Art Tube Pre as Direct Box vs direct to RME UCX

Author
gswitz
Max Output Level: -18.5 dBFS
  • Total Posts : 5694
  • Joined: 2007/06/16 07:17:14
  • Location: Richmond Virginia USA
  • Status: offline
2014/03/24 19:24:56 (permalink)

Art Tube Pre as Direct Box vs direct to RME UCX

The other day I was out in my garden getting back to nature and it made me want to pull out my old guitar from college. I practiced with it a little and wasn't loving the sound. I decided to compare the sound recording straight to the UCX with the sound recording through an Art Tube Preamp. I was just noodling around and comparing the tracks.
 
https://www.youtube.com/watch?v=J2LxRpakmOY
 
In both cases the guitar sounds kinda quacky to me. I'm used to listening to my newer acoustic guitar recorded with microphones.
 
Anyway... comments welcome.

StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
#1

13 Replies Related Threads

    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/24 20:55:57 (permalink)
    Hi Geoff,
     I didn't listen too carefully tonight... I've been up since 3 a.m. and don't have the attention span to be thoughtful enough to offer useful comment.
     
     One thing to consider; The impedance on the instrument input of UCX is actually 470 Kilo-Ohms.
     
     I didn't figure what the ART input impedance is. Which model is it?
     
     I don't see a spec for the line level input on the UCX at the RME site... it could be anything from 1500ohm to 10kohm. 
     
     The mic input on the UCX is probably 1500 ohm.
     
     FWIW a typical input for a instrument input on a tube amp/preamp has historically been something like 68-150 Mega-Ohms.
     
     I think the majority of the sonic difference you hear is attributed to gain or level and the clean solid state vs tube harmonics.
     
     If the guitar has a battery and an on board preamp it is unlikely that the impedance bridge to the UCX or ART preamp effects the tone very much. An on board the guitar, battery powered preamp is basically there to provide a buffer to impedance loading issues.
     
     In general, the lower the input impedance the less bright the tone will be, and in general a peizo pickup is so high in output impedance that it is easily loaded down and so that is why virtually every mass produced piezo pickup system includes a built in active buffer amp stage to minimize the effect of loading.
     
     I've never been a fan of the sound of direct injected acoustic guitar... so in the interest of being honest with a friend, I thought they all sounded like direct injected guitar tone.
     
     Having said that, I thought the ART examples sounded richer than the others.
     
     If you can verbalize what aspect of the the tone you like and don't like maybe I can offer some suggestions... I'll try to listen more closely tomorrow afternoon.
     
     all the best,
    mike
     
     


    #2
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/24 21:00:16 (permalink)
    duh... I've been up so long... I thought I was sending you a reply to your pm. :-S
     
     


    #3
    gswitz
    Max Output Level: -18.5 dBFS
    • Total Posts : 5694
    • Joined: 2007/06/16 07:17:14
    • Location: Richmond Virginia USA
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/24 21:37:10 (permalink)
    In part I was exploring the sound of the guitar I bought in 1993 when I was pretty broke and just finishing college. It takes two nine volt batteries that have to be inserted through the sound hole. If memory serves the guitar cost less than three hundred new including tax.

    I find that practicing fiddle tunes on the electric leads to bad habits. I can learn to expect a series of hammer ons to ring loudly. In my little house with my wife and daughter, practicing silently has advantages, but I only do this in the early morning before they are up. I mainly am interested in the acoustic electric guitar direct because I record people out this way sometimes. It is convenient for performing. If I could make it sound good I would be psyched.

    Also, the ucx has two mic pres and two direct inputs. If I could use these direct inputs instead of bringing along an extra pre and two extra mics, it would be handy. That said, I don't much like the sound. I notice th2 has an acoustic guitar pedal.

    I guess I'm crossing lazy with learning. I'm wondering if there is a way to use what I have differently to simplify recording out with friends.

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #4
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 07:55:16 (permalink)
    Using an acoustic guitars built in pickup for direct injection isn't lazy... it's expedient and practical.
     
    I think you'll find that it will always sound like a direct injected guitar. The character of the sound is probably most influenced by the design of the onboard pickup/mic system and so in the context of your live recordings it's going to be a crap shoot. Bring some fresh batteries.
     
    One useful thing to remember is that a lot of people really like the sound of direct injected acoustic guitar, including most of the musicians you record that aren't insisting on using mics instead of direct inject. 
     
