Does changing tube really make a difference in "starved plate" designs? opinions

How much does changing the tube matter in a "starved plate" circuit

  • No difference I can tell

    Votes: 2 25.0%
  • Some, not enough for the cost or trouble

    Votes: 1 12.5%
  • Enough for the cost of an expensive NOS tube

    Votes: 2 25.0%
  • Enough for a different, but not too expensive tube

    Votes: 1 12.5%
  • Feed me 250v

    Votes: 2 25.0%

  • Total voters
    8

Blue Jinn

Rider of the ARPocalypse
Does changing tube really make a difference in "starved plate" designs? opinions

Just curious, You see this come up fairly often, I bought an XXX "tube" preamp and I want to swap out the unbranded tube for a NOS or different modern manufacture 12AX7 (insert famous name here) to make it sound "better." Of course better is entirely subjective, but how much of a difference has it made for folks? We're talking the solid state with a low voltage tube stage which basically operates a tube in a way to deliberately cause exaggerated tube distortion, to "warm" up the signal.

Expensive NOS is also subjective, so whatever your def of expensive might be.

Also, you can include transformers in the 250v option.....
 
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I'm not that certain that it's the make, that makes the difference. Valves always seemed to meet, or exceed their published specs - and when I was using valves for radio transmitting applications, I found that swapping one could make a fair difference - maybe the output would go up, or other performance factors would change. I can't see that the same thing won't happen on audio usage. Plug them in and see?
 
Give me 250 volts (or more).

Just not into those starved plate things. I would consider them an effect. You can find the most esoteric, expensive NOS tube and its not going to do diddly squat to improve the product. Well OK maybe a little bit if the original tube is noisy or something. Seriously? Adding LED backlit mood lightning on the tubes? What part of the sound is that effecting? That is when I quit even looking at that stuff.
 
Give me 250 volts (or more).

Just not into those starved plate things. I would consider them an effect. You can find the most esoteric, expensive NOS tube and its not going to do diddly squat to improve the product. Well OK maybe a little bit if the original tube is noisy or something. Seriously? Adding LED backlit mood lightning on the tubes? What part of the sound is that effecting? That is when I quit even looking at that stuff.

It's def an effect. IMHO, the starved plate gimmick does do *something* I wouldn't question the late John Simonton who designed the TubeHead, and I've had a few boxes with the gimmick. It' spretty subtle which is why I get a little curious whenever someone posts about swapping in the Tungmulfunken tube.
 
LOL at the Tungmulfunken tube. Man those things are hard to find. I understand they went out of production when they could no longer source Unicorn spears to make the grid supports. Shame really.
 
get a mullard and compare the sound of it to the cheapest chinese tube you can find, there is a difference for sure, it's not just hype
 
All tubes will sound different to an extent. whether its better or not is personal preference.

If you are going for a saturation effect, a cheap garbage tube might work better than an nos good one. Tubes are not designed to distort, the good ones will only do it once you hqve run them out of headroom.
 
Starved Plate

Here's a interesting article on starved..imo

I have switched out pre-tubes before, a good handful maybe 4 or 5 different ones, and I dont notice a change.... but then I dont notice an earth shattering change changing pretubes in amps or anything, if anything its minor compared to EQ or mic positioning. imo...

Often times people associate a "starved plate" tube preamp design as being a negative thing. It really is not, and it may be the answer to your desire for affordable warmth in a cold digital world. Read on:

"Starved plate" is not necessarily as bad a thing as it is made out to be.

Without getting into gory technical details, in order to have the same or similar dynamic performance as a well-designed solid-state preamp, a tube preamp typically needs to have much higher operating voltages because it is much less efficient. This requires big, expensive power supplies so that the anode has a massive charge at all times (usually around 300V to reliably deliver 48V signal or around ~30dBu clean headroom). This is what it takes for a tube preamp to compete with a high-quality solid-state preamp in terms of clean, transparent, high-headroom technical specifications.

HOWEVER, most people who are shopping for a budget tube preamp are not looking for clean, transparent, distortion-free sound-- they are usually looking for the "warm," "fire-y," "fattened and flattened" sound of tubes that are pushed hard.

The fact is that a wide variety of fairly inexpensive solid-state preamps (like the VTB-1 in non-tube mode) (the Rane MS1b) (FMR RNP) (Black Lion Audio and many others) can deliver excellent, high headroom, and fairly uncolored sound in the budget price range. When people who already have such preamps go looking for "tubey warmth," directing them towards a super-clean high-voltage tube preamp is often simply directing them towards a more expensive tube-based version of the sound they already have.

The "problem" with starved-plated designs is that they distort and saturate earlier and at lower signal levels. Technically, of course, this is a bad thing, but the fact is that many people shopping for budget tube preamps are actually looking for that saturated/overloaded tube sound, and not for a super-pristine, super-clean high-headroom sound that compares favorably with high-end solid-state amplifiers or whatever.

