First gig with XLR outputs

Hello @thewicked, et. al:

Microphones are sensitive beasts. Te VMS4 Microphone circuit is set up for a wide range of microphones and is a "high impedance" circuit of 11kOhms. Since the SM58 is a low impedance microphone, the input receiver signal will be very low compared to a high-impedance microphone, meaning even if you crank the gain way up, still you may not be getting the full rich sound you are looking for. Hence the "muffly muffly muff" sound you describe.

Read this online FAQ about Microphone impedances:
http://www.deltamedia.com/resource/impedance.html
Scroll down to the headline "I'M CONNECTING A MIC TO A MIXER. IS IMPEDANCE A CONSIDERATION?"

What you need is an "impedance matching adapter" which converts the low impedance, low level microphone signal into a high impedance, high level signal. Once you use this the sound will be very good. If you go into any hi-fi store and ask for one of these they'll know exactly what you need.

In theory it might be possible to fix this by cranking the gain way up on the mic circuit. But then with other medium and high impedance microphones, the mic circuits are going to be even more sensitive to feedback issues. And still the sound result will not be nearly as good as if you use the impedance matching adapter.

Let us know how you make out once you get an impedance matching adapter.

I have a pair of Skytec radio mics - Not the best quality in thw world I know, but through my AA Q-SD mixer I got a very rich sound with good EQ from the mixer.

The same applied to the KAM radio mics I use in the club - neither gave me a problem with the Q-SD nor with the clubs own DJM600!

However, plugging either of these mics in to the VMS4 was absolutely shocking. Even the slightest amount of gain on either mic channel resulted in very loud, very distored output.

The only way I could combat this in the club, was to turn the gain waaaaaaay down on the front of the radio mic receiver. I then eliminated the distortion but obviously got a lower output.

As we are now getting mixed reviews on output levels I am now wondering whether some of the components shipped are dodgy.

I have heard of good output volume/poor mic, poor output volume/poor mic, and so on. Maybe if I returned my unit for a replacement, I would get anther combination!!!

Cheers,

Roy

It sounds to me as if the output from your radio mic receivers was way too hot - i.e. not mic level.

Try with a cheap (i.e. high Z) wired mic, with a jack, not XLR - and see how it sounds.

Alternatively you could feed the receiver output into one of the VMS4 channels switched to analog and see how that sounds.

Not that I want to repeat myself (again), but as I said both the KAM ans Skytec mics work very well on the Q-SD and DJM-600 with the same settings I have always used. FYI gain on the receivers is approx 50% never any higher!

So surely the input would be "hot" regardless of the mixer right? Apparently not - only the VMS4.

Also the fact that others are reporting the very same issue with top notch line and radio mics is only comforting to me in that I know it's not how I set up my equipment.

And even a VMS4 owned by an Atomix member of staff exhibits this issue - so is it really me???

Roy

Thanks Cornylius This has got to be a signal path issue. Do not compare this to the Q-SD record because the input sensitivity is different. you can not expect to mirror you settings on your gear and have the same results.

I would suggest that you start with your Mic plugged and test it with no other signal on the VMS4 and adjust you levels and see what works best for you mic.

I cant belive I found myself in a HI-FI store today lookin for an impedance matching adapter or a high Impedance microphone No joy they dont stock stuff like that only standard and high end band and dj gear ,
When I explained to the store owner what I needed it for he was shocked what would I want to swap my SM58 for a low priced cheap high impedance mic whan the SM58 is the "Industry standard and Performance tested" for years for vocal work,
Thats when It suddenly hit me what the hell am I doing here tryin to fix a brand new mixer myself and spend more money with the hope that it might work ,
Its got a fault no doubt it must have because it supposed to be a Pro piece of kit,
Don't tell me ADJ tested this unit with cheap mics and was not tested for using a Shure SM58 or any high end Micophone,
All my mics are Low impedance and not cheap ok they may not be the most expencive but they are pretty standard and work on any other mixer I have used them on ..

