Shure SM7B Too NOISEY???

E

Eddmann69

New member
Hello All......I recently made the purchase of a Brand new Shure SM7B, and a brand new Studio Projects VTB-1. Now I hooked them up last night for the first time, and as I was dialing in the levels, I hear this back ground hum...like a distorted amp? I tried killing all the dials one by one, but its just too damn quiet then??? It would seem that the SM7B needs way too much gain in order to come up to level? I am going to do a side by side tonight with my SM57 and see if the noise is still there. I dont think its a compuyer fan / noise issue, It just simply sounds like adding distortion onto a clean amp....just that background hhssssssssssssssssssss. There is nothing that takes it away barring removing all the input anf tube gain, but like I said, that makes the signal unusable. Please offer any suggestions???

Thank you....Ed
 
If you look around, it has been said a lot that the SM7 needs a lot of clean gain. In my experience that is completely true. You may just not have the gain it needs in a VTB1.
 
Dynamics mics have essentially no self-noise. The hiss you hear is your preamp choking on the amount of gain you need.
 
The SM7B does need a lot of clean gain. I love the sound, but oh my Lord finding a preamp to drive it is a pain. If you can swing it look into the Speck MicPre preamp. I wouldn't be at all surprised that Allan's pre has issues with it. Believe me, it's not the mic.
 
I don't have an SM7B (yet), but I do have the VTB-1 and it has plenty of gain for a dynamic (+72dB) and is actually pretty quiet for such a cheap pre. Make sure you have the Tube Blend all the way off (to SS), as that will add noise. Also, try the impedance switch on the back to see if that cleans things up. Then, set the output gain to unity (straight up) and adjust the input gain. If the input gain is maxed, but it still isn't loud enough, start increasing the output gain. Use the input/output meter on the pre to make sure you are getting a decent level that is not going into the red.
 
Eddmann69 said:
I dont think its a compuyer fan / noise issue, It just simply sounds like adding distortion onto a clean amp....just that background hhssssssssssssssssssss. There is nothing that takes it away barring removing all the input anf tube gain, but like I said, that makes the signal unusable. Please offer any suggestions???

Thank you....Ed
Click to expand...

...you definately do not want to add tube "blend" to the SM7...just use the "input gain" and "output level" controls on the VTB-1 for gain...leave the "tube blend" all the way to the left (full ss mode)...make sure the volume on your DAW software track is also sufficient (if you can raise the input level on the software DAW to a sufficient level without maxing the "output" level on the VTB-1, you should get cleaner gain)...
 
Thank you for all your QUICK replys wow. I meant to mention my set-up for reference. Its simple, M-Box 1 running Pro Tools 6.1.1. I have a Tascam US-122 for my MIDI interface, and also the M-Box as my mic in. The SM7 is running via Monster Cable to the VTB-1, and then into the M-box, then into my PC via USB cable. Another detail I forgot to mention, but goes hand in hand with my problem, I cant get any meter levels on the VTB-1 without a loud sharp clap of the hands RIGHT into the mic....I mean, if I turn the gains and outputs up to the point of annoying noise then yeah, I can hear the cat farting on the other side of the apartment, but it still has that Hisssssssssss like Jimmy Hendrix's marshalls at the begining of most of his recordings?? Now last time I checked, technology has taken leaps and bounds since then, and I should be able to get a non hissy sound from a properly working sm7 and VTB-1, and yet I am not. I am not sure since I am new to this site, but can I post anyway for you to hear a sound clip? Sorry, its a green horn question but ya know....Thanks again for your fast input!!!
 
Sorry to say that my VTB-1 also has a noise issue when I try to use it with some of my ribbons. I can get a lot more clean gain from the integrated preamps in my Aardvark Q10.
 
If you're looking for a good cheap amp check out the dmp3. It's two channels but only around 150 bucks and it has a good amount of gain, and have noticed vey little if any noise from the amp itself.
 
Hmmm, I dont think the tube is loose but that will be checked off on my list of things to do tonight. I will check out the DMP3, but I think my next preamp purchase is going to be the NEXT step up in preamps, in order to avoid any more issues that are caused by simply buying a preamp for 99 bucks. You know what I mean? I just BOUGHT this friggin preamp less than a week ago, and just recieved it yesterday, and I already cant wait to get a different one, it never ends.

