Which tubes for Art MPA Gold upgrade?

  • Thread starter Thread starter dickiefunk
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Monkey Allen said:
xstatic...what's your opinion of the 'tube debate' relating to the Gold over here:

http://forum.cakewalk.com/tm.asp?m=1543560
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My opinion is Mr. McCue should take his opinion that the purpose of a tube is to generate second-order harmonic distortion over to prodigy-pro:

Mr. McCue said:
The reason YOU want a tube is because it has a generous amount of even ordered harmonics... you may not know that, but I can assure it's safe to trust generations of tube enthusiasts who know it. That's why tubes persist in music production gear. Even ordered Harmonics with a dash of odd ordered harmonics thrown in for taste is the sound of tubes.
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Seriously, post that as a new thread on prodigy-pro and ask for opinions.

You know what drives me nutest about that? That's what a solid-state circuit will do too! Seriously, build a preamp that is just a single class A FET. You know what you get?

Even ordered Harmonics with a dash of odd ordered harmonics thrown in for taste
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So why does anyone use tubes then? It's much easier and cheaper to do that with transistors. (Actually you get mostly second order, with declining amounts of third, fourth, fifth, etc., but you get the point)

Please. I'm honest about my knowledge of EE, which is indeed limited. I have not used current mirrors in any of my circuits, although I have used a LTP in one circuit that might make it to market next year. And I tried it once inside a mic before I decided that was silly.

And I have used tubes too! And I have even shamefully used them purposely as harmonic distortion generators! And I'm probably going to do it AGAIN (much less distortion this time 'round though)! Real EEs mock me for such pursuits, so why would they laud someone who claims that is the sole purpose of a tube?

I don't think either one of us is going to win a Nobel prize, let's leave it at that.

How about this: if you keep the VU meter set on "tube", at 0VU, you will have second-order distortion at about -75dB and third at -80dB. Higher order distortion products I can't measure, I think due to my signal generator's noise but I will have to think about that. Strange because I usually don't have that problem, and the ART's input noise is plenty lower. Hmmm. Suffice to say they are below -90dB. At +3VU, the distortion is about 3dB higher. For those keeping score, that's 0.02% THD. Too high for a strictly clean pre, but I guess too low to make him happy.

But you know what? At low plate (+45V), you get -45dB, -48dB, -75dB, and -85dB. That's almost 0.7% THD!

Do you see why the points that:

a) tubes are supposed to generate harmonic distortion; and,
b) starved plate preamps are bad.

Are not internally consistent? Mr. McCue, why not build starved-plate if that is truly what you want? That harmonic series is EXACTLY what you say you are looking for! (Well, maybe less third :o)




. . . at least with vintage GE tubes, that is . . . ;)
 
Hey ms...hope you don't mind that I offer your thoughts over on the Cakewalk forum for a response from Mike?

I think I will leave it at that then.

Thanks for your views.
 
Monkey Allen said:
Hey ms...hope you don't mind that I offer your thoughts over on the Cakewalk forum for a response from Mike?

I think I will leave it at that then.

Thanks for your views.
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Yes, I do mind. Mr. McCue's opinion of this board is so dim I doubt it will be constructive. I think it is also time you formulate your own opinion without simply going back and forth saying "well, what do you think about this?"

I mean we can talk about this all night long, but until someone builds a circuit, takes a measurement, and has a listen, it will serve little purpose.
 
I wont be building a circuit. I think I will just attempt to formulate my opinion from the friendly help of people such as yourself.
 
Kidvybes... A couple of points I do agree with you on. First off, I don't know for certain how much of a difference a new tube will or won't make in the specific ART preamp that is being discussed here. Much of that really depends on the rest of that preamps circuit path and the tubes actual role in the process through design and implementation. Second, I agree that tube swapping often carries much more audible results in guitar amps etc... However, this is no way means that a big difference can't be a had in other equipment as well. I have noticed that generally speaking that tube mics don't seem to reveal as large a difference in tube swapping, yet the difference is definately still there. It is improtant to remember that changing tubes can have more impact than just overalll tonality. It can and does also effect dimension in the resulting output, things like how fast signals seem to be picked up and released which changes the timbre of a lot of things. These things may not be AS noticable in preamps and mics, but when placed on the right sources they become more apparent. In the end it comes down to how much you value certain things. For me, the generally low cost of adding a good tube to something instead of using a nasty chinese or russian tube is easily worth the money in my recording chain. Realistically, where else can you get such a change so easily and cheaply?

