[bochawa]

Dual 7A4 adapter arrived sooner than expected. Haven't had much time to listen, but it doesn't sound bad. Not sure if it's a huge improvement over the 6SN7.

 

[rgmffn]

I'll put a bid in on this. Guess I'll need to cut a hole in the top for a tube if I win though. ROFL!!!!!!!!!!!!!

https://www.ebay.com/itm/Schiit-Val...810874?hash=item2cedf4e5fa:g:-8sAAOSw8eBdGf1e

I have one of these. I haven't listened to it in well over a yr. I pulled it out and hooked it up just for Schiits & grins, and I was amazed. It sounds pretty GD good!

 

[bcowen]

Lyr rolling thread is dead, think I'll hang out here awhile.

That's 'cause you guys bought up all the $800/pair tubes already. Nothing left to talk about.

Here we spend more on the adapters than the tubes....

 

[bcowen]

I have one of these. I haven't listened to it in well over a yr. I pulled it out and hooked it up just for Schiits & grins, and I was amazed. It sounds pretty GD good!

I read a little on these and learned that there actually *is* a tube, it's just internal. Must be one of those flying lead tubes? Haven't seen a picture of the internals so just guessing. Makes tube rolling a bit more cumbersome, but if you can solder there are some really good flying lead tubes that can be had for cheap.

 

[Paladin79]

Dual 7A4 adapter arrived sooner than expected. Haven't had much time to listen, but it doesn't sound bad. Not sure if it's a huge improvement over the 6SN7.

Did you get the VT-192's I forget?

Did you not notice a difference in channel separation? Often we have to try several sets to get decent SQ but the VT-192's are pretty good.

 

[Paladin79]

That's 'cause you guys bought up all the $800/pair tubes already. Nothing left to talk about.

Here we spend more on the adapters than the tubes....

I have forgone adapters in order to build tube concealment devices. It is a long story, and a boring one, but it involves @bcowen so that is probably all I need say.

 

[Paladin79]

I read a little on these and learned that there actually *is* a tube, it's just internal. Must be one of those flying lead tubes? Haven't seen a picture of the internals so just guessing. Makes tube rolling a bit more cumbersome, but if you can solder there are some really good flying lead tubes that can be had for cheap.

That is the circuit upon which the Schiit Coaster amps are based I do believe. Notice the words Vali Mini on the blank board in the left photo? I know a bit about them since I was most likely the first person outside of Schiit to get one going once I discovered an error in the Bom and schematic. I want to say there are eight or nine of us now who have built them. There is a thread pertaining to these and I even incorporated one in a couple of headphone stands for Ripper. I went so far as to build one into a flying saucer for my granddaughter.

Part of my tube matching setup for these particular tubes will be used in the 6sn7 challenge but I will not go into details till after Bill picks his tubes.

 

[bcowen]

but it involves @bcowen so that is probably all I need say.

Then obviously a very good thing. Go Tom Go!

 

[bcowen]

That is the circuit upon which the Schiit Coaster amps are based I do believe. Notice the words Vali Mini on the blank board in the left photo? I know a bit about them since I was most likely the first person outside of Schiit to get one going once I discovered an error in the Bom and schematic. I want to say there are eight or nine of us now who have built them. There is a thread pertaining to these and I even incorporated one in a couple of headphone stands for Ripper. I went so far as to build one into a flying saucer for my granddaughter.

Part of my tube matching setup for these particular tubes will be used in the 6sn7 challenge but I will not go into details till after Bill picks his tubes.

What are those tube types?

 

[Robert Padgett]

I was kidding. The SB Pro (there was actually a Sound Blaster Pro) was definitely a very good card in its time, but time marches on. (I really liked my Gravis sound card better, but SB was very nice). I was posting tongue-in-cheek at @bcowen by suggesting I was still using my 90's desktop CPU as opposed to a laptop and acting as if it were a leading edge music server. Windows 3.11, 512KB RAM, Pentium I, a SB soundcard, and dual Voodoo cards in SLI mode. Those were the days!!



Why of course. How could I have possibly overlooked Billy Big Mouth ...

www.ebay.com/itm/HIFI-AUX-Stereo-Earphone-Amplifier-Audio-AMP-Headphone-Amplifier-for-Smart-Phone/123218825679

Now when you start talking about Pro Audio, this is the affordable audiophile choice instead of one of those expensive DAPs

 

[Paladin79]

What are those tube types?

6418 is one tube type that can be used.

You can buy the Coaster boards from Schiit for $12 for four as I recall. They post the Bom and schematic but you are on your own, they do not support it but I have helped several people with the build. This is not the first amp a person should build if they want to try DIY. I made this one so that the LED's reacted with the music and changed colors.

