Starved Plate Design

[CrowsofFritz]

Can anyone go into more detail regarding this? It seems to me that a starved plate design would produce saturation at lower signal levels, which may be what some home recorders want, and it’s not necessarily a marketing gimmick.

I read recently that someone called the ART MPA II I have a starved plate preamp, which is actually wrong. I think the old one was starved plate but the new one has a high voltage setting.

[Farview]

There is a lot of sillyness around this subject. Yes, a starved plate tube will distort more easily than one that is getting the proper voltage. If that is what you want, you're good to go.

There were a bunch of companies that made SS preamps and put a starved plate tube in parallel, sometimes with an LED behind it to make it glow, just to add a little distortion to the clean SS signal. That was a marketing gimmick, since the tube really wan't doing the amplifying.

High end tube preamps aren't designed to distort. Of course you can overdrive them into distortion, which might sound better than overdriving a SS preamp, but distortion wasn't the point of the design.

People will get tripped up on all of these things being call "tube preamps" and being lumped into the same category. The people with the high end stuff are offended by the low end stuff, and the guys with the low end stuff tend to think they have something other than what they have.

[CrowsofFritz]

Thanks Fairview. Not sure why companies are putting in LEDs to simulate tubes. Doesn’t it only take 7 volts for the tube to light up?

[Greg_L]

Thanks Fairview. Not sure why companies are putting in LEDs to simulate tubes. Doesn’t it only take 7 volts for the tube to light up?

Tubes don't glow bright enough to satisfy the people that really need to see the "tube glow" from their super cool tube gear. Some perfectly healthy fully functioning tubes have very little "glow" at all.

It's all bunch of hogwash nonsense.

[Tadpui]

I remember the old ART Tube MP Studio single channel preamp I had a long time ago. I'd just learned about the starved plate thing, so I took the cover off and sure enough, there was a little orange LED behind the tube to make it look like it was glowing

[CrowsofFritz]

Thanks Fairview. Not sure why companies are putting in LEDs to simulate tubes. Doesn’t it only take 7 volts for the tube to light up?

Tubes don't glow bright enough to satisfy the people that really need to see the "tube glow" from their super cool tube gear. Some perfectly healthy fully functioning tubes have very little "glow" at all.

It's all bunch of hogwash nonsense.

Lmao yeah, that’s silly. I need to do a test to see how much more gain I can get from my high voltage setting vs low. As of right now, I’m getting usable levels regardless of the button, but I don’t really push the preamp too hard. I notice that, at high enough output, it does distort quite a bit at low voltage even before the signal clips in my DAW, so it would be worth testing with the high voltage setting.

[CrowsofFritz]

I remember the old ART Tube MP Studio single channel preamp I had a long time ago. I'd just learned about the starved plate thing, so I took the cover off and sure enough, there was a little orange LED behind the tube to make it look like it was glowing

That preamp, I believe, IS a starved plate design. Not enough volts. The ART II pre doesn’t have a section where you can see tube glow, so none of that nonsense.

[Greg_L]

If your tube is glowing so brightly you can see it through a piece of gear, then it's probably red-plating and about to burst into flames. Enjoy.

[Greg_L]

I'm also curious about the term "starved". Starved compared to what? What is not starved? A plate on a 12AX7 can handle about 250vdc. Is anything less than max "starved"?

[CrowsofFritz]

I'm also curious about the term "starved". Starved compared to what? What is not starved? A plate on a 12AX7 can handle about 250vdc. Is anything less than max "starved"?

The ART MPA II has about 150+ volts when set on high, and it’s not considered a starved plate (though it still is to some, apparently). The MP that Tadpui was talking about only has about 40. I don’t know what the threshold is, though.

[rayc]

I did a review of a starved plate preamp here:
http://therecordingrebels.com/viewtopic.php?f=48&t=2584
It's a Behringer MIC100 and the tube dials in some dirt...not pretty. As a clean Preamp its was useful when I bought it.

[Greg_L]

The ART MPA II has about 150+ volts when set on high, and it’s not considered a starved plate (though it still is to some, apparently). The MP that Tadpui was talking about only has about 40. I don’t know what the threshold is, though.

150vdc is pretty standard for a plate in a 12AX7.

40vdc would have the plate so starved the tube probably won't even pass electrons through it.

[CrowsofFritz]

I just tested the high vs. low plate voltage on my pre. The low voltage definitely distorted with lower levels than the higher voltage.