A good example might be my Marshall stacks. In my TSL100 half stack, getting the right Mullard and Amperex tubes in the tone stack, phase inverter etc... was worth the cost to me for the improvements it made. Spending $100+ per Mullard XF2 EL34's though was not worth the cost to me, so I compromised and put a set of Siemens made EL34's in. It still sounded better than stock, not quite as nice as the Mullards, but at 1/4 the cost. When retubing my 1976 Super Lead however, I found no real hesitation to decide on more expensive power tubes like Mullard, Telefunken or Amperex. I view it as a kind of relative thing.

Also, sorry for leaving out Siemens. I do fully understand that not all tubes of a single brand were necessarily made by that manufacturer. I very carefully check all of my tubes before I give any info out on them. If I am not sure of something, I say so. Siemens is a good brand, and there are others that also weren't in my post. I was just trying to point out some of the more common and easy to find brands. Here in the US, it seems that Siemens tubes are not as easy to find as many of the others, so I talked primarily about the tubes which were available over here. Also keep in mind that when dealing with 12 AX7, AT7, AU7, AY7 that most of the US brand tubes WILL have been made over here in the US. The various different companies often only OEM'ed out for certain models of tubes that they weren't currently tooled for.
 
Ok. I've been looking around at tubes to upgrade the stock ones and I've decided to get Mullard and a Telefunken.

I noticed there are ECC81 and ECC83 models.

Which model do you use?
 
Remember to consider if you will use the Gold to record say, stereo acoustic guitar or stereo anything really...I think you want to have a pretty even sound when you record stereo otherwise you could get some issues with phasing or something like that. That's why they make matching stereo sets of mics. On the other hand, you might want to forget about that and favour the different tones you should get from 2 different tubes recording stereo. Or you might just think that it's for the best to have two tube options in the one unit...why not?!

Take anything I say with a grain of salt. I'm considering what tubes to get. Something that would be suitable for acoustic guitar, which is what I mostly track. I haven't even plugged in my Gold yet to hear the stock tubes.
 
I'm looking to record vocals with the MPA Gold so I would like a different tone for each channel.

I have the DMP3 for recording Acoustic Guitar and the Tampa for another tone.
 
A Mullard and a Telefunken should yeild pretty different results though. However, keep in mind, like was mentioned before, I am not sure how much difference the tubes will make in a unit like the ART MPA Gold. The Mullards and Telefunkens however generally sound very different though. If it were me, I might "experiment" with something a little more affordable though ;)
 
dickiefunk said:
What are people using - EEC81 or EEC83?
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That should be "ECC". It doesn't seem to make that huge of a difference in the ART. 81 has a lower gain figure than 83, that is circuit-dependent though, and I think I recall maybe a 3dB difference in the ART. Can't remember exactly. I suspect for most people it comes down to the quality of the individual set of tubes they try--if they get a nicer set of 81s, they will go with that.

I hear 81s are cheaper as they are less popular in guitar amps and thus less demands. But xstatic will know more about that than me.
 
tubes for behringer 1953 mic preamp

I am trashing the tubes that shipped with this rig as they do absolutely zero as far as warmth. any suggestions? I have a friend who collects tubes and hes going to give me a couple but if anyone has been this route with the 1953 any advice would be appreciated. Its good for adding volume and its not noisy at all, but i can crank the warmth knob and i notice nothing.


clevo
 
mshilarious said:
That should be "ECC". It doesn't seem to make that huge of a difference in the ART. 81 has a lower gain figure than 83, that is circuit-dependent though, and I think I recall maybe a 3dB difference in the ART. Can't remember exactly. I suspect for most people it comes down to the quality of the individual set of tubes they try--if they get a nicer set of 81s, they will go with that.

I hear 81s are cheaper as they are less popular in guitar amps and thus less demands. But xstatic will know more about that than me.
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If I used a EEC81 tube (possibly the 12AT7) would this reduce the MPA's 75dB gain?
 
dickiefunk said:
If I used a EEC81 tube (possibly the 12AT7) would this reduce the MPA's 75dB gain?
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ECC81 = 12AT7. They are just European and American names for the same tube. And I did say there is a reduction in gain, but it's not much, about 3dB going on memory (the difference in gain factors in the tubes is 3dB).
 
clevodrummer said:
I am trashing the tubes that shipped with this rig as they do absolutely zero as far as warmth. any suggestions? I have a friend who collects tubes and hes going to give me a couple but if anyone has been this route with the 1953 any advice would be appreciated. Its good for adding volume and its not noisy at all, but i can crank the warmth knob and i notice nothing.