    Treat it like any other tone, do what ever you need after the guitar output to get to where you want to be.
     
    I remember when direct inject acoustic sounded so unfamiliar that it seemed like everyone threw a chorus on it to make it distinctly different than the traditional sound of an acoustic. The systems have gotten a lot better sounding. Either embrace the sound or sculpt it agreessively with EQ, compression, and harmonic effects.
     
    Keep in mind that opinions about the sound of acoustic guitar are very much like ideas about piano tone. Every body has a different expectation, taste and opinion. All the ideas are valid, so work towards a balance that suits you and the people you are recording.
     
    best regards,
    mike


    #5
    gswitz
    Max Output Level: -18.5 dBFS
    • Total Posts : 5694
    • Joined: 2007/06/16 07:17:14
    • Location: Richmond Virginia USA
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 12:10:09 (permalink)
    You don't think that the difference in impedance from four hundred and seventy to eight hundred and fifty accounts for much of the tonal difference?

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #6
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 14:08:25 (permalink)
    I don't, but more importantly I'd like to know what I am actually comparing.
     
    For starters, It's not 470ohm it's 470kohm. The buffer amp is there to minimize any loading effects, but if there was a loading effect 470ohms is low enough to raise some su****ions, while 470k is not.
     
    Additionally I'd like to learn more about the impedance spec when you say "850"... I don't think it will matter because of the buffer amp, how ever if it really is 850ohms I would have to say that 850 is on the low side as the common input these days for line level starts around 1500ohm (1.5kohm) and goes up to aboit 10,000ohm (10kohm). A common instrument input will be something like the 470kOhm to 150megaohm. While mic inputs are usually around 1500ohm unless there is a special "low impedance" loading choice for experimenting with.
     
    It's hard for me to guess how the 850 fits in, and I'm assuming there is a factor missing in the description.
     
     
     
     
    Let's get back to the idea  of a buffer amp. I refer to it as a "buffer" amp because it effectively buffers the effect of impedance loading between the guitar and the preamp input. The guitar's designers placed a little preamp circuit in the guitar and mated it to the "acoustic pickup" and that is where the critical loading is happening. It happens between the pickup and the onboard preamp. The output of the guitar is a line level signal and it is relatively immune to impedance loading unless of course you plug it in to some extremely low impedance microphone input... maybe something like 300ohm.
     
    The folks that design those guitars realize that people will be routinely plugging them into anything from a 10kohm mixer input thru to a 150megaohm guitar amp input... and sometimes they'll stick them into a line level input at 1500ohm.
     
    All those different choices will have varying gain staging but it's not likely that you will notice big differences in tonality.
     
    If you didn't have a buffer amp it's highly likely that you would hear changes in tonality. A passive guitar pickup in a regular old electric guitar will display these effects if you try it with direct inject on various input impedances, and it will not if you plug a "boost pedal" before the preamp, as the pedal effectively acts like a buffer amp.
     
    I think the primary differences I heard was more likely the overall tone of the two preamps rather than impedance loading.
     
    Now, if it really is 470kOhm compared to 850ohm... maybe... just maybe.
     
    :-)
     
    Good questions!
     
    best,
    mike


    #7
    spacealf
    Max Output Level: -54 dBFS
    • Total Posts : 2133
    • Joined: 2010/11/18 17:44:34
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 14:43:11 (permalink)
    http://www.moore.org.au/pick/04/20030123%20Approximating%20the%20Electric%20Guitar%20Pickup.pdf
     
    not really entering into the debate. But from what I see on page 5, half of frequency response in a range you can not hear and 0.05 dB is well - nothing.
    from 1Mohms to 500Mohms on that chart.
    (53.3kHz to 26.8kHz whatever those figures are).
    The rest i am not sure about, but seemed interesting.
     
    Plus lerning to type would help!
     

