tubes

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Anonymous

Post by Anonymous » Sun Mar 19, 2006 8:55 am

I've heard contradictory reports about changing tubes in BC products. On the one hand, some 2nd hand items are listed for sale with "upgraded" tubes, while one fellow mentioned that the use of tubes other that what the product ships with is not recommended or safe.

I tried to find a quote by Gilbert where he says he will not comment on tube rolling. I thought it was on the bluecircle.com site, but couldn't locate it.

There is the review
http://www.ultraaudio.com/equipment/bluecircle_bc24.htm
of my amp, which whets my appetite. It would be lots of fun to play around with the sound of my BC24 and BC3 Galatea.

Are there guidelines for safe replacement? Anyone have experiences to share?

Thanks in advance,
Trevor

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Sugarbrie
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Post by Sugarbrie » Sun Mar 19, 2006 12:34 pm

You basically roll tubes at your own risk. If you use the correct type of tube I doubt you could ever damage the unit. But if you break something playing around inside the unit, then the repair is your problem.

While sound quality matters, the tubes a manufacturer uses has more to do with supply than sound. If the best sounding tube is one that has not been in production since 1945, how could a manufacturer buy a large quantity of brand new ones to put in their gear?

But you could pick up a pair (probably used) for yourself no problem.

If you think about it, you'll realize that Gilbert cannot comment for warranty and other related reasons. It would be like endorsing you to play around inside the gear.

Zero
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Post by Zero » Sun Mar 19, 2006 3:03 pm

I agree with Sugarbrie. Blue Circle's job is to build great sounding gear, not to get involved in the aftermarket tweaking world. But that doesn't mean that aftermarket tweaking can't be done -- it's just done at your own risk.

That said, I've had VERY good results rolling tubes in my BC3000. There are a number of 6922 variants that will work just fine, including 6DJ8 and ECC88. I've used some NOS Amperex 6922s and 6DJ8s, that, while not necessarily cheap in absolute terms, are among the best bang for buck improvements I've made to my system. For roughly $200 I got two sets of tubes that have surprisingly different sonic results: the 6922s increased the soundstage width and depth far beyond anything I'd thought possible in my configuration, given that the speakers are the weak link. The 6DJ8s seemed to flatten the soundstage but kicked some serious excitement into the mix. Everything seems livelier, more energetic without being fatiguing.

That's just two of the dozens of possibilities, and not all 6922s will do the soundstage trick I've mentioned here, just as not all 6DJ8s will flatten the soundstage. I highly recommend checking out Audio Asylum's tube forum, searching and posting questions there. A number of users have far more experience than I with tube rolling in BC gear and will be able to help. Chris Garrett in particular has tried a number of tubes in his BC3. I also recommend checking out Joe's tube lore at:

http://www.audioasylum.com/scripts/d.pl ... tubes.html

That man has heard more tubes than I'll be able to, albeit not in Blue Circle gear, and does a good job of reporting his findings. A must read if you're thinking of rolling.

What I don't know is whether there's as appreciable a difference when rolling tubes in BC amps as with their preamps. My BC8s are 100% solid state and I haven't read much about tube rolling in the amps.

Finally, I can recommend the AudiogoN seller Sam1104 for some hard to find 6922s at reasonably good prices. He's also a good resource and may have recommendations for you beyond his current listings.

Have fun and keep us posted.



Anonymous

Post by Anonymous » Mon Mar 20, 2006 10:56 am

Thanks guys!

That is just what I wanted to hear. I appreciate Gilbert's position on messing with his equipment. As a newbie, I needed to know that tube rolling was a "do at your own risk" activity rather than a "this will ruin you equipment" warning.

I take it that the venture is more like putting another component 5" from my amp instead of the recommended 6" versus dropping it in the bathtub when turned on.

I will pursue the recommended paths to further knowledge, and post results. And if my house burns down as a result, I will also let you know.

Anonymous

Post by Anonymous » Tue Apr 11, 2006 12:46 am

The 6dj8 may be ok in your preamp but I have been advised against using them in my BC 24. The stock tubes are more robust than other stock 6922's which makes me wonder if even a standard spec 6922 is safe. Anybody know.

I've read of gear being designed to the higher capability of the EH and Sovteks. Does this mean 6922's that are standard spec ok or not. This worries me because I love this amp. I can't believe how good it sounds through my Vmps RM 40's which are a planar/ribbon hybrid with cones handling the lower and mid/upper bass.

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bjh
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Post by bjh » Tue Apr 11, 2006 9:37 am

I've seen numerous reports of successful tube rolling experiments with BC gear, especially with the preamps. That said I guess I'd admit there appears to be fewer reports than might be considered the norm for what I've seen with other manufacturers.

One reason may simply be, owing to mode of production, there's not as much BC gear in circulation vs. some of the other players, especially the long established ones, e.g. ARC.

But I personally suspect another reason, at least a reason that I can attest to in my own case ... the stuff just sounds so 'right', so 'excellent', that the urge to experiment is largely absent.

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