topic=141178.20
It seems unusual that phono grade tubes in a DAC would be problematic. I don't have a Modwright Oppo player but have had a Modwright modded Sony 999. I generally used lesser linestage graded tubes (5687s). I have an active tube preamp, and 102db efficient speakers and had no noise audible from the listening chair, about 7' away. The tube preamp will ring momentarily when switching the selector switch, or if I tap the chassis hard, but not constant ringing/hiss. Is it only a problem with the tray opening/closing or is it constant ringing/hiss? Is it a particular frequency that sets off the microphonics? Do you listen in the nearfield?
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The main reason to use Stillpoints is indeed overall better sound, but I also found less mechanical noise pickup by microphonic tubes after I got them. In any case, it should be clear by now that there are good sounding tubes that are quiet in the Modwright/Oppo 105. I'm currently breaking a pair of these
http://psvanetube.com/wordpress/store/products/cv181-tii-pair/
which are dead quiet in all respects. I only have a little over 100 hrs on them, and users report a break-in period of 200-300 hrs, so I won't otherwise comment on their sound yet except to say that there was an initial decline in quality (they sounded better out of the box than they did after 24 hrs or so) but now they are steadily improving.
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Thanks for the replies. I reposted the problem here in the event someone who's experienced with this didn't see it in the Modwright thread.
Anyway, the problem is most apparent when the drawer opens and closes, or I tap on the chassis.
This has been a good exercise to flush out areas that need dampening if nothing else.
When the player is spinning I can feel the chassis vibrating, and hear it whirring.
I'm sure the tubes are picking all this up. I listen fairly near field, about 7 feet. The microphonics are not overbearing on the music, but its got to be raising my noise floor. I suppose I could try a separate transport as well....
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Thanks for the replies. I reposted the problem here in the event someone who's experienced with this didn't see it in the Modwright thread.
Anyway, the problem is most apparent when the drawer opens and closes, or I tap on the chassis.
This has been a good exercise to flush out areas that need dampening if nothing else.
When the player is spinning I can feel the chassis vibrating, and hear it whirring.
I'm sure the tubes are picking all this up. I listen fairly near field, about 7 feet. The microphonics are not overbearing on the music, but its got to be raising my noise floor. I suppose I could try a separate transport as well....
Maybe your Oppo 105 is the problem. I have the ModWright tube mod on an Oppo 105D with the Sophia tubes and I do not feel the chassis vibrating or hear it whirring when the player is spinning.
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Maybe your Oppo 105 is the problem. I have the ModWright tube mod on an Oppo 105D with the Sophia tubes and I do not feel the chassis vibrating or hear it whirring when the player is spinning.
This
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Thanks for the replies. I reposted the problem here in the event someone who's experienced with this didn't see it in the Modwright thread.
... (snip) ...
It's bad form to post the same question in two forum topics. People who are the type to answer questions like this will be checking out the new posts where both will show up on the first page of results, rather than perusing a specific forum.
You are running the risk of annoying the very people most likely to help you, who might decide not to answer when a member shows bad forum etiquette.
In the future pick an appropriate forum and post there, once. That way you will avoid the possibility that someone who can help you instead chooses to ignore you. And be aware that it is exactly the same across the entire internet ... not just here.
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.....Anyway, the problem is most apparent when the drawer opens and closes, or I tap on the chassis......
So, if the system is on with no music playing, there is no "ringing" or "hiss" audible from your seat at 7ish feet away?
It's bad form to post the same question in two forum topics. People who are the type to answer questions like this will be checking out the new posts where both will show up on the first page of results, rather than perusing a specific forum.
You are running the risk of annoying the very people most likely to help you, who might decide not to answer when a member shows bad forum etiquette.
In the future pick an appropriate forum and post there, once. That way you will avoid the possibility that someone who can help you instead chooses to ignore you. And be aware that it is exactly the same across the entire internet ... not just here.
Tell us how you really feel about it. I don't think it's a big deal.
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Hmm... It's been my experience when you can hear some "whirring" noise coming from a disc player when it's spinning a disc, it may indicate the transport isn't being held as tightly to the player's chasis as it should be.
I'm not sure how the Oppo's transport connects to the player, but the entire player should be enough of a "vibration sink" if everything is as tight as it should be. If you are able to hear the whirring sound from the spinner from elsewhere than very close to the player, it means something is vibrating to a higher degree than it should be (because it's loose)
( You might want to give Dan Wright a call (or an Email) to ask him if this is a feasible cause of your microphonics issue: & just talk about the transport whirring in general)
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Rusty, to answer your questions, no there is no noise from the transport at 7 feet away.
Thanks Steve, I don't think the transport was removed for the mods, but I will check the screws. One notable 105 modder in DIY audio
noticed that the transport suspension is very stiff...too stiff to even be called suspension, the springs are super hard. He built a new spring/rubber system. The problem is not just with the transport, tapping the chassis is getting to the output board. maybe I'll try rubber posts if i can find such thing.
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Rusty, to answer your questions, no there is no noise from the transport at 7 feet away......
Not transport noise. Are the tube microphonics audible from your chair with the system at idle, no disc playing, or only when the cd drive is moving?
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Sorry misunderstood. No, the microphonics do not overpower the music, nor are audible at idle from the listening position.
Andy from Vintage tube services agreed with my notion that they would be amplifying vibration while playing, thus raising the noise floor.
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I would seriously consider shipping your player back to Dan and have him make sure it is operating correctly.
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Well, I'm in Canada so shipping and the boarder are killer.
Not all tubes do it badly, short ones like GTA or GTB are much better.
Unfortunately, my "best" tubes do it.
Just trying to figure out a way to damp them or the player better.
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Sorry misunderstood. No, the microphonics do not overpower the music, nor are audible at idle from the listening position.....
Okay, thanks. How much gain does your preamp and amplifier have? And how efficient are your speakers?
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No idea how much gain there is, but the speakers are 86 db