NOS tubes for Sonic Frontiers Line 1

Jea48: Based on your posts are you saying that the 2 and 3 slots yield the greatest results? The reason I ask is I have two sets of two matched pairs (Electron Tube, Russian) and Amperex Greens, as well as a complete set of 6 Amperex JAN 7308 Greens. All of the tubes came from Upscale Audio where the Line 1 was originally purchased. I started playing with rolling the tubes over the weekend, but wasn't quite sure what to do with just a set of 4. Sounds like I can still play.

I've had this pre for about 2 years. It's my first tube based piece of gear. The information I've come across during that time suggests that putting it into standby is a trick used by SF to increase tube life ( as opposed to leaving it on all the time). Supposedly it runs at about 10% of the normal operating mode while in standby. I've seen this number referenced by more than one person. The only time I completely shut mine off is when I'm going out of town for the weekend. Mine is tied into my HT rig so between listening to music or just using the HT bybass to watch TV/movies it's on every day. I would think turning it on and off daily would do more harm than just leaving it in standby when I'm not home. Recently music has started to sound a little dull and lifeless so I decided to break out of the extra tubes that came along with it when I purchased it from a gentlemen here on Audiogon. The tube life of the Amperex's is supposed to be 10K hours, that's about 2 years. So I'm going to see what type of changes I can hear from trying out the different tubes, including the stock ones. Hopefully my tubes are still good and I don't have to dip into my stash, but we'll see. I can post my results if you like? It will be a week or two before I will have meaningful information. Please update the thread when you have some info on the tube dampers, I've never heard of them before.

Jea48: I posed the same question to SF tech support yesterday before I read your response. I'll post their answer when I receive it.

Here is the reply from SF Tech support concerning what happens during standby. It seems to match up with what has already been posted here and on the AA thread referenced by Jea48, but it's always good to hear it from the source.

First response:

Standby mode leaves the filament of the tubes running, so when voltage is applied to the plate (i.e. when switching on operating mode) the tube is of course already warm. When voltage is applied while the tube is cold, the cathode gets stripped of electrons rather quickly (especially if signal is applied at that time). Kind of like heating and circulating engine oil before cranking the motor in freezing weather.

Second response when I asked for clarification on a few points:

When a tube is running, voltage is applied to:

1. filament, because tube needs heat to run

2. plate, to give the tube a charge

3. grid gets negative bias - think of it as the spring on the accelerator pedal without which the engine would self-destruct

There are other grids in output tubes but just covering the basics here. In standby mode, only voltage #1 is applied. Standby mode increases tube life simply by keeping tube warm all the time. The rest of it is off.

In HT pass-through, tubes are in operate mode in case you want to change inputs back and forth.

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Hopefully this was informative for someone other than just myself. I'm still not 100% clear on whether or not leaving it in standby mode cuts down on the tube life. For example, does 1 hr. in standby mode = 1 hr. of music listening? If not is there a ratio? My tubes supposedly have a 10K hr. life expentancy, is that 10k of music listening or just on?