[Blue Warper]

Quote:

  Schiit shipped my Freya today. I"m already looking for 6sn7 tubes to try. I have a bunch of very nice 12au7's wonder how these might work in the Freya with an adapter? Any thoughts?
 
I don't have any data on the tube section of the Freya so not real sure they will interchange.
 
Damn, back to hunting tubes again. Tube prices are a joke. Makes want to sell off some of mine.

 
 
Originally Posted by watchnerd /img/forum/go_quote.gif
 
 
Thoughts?
 
Bad idea.
 
The 6SN7 is far more linear with small signals than the 12AU7.
 
So even if it doesn't end in a catastrophe of smoke and flame (which it might), it's still likely to be more noisy and distorted than the 6SN7.
 
Plus if you damage the amp, it's probably a warranty violation.

 
I'm not a Freya owner myself (hoping to get one in the future, though), so I just keep reading your thoughts and impressions.  I've read some of you inquired about 12AU7/12AX7 family of tubes.  I thought it might be useful for you tube-rollers to point out what's Mike/Baldr's opinion about it.
 
You'll find it in Jason's thread:
http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/9405#post_12202705
 
Happy listening!

 

[belgiangenius]

  Quote:
 
I'm not a Freya owner myself (hoping to get one in the future, though), so I just keep reading your thoughts and impressions.  I've read some of you inquired about 12AU7/12AX7 family of tubes.  I thought it might be useful for you tube-rollers to point out what's Mike/Baldr's opinion about it.
 
You'll find it in Jason's thread:
http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/9405#post_12202705
 
Happy listening!

Yes, but Mike is referring to the high gain 12AX7.  A preamp would do fine with 12AU7/12AU7 or 12AT7/12AU7, which would undoubtedly be better than the 12AX7.

 

[belgiangenius]

To answer that I'll give a rundown of what I've listened to and how they sound on Freya. First of all, to my ears matched quads sound better than using the stock tubes for output and swapping out the input. With that said there are several tubes that I only have two of, so I have no choice.

1. RCA NOS 5692 red base matched pair (stock tubes for output buffer) are the best I've heard so far. Amazing detail and fantastic bass. Really amazing!
2. CBS NOS 5692 matched pair (I'm pretty sure these are also RCA red base because they sound almost identical and look identical). Probably 98% of the RCA.
3. Tung Sol matched quad new production- unfair advantage here because I have a quad... BUT they are probably 90% of the 5692 to my ears. Also they are very good looking tubes. The disadvantage is in the bass compared to RCA. Still strong and if you didn't know it you would not be able to tell the difference, until you put in those RCAs.
4. Tung Sol mouse ear matched pair (stock tubes for output buffer). They sound good but I was sadly disappointed, bass is ok and detail is high but they sound... subdued I guess. Just a little flat, not as sharp as the Tung Sol new production. These are probably 75% of the RCAs and 85ish% of the Tung Sols.
5. RCA black base matched pair- good tubes, much better than stock. Slightly less detailed than the mouse ear but far more detailed than stock. Probably 65% of RCAs
6. Philco NOS (GE 6sn7GTB) matched pair, these are slightly less detailed and worse bass than the RCA black base. Probably 55% of the RCAs
7. Stock quad (I think 6h8c, Russian NOS), these were impressive the first time I ever heard tubes (which was the Freya) but after some quick swapping, they are clearly not as good. Probably 35% of the RCAs.

I have a very closely matched RCA grey glass NOS quad from 1945 JAN that I have not tested yet. I'm thinking of keeping it for the Vidars so the quad can really shine. I suspect that one will slip between the CBS and the Tung Sols but that is pure speculation.

I hope this helps. My recommendation (and what I'm going to do) is to purchase a matched new production Tung Sol quad for regular/daily use (which I already have) and a matched pair for the output buffers (which I need to order). I do feel like the stock tubes are effecting my NOS tubes in a negative way acoustically so trading them for the new production Tung Sols makes a ton of sense.

 
OK.
 
I'm currently using Sylvania VT-231 in the buffer stage.  Wonder, transparent tubes, but a little base shy, so they got put in the buffer position pretty quickly.
 
I got some RCA VT-231 grey glass this week, as well as some 5692 CBS.  Both tubes are excellent.  The RCA seems a bit more neutral, while the 5692s seem to blow up the vocals and sound stage a bit.  I like the 5692s very much - huge sound stage and absolutely visceral bass.
 
What still gives me pause is that you said that a matched quad of Tung-Sol new production sounds 90% of the CBS?  Really?  Do you still stand by this?  If this is true, I may be ordering a case of them. 

 

 

[Blue Warper]

 
Yes, but Mike is referring to the high gain 12AX7.  A preamp would do fine with 12AU7/12AU7 or 12AT7/12AU7, which would undoubtedly be better than the 12AX7.

Fine, got it! Thanks for the clarification!

 

[RoundRound]

7N7 anyone??

