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OLDER DECWARE GEAR SUPPORT >> SE84A, SE84B, SE84C, SE84C+,SE84CKC >> SV83 output tube questions
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Message started by ski bum on 07/26/09 at 23:08:56

Title: SV83 output tube questions
Post by ski bum on 07/26/09 at 23:08:56

Noob questions here.

What happens when output tubes fail? Silence, or something akin to a roman candle? Can I damage my zens by leaving output tubes in too long?

What are the differences between the different versions of the 6P15P tube? I've seen EB's, ER's, EV's, and a couple different brand names, Sovtek and the one's Steve sells. Are any of the variety of 6P15N's suitable? Will any/all of them have the floating suppressor grid (so that the CCE mod is effective)? Any sonic differences? Tube life different between the variants?

Thanks for any help!

Title: Re: SV83 output tube questions
Post by Steve Deckert on 07/27/09 at 16:03:01

Output tubes will either slowly wear out over a couple years, or in some cases they can short.

When the wear normally, the power decreases and detail decreases. Best way to find out if they are getting weak is to install a fresh pair and compare the sound. If you don't hear a difference, reinstall the old pair and try again in six months.

If a tube shorts, it will take out the 1 k 2 watt resistor on the power tube socket inside the amp. When this happens, you'll either get scratchy sound at a low level from the guilty channel, or silence. This requires that the amp be sent back so the resistor can be replaced, and the bad tube should be destroyed so as not to be installed in another amp.

There are 3 versions of the 6N1P. 2 of them have plated pins, 1 does not. Avoid the ones that do not have plated pins. Of the two that do, the 6P15P-EV is the military grade, long life tube that we sell. This tube has been re-branded as Svetlana in the past. All of them have the floating suppressor grid.

Hope this helps.

Steve

Title: Re: SV83 output tube questions
Post by veryoldcat on 07/28/09 at 02:47:21

If I might add: I think Steve meant the SV83, not 6N1P (perhaps a senior moment, of which I've contributed many--- :-? )

To further add to the confusion, the 6P15P-EV is spelled with some cryillic characters, so the same tube is sometimes described as "6n15n-EB" also, because the "n" is really a pi symbol.

These military grade SV83's are really superb sounding tubes!

Cheers,
Karl