ART Pro VLA II Question

Ignatius-

Ignatius-

New member
I just picked one of these up from some guy on Craigslist and have been having a bit of trouble with one of the channels... it was supposed to be brand new, but the first channel starts distorting if the signal gets too hot going in or out.

The second channel works great (meaning I can crank the signal way higher than the first channel w/o distortion), but I am at a loss as to what to do. I opened it up and everything looks fine, so I am thinking it might be something to do with the tube in the first channel(?). Any help would be appreciated.

Oh, and I have read that it is super easy to change the tubes, but I can't for the life of me actually get the tube out... maybe I am being a little too tender. Should it come right out, or do I have to give it a little tough love?
 
I'm with you - I'd want to swap the tubes to see if the problem switched to the other side.

I just looked at the online manual and it talks about replacing the tubes, but doesn't say how.

They're just 12AX7A's... very common. How about spray a tiny amount of Deoxit D5 (or whatever electronic cleaner you have) around where the tubes plug it... maybe they are just stuck from being dry and heating up a bunch of times.
 
Gently rock the tube as you pull. It'll come out. Just work it.
The 12AX7 is a dual triode; one half is running channel 1, the other half channel 2. If that IS your problem, that'll be a cheap and easy fix.
You can also try substituting different 12A_7 models- example-12AU7. They have different gain values. 12AX7 is the highest iirc.

Edit: Oops. I just looked it up... it actually does use 2 12AX7s, so you could try swapping them.
Hmm. I'd like to see the schematic to see how they actually use them....
 
I switch out tubes all of the time. Some are very easy and some can be a ****** but they do come out.
The last one I changed out was from a MXL V77 and I thought that I was going to break it before it would come out but I finally got it.

I have the e-mail of a person who specializes in NOS tubes and will be able to suggest from his stock what ones will be the best to install I'll be back later to post or PM you his info....got to run now though.
If I should forget PM me.






:cool:
 
http://www.audiotubes.com

this is a great resource and the guy is super helpul and will even make recommendations on which tubes will work best for you based on the sound/charater/coloration you are looking for in your tube gear. However he mainly stocks N.O.S. (New Old Stock = vintage tubes) so they can be a little pricey. I just got some tubes from my recently aquired ART Pro VLA from him

http://www.tubedept.com
Has new manufactured tubes as well as N.O.S. so more variety in price from low to high
 
Bristol Posse said:
http://www.audiotubes.com

this is a great resource and the guy is super helpul and will even make recommendations on which tubes will work best for you based on the sound/charater/coloration you are looking for in your tube gear. However he mainly stocks N.O.S. (New Old Stock = vintage tubes) so they can be a little pricey. I just got some tubes from my recently aquired ART Pro VLA from him

http://www.tubedept.com
Has new manufactured tubes as well as N.O.S. so more variety in price from low to high
Click to expand...

Hey Bristol ...these are great resources as well ! The one I was thinking of is proaudiotubes@aol.com..... A great person and even better quality tubes.

It's to bad that we get those cheap Russian or Chinese tubes to start with but I guess it's to keep the prices of the units and tube mics as low as possible.





:cool:
 
moresound said:
Hey Bristol ...these are great resources as well ! The one I was thinking of is proaudiotubes@aol.com..... A great person and even better quality tubes.

It's to bad that we get those cheap Russian or Chinese tubes to start with but I guess it's to keep the prices of the units and tube mics as low as possible.





:cool:
Click to expand...

Well I just found I got an absolute score on my second hand VLA. Got it off craigs list for $90 bucks, just opened it up an found that it has been retubed with N.O.S. RCA and GE tubes that probably cost more than the original unit new.

Sweet:D

I'm gonna keep the mullard and phillips N.O.S. tubes I ordered for flavor variations but I have to say I love this unit even more than I did when I got it initially
 
WOW Bristol, that is a great score, the fellow selling you the unit didn't tell you about it?
Or did he get it second hand as well and didn't know about it?

How about a picture!





:cool:
 
There may be a problem with the trim pots, which is used to fine tune the gain for each channel. You might want to start there.

Replacing the stock tubes with expensive NOS tubes is like putting high octane racing fuel in a low compression engine. The Pro VLA does not run full plate voltages. It uses a low plate voltage. The newer units are designed for dual triodes of *low mu* such as the 12AT7 (ECC81), which were originally designed to handle high plate voltages, not the low plate voltages found in the Pro VLA.

If we were talking about a tube in a preamp in stage one (V1), you might hear some sonic differences if you swapped out tubes. But, you are NOT going to hear any difference by swapping tubes in a Pro VLA! The whole purpose behind tubes is to get some of that musical distortion when a tube is running at its *intended* plate voltage - not when it's starved for voltage.

I like the Art Pro VLA, but I don't consider it a tube compressor. Nor do I hear any smooth tube distortion. What I hear is solid state with some subtle coloration.
 
sound125 said:
I like the Art Pro VLA, but I don't consider it a tube compressor nor do I hear any smooth tube harmonic smooth distortion. What I hear is solid state with some subtle coloration.
Click to expand...

