I have an SF Anthem tubed LS preamp. It plays fine for about 20 mintes or so then it looks there is no power to the tubes, it just sort of fades out, I look at the tubes and there is no glow in them at all. No noise when it dies, just silence. I'd guess power supply problem of some sort. The little green LED that indicates power is on stays on.

Is anyone here familar with this on a Sonic Frontiers (Anthem) product?

I don't have a back-up at this location, so I kind of stuck out here in the boonies with no preamp or receiver (to use as a preamp).

Hmmm, that almost sounds like a winding short. Do you have a meter handy?

Also, does the power transformer get firecracker hot?

I think the SF/Anthem amps use a resettable Raychem PTC circuit breaker in some circuits. They won't reset usually until you remove power for a bit. So you probably have an internal issue that will need diagnosis. I would call the boys at Partsconnexion on Monday. They are infinately familiar with those amps. ;)
WopOnTour

Hey .. Thanks for replies. I put another matched quad in there, and it was fine. So one of the tubes in the other quad may be out? All I can think of.

I have some Amperex Bugles Boys, and they were real noisy. Have 2 more quads of Sovteks. I love the deep bass of these tubes.

For now they are working well.

WTF is this one about? Any ideas?

Another quad is going to be expensive.

I am looking for an inexpensive quad of 6922's as a spare. Any ideas? ~100

I don't want to contact SF, have heard a lot of bad crap about them. Need to have a backup.

This preamp has worked well for me, but I am the second owner. Not sure of any hours on the tubes for the original owner.

Don't bother with SF themselves (i.e, the Paradigm group). Try Parts Connexion... they're the guys who designed the SF stuff, before SF was sold off to Paradigm...

Regards,
Gordon.

Preamp is dead, I am shipping it up to Parts Connection for repair.

This may get ugly. I do not have the preamp back in my hands yet, so stay tuned.

Its only been gone 10 days right?

Preamp is on the way back from Parts Connection. They turned it pretty quickly.

They only replaced two resistors. Took them 2.5 hours to diagnose it.

Shipping to and from Canada is a long story. Very pricey, and complicated if you do not know what you're doing. I got nailed with a brokerage fee going in, cost me 25 plus the insane UPS ground of 58 (for a 26 lb box).

Preamp is in the back of the Jeep, I am back to all tubes tonight!

The unit was properly packed in my "better than factory" shipping container. I spent a few years in engineering at Koss, so I know how to pack heavy items like 74 pound speakers.

Got rid of that rental POS tonight at Worst Buy. I have $107 to add to the power conditioner fund.