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VV300b tube specs

I own a pair of tubes that are labelled VV300b, and came in a box labelled KR Audio VV300b. Neither the glass nor the base have any branding. The internal structure is identical to another pair of KR 300b tubes I have (WE clone type w full KR labeling on bottle) but the glass bottles are slightly different. Both are shoulder-types but one set has a higher "crown". In other words, the height of the bottle is higher from the shoulder to the top. As I said, even w a careful look, the internal metal structure is identical, the bases appear to be identical, even the apparent weight/transparency of the bottle. I've sent an email to KR's U.S. distributor but thought someone here might be able to shed some light on the provenance of these tubes and most importantly, what their specs are. I own a VAC 30/30 MKIII which requires that the 300bs meet WE specs and I would like to try them if possible.
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swampwalker OP
5,138 posts
 
Rodman99999 (you a surveyor?) "I've sent an email to KR's U.S. distributor" who actually answered pretty quickly to ask me to call them (but then my cellar flooded so I've not yet had a chance).

Brf- Hmmm. that makes sense. I thought that they also looked v similar in some ways to a pair of AVVT 300bs I also have. Do you know if the AVVTs also standard WE 300b specs?
brf
1,715 posts
 
Yes, the AVVT 300B is a WE 300B equivalent. I own a pair of the AVVT 300B with the SL-C37 glass, best 300B IMHO. AVVT also made the AV32B which is a high output 300B similar to both KR and the EML 300B XLS.

My understanding is that you can use the higher output AV32B or an 300B XLS tube in a WE300B spec'd amplifier as these tubes can perform at the WE spec'd (filament voltage 5v, filament current 1.3a, plate current 300v, bias 60Ma) and can go up to 500v on the plate with a bias 120Ma without any issues. If your amp is auto biased, you may not get the benefit of the higher output potential of the XLS tubes, but they will work and sound just fine.
brf
1,715 posts
 
I forgot to mention, if you need additional info on either Vaic or AVVT tubes, send an email to 2011@jacmusic.com as they use to distribute AVVT tubes.
swampwalker's avatar
swampwalker OP
5,138 posts
 
Brf- Many thanks. I'm going to call Alfred from KR and then will follow up w your email address.
brf
1,715 posts
 
Please note that the contact info for KR tubes that Rodman99999 has posted in not an authorized dealer or a representative for KR tubes. Please see kraudio.com under disclaimer for details. The US representative is another Alfred; Alfred Kainz of http://www.highend-electronics.com tel: +1 760 490 2410.
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