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NEW Vali Schiit AMP!!! - Page 140

post #2086 of 4355

I am looking into possibly getting a Vali for my DT 880 250 ohm, but I have a few questions.  Is there any problem with using the Hifimediy Sabre DAC with the Vali?  I already have the 3.5 mm to RCA cable that I would need, but I am wondering if I would be losing something in comparison to using a DAC with an RCA output.  If anyone has thoughts on this, how does the Vali compare to the slightly cheaper Bravo Audio Ocean and the somewhat more expensive Little Dot MK II?

post #2087 of 4355
Quote:
Originally Posted by purrin View Post

 

DO NOT USE Vahalla with low impedance cans like orthos. The Vahalla output impedance is almost as high if not higher. It will sound bad. I have tried it for fun just to see. Just a bad idea and even Schiit recommends against this on their website.

 

Not to get too OT, but this has always confused me. As of late, I thought the output impedance on amps didn't matter so much with orthos, since most have a flat impedance curve. At least, that was what I was told when I asked why a vintage receiver with a super high output impedance still drives orthos well...

post #2088 of 4355

Regarding the tube foam--actually, heat won't hurt it--it's rated to 65 degrees C continuous.

 

I suspect what's happening with the loose tubes is cold weather. During shipping, if it gets cold, the adhesive gets less effective, and might come unstuck. I've talked to the board house already and all production is now shipped with bent, strain-relieved tube leads to help eliminate the problem.

 

And--if you choose to re-stick them, don't worry about touching the tubes. They run at room temperature. The only parts that get hot are the large transistors for the Class AB output stage. We push the tubes down, hard, by hand, during production.

post #2089 of 4355

Thanks for the response, Jason :)

post #2090 of 4355
Quote:
Originally Posted by Jason Stoddard View Post
 

I've talked to the board house already and all production is now shipped with bent, strain-relieved tube leads to help eliminate the problem.

 

Now I'm wondering if mine is one of those...it was shipped on Thursday/Friday ...

 

Either way, I'm really excited to pair it up with my incoming HE-400 as well!

post #2091 of 4355
Quote:
Originally Posted by Jason Stoddard View Post

Regarding the tube foam--actually, heat won't hurt it--it's rated to 65 degrees C continuous.

I suspect what's happening with the loose tubes is cold weather. During shipping, if it gets cold, the adhesive gets less effective, and might come unstuck. I've talked to the board house already and all production is now shipped with bent, strain-relieved tube leads to help eliminate the problem.

And--if you choose to re-stick them, don't worry about touching the tubes. They run at room temperature. The only parts that get hot are the large transistors for the Class AB output stage. We push the tubes down, hard, by hand, during production.
This won't affect the warranty right?
post #2092 of 4355
Quote:
Originally Posted by Transformatron View Post


This won't affect the warranty right?

 

Probably will void the warranty if you choose to fix it yourself. That is unless Schiit authorizes it, which probably won't happen.

post #2093 of 4355
Quote:
Originally Posted by Transformatron View Post


This won't affect the warranty right?


Yes I am wondering this too. Since I have the constant ringing in the left channel I suspect one or both tubes has come loose from the pads, but I am reluctant to open the unit fearing that it will void the warranty, even though it seems like a pretty easy fix. As to what Jason from Schiit said about the cold, to me makes perfect sense. When I received my Vali, it was very cold, I actually waited for the unit to warm up to room temperature before turning it on the first time.

 

If pushing the tube back on the foam carefully with a little pressure will fix the issue then I would much rather do that then have to contact Schiit and bother them with something I could easily fix myself, however I do not want to do anything if it will void the warranty.

 

Edit: I used an LED flashlight to look inside the top of the Vali through the holes and I can see the left tube is definitely up off of the foam, the tube on the right looks like it still may be attached to the foam, but it is difficult to get a good look at it without having to open the unit, which I am afraid to do.


Edited by TheGame - 12/8/13 at 10:00pm
post #2094 of 4355

Has anybody paired the Vali with Audio Technica's AD line yet?

post #2095 of 4355

Poor match on paper-but worth a shot. Someone here keeps posting about their W1000x, maybe search out those posts.

 

-Daniel

post #2096 of 4355
Quote:
Originally Posted by BournePerfect View Post
 

Poor match on paper-but worth a shot. Someone here keeps posting about their W1000x, maybe search out those posts.

 

-Daniel

Thanks for the feed back; would there be another tube'd amp that you'd recommend for the AD900X?

post #2097 of 4355
I would assume since Jason is telling you to do it, if it is needed, that there won't be any warranty repercussions. Correct me if I'm wrong, though, Jason.
post #2098 of 4355
Hey guys

I need some technical information. I'm not so aware of electronic science so keep calm if my question isn't fault free.

I know that tubes need to reach an optimum voltage to work their best, so what is the optimum Impedance for using with Vali?

I realy appreciate any advice (theoretical or practical) that you guys can give me.
post #2099 of 4355
I used to use a leather punch to make small dots out of this vibration damping material:

http://www.partsconnexion.com/damping_soundcoat.html

I would place them on primarily around circuit boards. Other times I would use larger strips or sheets inside sheet metal chassis.

Sometimes there was no change to the sound; sometimes the sound changed to my liking, and sometimes it was worse. Hard to say until you've messed around a bit.

Since the tubes run at room temperature, I don't see any harm in trying something like this on the glass envelope of the tubes. Again, it's unpredictable how it will affect the sound. Since these tubes are extremely sensitive to vibration, I would think it would have some effect, whether for better or worse.

I've long since run out of this stuff, but I'm tempted to get more and try it.
Edited by K.T. - 12/9/13 at 12:48am
post #2100 of 4355
Quote:
Originally Posted by hans030390 View Post
 

 

Not to get too OT, but this has always confused me. As of late, I thought the output impedance on amps didn't matter so much with orthos, since most have a flat impedance curve. At least, that was what I was told when I asked why a vintage receiver with a super high output impedance still drives orthos well...

 

Think current delivery / power transfer. Tubes are high voltage and low current devices. Think water spraying from thin pipe with high pressure. Low Z orthos need current. Think huge diameter pipe receptacle which doesn't expect a lot of pressure.

 

Most tube amps use a transformer which lowers the voltage and trades that voltage for current. In other words, the transformer a gizmo which converts the the thin pipe to a thicker pipe. Vahalla is an OTL, so no such luck. It's like using a Water Pik to clean your bathtub, when buckets of water dumped on it are more effective.

 

As for why vintage receivers work well I have no idea. I've only used low Z power amps. It's possible the receivers just have that much more power to be able to push through that small pipe (resistor at phono stage).


Edited by purrin - 12/9/13 at 1:09am
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