ART Digital MPA...Golden?

V

Vantage

New member
The other day I spotted this great looking 2 channel pre on sweetwater for 200 hundred less than anywhere else(yes it's brand new, and not discontinued AFAIK). MSRP is ~750, it usually streets for ~580. The magazine reviews downloadable from the manufacturer's site tend to like it, but real world info on message boards(if that can be considered "real world") is few and far between. I like the fact it has digital out in the form of coax so that I can route it directly to my AP192. Anyone have a remote clue about this product? any experience with it would be even more valuable. Despite higher logic, my 6th gear sense said I should order it, so it's arriving tomorrow...hopefully I'll hear something positive from you guys :eek:
 
Vantage said:
The other day I spotted this great looking 2 channel pre on sweetwater for 200 hundred less than anywhere else(yes it's brand new, and not discontinued AFAIK). MSRP is ~750, it usually streets for ~580. The magazine reviews downloadable from the manufacturer's site tend to like it, but real world info on message boards(if that can be considered "real world") is few and far between. I like the fact it has digital out in the form of coax so that I can route it directly to my AP192. Anyone have a remote clue about this product? any experience with it would be even more valuable. Despite higher logic, my 6th gear sense said I should order it, so it's arriving tomorrow...hopefully I'll hear something positive from you guys :eek:
Click to expand...

I saw that too . . . and bought the demo for $379 :D One thing I like about ART gear is that it's pretty easy to mod. I used to have a Pro MPA and that was a decent unit, the Gold has a couple of improvements plus the converter . . . should be interesting, I think.
 
Cool! Well, when it arrives we'll have to trade opinions. My feeling is that it will be an excellent piece of gear. On the otherhand, I'm not expecting as much from the C1 that I ordered along with it...male vocals if nothing else I guess. In any case it will be better than the old dynamic I was using when I didn't know any better. I saw the demo unit on sweetwater too, but personally I dont mind paying the extra twenty for a factory seal and absence of fingerprints.
 
Vantage said:
Cool! Well, when it arrives we'll have to trade opinions. My feeling is that it will be an excellent piece of gear. On the otherhand, I'm not expecting as much from the C1 that I ordered along with it...male vocals if nothing else I guess. In any case it will be better than the old dynamic I was using when I didn't know any better. I saw the demo unit on sweetwater too, but personally I dont mind paying the extra twenty for a factory seal and absence of fingerprints.
Click to expand...

Yeah I will void my warranty within 15 minutes of receipt so it's no biggie to me :o :D
 
mshilarious said:
Yeah I will void my warranty within 15 minutes of receipt so it's no biggie to me :o :D
Click to expand...
What kind of tubes are you putting in it and how would that change the sound? Do the stock tubes leave alot to be desired? questions, questions, blah...
 
What's the difference between the Digital and non-Digital? Just the fact that it has digital outputs and such? The regular one is only $299.....tempting....very tempting.

Wonder why so cheap? Is it a good pre? Better than my VTB-1?
 
Vantage said:
What kind of tubes are you putting in it and how would that change the sound? Do the stock tubes leave alot to be desired? questions, questions, blah...
Click to expand...

You won't void the warranty changing tubes. I use vintage US tubes, I've found GE to be pretty reliable, but really it's best to get a lot of them, test them all, and then resell the ones you don't like. It's tougher to take this approach if you want it for a stereo pre, then you might want to buy new tubes.

As for other changes, I swap some capacitors, beef up the power supply, and swap opamps. On this unit I might try changing the inputs to transformer balanced, I just picked up a couple of good transformers that would be perfect.
 
Myriad_Rocker said:
What's the difference between the Digital and non-Digital? Just the fact that it has digital outputs and such? The regular one is only $299.....tempting....very tempting.

Wonder why so cheap? Is it a good pre? Better than my VTB-1?
Click to expand...

Well ART has a bit of a reputation hole to dig itself out of before I'd go that far, but the Pro VLA has been well received. This unit has switchable plate voltage--which is a clever idea, but they are a bit cagy about the high voltage setting--supposedly it's 300V, but they use some funny language to describe it. I'll slap a multimeter on it real quick, as soon as I get it. If it is full plate, and it sounds as good as the usual marketing hype, I'd say it should be a good deal.

I'll try to post a clip too, with both voltage settings. Y'all might have to suffer my singing since I don't know anybody nearby who has actual talent :eek: :o ;)
 
mshilarious said:
they are a bit cagy about the high voltage setting--supposedly it's 300V, but they use some funny language to describe it. I'll slap a multimeter on it real quick, as soon as I get it. If it is full plate, and it sounds as good as the usual marketing hype, I'd say it should be a good deal.
Click to expand...