 

[lukeap69]

I have some noise coming only from the left speaker in tube mode on the Freya . I'm using all balanced cables . It's weird . It comes and goes . If I lift the Freya and move it around a little i can make it go away . Maybe power cables to close to one another ?
This is not ground loop .
Any suggestions ?
Sometimes when I start the Freya up and it's ready I can hear the noise and then sometimes when I start it up the noise is not there .

Check if there is a cellphone or smartwatch near your rig. It happened once to me when I moved my tube amp (not Freya) on another location and it made me almost mad finding out the issue I did not have before.

 

[MefAudio]

   
OK.
 
I'm currently using Sylvania VT-231 in the buffer stage.  Wonder, transparent tubes, but a little base shy, so they got put in the buffer position pretty quickly.
 
I got some RCA VT-231 grey glass this week, as well as some 5692 CBS.  Both tubes are excellent.  The RCA seems a bit more neutral, while the 5692s seem to blow up the vocals and sound stage a bit.  I like the 5692s very much - huge sound stage and absolutely visceral bass.
 
What still gives me pause is that you said that a matched quad of Tung-Sol new production sounds 90% of the CBS?  Really?  Do you still stand by this?  If this is true, I may be ordering a case of them. 

 

 
So to make sure, I put the CBS pair in the input buffers (with the new production Tung Sol in the output buffer, it makes it a cleaner comparison rather than using the stock tubes for the output as the CBS sounded worse with the stock tubes in the output buffers). I also have my cousin with me for a second set of ears. The CBS have slightly heavier bass, noticeably better but by a small margin. I can't tell much of a difference with clarity- the Tung Sol clarity really sticks out in general and the CBS is expected to and it does. Highs are pretty frikin close. I can't tell a difference. My cousin can also tell a difference in the low frequency and the volume- I think the low frequency difference is giving a perception of a different volume level but we are talking maybe the equivalent of 2 clicks on Freya.
 
In my system and to my ears, if the Tung Sols are not 90%, they are no lower than 85% of the CBS tubes (and to me I still think 90%). They sound really good to me. 
 
I actually ordered a second matched quad and a matched pair to use with my exotic pairs. In a couple months I might be ordering a couple more matched quads, actually a matched set of 8. You might want to order a matched quad (I think I paid $90, so not too bad) and see what you think and go from there but for me, yeah a case is in my future for sure
 
My disclaimer is that the 5692s only have about 10 hours on them, the Tung Sols have about 30 hours on them. I did play them side by side with 0 hours on both sets and I came to the same conclusion. Your mileage may vary... etc.

 

[Baldr]

I need to clarify that I am not a fan of 12A(any)7 tubes.  The 12AU has bad curves, and although I have never used it the 12AT also suffers from curves far worse than the 6SN7/5692.  The main application for 12AT7 tubes is audio circuits in shortwave transmitters and receivers where audio non-linearity and punch help intelligibility over weak, noisy, signals.  For line level (not phono) tubes, the 6SN7 family just rules.  6DJ8 and 5670 are quieter, but this is useful for phono apps.

 

[theveterans]

We need a 5692 reissue with the same materials and construction as the NOS ones. Not the new Sylvania style but the REAL 5692s, triple mica, support rods, chrome dome with 2 getters, red/brown base only.

Burning through these awesome NOS tubes costs too much for my musical enjoyment, especially in this generation.

 

[US Blues]

We need a 5692 reissue with the same materials and construction as the NOS ones. Not the new Sylvania style but the REAL 5692s, triple mica, support rods, chrome dome with 2 getters, red/brown base only.

Burning through these awesome NOS tubes costs too much for my musical enjoyment, especially in this generation.

The new production Tung Sols have a brown base. 

 

[theveterans]

 
The new production Tung Sols have a brown base. 

 
But everything else is different. I'm talking about a 5692 clone with all of the strings attached (same mica material, heater and plates, rods, getters, glass, base, etc) and the construction and attention to detail are of NOS levels.

 

[US Blues]

 

 
The new production Tung Sols have a brown base. 

 
But everything else is different. I'm talking about a 5692 clone with all of the strings attached (same mica material, heater and plates, rods, getters, glass, base, etc) and the construction and attention to detail are of NOS levels.

I know, that "winking face' was intended to convey that I was being playful/sarcastic.

 

[Baldr]

 
The new production Tung Sols have a brown base. 

Could someone please post a link on these new production Tung Sols?  My endorsement is of the old production, made in US ones.  None of those had a brown base.

 

[US Blues]

 

 
The new production Tung Sols have a brown base. 

Could someone please post a link on these new production Tung Sols?  My endorsement is of the old production, made in US ones.  None of those had a brown base.

Here you go:http://www.thetubestore.com/Tubes/6SN7-Tube-Types/Tung-Sol-6SN7GTB

 

[watchnerd]

 
Could someone please post a link on these new production Tung Sols?  My endorsement is of the old production, made in US ones.  None of those had a brown base.

 
 
From New Sensor, the same factory that makes the 'new issue' Sovtek and Electro-Harmonix tubes.
 
http://www.thetubestore.com/Tubes/6SN7-Tube-Types/Tung-Sol-6SN7GTB
 
I don't know how different they really are from the EH and Sovtek branded tubes from the same factory.