PreSonus BlueTube distorting? Help!!

M

michael12

New member
For anyone who's bought and used the Blue Tube - I got one last week and the 2nd channel was easily distorting when I turned the 'line' level past 1 o'clock, though the lights never even got past green. So I called PreSonus and exchanged it at the store, and now my new one is distorting on the *1st* channel, whenever you turn the 'drive' up! This is in use with the Rode NT1, or with a cheap AudioTechnica mic, or with an acoustic pickup straight in to the BlueTube.

Did I get 2 lemons? What am I doing wrong? I have troubleshot and it seems to have nothing to do with phantom power, and the lights are working, but certainly not in the red (or even orange) when I'm getting this distortion.

Has ANYONE had any kind of similar problem??? I know these are new - are these bugs or poorly made or am I just too newbie?

thanks,
m.
 
Damn, sorry to hear that. I can't help you with your problem, but I would be interested in hearing your opinion of the channel that works on your Blue Tube. I am considering buying one, but hearing about your problem kinda scares me off.
 
I went to presonus and looked at the unit and I can't see what it could be - you are not using the pad are you?? - so long as each is set the same they should sound the same - got me beat
cheers
 
Things to consider before we all flip out :)

I'm going to buy 2 of these too. Before we're all scared off, let's think about a few things. I remember reading the manual at the store.

I'll make a few assumptions, you test them on your Blue Tube and let us know.

The led-s on the Blue Tube are OUTPUT meters, which must mean that even if you overdrive it at the INPUT, the output LEVEL won't necessarily be in the RED zone. The Drive knob is meant for that - setting the input gain. The manual says it can be used to overdrive guitars, so it's no surprize that you get "distortion" when cranking the Drive. The 20db pad is just like on TubeMP, if you already have a pretty strong source and if you add 20db to it, it's bound to distort. The idea is to set optimal INPUT level (or gain), so that the preamp itself isn't overdriven and then to use the gain knobs (output level) to set the level of the signal that feeds the board (or deck). One thing I don't know is whether the Blue Tube has an input meter. Tube MP has a single LED light which changes from green to yellow to red. You'll have to study your manual to see how to set the input gain.

I don't want to be presumptious here, but the probability of getting even just 2 lemons in a row is approaching ZERO with the speed of light :-D Try these things and let us know how it works out. If it doesn't, exchange it again and if it still doesn't work we'll know for sure that you're doing something wrong ;-) That's because the probability of 3 lemons in a row is probably less than zero :D
 
I don't want to be presumptuous either (but that never stopped me before), but there *is* the possibility that the blue tube's low on quality, considering the price. There are two truths I've picked up from this board, and from experience:

* You get what you pay for, usually.

* You don't know until you, or someone you trust, tries it out.

Well, I know the blue tube's cheap, cheaper than the
ART. I don't know Michael, but he sounds like someone with a genuine report. When I put these two bits together, I'm slightly less interested than I was in the Presonus preamp.

By contrast, I haven't heard *one* complaint about the dbx 386, for example.

We need more reports.

Next... You first. :)
 
I'm not convinced this pre is having the blues from a bad circuit. Uneven "drive" could be due to the thing not being warmed up yet and the actual settings. Try cutting the drive gain and upping the output gain.
 
Oh man... You guys are gonna ban me after this confession. 1)I totally missed the fact that the BlueTube is set up in mirror-fashion, i.e. Ch.1's knobs go drive-gain, Ch.2's are gain-drive - no wonder Ch.2 was distorting when I was turning up the supposed gain knob(actually drive). I just never payed attention to the tiny words below the knobs, didn't have the thing at eye-level, etc. Man I'm newbie.

2)I also missed the fact that Gear Junky pointed out - the meters are for OUTPUT not INPUT, and that the Drive knob is *meant* to give distortion if you crank it enough. Duh.

But there is still some weird ground loop buzz thing only on Ch.1, which goes away when I put my hand on the BlueTube, although it's pretty quiet anyway with the NT1. But I'm hoping this isn't permanent. I haven't tried it on different outlets yet.

And lastly, Ch.2 seems quieter on the whole, although not by much. I think.

