[winders]

Right tubes are gain stage.

 

[Ghosthouse]

Gain tubes are definitely the right hand pair. Sorry, don't recall which pair is left vs right channel (guessing it's back right, left front but that is just a guess)...should be easy to figure out doing the musical tubes things as you noted. Hum isn't necessarily a tube dying; 6SN7s can be/get noisy. Try shutting things down, letting them cool and removing and then reinstalling the tubes. Reverse gain tubes front to back first. See if the hum changes channels or (better) goes away. Reseating the tubes might possibly help...if only temporarily. Repeat with buffer tubes after the next listening session if the hum didn't move or go away.

Some EH or Tung-sol new production tubes won't set you back much if you do need to replace a noisy one. Gain tubes should be matched sections and balanced. Buffer tubes should be balanced vs gain tubes but I do not believe their sections have to be matched. Good luck.

 

[Ghosthouse]

@Synergist969 -
FYI, quoting Intruder35 below (taken from their March 6 2017 post)...

"The front two tubes are for the left channel, back two for the right. Right two tubes are the gain stage and the left two the followers."

 

[RonO]

Hi everybody.
I'm on holiday and my main occupation these past few days has been reading this thread.
Thanks for all valuable info!
A quick question for whoever wants to answer...
How do tou see Freya as pre in combination with a 250W Nord Acoustic Amp?

https://www.nordacoustics.co.uk/product-page/nord-one-mp-nc250-stereo-power-amp

Anybody running something similar?

Speakers are ELAC UB5.

I've got a Wyred4Sound ST500mkii, a very similar amp to the nord's, well at least in that they are both class D amps. Wyred uses the B&O Icepower modules instead of the Hypex modules. I also use the Elac UB5's, but I'm considering to go to the UF5's shortly. It's a great setup, massive sound stage, incredible detail. For the first couple months, I ran JFET, and had no tubes in the sockets. Later, I started using the tube stage, I use the Tung-sol new production tubes in all 4 sockets. Lately, I'm using the tubes more often. One had a buzz, and running it for couple weeks seems to have settled it down now.

 

[Ghosthouse]

Hopefully relevant to @franz159 ...
I continue to be very happy with the Freya. Recently installed some NOS clear glass RCAs in the gain stage positions. Left EHs in the buffer position. Thought there was an increase in musical "heft"...someone else had called it "meat on the bone" (albeit with a different set of NOS tubes, I think). Anyway, using the Freya mainly in front of a Merrill Audio Taranis amp (Class D using Hypex Ncore NC500 modules). It's a very enjoyable combination driving Totem Forest speakers. Sorry, not used for head phone listening. The main source these days is an Auralic Aries Mini playing ripped CDs or Tidal. That runs through a Gungnir with MB upgrade. The MB upgrade to the Gungnir is one of the better investments made to the system. I have a Hegel H200 as backup amp. Decided yesterday to hear how that would sound with the Freya. The Hegel is an integrated but can be put in HT/by-pass mode. Acts like a power amp. Volume defaults to "full on". I was pleasantly surprised by the presentation. My impression was of a wider and deeper soundstage with even more "presence" in the music. The Taranis is definitely more "neutral" tone-wise, however. With either the Taranis or Hegel in combination with the Freya, it's hard not to want to crank things up because the sound is so "clean"...and by that I do not mean sharp or edgy or bright, rather clean as in free of distortion or fatiguing artifacts. Metal dome tweeters on the Forests can be punishing with bad source material or bad matches with electronics or wire. These days, that's all a distant memory. BTW - like RonO notes above, I too started out mainly listening in JFET mode. Someone gave me a quad of new production EH 6SN7s. They got me back listening in tube mode. I didn't care too much for the as-supplied Russian tubes. The RCAs make tube mode listening even better though I think interconnect changes had a bigger effect on sound with Freya than tube changes. I am curious, however, about the new production Tung-sols. Actually thought I was getting out of tubes when I bought the Freya which was purchased to replace or at least back up a 6H30, EZ80 rectifier pre-amp. Got the Freya because it was solid state and for its ability to operate as a passive device and for its balanced design. Now I seem to be back collecting glass bottles.

 

[JohnBal]