The way the advertising reads is: "provides the equivalent of a 300V power supply on the high voltage setting".

I'll be interested in what the results of your multimeter test come up with. I'm curious what they mean by the "equivalent" of 300V.
 
SonicAlbert said:
The way the advertising reads is: "provides the equivalent of a 300V power supply on the high voltage setting".

I'll be interested in what the results of your multimeter test come up with. I'm curious what they mean by the "equivalent" of 300V.
Click to expand...

OK, here is the verdict:

170V.

Dunno why they market it as 300V, 170V is certainly not starved plate :confused:

Here are my other observations from a peek under the hood:

This is a big step up for ART. The PSU has a toroidal transformer, a goodly amount of capacitance (don't know the brand though--Jun Fu?), and heatsinks on all the regulators. It has the usual ART opamp stages around the tube, but this time, they are socketed and BB OPA2134!! The variable impedance control works off a circuit of about a dozen transistors. It is remote from the rear input PCB, and not easily isolated, so I'll scrape my ideas for a transformer balanced input. The other opamps on board are 5532s, I'm guessing those are for the differential input & output.

The plate voltage must be stepped up right near the tubes, because the PSU caps are 100V, but there is a big 100uF cap right next to each tube at 250V and a diode feeding it.

Converter chip is AKM5394A :) and it's got a couple of Wavefront chips to drive the ADAT.

Tubes are generic Chinese 12AX7. This will probably be the only change I make, other than maybe swapping some of the signal path caps.

Haven't listened to it yet :rolleyes: but all this is very encouraging. :)

Oh, one more weird thing: the low plate voltage setting is a mere 14V, but the ART Tube MP is 45V :confused: On the "Normal" :rolleyes: setting, this thing is probably gonna distort like a beast. That could be a good thing for instrument DI if ART tamed the dreadful clipping noise the Tube MP makes.
 
OK I spent all day playing with this. I did swap the stock tube for a vintage GE I had. This is my cleanest tube from my stock; I have tubes I've selected for more pleasing harmonic distortion, but this is a nice clean one.

First reaction: the gain staging is complicated. The manual spells out some things I wouldn't have known before, but are probably unchanged from other MP versions. The input gain control is for the first opamp stage, and the +20dB switch increases tube gain. There are separate output gain controls for analog and digital output. I'm guessing this is the second opamp stage, maybe it's fixed gain at +10 and the controls independently attenuate that level :confused:

The metering is cool. There is a dedicated LED strip for the digital outs, with peak hold. The VU meter is switchable between output and "tube", which shows you how hard the tube is being drive.

Armed with this knowledge, with the plate voltage set on high, I cranked the input gain to +20dB and engaged the +20dB switch, for max possible tube drive. Those settings would be suicidal on the MP, but generally they worked fine here. Checking the difference in tone between the two voltage settings, I don't hear a reason to ever use the low voltage setting. It distorts earlier and more nastily.

I tried it with acoustic guitar, electric, and bass DI, and it was great for all three. Also did a vocal with no complaints.

In summary, I think ART has gone from making a good DI box to a great DI unit. I wish I had a decent vocalist to try it with mics :o but with all the gain options and the impedance control, it seems you could dial in about anything.

Edit: On the basis on the "Ramones Rumble" track being too prejudicial to the poor MPA, here's a few bars of "Every Breath You Take", NO SINGING!:

Full Voltage Police

At the end there is an arpeggio at the 13th fret, once with max tube gain, once with min tube gain, you can hear the range there pretty well. Note that this is a Gibson The Paul (thinbody Les Paul), so it's a pretty mellow instrument to start with. I like mellow :) This is with both pickups on, and full volume/tone on both, DI, no effects, dynamics, or EQ whatsoever!







Here's the Ramones Rumble thread for those looking to hear something funny:

http://www.homerecording.com/bbs/showpost.php?p=1736455
 
Last edited:
Big Kenny said:
i mean no disrespect but....ewwwwwwwwwwwww. I don't think that sounds so good.
Click to expand...

Hehehe, yeah I have no illusions about the vocal talent ;) This is why record and not perform.

I clipped the acoustic a little, but that didn't bother me enough to retrack. I do like the bass tone.

