2. amps-preamps
  3. 165258-148003

Tube Rolling Woes

I recently took delivery of my first tube preamp. Schiit Freya+. It came with new production Tung Sol 6SN7GTBs. I'm running fully balanced from my source components right through to the power amp. My first impression was wow! What an improved soundstage with width and a 3D quality that I've read about. What surprised me is how quiet the system is. I had expected tubes to be noisy. But the Freya+ running with the new Tung Sols is dead quiet. The openness and air in the presentation is tremendous. However, from a voicing perspective, the top end is bright, and the mids and bass are very thin. I have about 75 hours on the system. Ive read and listened to almost every review on this model and no one has complained about the tonal balance. I left an email with Schiit just to make sure that I haven't done something wrong, but haven't heard back yet. 

I thought I'd experiment with some NOS and used vintage tubes. I've purchased from established, well respected vendors as well as folks with excellent feedback ratings on eBay. Of the 8 tubes I've purchased - claimed as tested matched quads (1) or pairs (2) - all but 2 have been either prohibitively noisy, or just didn't pass a clean signal. From my (admittedly small) sample, there has been no quality differences between the well-respected companies selling NOS tubes vs. people selling used stuff on eBay. The good tubes I've received were used tubes (RCA) sold by an eBay vendor. 

So I'm running out of patience. If I go with new production tubes that a vendor will have tested, matched and stand behind the quality, how do I know what to buy? Note that this is a $900 preamp. So, there are limits to what is practical in terms of price point. I can't justify spending more than $200 on replacement tubes. My concern is that even if I spend this kind of money, how do I know what the results will be? 

Any advice is appreciated.

Glen 

spacecadet65

Showing 4 responses by spacecadet65

spacecadet65's avatar
spacecadet65 OP
58 posts
 
First to everyone: THANK YOU for the great advice! Some have asked about what the rest of the system is:

Freya+
PS Audio Stellar S300 Power Amp
ifi NEO iDSD DAC
Denon Pro DN-500BD MKII DVD
APC H20 Power Conditioner
Bluejeans Cables throughout
Triangle BR03 speakers (waiting for Tekton Impact Monitors on order)

I completely get the risk of eBay. As usual, the cheap way doesn't work. 

Ghost: All great feedback. I'll try the patience thing - I'm going to put the OEM tubs back in and use them for a few weeks, leaving the pre on 24/7 and see how it goes. I listened to an Upscale Audio YouTube video and he was emphatic about all tubes - new or old need a minimum of 200 hrs. before evaluation is meaningful. I'll mess around with the speaker placement and see if that helps. I've played with the toe-in and it helped a bit. More work needs to be done there. 

OldHvyMec: Always good advice. So far, I did a lot of research, spent then listened... So I'm listening to you all now and appreciate the feedback. I'll let the OEM tubes settle in for a few hundred hours and see where I stand at that point. If the voicing issue is still there, Checking in with Brent, McShane, and Upscale and see what the options are. 

Miller: I've been lurking a bit and have always appreciated your comments. Thanks for affirming what others have said on this one. There's no doubt that my little system has all manner of flaws, and the Freya has likely uncovered some of them. With 2 kids in college, this is the budget I'm dealing with. It's a good reminder that tubes aren't effective tone controls.  As an aside, I have a pair of powered Tannoy nearfield studio monitors that I use in a small room system. While they are revealing, there is something in the upper midrange that goes right through me. So I purchased a Schiit Loki EQ (a very very poor man's Cello Audio Pallette) and learned that an EQ won't fix a speaker voicing that you hate...

Thanks All!
spacecadet65's avatar
spacecadet65 OP
58 posts
 
One of the vendors who sold be noisy tubes said to clean the prongs. Would regular spray contact cleaner work?
spacecadet65's avatar
spacecadet65 OP
58 posts
 
Thanks for the tips on the contact cleaner and alcohol. It's alway interesting to find that old technologies like WWII tubes have survived the test of time! I'll check out the Bang It method from Jessee and see how that works. I have nothing to lose from these noisy tubes at this point.

G
spacecadet65's avatar
spacecadet65 OP
58 posts
 
DJSpinner: Yes, the voicing seems to be similar but it's hard to tell. The soundstage collapses and the gain is so much different between the two modes that it's tough to tell. It's a good question because it would speak to the effects of the tubes...


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