Hopefully relevant to @franz159 ...
I continue to be very happy with the Freya. Recently installed some NOS clear glass RCAs in the gain stage positions. Left EHs in the buffer position. Thought there was an increase in musical "heft"...someone else had called it "meat on the bone" (albeit with a different set of NOS tubes, I think). Anyway, using the Freya mainly in front of a Merrill Audio Taranis amp (Class D using Hypex Ncore NC500 modules). It's a very enjoyable combination driving Totem Forest speakers. Sorry, not used for head phone listening. The main source these days is an Auralic Aries Mini playing ripped CDs or Tidal. That runs through a Gungnir with MB upgrade. The MB upgrade to the Gungnir is one of the better investments made to the system. I have a Hegel H200 as backup amp. Decided yesterday to hear how that would sound with the Freya. The Hegel is an integrated but can be put in HT/by-pass mode. Acts like a power amp. Volume defaults to "full on". I was pleasantly surprised by the presentation. My impression was of a wider and deeper soundstage with even more "presence" in the music. The Taranis is definitely more "neutral" tone-wise, however. With either the Taranis or Hegel in combination with the Freya, it's hard not to want to crank things up because the sound is so "clean"...and by that I do not mean sharp or edgy or bright, rather clean as in free of distortion or fatiguing artifacts. Metal dome tweeters on the Forests can be punishing with bad source material or bad matches with electronics or wire. These days, that's all a distant memory. BTW - like RonO notes above, I too started out mainly listening in JFET mode. Someone gave me a quad of new production EH 6SN7s. They got me back listening in tube mode. I didn't care too much for the as-supplied Russian tubes. The RCAs make tube mode listening even better though I think interconnect changes had a bigger effect on sound with Freya than tube changes. I am curious, however, about the new production Tung-sols. Actually thought I was getting out of tubes when I bought the Freya which was purchased to replace or at least back up a 6H30, EZ80 rectifier pre-amp. Got the Freya because it was solid state and for its ability to operate as a passive device and for its balanced design. Now I seem to be back collecting glass bottles.

Thanks for the impressions!

 

[purehifi192]

I'm in the process of experimenting with non-stock tubes for the Freya with a couple different tubes. I have a pair of RCA redbase as well as Sylvania VT231. I'm thinking the redbase for Freya's output stage on the left and the VT231s for the gain stage on the right.

In general, what type os tube qualities would I look for in the output stage vs the gain stage when I do not have a 4 matching tubes? Any rules of the road to follow?

 

[purehifi192]

The left tubes are the output buffer stage and the right tubes are the gain stage. Put the good tubes on the right!

Per my above note, I'm under the impression the "better" tubes go on the output, i.e., left, positions, not the gain position on the right.

 

[sam6550a]

Per my above note, I'm under the impression the "better" tubes go on the output, i.e., left, positions, not the gain position on the right.

The 'better' tubes should go in the gain stage position. The output cathode follower stage has voltage loss [rather than gain] and is less sensitive to tube differences. That said, try them in either position, and decide which configuration sounds better to you in your system.

 

[purehifi192]

Thank you for the clarification. Definitely planning on trying them out in different locations.

 

[winders]

I guess I don't need to post anymore.....

 

[brad1138]

To deal with the fact the Freya has no HT passthrough I use a quality RCA switch box to switch between it and my Emotiva PrePro into my Citation Amp. The one I had custom made failed and I want to go a different route. I have found 3 options:

http://www.decware.com/newsite/ZSB.html

http://www.goldpt.com/sw4.html

http://www.homehifi.co.uk/S/tc-7240.htm

The first 2 are good looking and very good quality units, but at nearly $400... And if I want to upgrade the ZSB connectors, that another $150...

The 3rd one looks good quality and has good reviews (like the rest), I almost pulled the trigger on it last night, but having 2 switches, it has twice as much potential for signal degradation.

I hate spending so much on a darn switch, but I didn't spend so much time putting my system together to have it degraded at that point.

Anyone have any thoughts? (maybe I should start a separate thread). Or is anyone else doing the same thing and have a recommendation?

Thanks

 

[roxrite]

I want to use Freya as an active preamp connected to a ragnarok and use the rag as a headphone amp.
My aim is to make the rag a little warmer with the Freya ..
So a mix between solid state and a little tube Sound.
Did anybody try it out with headphones and got good results ?

Would actually any tube preamp would do the same Job with headphone amps or are there things to consider ?

thanks a lot

 

[DrJam]

To deal with the fact the Freya has no HT passthrough I use a quality RCA switch box to switch between it and my Emotiva PrePro into my Citation Amp. The one I had custom made failed and I want to go a different route. I have found 3 options:

http://www.decware.com/newsite/ZSB.html

http://www.goldpt.com/sw4.html

http://www.homehifi.co.uk/S/tc-7240.htm

The first 2 are good looking and very good quality units, but at nearly $400... And if I want to upgrade the ZSB connectors, that another $150...

The 3rd one looks good quality and has good reviews (like the rest), I almost pulled the trigger on it last night, but having 2 switches, it has twice as much potential for signal degradation.

I hate spending so much on a darn switch, but I didn't spend so much time putting my system together to have it degraded at that point.

Anyone have any thoughts? (maybe I should start a separate thread). Or is anyone else doing the same thing and have a recommendation?

Thanks

Schiit SYS?

 

[brad1138]

Schiit SYS?

I had thought of that and I actually use a SYS in my secondary system, but even with the volume maxed, the signal path still goes through the potentiometer. Seems like needless "extra signal path". May or may not make a noticable difference, but I would like something with just 1 clean as possible "switch".