Anyway this was based on the original Vali so I guess it is not too far off topic, and you can roll the tubes, but you have to un-solder them. I made one board with sockets so I could plug in tubes under test.

 

[bochawa]

Did you get the VT-192's I forget?

Did you not notice a difference in channel separation? Often we have to try several sets to get decent SQ but the VT-192's are pretty good.

These are just some random Sylvania's I got from eBay - not sure what year they were made, and they are slightly different construction from each other. I have some RCA tubes on the way, both are supposed to be from '52. The separation seems a little better than the new Tung-Sol 6SN7 tube I have, but overall SQ didn't impress me as much.

Side note: my adapter was off by about 30 degrees, but I was able to loosen the center screw and align it with the amp.

 

[Paladin79]

These are just some random Sylvania's I got from eBay - not sure what year they were made, and they are slightly different construction from each other. I have some RCA tubes on the way, both are supposed to be from '52. The separation seems a little better than the new Tung-Sol 6SN7 tube I have, but overall SQ didn't impress me as much.

Side note: my adapter was off by about 30 degrees, but I was able to loosen the center screw and align it with the amp.

Yep, I turned each of my adapters so they lined up better.

It took me a while to find 7A4's I really liked, same with the 6J5 octal single triode tubes. Once you find them though, you really have something that sounds quite a bit different than the 6SN7 IMHO.

Here is more info on the Vali Mini, Coaster amp:

https://www.schiit.com/coaster

Jason was kind enough to mention me in a chapter concerning said amp.

 

[Old Deaf Donkey]

@Paladin79 Two things. First, I completely agree with your view that different tubes sound to the same person differently even with the same equipment and same music, depending on other factors: mood, as you mention, other psychological factors (to me, e.g. novelty of sound signature is but one of them) but also influenced by the "objective factors" such as inner climate of the room, atmospheric pressure, and biochemical condition of the body. I think I have someone in the family who knows something about the latter professionally, and I shall enquire.

Now, about need to run the tubes that have been dormant for a long time for some hours to make sure that the gas residue is absorbed by the getter. @bcowen mentioned that recently, and before that, I posted the same assumption that was conveyed to me by a Russian engineer from who I have bought some tubes. With all due respect, it is enough to look at https://en.wikipedia.org/wiki/Getter; this offers the following position with 5 references: "the inner surfaces of the container release absorbed gases for a long time after the vacuum is established. The getter continually removes this residual gas as it is produced. Even in systems which are continually evacuated by a vacuum pump, getters are also used to remove residual gas, often to achieve a higher vacuum than the pump could achieve alone. Although it weighs almost nothing and has no moving parts, a getter is itself a vacuum pump". This position supports the idea of residual gas being absorbed by the getter once a long dormant NOS (or even used) tube is first used after many decades, hence eventually changing its electrical and hence sonic characteristics, in terms of a straightforward scientific explanation in the sense of engineering.

 

[Paladin79]

@Paladin79 Two things. First, I completely agree with your view that different tubes sound to the same person differently even with the same equipment and same music, depending on other factors: mood, as you mention, other psychological factors (to me, e.g. novelty of sound signature is but one of them) but also influenced by the "objective factors" such as inner climate of the room, atmospheric pressure, and biochemical condition of the body. I think I have someone in the family who knows something about the latter professionally, and I shall enquire.

Now, about need to run the tubes that have been dormant for a long time for some hours to make sure that the gas residue is absorbed by the getter. @bcowen mentioned that recently, and before that, I posted the same assumption that was conveyed to me by a Russian engineer from who I have bought some tubes. With all due respect, it is enough to look at https://en.wikipedia.org/wiki/Getter; this offers the following position with 5 references: "the inner surfaces of the container release absorbed gases for a long time after the vacuum is established. The getter continually removes this residual gas as it is produced. Even in systems which are continually evacuated by a vacuum pump, getters are also used to remove residual gas, often to achieve a higher vacuum than the pump could achieve alone. Although it weighs almost nothing and has no moving parts, a getter is itself a vacuum pump". This position supports the idea of residual gas being absorbed by the getter once a long dormant NOS (or even used) tube is first used after many decades, hence eventually changing its electrical and hence sonic characteristics, in terms of a straightforward scientific explanation in the sense of engineering.

I have heard that theory passed around and with all due respect to wikipedia you have to be cautious what is posted there in terms of accuracy. Believe what you wish, I studied tube theory and was taught differently. There are things that get passed from one person to the next and it gets a little fuzzy when you try to find the actual source, in science. Stating the parts of a tube, or its construction does not carry over to what might or might not change to cause it to sound "better" or "worse". I have never heard of it being quantified and it is easy enough to test the output of an audio device when a tube is brand new or ten hours or fifty hours or 100 hours into its usage.