Please confirm to me ADJ that I have a faulty VMS4 as a shure Sm58 won't work through it and that not all the Vms4's all have the fault or designed to only use cheap low end microphones all the same I need to know so I can swap for a non faulty one !!
Come on I am so trying so hard to Love the VMS4
So close but yet so far !!

quote:

a shure Sm58 won't work through it

Not true - at least not on my VMS4.

I've tried it with my SM58 and it works. Yes I have to tweak the EQ so it sounds OK but that's the same with lots of DJ mixers, including my normal Xone:92

@GroovinDJ
no matter how much I tweaked the EQ the mic sound distorted and also was the same on my other back up mic I really must have a faulty unit thats good news in bad way or bad news in a good way .. not sure ..LOL

@thewicked: It sounds like you ran into a real jerk at the Hi-Fi store you went to. I'd suggest you call around first or search on the internet to see who has an impedance adapter first so you don't run into the same situation. If you've already invested in such a good microphone you shouldn't be downgrading.

I used an impedance adapter before when I set up a high end Shure mic with a good quality Mackie mixer with 120dB S/N ratio, based on the suggestions of a salesman with a bit less of an attitude.

An impedance adapter is a small plug adapter piece. An example of one goes for $15 at Guitar Center in the US:
http://www.guitarcenter.com/Wh...r-427600-i1134878.gc
You definitely should be able to find something like this in the UK. It's an inexpensive solution and worth a shot.

@GroovinDJ: Can you show us how you hooked up the SM58 (EQ, mic settings, adapters, cables) to the VMS4?

@thewicked: There are 2 mic inputs. What happens when you try the other one?

The second mic channel is the same, just like the adapter you have in the link the only ones I see on the Internet are not any use to me as I thought you might have known that the vms4 has xlr inputs not a jack ? Also I have discovered from this forum that not all are faulty like this even with the same mic. I also really do think I have a fault as I'm a Dj for over 25 years and know how to setup a mic but even so I have followed all suggestions given to me and still not working correctly also I should not have to got to more expence when I'm one of a few that has this problem . I also don't really want to have an adapter sticking out the back of my vms4 not leaving room if I flightcased it or was in a tight space , I am willing to try a correct adapter to test your theory if ADJ will supply one to me and I would test it to see if it worked as a fix other than that I would like a tested replacement as so for everything else with my unit It is 100% and I love it just this important fault is letting me down .

quote:

Originally posted by Ihearyou(American Audio):
Thanks Cornylius

It's Corneloues, but hey close enough ;-)

quote:

This has got to be a signal path issue. Do not compare this to the Q-SD record because the input sensitivity is different. you can not expect to mirror you settings on your gear and have the same results.

I would suggest that you start with your Mic plugged and test it with no other signal on the VMS4 and adjust you levels and see what works best for you mic.

I will try that. Also just been playing n analogue mode and my channel 2 is completely screwed. Distorted at any level.

I plug the left output of my SDJ1 in to channel 1, have the gain set to 45%, master at 50% and the fader to max. The channel peaks and +4 and is as clear as anything.

Plug the same SDJ1 in to channel 2, same levels and the channel is completely distorted. Even if I turn the gain down to 0% and then back up to 5% or 10% its completely distorted.

Will feed back on the mic situation shortly

Roy

quote:

Originally posted by Ihearyou(American Audio):
Thanks Cornylius This has got to be a signal path issue. Do not compare this to the Q-SD record because the input sensitivity is different. you can not expect to mirror you settings on your gear and have the same results.

I would suggest that you start with your Mic plugged and test it with no other signal on the VMS4 and adjust you levels and see what works best for you mic.

THANK YOU!! i agree, turn down all the bass/mids/treble THEN work from there and adjust so you dont come in so hot, PLUS dont have a monitor close to you either, or you will get feedback as well...for me, a corded mic has worked best

quote:

Originally posted by Corneloues:

quote:

Originally posted by Ihearyou(American Audio):
Thanks Cornylius

It's Corneloues, but hey close enough ;-)

quote:

This has got to be a signal path issue. Do not compare this to the Q-SD record because the input sensitivity is different. you can not expect to mirror you settings on your gear and have the same results.

I would suggest that you start with your Mic plugged and test it with no other signal on the VMS4 and adjust you levels and see what works best for you mic.

