Does the Quickie tubes glow or get hot?

[Sonido]

Just finished building it, and couldn't resist plugging it in and trying it out so I skipped the resistance checks  Did the same thing when I built the Crack and it worked the on first try.

Anyways I thought my luck ran out this time as the tubes neither glowed or got warm, but when I started playing music, it worked to my surprise. The music didn't sound bad at all, and I've used other tube preamps where if I turned it off, the music started fading and crackled until it was gone. However, for the Quickie, it sounds fine to me and the volume knob works as well. I noticed the tubes were microphonic when I tried touching them. So I'm wondering if the tubes just don't get warm or glow, or is something wrong? The fact it runs off batteries I can understand if it doesn't glow or get warm.

[Paul Birkeland]

The 3S4's do indeed not glow.  These battery tubes are "high efficiency", and the filament draws very little current.  They don't get warm for the same reason.

(If the music comes out, it's workin)

[Sonido]

Thanks! One other question if I may. Since the potentiometer is resistor controlled, I'm assuming, does the volume level affect how much power is being used from the battery? I assume it uses the full amount of power always, and the volume knob just applies varying levels of resistance to lower the volume.

[Paul Birkeland]

Yes, the volume pot picks how much of the incoming signal is applied to the grid of the 3S4.