Anyways, can somebody please let me know, or direct me to any place that pairs the Shure SM7B along with the Grace 101 single channel preamp? I have heard marvelous things about the Grace 101 and since I am using my equipment purely for home based voiceover recording, then I only really need the single channel. Any info on this preamp other than the factory specs out there???? Like I said, I just spent $350 bucks on this SM7B, and I already know its a great voice over mic (as long as mine isnt a dud?) so at this point, I want to cater to the mics needs, I know its a low output Dynamic mic with a cardioid pattern, and it needs ALOT of clean gain in order to come up to level, so my question is, will Grace 101 provide this so-called clean gain that I need?
Thank you again for any help....-Ed
Thanks in advance. Ed
 
The VTB-1 does not have 72dB of clean gain, hook a SM57 to it and start cranking the input gain and after ~50dB you are going to notice hisssssss, drop it to 50dB or one notch below that, then crank the output gain to +12dB, use the balanced outs (XLRs) and you will have just over 60dB of CLEAN gain. I would assume the same happens with a SM7. If you are using the 1/4" outs you just lost 6dB of output as those are unbalanced.

If you want 73dB of clean gain for a dynamic you may want to look into the AEA TRP, its designed for ribbons but will work nicely with dynamics, tube microphones that don't need phantom (99% don't need phantom) and of course ribbons. But then its $700 (its two channels, 1u half rack space).

But I would first really look into your NEEDS, I know you may want protools to show you -3dB peaks when recording. But as a lot of the pros on this forum will tell you, shoot more for -14dB peaks, 24bit recording affords you great headroom over the noise floor of your conveters, and hitting your conveters at -10 to -14dB is really all you need do. Just try a lower level with your VTB-1, and boost in the mix. I had a hard time at first with my ribbon mic, I thought I needed to hit the same levels during recording that my other dynamics and condensers were giving me. But as soon as I figured out that hitting the converters with -12dB was enough, I backed off the VTB-1 and found it to have just enough gain, and it allowed me enough room to boost with the faders in my recording program and plugins like the make up gain on a compressor, or the master channel limiter.

Good luck!
 
Last edited:
OK buddys, I have a small update.
I have done an A/B comparo of the sm57 and the SM7, and well the sm57 was like a condenser compared to the output of the SM7.I had to SCREAM to register on the SM7 while I could scrathc the wall across the room from the SM57 and still hear it on the mic. I tried useing my Presonus TubePRe and the VTB-1 out with both mics in different tests, and I realized that the background slight noise that I hear through the VTB-1 is ALLWAYS there, no matter which mic I hook up, in fact, even with NO mic hooked up. I unplugged the SM7 to plug in the SM57 while still monitering on the headphones, and the backgound noise is still there with no mic at all, it is the output from the preamp that creates the noise, reguardless of the setup. SO it appears that this preamp is worhless, I am very surprized at how worthless it is with all the Hype i have been reading about it being at least an OK preamp, but obviously if this noise normal for this thing, then other people must not have needed a total or even ALMOST silent background or something. If I was useing it for guitar then you wouldnt notice it so much, but for voiceover, this combo WILL not give me a single usable signal.

I am hopeing this posting inspires a fellow VTB-1 OR SM7 owner to comeback with some bad ass advice and make me feel like a total Chachie. Or even one of you pro home guys who can surmize a plan to try and make my current (and brand NEW) set up somewhat useful to me.

Thanks again. Ed
 
Sounds like your VTB could be broken. I ordered one from zzounds in March and when it got here it had a hum/buzz to it, I sent it back and they replaced it with a working one.

I have used a SM7b with my VTB successfully if that helps any... GL
 
You might be able to get a Small Signal Booster (Preamp) that you put between the Mic and the Pre that boosts the signal comeing from the Mic so you can use mics that have weak signals with pres that have low gain....

I am actually designing a simular type unit that I was thinking would be good for ribbon type Mics but would work for any low output mic.....

So far the design uses a discrete ballanced Transistor stage to add up to 30db of extra clean gain and will probably be powered with a 9v battery or a 12v-15v adapter or maybe even Phantom power but that would be harder to implement..... The device will be quite small ,about the size of a effects pedal or even smaller and just have a Gain knob and possibly a 20db Pad and a Clipping Indicator if I can incorporate them in the design......I am also working on a Active DI Design so I might merge the 2 designs ......