This is my first ever pre-amp and I'm still learning the ropes, so, sorry to cry wolf on the BlueTube. I am really happy with it, after all. And I have to say that the few times I called to PreSonus, they were *very* nice and seemed ready to do anything to set it right.

As far as the actual sound of the unit, all I know is it's better than the pre's on my VS880, but I've never heard an ART or anything so I can't compare. I don't notice any sound 'coloration', but then again I'm only using headphones. Plus, the thing just looks cool. And isn't that what matters in the end?

The Blue Max is my next purchase....

-m.
 
Ok, I'm glad that the Blue Tube worked out after all. I have high hopes for it.

Oh, and when you get the Blue Max, do tell us how you like it.

Are you going to put them in a rack? I know they designed them to be in a rack together (Tube+Max), but I'd like to put in 2 Blue Tubes in one space. Wonder if that'll work with their rack adapter. If anybody has info on this, please share! Thanks.

And if anybody knows where the Blue Tube is cheaper than $149.99, please let us all know!
 
I wouldn't put the BlueTube in a rack unless you leave some space between modules because it gets hot. Tube pre-amps too close to CPU's, power supplies and other electric devices can create hum and audio artifacts into the signal. I wouldn't rack mount these things at all, that's why I like 1/2 rack units because they don't take up much desk space. I am getting good results from my BlueTube, my digital piano and drum machine sounds are better than ever. I wish that the phantom power didn't affect both channels when engaged so I could use a condenser mic on one channel and a dynamic mic on the second. I think Gear Junky is incorrect about what the gain and drive knobs do. The drive knob controls the amount of signal routed to the tubes and the gain knob governs the amount of boost to the signal being processed by the pre-amplifier. I would love to know peoples experience with outboard solid state pre's vs. tube pre's. If you don't drive the tubes in a tube pre-amp, is the sound much different than a solid state unit ?
 
Why can't you use a dynamic mic when phantom is engaged? Shouldn't affect anything.

You're right about the drive knob, it did say that in the manual.

Well, I probably would leave a space between Blue Tube and other units in a rack. Thanks for this info.
 
I think I read that phantom power is only for condenser mics or mics that require it and can damage other mics. If someone can clear this up I would appreciate it. I am looking for a couple of good books on recording so I don't have to ask too many "beginner" questions like this. Most of my recording knowledge comes from back issues of Electronic Musician magazine.
 
Phantom power can not damage a dynamic mic. The dynamic dosen't even recognize it. There are mics that can be damaged by phantom power. These are specifically some ribbon mics and condensors than are made to accept other types of power.

Heres some more details...

(from a mackie 1402 manual- which rocks BTW- the manual and the board!)

DO

If you are plugging in a condensor mic, do verify that it can be phantom powered.

Ensure that the mic's out put is low inpedence, balanced and floating. This is especially important for vintage ribbon mics like the RCA 44BX and 77DX. (I hate it fot the guy who found this out the hard way!)

Mute the soud system when turning the phantom power on or off, or when connecting or disconecting microphones.

DONT

woryy about your other microphones as long as their output is balanced and floating.

connect mic's that do not conform to the DIN 45 596 standard.

connect A-B or T-system mic's (another remote powering system) without suitable adaptors.

-jhe
 
hi!
i jus got my blue tube yesterday, and i must say that i am quite impressed! i do not have any precious experience with mic preamps, but to me the blue tube sounds quite good! (i almost didn't believe it at first!) i am very excited to try it w/ digital recording! the lead guitarist in our my band has a vs-1880 and we tried putting my condensor right into its built in preamp....... ewwwww!! it sounded soooo bad! it was the only time i had heard my mic at that point so i thought my mic was bad. after using it w/ the blue tube, i am simply amazed! my mic is a akg c2000b. i recorded myself playing acoustic w/ this setup (w/o even experimenting w/ mic placement first) and it make my cheap old little acoustic guitar sound way better than it actually is! i love it for vocals too! i have also tried it w/ direct bass and my drum machine (boss dr-5) and got similarly good reslults!
 
Wide Awake - here's a good book - "Practical Recording Techniques" by Bruce and Jenny Bartlett. It's designed for engineers rather than home recordists, but really useful nonetheless. The author drops by here from time to time and answers questions.
 
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