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Help With Mic/Preamp

Discussion in 'Preamps / Channel Strips' started by agarcia, Aug 8, 2005.

  1. agarcia

    agarcia Guest

    Ok I have
    a)ART Tube Microphone Preamplifier and
    b) AKG Acoustics D880m

    ...i didn't have much money to spend so i didnt get the best things out but...it feels as if when i record i get a kind of dull sound...or dry or something, i dont know..but i need help if anyone can help me...on the preamp i dont know where the input knob should be turned to..or the output or if i should use the phase reverse or +20 db gain or anything lol...i need help..ive been trying some tutorials ppl show me about editing vocals but it doesnt help much..just feels the natural sound of my vocals arent there ..i dont know..i need some help...if anyone can help it would be appreciated...
     
  2. roguescout

    roguescout Guest

    What other gear are you using?

    What are you recording onto?
     
  3. agarcia

    agarcia Guest

    oh just my computer...im not trying to have like perfect studio quality or anything because i know i wont be getting that...just wonderin because i can record on a radioshack mic for like 20 bucks and the vocals wont sound dull..like drowned out or something..but on here it kinda does...i figure its cause i dont know where i should have my input/output knobs..or if i should have phase reverse on or off and the db gain and wahtever
     
  4. roguescout

    roguescout Guest

    Are you just going into your sound card?

    If so, you need to have a sound card that accepts XLR or 1/4" TRS connectors and has a analog to digital converter. Check out sound cards from E-Mu, RME, or M-Audio.

    Normal sound cards are not designed to work with the impedence of studio mics. Desktop computer mics with a 1/8" mini plug are fine for the millivolts these cards use.

    You should get an inexpensive USB interface from Tascam, M-Audio, or Edirol.

    Phase reversal is for recording with multiple mics. Basically if you have two mics facing each other and recording at the same time, they are out of phase and the two opposing signals will cancel each other out... resulting in silence instead of audio.
     
  5. agarcia

    agarcia Guest

    yse its going into my soundcard...the one that came with the computer....i have the wires that convert to go in already..i record off of it....i just need info on where i can put the input knob..output knob...whether i should have the db gain on/off and whatever...so it feels more presence from whoevers recording on it instead of a dull dry vocal sound
     
  6. vividsonics

    vividsonics Guest

    There are no standard settings for how to set up a mic preamp. You engage the 20 db pad if your signal to the input of the mic pre is too high (the 20db pad reduces your input gain by 20 db). The phase invert switch is used if you have a signal from 2 different mics that are causeing phase cancellation (not gonna happen with one mic). Your input and ouput gain knobs are used to set the optimal level to the computer. However you'll have more tube distortion if the input gain is higher and the output gain is lower (kind of like a master volume on a guitar amp). For the cleanest sound you would raise your output and gradually bring up the input until the levels are right. You basically have to play with it until it sounds good to you. Good Luck!
     
  7. agarcia

    agarcia Guest

    ok thanks man im going to try it
     
  8. CoyoteTrax

    CoyoteTrax Well-Known Member

    Keep in mind also that using the phase reverse switch can make some mics sound "better" (even in mono recordings) and can also "thin out" a signal you want to "lighten up" a little.

    The MXL 990 is a good example. Sometimes that particular mic just sounds a little better for some mono applications with the phase reversed.
     
  9. agarcia

    agarcia Guest

    ok thanks all who gave advice to help...im going to try this stuff..hopefully they sound a lil better...l8
     
  10. Kurt Foster

    Kurt Foster Distinguished Member


    That's the first time I have ever heard that! Are you sure? It doesn't seem that flipping phase would make any difference ... you are simply swapping neg to pos and vice versa ... I have never heard a difference myself and everything I have ever read or heard said flipping the phase of a mono signal will not change the sound one bit unless the equipment you are using is built incorrectly.

    Perhaps this only applies to "Budget Gear" which I admit, I have very little expierence with?
     
  11. CoyoteTrax

    CoyoteTrax Well-Known Member


    Flipping the phase on most preamps will "thin" the signal from the mic a bit ,whether it's budget gear or not. Give it a try. Just because it's the first time you've heard about it doesn't mean it's not true.

    You are right about one thing you guessed in this post though...with some cheap mics that are poorly built it can actually correct a design or component flaw and make the mic sound "better". That was a good guess on your part Foster.
     
  12. Kurt Foster

    Kurt Foster Distinguished Member

    It's not a guess, it's a deduction ... as far as I can see, it's the only thing that could be happening.

    But just to be sure, I tried it myself wirh my U87 and a GT Brick .... and no difference (doh!). I have heard a change when switching phase from + (pos) to - (neg) when there are several mics open in one room, even if they are not all on the same source but never with one mic on one source.

