Darn, I just put the Tungsram tubes in last week! Now I have to shut it down, remove the top and change the bias setting to 5 mA. This hobby is so labor intensive…
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Perhaps “labor intensive,” but I think you will find it worthwhile to change the Tungsrams settings to 5 mA.
Enjoy the music even more!
Just know you’ll be driving the tubes harder, 20% harder, and will shorten their life. I’ve read it’s best to run at lower current for the first 100 hours before increasing. I’m enjoying the improvement in air vs. psvanes even at 4ma.
Thanks. Yes, I know but if BHK says I’m supposed to run up that hill, off I go!
I’ll have to change the current bias today down to the lower setting to hear what it sounds like. I didn’t read the comment from bhk about his recommendations of using the lower setting. I think the psvane are quite polite. They would never offend that’s for sure. I can see why someone who’s never tried the tungsrams would be perfectly happy with psvane tubes. But once you’ve heard the tungsrams there’s no going back! Well for me at least.
I changed the current on my BHK Preamp down to BHK’s recommended setting. I think it sounds a bit more relaxed in the top end. I don’t think I could pick it in a blind test though. At least I’m not inadvertently killing my tubes 
Bascom stated in post #8:
The intent of the bias or tube operating switch was to allow for the use of the 12AU7 and the 6922 family of tubes. For the 6922 (7DJ8/PCC88) types, the current was set for 5 mA and for the 12AU7, 4 mA. It would be interesting to see what you think of the sound when set at 5 mA vs. what you observed when set at 4 mA, the factory setting for the 12AU7.
I read this to mean try it both ways and run whichever you prefer. Kevin as Upscale is decidedly against running them hard at 5ma. To each his/her own.
Are 6189s and 5814s acceptable for use in the BHK preamp?
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Yes they are 12AU7 compatible tubes.
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While we’re rolling tubes, I just installed some Cifte 12AU7’s that I forgot I had. I like them a bit better than the Tungsrams in the mid range; piano, trumpet. They seem more open and detailed. But I just looked them up at Upscale and they’re nutty expensive.
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Has anyone tried the Gold Lion reissues of 12au7 for the pre-amp?
The Mazda/Cifte 12au7’s are very nice for sure. They have a 3D image and presence/clarity that can be addicting… The triple mica’s take it a notch higher with very low feedback noise.
There are quite a few pairs of the Cifte / Mazda 12au7’S floating around Ebay and the usual websites. Not cheap but I’ll have to bite the bullet and try a pair based on their reputation.
Big danger buying tubes is getting mediocre low emmision tubes. They work, but will have a shortened life. Unless you have a tube tester, or access to one, I recommend buying from a trusted source.
Just installed Brimar 12AU7 in Bkh Prem. The improvement in midrange texture and overall sound quality over Psvanes and Tungsrams suits me perfectly. I feel much more LIVE performance with these tubes. Heaven sent!!!
Listening to a great “test” cd for me------Ruby Braaf and Howard Alden just trading back and forth and leaving acoustic traces everywhere. The Brimar’s are again simply the best enhancement that can be contemplated.
If you have a BHK preamp, you have no idea what can happen with these in place. Tungsram pales in comparison!
I’ll second on the Tungsrams. They didn’t do it for me either.
Hi just wondering what jumper settings your using
Thanks
I’m assuming you’re asking about current and with 12volt tubes, use 4mA.
Hey RonP. If you really like the standard Brimar 12au7 from Upscale… you would absolutely love the ‘premium quality’ and very rare Brimar 12au7WA cv4003 3987/6067. These are the 17mm long plates that sound amazing.