I don't believe ART claim it is a tube compressor, From the owners manual:

A R Ts PRO VLA circuitry is a hybrid design utilizing the latest
and most advanced solid state and tube technology. Using a
transformerless design throughout, the PRO VLA maintains
exceptional signal integrity and extremely low noise. Its VCAless
design utilizes optical electronics (Vactrol) coupled with a
12AX7 vacuum tube gain stage for superior musical performance.

Which completely agrees with your consideration that it is a solid state compressor with a tube gain stage for coloration
 
moresound said:
WOW Bristol, that is a great score, the fellow selling you the unit didn't tell you about it?
Or did he get it second hand as well and didn't know about it?

How about a picture!

:cool:
Click to expand...

The guy didn't know what he had, from what he told me he was resellling it after getting a bunch of stuff from a local studio that was cleaning house, initially he thought is was a pro VLA II and was basing his pricing on that, I got him down to under $100 bucks when I saw it and found it was infact the now discontinued VLA and was no longer available and haggled him down due to it being the older version. So the NOS tubes were a nice surprise

I'll see if I can post some pics at the weekend
 
So... I guess I didn't ever reply to you guys! Sorry about that (whoops), and thanks for the help.

I finally got around to purchasing new tubes for my Pro VLA II just this week (a pair of JAN Phillips 12AT7WC's - yeah, I know how long it took) and the problem is still, well, a problem. I don't know what is wrong. Again, I am having trouble with the first channel. Probably 75% of the time it is fine. But sometimes it will linger in this low-level, semi-distorted sound and then cut out completely. Other times I will be rolling along, and this wave-like distorted sound will come through once or twice and the signal will drop out completely, etc.

Basically, I was wondering if anyone has any ideas as to what else it could be if it is not the tubes. I don't know if the description of the tone helps, but it is very distinct... Anyway, if you guys have any ideas let me know. It is not that big of a deal, I just don't want to be in the middle of a mixdown and have the left channel shit out on me. It could get irritating!
 
No, I use it to track as well, but it isn't a problem since the second channel works fine... is that what you're asking? I think I might just pick up an FMR RNC. I am feeling like that might be the way to go. There is one available around here and I have heard so many good things about them. Is $125 used a good deal? I feel like I could work that price down a little bit... maybe.
 
Ignatius- said:
No, I use it to track as well, but it isn't a problem since the second channel works fine... is that what you're asking? I think I might just pick up an FMR RNC. I am feeling like that might be the way to go. There is one available around here and I have heard so many good things about them. Is $125 used a good deal? I feel like I could work that price down a little bit... maybe.
Click to expand...

No that's pretty common for a used unit maybe as low as $100.
Take a look at the FMR RNLA 7239. ;)







:cool:
 
Thanks, I will look into that piece. I've heard great things about almost all of FMR Audio's products, but I might just go with the RNC since it is readily available. I still want to try and fix this ART though. I don't know where I'll start, but I'll try and figure it out.
 
my experience (though not vast) is that the tubes in the low/mid priced gear are production tubes, and who knows where they fall in the specs, and if you'll immediately plan on replacing the stock tube with NOS that were designed to be non-microphonic and very low noise you'll be pleasantly surprised at the clarity, the lack of graininess and/or phase issues most of the stock tubes seem to possess, compared to the stock tubes

yes, it's a bit pricey, but there is a real reason beyond bragging rights- and you'll find your favorites over time

I'm rather partial to the NOS/Mil spec RCA black plate D getters or the GE 5 stars

The UK Mullards are quite nice too
 
Thanks for the info. I am actually pretty happy with these JAN-Phillips tubes... maybe sometime down the road I'll get some NOS tubes. I really considered it, but I didn't feel like shellin' out $60 on tubes. ($20 was more in the budget). :)
 
Sorry to resurrect this thread, but since I replaced the tube that was giving me problems I still have been having the same issue... I've just been too lazy to figure out whats wrong with it. Again, the left channel on my Pro VLA II sometimes works right after I turn the unit on, but it cuts out shortly after and I get no sound after that. I have been using it as a one channel type thing, but I am getting annoyed not being to do a stereo mixdown with compression. Any ideas? I don't know what's wrong. Thanks again for the help.
 
It could be just a bad solder or ribbon cable connection inside the unit.

I don't have the VLA II...but I've had a VLA for quite a few years (one of my favorite tracking comps, I've used it on guitars, keys, bass...). I also just picked up another used VLA on eBay for $115...actually, it only cost me about $20, since I had about $90 eBay "dollars" that they gave me.
It had blown meter bulbs, and ART sent me 4 new ones, free of charge, plus it needed some meter and over level adjustments internally, so I ended up doing both units...cleaned all the ribbon connections inside, adjusted the trim pots and the meters after installing some matched tubes. Both units are now in equally good operational condition.

Anyway...those ribbon cables might have some oxidation...but I think there may be some key spots where the solder connection can come loose...you just have to give it a close check, and then re-solder anything that looks suspect. Use some DeOxit on the the ribbon connections (pull them off...apply to the metal contacts, replace connector.

Other than that...you might just send it in to ART and let them look it over or if you know of any decent audio repair shop....it shouldn't be anything major.
 
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