This all depends on the tube...12AX7 vs 12AU7 or other ECC82-ish require different voltages on the plate...so in answer to your question at 300v this is normally NOT starved plate...(the plate is the part of the tube where the electrons are headed to so the voltage builds up there and this is normally where the high voltage is required)...you can build up plenty of electrons with 200volts...

My main point in this was that there are a lot of "tube" things that are really not functioning the way tubes are designed, they are simply exploiting the low voltage requirements of the grid and applying very little voltage to the plate...probably for safety, also its really kind of hard to tame the noise that is the magnetic field created by a really big transformer that provides the high voltage...you cannot generate high voltage without a huge transformer somewhere and that thing creates its own set of issues in way of hum, vibration and heat dissipation....so if your tube device is sitting in a 1RU rack or using a little 12v/9v dc wall wart you can almost guarantee there is not a huge power transformer providing high current, its just physics.

Thats one of the reasons people love the LA2A because they are using a full saturation on the tube, but if you have ever seen the guts of one you see a huge transformer (the originals hung them off the back outside the unit)

I just built a REDD 47 2 stage tube pre, it took 3 days to solder and a week and a half to tame the noise...swapping out input transformers and out puts, shielding, moving the power tranny etc...

That being said there are ways to get enough voltage on certain tubes (12AU/AY/AT-7) so that the plate is generating the voltage buildup that makes it a true tube design...

The Sebatron is a nice device and follows a high voltage design as does the Summit...I think it might help to think of it this way...

A Fender, Marshall, or Vox guitar tube amp generally uses two tubes at least...these things are heavy, hot, and high voltage...now put one of those in a pre-amp...if you think you can run a Marshall JCM800 on a wall wart you've never turned one on...if you think you can slide it into a 1RU rack case or stomp box it is obviously NOT going to be the same beast...but there are companys selling"tube" stuff that advertises "true tube" design...Bear-Ringer and the little Presonus tube thingy comes to mind...but there is no way they can possibly be doing what an amp is...

The plate needs a lot of voltage (more than 110) this will require a huge power-up transformer somewhere...200v COULD be starving the plate but it depends on the design...the U67 typically requires about 210volts at the plate...(psu side)

You know tube stuff when you hear it...its the difference betrween a JCM800 gold head and one of those opamp amps they sell to replace it...

Don't get me wrong, there's a place for opamp pre's (The Mozart console and many others are all opamp based and made tons of great albums) its just that at the smaller studio level a really hot tube mic into a tube pre has the capacity to set your signal chain apart from all the other IC based studios and when just about everything now-a-days is done in the box, capturing iron and tube in the signal chain makes a huge difference in the mix where code just can't keep up...

This is obviously my opinion...but the records we call "classic" are that way for a reason...if modern technology is all that and a bag of chips then everyone and their dog would be able to match the White Album for tone and space, but its been a crap-shoot ever since "Jagged Little Pill" and the advent of the Nyquist theorem in the studio...I love some of the new technology and theirs plenty of good stuff being made, but there is also something we have left behind that had value, my opinion is a great song performed well into a classic signal path is a great forumla for a lot of fun...

And being a DIY guy I think its not outside the lines to create some of it yourself...if you can solder and have the time to learn its a really fun expereince to build your own...the 1176's I have built blow away the units I bought from UA...and maybe thats a big part of whats missing, the REDD 47 consoles were built bu the engineers at Abby Roads...no one does that anymore...

Razorwit


Hi Psychobillybob,
The starved plate stuff is interesting to me (and a topic that I freely admit I know nothing about). Is +350 kind of the mark at which it becomes no longer a starved plate? I ask because I use some tube gear and I'm curious about it's design. For example, Sebatron says of their preamps that their "Anode Voltage is approximately +300VDC". 

Another example, Summit (more gear I own) says: "We use 185V there, and never use starved plate, low voltage designs. All amplifiers operate on a gain curve with a certain 'sweet spot' where the vacuum tube manufacturer's specifications are ideal. We stay in the sweet spot. Starved plates are often characterized by unexpected gain curves and poor consistency from device to device and over time, with exaggerated distortion characteristics".

Just wondering about your thoughts on this stuff and I certainly value your opinion on this.

Dean

I gotta give props to the new Art stuff. I have serveral of the ART MPA II Reference Series Tube mic pres and I especially like my 2 ART Pro Channel II for the additional eq/comp options

Also I was just over ar GS and a thread over there had some sound samples of a hardware LA-2A against the ART Pro VLA II Tube Compressor  and it was quite telling how nearly identical these units sounded. Not exactly the same mind you, but waaay in the same ball park
These are all great gear for the money

Can I buy a REDD 47 2-stage from you, Physchobillybob? 

Del

gunboatdiplomacy




............ so I purchased a BAE DMP which is solid state. my first choice was a UA 610 Solo, but valve+valve might be a little too much. 

Hey gunboat!
You say something here that peaked my interest. "valve+valve" can you expand on that?


Do you mean a valve mic plus a valve pre amp? And what effects will that create?


Thanks for your reply and from those of others!

yeah, a valve mic plus a valve pre.  i didn't go that route; i thought that perhaps using a mic with a  colored sound along with a pre with a colored sound might be too much coloration (if that's even makes sense). and so i ended up with a solid state pre (BAE DMP). of course, that's "colored" as well; it's not like the Grace or some other super clean pre, but i figured that the combination would sound good once you start stacking vox and other tracks and i wouldn't be stuck with that "dark" tube sound on everything.
 
oh and sorry to be a pendant, but it's "piqued my interest".
/english major

Not yet...we have proto-boards coming back from the pcb company...but this will be available in a 2RU rack unit by mid-summer...(< than 2k for 2 channels depending on tube sources)...also trying to source those really cool "airplane faders" just for nostalgic emphasis!

Units will be hand soldered, and include a few customization choices.

brconflict


Can I buy a REDD 47 2-stage from you, Physchobillybob? 

Pretty cool! Keep us posted!

FWIW
Im a singer, and so I am always trying to get a nice sound for my vocals.
Mics seem to make the biggest difference I have found.

Pre amp wise, I use a Focusrite Trackmaster Pro Platinum in my studio.
Although it has a long fancy name, the focusrite is not that special sounding, but I use it for it's other features rather than the sound of it.

I bought and subsequently sold straight away a small Art Studio V3 Preamp.
It had a low volt driven valve in it.
It was utter rubbish. Ebayed that back out from whence it came.

I also have TC Helicon Harmony-G xt.
Now this little baby really sounds good when simply used as a pre amp.
I don use the harmony features, but just use it in the mic chain.
It sounds great, really great, only cost around £220 ($240)
I'd never part with it.

I use mostly a Beyer-Dynamic Tgx480 onstage and a Shure KSM27 in the studio. Both sound very nice and suit my voice (IMO).
Also, sometimes use Shure Beta58 for a change.

Never been lucky enough to use any decent pro Pre amps at all, so can't talk about those.

C ya