    All that happens when you switch phase on a (single) mic pre is the speaker pulls (createing rareification) instead of pushing (creating compression) on what was the + (positive) side of the wave form ... but it should not make any change in amplitude unless your speakers are wired out of phase with each other, at least not on a single source mic'ed in mono. :roll: I suppose if you flip the phase of a mono track in a dense mix, you may hear some difference, seeing as it will want to pull on the speaker when other things are trying to push ... but now this is really getting beyond my abilities. I would be interested to hear some other thoughts on that.

    Look at a wave form in your DAW ... is there a difference in the + (pos) and - (neg) sides? Of course not, they're identical ... so what would change the timbre of the signal when you flip phase? Nothing unless there is some kind of anomaly or you are hearing a placebo effect. I admit to experiencing placebo effects at times myself, so that's "nothing to get up about" as John Lennon said ...

    But as far as flipping phase changing the tonal quality of a mono signal ? I think the whole idea is silly :-?
     
  13. CoyoteTrax

    CoyoteTrax Well-Known Member

    Some mics
    Some pre's
    Mono signal (yes mono)

    Flip the phase and the signal thins out. That's all I'm saying. No big deal, just handy sometimes.
     
  14. jonnyc

    jonnyc Member

    So I tried flippin the phase reverse several times, even had a fellow producer come over to see if he could hear a difference, nothin. We tried with a shure ksm109, and blue baby bottle and an mxl 990. We also flipped the phases on the plug ins on and off, not a difference either. Seems like none of the mono signals were effected on bit by hitting the phase reverse. As much as I hate to admit it I think Kurts right about this one. If you hear a differece coyote could you maybe track something on acoustic and have someone flip the phase back and forth while you record so we can hear what you're hearing? If this is something that does happen with some pre's or mics I'd like to know about it.
     
  15. CoyoteTrax

    CoyoteTrax Well-Known Member

    You definitely should have noticed with the mxl 990. I've got a 990 that shows a rather significant difference in transparency, dimension, and output when the phase is flipped on it (as a mono source). As I mentioned...some mics, with some pre's. I also have an 012 that's one of a pair that shows a considerable difference over the other when the phase is flipped on it.

    If I have time tonite I'll do an A/B session to post.
     
  16. jonnyc

    jonnyc Member

    That would be awesome if you can do that coyote. I'll go back home tonight and try it again. See if I get a db drop or something.
     
  17. CoyoteTrax

    CoyoteTrax Well-Known Member

    Sorry guys, I didn't get a chance to work in this last night. I'll see if I can get home at a reasonable hour this evening.
     
  18. CoyoteTrax

    CoyoteTrax Well-Known Member

    OK, I finally got some time to track a short clip as an example of how reversing the phase on some mics can thin out the signal a bit and change it's characteristics.

    Sorry it took me so long but it's been an extremely busy time for me at the day gig.

    The mic is an MXL990 and you can clearly hear the phase switch being flipped on the mic pre several times throughout the clip. Notice how the signal thins and thickens a bit each time the switch is flipped. Hopefully this will help some folks in getting different sounds from or or more pieces of gear in their locker. It's the first song at the top of the page appropriately titled.

    http://www.soundclick.com/pro/default.cfm?BandID=117445&content=music
     
  19. Davedog

    Davedog Distinguished Member

    Hi Ken.....While its obvious there's something going on there with that phase switch, its not possible for to be an actual phase situation since there is only one source. Unless there are two diaphrams in the mic that for some reason are demonstrating this phase anomily. There IS something going on though and I am at a loss to explain it. Being an electrician for 30 years has taught me a thing or two about 'phase' and how it relates to waves but this ALWAYS involves two or more sources to truly be a phase issue. Anyway, its a cool discovery and will no doubt be a help to those who have bought that particular mic.
    Also...what pre were you using?

    The only thing I can think of is in this particular setup, the + and the - have to be correct in order for this ........naw.....I'm just speculatin now....Anyway thanx for the demo.
     
  20. CoyoteTrax

    CoyoteTrax Well-Known Member

    Hi Dave. The MXL990 is a single diaphram mic. It doesn't even have a removeable high frequency booster disc like most cheap LDC's (otherwise I would have removed it and filled in the back of the capsule to change it to an omni pattern mic).

    For this simple example I used a Behringer T1953 with Tesla/JJ ECC83S tubes. 1 mic IN (the 990) and a single, balanced, Mogami XLR cable OUT. Works the same w/balanced 1/4" cable as well.

    It's not a discovery on my part. I read about it in a book a few years back and have come across it in a few sources since (even recently). Comes in handy sometimes when your tracking in mono and can use just a slight change in color , tone, or transparency.
     

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