Maybe I should post a file sans vocals :rolleyes:
 
Kenny et al: please note new clip above :)

Also, not the best comparison, but on the Acoustic Piezo Rumble I did a track with my modded Tube MP. There's no question to me the Digital MPA sounds better, given that ART adopted my opamp mod :D, and I used vintage tubes in both, it must be the plate voltage making the difference. There are a few places in this track that the MP clips where the DMPA wouldn't have:

http://www.homerecording.com/bbs/showpost.php?p=1730950&postcount=80
 
The clip you posted with the LP sounds warm and mellow....it's nice.

But...would this pre-amp be much better than the VTB-1, which is what I currently own? In your opinion, of course.
 
Myriad_Rocker said:
The clip you posted with the LP sounds warm and mellow....it's nice.

But...would this pre-amp be much better than the VTB-1, which is what I currently own? In your opinion, of course.
Click to expand...

Haven't used that, so it's hard for me to say. I know the VTB-1 is regarded as the best of the starved-plate units.

The feature set is very similar, except for the digital out of course (and going out via SPDIF, I found the ART to be a nice quiet unit). But this is still a hybrid unit, still no transformers, and it doesn't inspire a reaction in me of "I must kill for this preamp!" It's also twice the price per channel of a VTB-1, and that's only at Sweetwater, other stores still list it at $599.

If you need the digital output, I would give it serious thought. That was the main reason I traded up. I was pleasantly surprised by the sound as well as the components they improved.

One thing I didn't think of last night: here is the same guitar part, same settings but on low voltage--that might give you a sense of the difference you would get going from another starved plate unit:

Starving Police
 
Digital MPA

Yes the sound is fantastic, and their is no noise AT ALL. I'm running my Vantage vs600 electric guitar as a DI and vocals and acoustic through a mic on the other channel, both through the spdif digital out to my M-Audio AP 192 digital in. I always keep the input gain at 12 to 3 O'clock as anything more seems to distort and have a really dirty sound. Everything is warm, full, and punchy...a steal for $400 in my opinion. I opened 'er up and even though I don't have the knowledge of electronics that mshilarious does, everything looks tidy and high quality.
Now, as far as ART's QA department, I don't have very nice things to say. From what I wrote to sweetwater...
"...The measurement paper in the 1st channel VU is deformed and protruding
> into the display a few mm because of moisture or some other reason.
> The indicator is now stuck permanently on the right side of the graph
> because the paper prevents it from going back to its resting place..."

IT could have happened once it left the factory, but from the extent of the deformation I really doubt it. I hope this is just an issue with the one I received, because other than that problem, it's a great unit. When I get my second one, I'll look into replacing the tubes and I should be happy as a clam.

mshilarious... would the issue of distortion when the gain knob is near the maximum be fixed if I replaced the tubes or is that a problem with the unit itself?
 
Vantage said:
...The measurement paper in the 1st channel VU is deformed and protruding
> into the display a few mm because of moisture or some other reason.
> The indicator is now stuck permanently on the right side of the graph
> because the paper prevents it from going back to its resting place..."
Click to expand...

I would send that email to ART as well, and ask them to ship you a new VU meter as it's under warranty. Manufacturers prefer to avoid returns, so they will probably be accomodating.

mshilarious... would the issue of distortion when the gain knob is near the maximum be fixed if I replaced the tubes or is that a problem with the unit itself?
Click to expand...

I wouldn't call it a problem, that's just the nature of the distortion you're going to get when the tube gets way oversatured. Actually with the higher plate voltage in this unit, compared to ART's other tube pres, that distortion comes at a higher level and sounds a bit better. I cut a harmonica track that was deep into tube distortion, and while not as good as a nice tube guitar amp, it wasn't bad. So I would consider a "feature", albeit one that is usually best avoided.

I'm not very familiar with tube amp design, so I don't know if that is inevitable, or if there are still corners being cut. There are good reasons for hybrid design, but this type of distortion might be the result :confused: Like I say, easy enough to avoid. In total this unit has plenty of gain before distortion.

The input gain knob sets the level going into the tube from the first solid-state stage, so it's very dependent on the level of your source as to what the proper gain setting is, whether 12:00 or 3:00. For example, with a dynamic mic on a quiet source, you might need all that gain and still not distort. I find that setting the VU meter to tube, engaging the +20dB switch, and setting the input gain to keep the meter below +3VU on the peaks gives me the best possible tube tone from the unit.

With a better tube, that distortion might sound nicer, but it will still be there.

An interesting experiment might be to keep that knob as low as possible, and daisy-chain the two channels to get two tube gain stages.
 
You must log in or register to reply here.
Back
Top