My EMG @ 18V experiment

[Mutant]

Equipment:
Guitar: ESP LTD VIPER 407
Pickup: EMG 707 / neck
Volume=100%
Tone=100%

Cable:
3 meters fairly high quality.

Soundcard:
E-mu 1212M line in

Room:
Full of EM fields from:
unshielded power cables in walls,
computer case open()
neighbor watching his TV (15625hz peak)
CRT turned off

Method:
1) To get the highest possible amplitude i just banged all 7 strings as hard as possible without creating too much fret buzz.

2) To get the lowest possible amplitude i placed the guitar upside down on my bed to mute all strings and eliminate all noises coming to the strings/pickup from my natural body movements.

3) To get the difference between 9V and 18V dynamics i normalized both waves to 100% and examined their silent parts.

Wave #1:
One battery
http://www.sneapforum.celtiaproductions.co.uk/Mutant/1x9v_to_line_in.wav
After normalizing to 100% this wave's highest peak (and many other peaks) looks like this:

and the "silence" from 0:19 to 0:22.499 oscillates around -84dB (+-1)

Min Sample Value:	-2.45
Max Sample Value:	2.38
Peak Amplitude:	-82.4 dB
Possibly Clipped:	0
DC Offset:	0 
Minimum RMS Power:	-94.63 dB
Maximum RMS Power:	-92.89 dB
Average RMS Power:	-93.95 dB
Total RMS Power:	-93.94 dB

Wave#2
Two batteries
http://www.sneapforum.celtiaproductions.co.uk/Mutant/2x9v_to_line_in.wav
After normalizing to 100% this wave's highest peak (and all other peaks) looks like this:

and the "silence" from 0:23 to 0:26.499 oscillates around -90dB (+-1)

Min Sample Value:	-1.33
Max Sample Value:	1.11
Peak Amplitude:	-87.75 dB
Possibly Clipped:	0
DC Offset:	0 
Minimum RMS Power:	-101.2 dB
Maximum RMS Power:	-99.48 dB
Average RMS Power:	-100.33 dB
Total RMS Power:	-100.32 dB

[edit]
Before normalization 9V wave peaked at -19.17 dB and 18V at -12.68 dB (6.49 dBs louder).
[/edit]

Conclusion:
6 to 7 decibels more with 18V and no distortion from clipped peaks - the second battery stays.

 

[Jaymz]

Ive got an 18v SD's in my jackson. Quite decent.

 

[JBroll]

Hmm, I wouldn't have thought that as much clipping would occur, that's some serious looking shit. I can't help but wonder how much of the 'sterile' reputation would go away if they all came with 18V configurations shipped...

Jeff

 

[Mutant]

Hmm, I wouldn't have thought that as much clipping would occur, that's some serious looking shit.

Remember that banging on all 7 strings is not a normal situation.

I can't help but wonder how much of the 'sterile' reputation would go away if they all came with 18V configurations shipped...

Bass players seem to love 18V.

 

[LSD-Studio]

yeah I had the problem on a recording I recently did.
the gutarplayer hit like a berserker and the DI-track was clipping all over the place (meaning the pup-circuit, not preamp or AD or anything), I lowered the pup waaay down, still some clipping on louder parts, so I soldered a 2nd batt in there and could place the emg right under the strings again without any problems.

I've been doing that with my emgs now for 2or3 years and wouldn't play a 9v emg anymore (cept in my strat, it does only 1 batt fit in there but that bothers my alot)

 

[FretsAflame]

Is this a complex mod at all? I'd have to find a place for the second battery in my hellraiser...

 

[Mutant]

Is this a complex mod at all? I'd have to find a place for the second battery in my hellraiser...

No !
You just need 3 9V battery connectors.
Connect red wires to black ones.
You will know that you have 18V if you try it with your tongue (i always check 9v batteries this way hehehe).

 

[Mutant]

btw There is no room for even a single battery in my Viper anymore because of the two additional connectors here so i had to put both batteries in the other (knob&switch) cavity.
I wrapped the batteries in paper tissues to prevent them from bouncing inside.

 

[DFGeneer]

Mutant, when did you measure the noise levels? Before or after normalizing?

I don't see any physiscal reason for that noise reduction you report...

 

[Mutant]

Mutant, when did you measure the noise levels? Before or after normalizing?

I don't see any physiscal reason for that noise reduction you report...

After

Before normalization it was ~-103.5dB on both waves.

 

[JBroll]

Remember that banging on all 7 strings is not a normal situation.

I hit the strings pretty hard, although no more than four at a time - how do the peaks look when you're just slamming a thrash rhythm?

Jeff

 

[Mutant]

I hit the strings pretty hard, although no more than four at a time - how do the peaks look when you're just slamming a thrash rhythm?

Jeff

Sorry Jeff i'm too lazy to switch back to one battery (5 screws & 3 connectors x 2) just to check it for you, but i guess if you have EMG equipped guitar you can check it yourself by connecting directly to line in (additional circuits between guitar and recorder will smooth the clipped peaks a little bit).

 

[Sloan]

this is why i play rock n roll. fuck batteries in guitars.

 

[JBroll]

Sorry Jeff i'm too lazy to switch back to one battery (5 screws & 3 connectors x 2) just to check it for you, but i guess if you have EMG equipped guitar you can check it yourself by connecting directly to line in (additional circuits between guitar and recorder will smooth the clipped peaks a little bit).

Can't say I blame you, tech work just gets annoying, but if I ever wind up with one I'll try and likely post. For now, though, I'm passive only.

Jeff

 

[JeffTD]

Just looking at it is one thing... listening is another.


I've tried it, and in all honesty, it took away what I like about 81's - the compression, the super tight low end, the sterile, grindy midrange. It made it more organic, responsive, and bassier, for sure... but that's not what I bought an EMG for.

FWIW, I found the 18v mod to have almost no audible affect on the 85.

 

[JBroll]

Well, if that's what you're looking for, glad you're happy.

Now, keep in mind that another thing you could do would be to vary the voltage going to your EMG to get more or less compression and tightness - anyone feel like being a guinea pig for this one?

Jeff

 

[nwright]

3 battery clips? Where'd you get that?

It only takes 2...

I love my 18 volt mod Vipers. Have used the mod for a long time now. It does change the characteristics of the pickup, but for me it removes the stuff about EMG's I hated (pickup preamp clipping, sterile lifeless type tone). I like passives more in tonal quality and the 18v mod bridges the gap perfectly between the 2 types, for me anyway.

 

[Mutant]

3 battery clips? Where'd you get that?

It only takes 2...

Look at "Figure 3: The temporary harness".

I wanted the mod to be more a removable addon than a mod.