As such, delivering lower power to the plate can simply be a way to induce that "tubey" saturation at lower signal levels, something like a guitar distortion pedal that uses an overdriven circuit to achieve a saturated sound that would technically be regarded as "bad," but that is in some cases desirable.

In short, there is nothing wrong with using a "starved plate" tube preamp as a deliberate effect, which is frankly what most home studios would use it for. Dismissing them out of hand is a bit like dismissing a distortion pedal because it distorts the sound-- that's the point, really.

Super-clean, pristine, high-headroom, low-noise preamps typically require big, expensive, high-quality power supplies and components, and tube-based designs even more so. And if clean, transparent, and pristine audio signal is what you're looking for, you're likely going to have to spend some money to get it in a tube design.

But if what you're after is distinctly "tubey" analog saturation, then "starved-plate" design is perfectly capable of delivering it at a much lower price. Whether any particular preamp at any particular price is as good as another is a rather subjective call, but people looking for a "hot" tube flavor should not necessarily dismiss so-called "starved plate" designs out of hand. They are, in effect, a sort of "distortion pedal" whose explicit purpose is to deliver overloaded, distorted signal that approximates the effect of the high-end preamps when driven to capacity.

So, don't go throwing the "Starved Plate" pre's under the bus!
 
On a slightly different tack..?

The company I worked for produce a range of guitar pedals that incorporate an ECC83 valve.

Each of the pedals is essentially an overdrive device designed to produce valve distortion that is an extreme version of what the pre amp guys call "warmth". Each pedal contains 2 large (~150 x 100mm) and one small PCBs and almost half of one of those larger boards is taken up with the DC-DC generator that produces 300volts.

This high HT results in the pedals being rather bigger, taller than most on the market and the power supply that feeds them is a non standard, i.e. NOT 9volts, 22volt 2A unit. This size and power requirement has been a cause for considerable market resistance (tho' the pedal do still sell well enough because they are brill!) Therefore, do you not think that IF the designers could have gotten away with an 18volt (say) anode supply they would not have done so?

That all said, if my circumstances change in terms of family health and my own energy levels and time, low voltage valve circuits are one of many things I would like to investigate.


Dave.
 
Here's a interesting article on starved..imo

I have switched out pre-tubes before, a good handful maybe 4 or 5 different ones, and I dont notice a change.... but then I dont notice an earth shattering change changing pretubes in amps or anything, if anything its minor compared to EQ or mic positioning. imo...

Often times people associate a "starved plate" tube preamp design as being a negative thing. It really is not, and it may be the answer to your desire for affordable warmth in a cold digital world. Read on:

{Snip}

I'm not bashing 'starved plate' and maybe the expression invites scorn. I am skeptical that changing out a $3 unmarked tube for a $70 NOS in one of these units will really make a difference and is therefore, not worth the trouble and expense. I admit I've not taken the time to do so and make any meaningful comparison. Audiophiles are will to pay US$1000 for a pair of hand rolled output tubes, so there must be some difference. (!)

I think there is a lot of confusion about "cheap" vs "expensive" tube preamps. My point is there should bey no comparison between a solid state preamp with a low voltage tube stage to add distortion **as an effect** and a tube preamp where the tubes are providing the actual gain. It's not a matter of what is superior.

The former solid state pre will sound and distort differently than the tube pre, in my subjective opinion, and isn't designed ot be driven hard. If I get a chance I might swap in some RCA 12AX7's that probably aren't top of the line but certainly "vintage."

I think the marketing geniuses confuse the issue. The starved plate *does* exactly what the article says it does, and that isn't a bad thing, it's just a different thing altogether.
 
I'm not bashing 'starved plate' and maybe the expression invites scorn. I am skeptical that changing out a $3 unmarked tube for a $70 NOS in one of these units will really make a difference and is therefore, not worth the trouble and expense.
It will make a difference, just like putting a different brand new tube in there will. Not necessarily better, just different.
Audiophiles are will to pay US$1000 for a pair of hand rolled output tubes, so there must be some difference. (!)
Some of them will pay $1000 for special power cables to plug their amps into the wall with. Some of these people are just stupid.
 
It will make a difference, just like putting a different brand new tube in there will. Not necessarily better, just different.

Fair enough, that was why I did the poll. :-) It's not a priority for me.

Some of them will pay $1000 for special power cables to plug their amps into the wall with. Some of these people are just stupid.

I heard that mithril has the lowest capacitance....
 
Fair enough, that was why I did the poll. :-) It's not a priority for me.
The assumption is that NOS tubes will be 'better', more accurate, or what ever. With a design meant to make a tube do things it really wasn't designed for, it seem unlikely that getting an exotic tube for a cheap preamp with distortion effect would be a wise idea.



I heard that mithril has the lowest capacitance....
Yup, the lowest capacitance on the last 6 feet of cable. Never mind the 6 miles of cable between the power station and your house is aluminum... :)
 
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