     
     
    #8
    Cactus Music
    Max Output Level: 0 dBFS
    • Total Posts : 8424
    • Joined: 2004/02/09 21:34:04
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 15:05:31 (permalink)
    Back when I sold a lot of Seagull acoustic guitars made in Quebec. I sold more of those than any other brands I carried. ( Yamaha,Takamine,Ovation, Ibanez. ) It was the warm tone they put out. 
    They sported a LR Baggs PU system that I generally never run into elsewhere.
    http://www.lrbaggs.com/pickups/lb6-acoustic-guitar-pickup
     
    They were this bone type material base with a brass bottom. Of all the peizo type PU's I've used these were by far the most evenly balanced and "un Peizo" sounding. 
    You could order the guitars with or without the PU and with or without the pre amp. 
    For myself I ordered the one without a Pre Amp. It was a solid Spruce top and mahogany back. 
    Funny thing and what triggered my reply here , is I also bought a Art Tube pre amp to drive it. It was still the best acoustic sound I have ever recorded. This combination work better than using the on board type pre amps.
    Only thing was the Seagull guitars were clunky to play so I ended up with a Yamaha APX for stage use. I continued to use the Seagull for all recordings. But one day I sold it ito a friend who loved it more than I did. 
    My Yamaha has served we well on stage but now I find myself recording acoustic music again I miss the Seagull, not it's 2x4 neck, but the recorded sound. I don't get along with Mikes on acoustic instruments even in the studio. And I like to record with the monitors up. 
     
    I was disappointed to find that  Godin who makes the Seagulls, Art& Luthier and Simon & Patrick lines has opted for there own PU system which is the crappy under saddle thin type used by everyone else. 
     
     Here is the LR Baggs PU that works! The LB 6. The best thing about these is you don't have to worry about the saddle bottom being perfectly even. 90% of the thin type saddle PU's are totally uneven volume from string to string. This is because they rely on the pressure of the string. If the installation is sloppy they are uneven. This design solves that problem. Why it is not widely used is beyond me. 

    post edited by Cactus Music - 2014/03/25 15:09:36

    Johnny V  
    Cakelab  
    Focusrite 6i61st - Tascam us1641. 
    3 Desktops and 3 Laptops W7 and W10
     http://www.cactusmusic.ca/
     
     
    #9
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 15:12:54 (permalink)
    spacealf
    http://www.moore.org.au/pick/04/20030123%20Approximating%20the%20Electric%20Guitar%20Pickup.pdf
     
    not really entering into the debate. But from what I see on page 5, half of frequency response in a range you can not hear and 0.05 dB is well - nothing.
    from 1Mohms to 500Mohms on that chart.
    (53.3kHz to 26.8kHz whatever those figures are).
    The rest i am not sure about, but seemed interesting.
     
    Plus lerning to type would help!
     



    That describes passive pickups rather than active pickup systems.
     
    best,
    mike


    #10
    spacealf
    Max Output Level: -54 dBFS
    • Total Posts : 2133
    • Joined: 2010/11/18 17:44:34
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 15:17:28 (permalink)
    As far as I can ascertain it is about a simulation which defines electric guitar pickups.
    The title is:
    Approximating the Electric Guitar Pickup
     

     
     
    #11
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 15:26:00 (permalink)
    It's more like an examination of a LCR filter.


    #12
    gswitz
    Max Output Level: -18.5 dBFS
    • Total Posts : 5694
    • Joined: 2007/06/16 07:17:14
    • Location: Richmond Virginia USA
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/25 21:46:13 (permalink)
    Mike, this is the Art Tube Pre...
    http://artproaudio.com/art_products/signal_processing/signal_channel_tube_preamps/product/tube_mp-original/
     Input Impedance XLR, l/4”2K ohms, 840K ohms
     
    Cactus, my Seagull has the same LR Baggs system.
     

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #13
    The Maillard Reaction
    Max Output Level: 0 dBFS
    • Total Posts : 31918
    • Joined: 2004/07/09 20:02:20
    • Status: offline
    Re: Art Tube Pre as Direct Box vs direct to RME UCX 2014/03/26 08:06:46 (permalink)
    840k. Good.
     
    The next step is to find out what the output impedance is for the particular LR Baggs system that you have.
     
    It's probably something like 840ohm.
     
    If the ratio between output and input is greater than 1:5 or 1:10 you can probably discount a concern about impedance loading altering the tonality of the signal.
     
    As an example 840:840,000 is a 1:1000 ratio. The 470k input on the UCX represents something like a 1:500 ratio.
     
    You might want to look to the innards of the preamp circuit for reasons why the different patches sound different, or you might just want to remember which patch you like better and roll with it.
     
    Have fun!!!
     
    best regards,
    mike
     
     


    #14
    Jump to:
    © 2024 APG vNext Commercial Version 5.1