I am going to be working on this design for the next few weeks and once I get it perfected I might be offering the units for sale as a DIY Kit or as an allready built and tested unit so if anyone if interested let me know.....


Cheers
 
I've never used an SM7 or a VTB-1, so I'll say that right up front. But it seems odd to me that your SM7 is displaying that much less sensitivity than a 57. From the specs:

SM57
Sensitivity (at 1,000 Hz)
Open Circuit Voltage: -56.0 dBV/Pa* (1.6 mV)
*(1 Pa = 94 dB SPL)


SM7B
Output Level (at 1,000 Hz)
Open Circuit Voltage*: -59.0 dB (1.12 mV)
*0 dB = 1 volt per Pascal

This makes me wonder if your SM7 might have a problem. That and the fact that theres a few others that use them, and I've never heard of them having this degree of sensitivity issues.

On the VTB-1, there's a reason they spec the EIN at 60dB of gain rather than at full gain. The Grace 101 may be a good mid price fit for this, but don't rule out the afore mentioned DMP3, the little pre that could. It never ceases to amaze folks with it's off the chart price/performance ratio, and specs it's -128dbv EIN at full throttle (66dB of gain).
 
Wow...thanks alot for the info, and those specs you posted Robert.
I have talked with Brent, a tech over at Studio Projects and he says (althogh he DOES work for the company that makes it) he says that I should be able to get enough clean gain from the VTB-1 do drive the SM7 without the background Hiss that Im getting. Its a hiss and not a Humm mind you, he made that more specific for me as well. He also directed me to the Harry Gerst REP forums for advice? I havent registered there yet, but he says that Harry uses the SM7 alot and has also reviewed the VTB-1 from what I have read in tidbits. So I REALLY hope someone there actually has an SM7 AND the VTB-1 and maybe even an SM57 for that matter, so they could tell me if maybe what I am dealing with is either a faulty mic, or preamp? Unfortunatly, either one of those would suck HUGE royal ass. So I guess I had better get busy livin or get busy returning???
 
Minion said:
You might be able to get a Small Signal Booster (Preamp) that you put between the Mic and the Pre I am going to be working on this design for the next few weeks and once I get it perfected I might be offering the units for sale as a DIY Kit or as an allready built and tested unit so if anyone if interested let me know.....


Cheers
Click to expand...

I'd be interested only if it runs on 9V. The
more compact in size the better.
Would be interested in pre-made, not DIY.
 
Eddmann69 said:
I have talked with Brent, a tech over at Studio Projects and he says (althogh he DOES work for the company that makes it) he says that I should be able to get enough clean gain from the VTB-1 do drive the SM7 without the background Hiss that Im getting. Its a hiss and not a Humm mind you, he made that more specific for me as well. He also directed me to the Harry Gerst REP forums for advice? I havent registered there yet, but he says that Harry uses the SM7 alot and has also reviewed the VTB-1 from what I have read in tidbits.
Click to expand...
Well, I'm not "Harry" (wonder if Brent meant "hairy"), but I have two SM7's and a VTB-1 and it puts out a lot of clean signal, without hiss. Try pulling the tube out of the VTB-1 and see if the hiss goes away. Just use the first gain control up to about 55dB and turn the Master up to give you the rest of the gain. There's only a 3 dB difference between the 7 and the 57, so there shouldn't be a huge gain difference.

Oh, and make sure you have both the tone switches on the SM7 set to FLAT. The fact that there's a huge difference in output compared to a 57 would seem to me to be either switch settings, or a bad SM7.
 
Well, I feel like an idiot, sorry to screw up your name Harvey, I VERY much appreciate your input on this matter, you are the man with a reputation for greatness in this field. I have not yet changed any of the settings on the SM7, so I am assuming they are still set to flat response, but I will double check that tonight, as well as pop the cover off the VTB-1 and remove the tube and try again. What I came to realize last night is, there is a hiss whenever EITHER of my preamps are hooked between the mic and the Mbox, so since the Mbox already has Focusrite Preamps built in to the inputs, could the hiss be caused by a preamp going into a preamp? Or could I possibly have a noisey/shorted Mbox? I did NOT try the preamp comparo through my Tascam US-122 yet, so if I DO get the hiss with both preamps through that as well, then I will be able to narrow it down a little further...
Thank you for your continued help with my dumb problem...........I really appreciate everyones input.
Eddie.
 
You must log in or register to reply here.
Back
Top