Alternative 6SN7 family tubes

[2FarGone]

I have a Von Gaylord LAD-L2 preamp that I’ve been running brown-base 5692 tubes in and the combination has been exemplary, but the last matched set of tubes (purchased from a reputable tube reseller) lasted only about 7 months before beginning to produce an unacceptable noise level. Does anyone have a suggestion for 6SN7 family tubes that may have comparable performance to the brown-base 5692? I’m okay with spending the money for good tubes, but I consider 7 months to be an unacceptable lifespan for tubes this expensive.

I prefer not to purchase Russian or Chinese tubes of current manufacture for personal reasons I needn’t go into here. Any suggestions?

 

[Michaels HiFi]

Hi - 2 things:

Possible there is something in your unit that may be causing them to last a shorter time;

What year are the tubes you currently have? Without knowing year/mfg it's impossible to make suggestions.

Happy to help but need to know exactly what tubes you have now. If you can post 3-4 pics of what you have now that would help as well.

 

[2FarGone]

Thanks for the response.

I’ll pull the tubes that are in the preamp today or tomorrow and install the backup set that I bought at the same time as the first ones. The set in there now came from a different reseller. I’ll post photos of both once I get them switched out.

I doubt there’s a problem with the preamp. It’s only a few years old, and Ray at VG tells me that tubes should last about 5 years before being switched out. There’s no power switch on the front of the unit, since it’s Ray’s feeling that inrush current shortens tube life as much as leaving the preamp on.

The tubes just removed are on the white tablecloth. The ones just installed are on the receipt, purchased from SND Tube Sales about 5 years ago. The ones just removed came from Brent Jessee.

Even the “new” ones aren’t as quiet as I’d hoped, though. This rig is already on two dedicated 20-amp circuits, so I’m not quite sure where to go from here. I'll dig into it further tomorrow.