clevo
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Try NOS Mullard 12AT7's.
$30 a pop.
You should like them
I have them in my MPA Gold
It is a darn nice pre for $300 plus $60 for the NOS tubes
T
PS--check out this web site: http://www.dougstubes.com

OOPS-I see you mentioned the 1953...not the MPA
 
What's always troubling about the ART products to me is that if there wasn't a tube in the things, I'd doubt anyone would give them a second glance. For the record this topic was briefly kicked around at Prodigy Pro, and upon viewing the ridiculously complicated schematic (the tube preamps which made the recordings that we associate with a tube sound are VERY simple), I'll side with Gyraf, in that the most troubling thing about the circuit is the absence of input or output transformers. Yes, the tube is running at a voltage above your typical starved plate designs, but it's not reasonable to assume that this resembles any classic tube circuit. The schematic showed a mile of solid state input circuitry, a tube, and a mile of solid state output circuitry.

Every sample I've heard posted of the MPA Gold show it to have a nice clean sound. That's great, but there nothing of the character that you'd get from a UA or Sebatron pre, or the exaggerated hi-fi character of a Telefunken. If they just stuck to a nice solid state circuit, they could probably achieve the same result at a much cheaper price.
 
craigmorris74 said:
What's always troubling about the ART products to me is that if there wasn't a tube in the things, I'd doubt anyone would give them a second glance. For the record this topic was briefly kicked around at Prodigy Pro, and upon viewing the ridiculously complicated schematic (the tube preamps which made the recordings that we associate with a tube sound are VERY simple), I'll side with Gyraf, in that the most troubling thing about the circuit is the absence of input or output transformers. Yes, the tube is running at a voltage above your typical starved plate designs, but it's not reasonable to assume that this resembles any classic tube circuit. The schematic showed a mile of solid state input circuitry, a tube, and a mile of solid state output circuitry.
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I think you raise good points. I can and can't blame ART for tube mania. In one sense, the MPA Gold is the pinnacle of the modern starved-plate tube preamp, except that it isn't starved plate ;) If no one had ever done a starved-plate preamp, then the MPA Gold would not exist.

Compare to the Rane MS1B, which is lauded, but in reality nobody buys. OK, that's an exaggeration, but Rane should sell more of those than the ART, but they don't. So tube marketing wins out.

In the case of the MPA Gold, ART has made it so the tube marketing doesn't come with a sonic penalty. You decide if that is good or bad. The box has a lot of other nice features, but would it get attention without the tubes? It would probably have to drop $100 in price, which is $40 or $50 to ART, and the tube bits of the circuit probably only cost them $10.

I have on more than one occasion decried the lack of a truly affordable basic solid-state pre. I would do it myself, but the metalwork and especially UL testing are daunting. And whenever you see a simple solid-state design, immediately there is the temptation to make it a lot more complex and thus expensive. I will say that the ART doesn't sound like a basic dual-stage OPA2134 pre, that is quite obvious.

Transformers are really expensive, too. That's why ART doesn't use them. But I wouldn't condemn hybrid design altogether, it has a lot of possibilities. Purist notions forbidding audio-path transistors seem silly when so many discrete and even IC solid-state designs are prized. And back in the day, would designers have used 20 tubes in a circuit if the financial, heat, and power budget allowed? Most of the basic circuit configurations have been known for a long time.
 
Excactly, I'd feel better about what they were selling if they'd offer one simple, but very good solid state design, and maybe a transformer input, tube pre with maybe a nice, simple solid state output stage.

But you're right, mshilarious, they probably wouldn't move a lot of units if they listened to this adivice.
 
craigmorris74 said:
Excactly, I'd feel better about what they were selling if they'd offer one simple, but very good solid state design, and maybe a transformer input, tube pre with maybe a nice, simple solid state output stage.

But you're right, mshilarious, they probably wouldn't move a lot of units if they listened to this adivice.
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Presonus used to do the MP20/M80, which had a Jensen transformer input, OPA134 gain stage, and I think a DC servo on the output (not sure about the servo though, it's been a while). It was popular for a while, around 1998-2001, but after that nobody seemed to like it much. They switched from Jensens to some sort of Jensen-clone, but I had a unit with both and they weren't that different. It was not that expensive, but they discontinued it a couple of years ago. You can find them used for less than $100 per channel.

Anyway, ART has done a nice IC solid-state design that happens to have a tube in it. If that's what you want, I don't see why the tube would stop you (other than the need to upgrade the tube).
 
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