I will try that. Also just been playing n analogue mode and my channel 2 is completely screwed. Distorted at any level.

I plug the left output of my SDJ1 in to channel 1, have the gain set to 45%, master at 50% and the fader to max. The channel peaks and +4 and is as clear as anything.

Plug the same SDJ1 in to channel 2, same levels and the channel is completely distorted. Even if I turn the gain down to 0% and then back up to 5% or 10% its completely distorted.

Will feed back on the mic situation shortly

Roy

ive read all your posts too and it sounds like you have a messed up unit, just take it back and get another, or get something else already

@Cornelius: Make sure you set the Line/Phono switch in the back on MIDILOG2 to Line. The Phono will definitely give you really bad distortion on a line level input from the SDJ1.

@thewicked: The jack on the VMS4 is a combo jack which will accept either a 1/4" jack or XLR. So the links I showed you would work. Another simple thing to try is just hook up another mic see if it works and if you get the same distortion then perhaps there is an issue with the circuit. Anyways I'd suggest you contact American Audio support directly by email to resolve this.

Doh i had not checked to see if it was a combo thats good
Question on that ,will converting it to a jack reduce output on the mic or remain the same as its the same input socket ?
will contact europe support by email just tring to work out the message so i get my point across correctly

@emarx I have bought an impedance adapter as you suggested my final attempt to make this right will try it the club this week I will post the outcome

Well my first gig using the impedance adapter bought in Maplins about 12 euro(8uk pounds) http://www.maplin.co.uk/Module.aspx?ModuleNo=12151

I plugged in the adaptor into the Xlr of mic channel one through the combi jack input as the adaptor has a jack end,
I noticed a hum from the when I turned up the mic gain with or without the microphone plugged into the other end then I proceeded to try the microphone for volume and Eq but most important to see if my big distortion problem had gone,
The impedance adapter was set to HIGH impedence and the result was a major difference the volume was as loud if not a little louder then the music channels levels,
before it struggled to match the sound music levels and it sounded distorted and muffey,
The eq seems a lot chrisper aswell
As it was a big club I was doing the hum really didn't matter but Im not sure how the hum will sound in a bar or in a moblie gig , that said the hum is most likely from the Adapter itself Im guessing its not the most high end of kit.
So if the hum was gone and the stupid adapter was not sticking so far out the back of the VMS4 I would be totally happy of course I would have been even more happy if the input matched the Shure Sm58 microphone or any of my low impedence micophones in the first place,
maybe a future batch of the unit could have a high/low switch.
I would hope I could track down a good High impedence microphone then I would not need an adapter but this is only a guess on my part maybe the adapter does more than if you just stuck a high impedance mic into the channel .
Anyone know of a good type of high impendance micophone ?
most I have come so far across are very cheaply built .

quote:

Originally posted by thewicked:
Anyone know of a good type of high impendance micophone ?

This is the problem.

Professional mics are low impedance.

Cheap and nasty mics are high impedance.

AA make the VMS4 with inputs designed for high Z mics, implying that they expect it to be used only with cheap and nasty mics.

as there are 2 inputs they could have had one high and one low input?? just a thought.

Hello thewicked,

Thanks for your patience and testing out my suggestions. Since you set the adapter for "HIGH" what you actually ended up doing is reducing the mic gain to the point where it won't distort. This is actually the correct thing to do.

It's becoming clear to me that this is a hardware issue we need to address. Please see my post here:
http://forums.americandj.com/e...27105965/m/688105207

As far as me personally, I use a Sennheiser E815S microphone and the sound is very crisp and clean on the VMS4:
http://www.sennheiserusa.com/p..._wired_evo800_009425
It's also cosidered a low impedance microphone, but apparently compared to your SM58, the output is slightly lower, which may be just enough to eliminate distortion on the input circuit.

Both the mic circuits are identical on the VMS4 FYI.

@Emark i cant belive it I have two of the 815s mic I bought one for back up to the sm58 and found it to sound just as good with the added on of switch I have try them as well and the same distortion but none with the adaptor .
used it at the gig here in the post ..
http://forums.americandj.com/e...27105965/m/535106307

http://www.youtube.com/watch?v=TfT-iwSs1f4