EMG insertion loss

[Aharon]

So I have two 35DCs installed and am experiencing the phenomenon known as 'insertion loss'. This is when the signal is weakened / altered by the fact that it is being split.

EMG sell an active balance control (EMG ABC) which would remedy this issue, however I am confused about whether I need one or not if I plan on buying an active Preamp?

My question:

is one of these....

http://www.emginc.com/products/index/206/147/4

in built into all of EMGs active preamps?

[walterw]

split, or combined? what exactly is happening?

[Aharon]

hi walter,

I am using two EMG 35DC humbuckers using the standard passive tone / volume controls supplied. The combined output of the pair is less than one individual pickup. It is also affecting the tone slightly, similar to as if phasing is occuring.

for example If I were to slowly roll up the volume on the neck pickup to add it to the bridge pickup signal, there would be a decrease in output. I would like to know if this is an issue when using an active preamp, or if this requires the purchase of the ABC (seemingly hard to find).

[KramerBassFan]

I think you might have them out of phase.

Try reversing the lead/ground on one of the pickups.

Hope that helps.

[SGD Lutherie]

You can't reverse the leads because they are active.

This is sometimes just a product of having two pickups on. It seems to happen more when both pickups are voiced the same. So for instance if you had used a DC and a CS, you might not have had such a noticeable drop.

Generally what happens is the common frequencies are being reinforced, so you end up with a drop in mids.

[walterw]

you can't flip the leads on EMGs, as you're connecting to the preamp, not the coil. (edit: david beat me to it)

that loss is from the two pickups being in parallel, not a polarity issue. (edit: ok, it's from the two preamps being in parallel, as well as some frequency cancellation from the two pickups sensing different parts of the string.)

i suppose that their new active combiner would solve this, as it's basically a 2-in, 1-out mixer, but EMG seems to have made odd choices for the design of the thing: the "active" version has a 25k input impedance, while the "passive" one has a 200k input impedance. this seems a little low for both applications and might load the signal slightly.

it does seem interesting that the EMG built-in preamp's output seems able to take abuse that other preamps can't, like being summed together with another preamp (both jazz bass pickups on at the same time) or shorted to ground (either jazz bass volume turned off). these are both things you should not do with say, the headphone outputs of your ipod, or the left and right outputs of a regular mixing board.

[Aharon]

It is definately not phasing and it is a result of them being in parallel. Can you spot any of the design of the ABC in say the BQC preamp?

I essentially want to know if it is necessary to have both?

[walterw]

Originally Posted by Aharon

Can you spot any of the design of the ABC in say the BQC preamp?

i don't think so. the BQC control is just the EQ portion, with no pickup combining or volume control. the BQC system is the same, but with a regular volume control and passive pan pot added on.

you'd want to use the active blend before the volume, and then into the BQS control.

[Aharon]

thanks for the tip walter

So potentially there are thousands of bass players out there using EMG pickups who arent even aware of this phenomenon? The ABC seems relatively unheard of compared with the standard preamps. What do you think?

[mongo2]

Originally Posted by SGD Lutherie

This is sometimes just a product of having two pickups on....

Generally what happens is the common frequencies are being reinforced, so you end up with a drop in mids.

Closer to reality.

[Getaway Driver]

Originally Posted by Aharon

thanks for the tip walter

So potentially there are thousands of bass players out there using EMG pickups who arent even aware of this phenomenon? The ABC seems relatively unheard of compared with the standard preamps. What do you think?

i'm guessing a large chunk of bassists don't install the pickups themselves. they hand the bass to a lutheir and say "here, put two EMG's in it". The luthier knows either to use the ABC or wire it differently. The bassist gets the bill later, pays it, and goes about their life.

[Aharon]

Originally Posted by Getaway Driver

i'm guessing a large chunk of bassists don't install the pickups themselves. they hand the bass to a lutheir and say "here, put two EMG's in it". The luthier knows either to use the ABC or wire it differently. The bassist gets the bill later, pays it, and goes about their life.

Maybe you're right. I think an even larger chunk of bass players just buy production line instruments and dont mod them at all, wheres the fun in that!

[SGD Lutherie]

Originally Posted by Getaway Driver

i'm guessing a large chunk of bassists don't install the pickups themselves. they hand the bass to a lutheir and say "here, put two EMG's in it". The luthier knows either to use the ABC or wire it differently. The bassist gets the bill later, pays it, and goes about their life.

If you follow the instructions that come with the pickups, they just have them going to two volumes or a blend pot. I had been using them since the mid 80's.

They only just came out with the ABC recently. So luthiers just followed EMG's wiring schematics. One thing I did find on my own was that some of their pickups, like the J, sound better with 100K volume pots.

My experience is if you ran the pickups through the volumes or blend, and then into a preamp, such as the BTC, the interaction between pickups was less noticeable.

[Aharon]

Originally Posted by SGD Lutherie

If you follow the instructions that come with the pickups, they just have them going to two volumes or a blend pot. I had been using them since the mid 80's.

They only just came out with the ABC recently. So luthiers just followed EMG's wiring schematics. One thing I did find on my own was that some of their pickups, like the J, sound better with 100K volume pots.

My experience is if you ran the pickups through the volumes or blend, and then into a preamp, such as the BTC, the interaction between pickups was less noticeable.

That is useful to know. Unfortunately the ABC isnt compatible with the EMG systems, it is a dedicated volume control which can be used with the EMG BQC/BTS/BTC 'control' preamps, which means I'll be looking at one of those probably. Are they sonically identical to their 'system' equivalents?

[SGD Lutherie]

The "Control" version and the "System" version of the preamps are identical. The difference is in the volume or blend pots.

The control version will work with passive pickups, while the system version only works with active pickups.

I have taken a BTC System and changed the pots to 500K and used it with my passive pickups. It worked great.

The ABC comes in two versions, the ABCX for EMG-X active pickups, and the ABC which they say is "designed to work with all our non-X series pickups" and they also say for passive. That's a bit confusing, because for the ABCX they say there is a passive (P) version.

Calling them up might be a good idea.

[Aharon]

Originally Posted by SGD Lutherie

The "Control" version and the "System" version of the preamps are identical. The difference is in the volume or blend pots.

The control version will work with passive pickups, while the system version only works with active pickups.

I have taken a BTC System and changed the pots to 500K and used it with my passive pickups. It worked great.

The ABC comes in two versions, the ABCX for EMG-X active pickups, and the ABC which they say is "designed to work with all our non-X series pickups" and they also say for passive. That's a bit confusing, because for the ABCX they say there is a passive (P) version.

Calling them up might be a good idea.

Yeh might have to bite the bullet and pay for a phone call to the states Its really annoying when companies dont make their information absolutely crystal clear.

Glad to know the system and the control are identical, looks like my set up will be an ABC / ABCX with a 3-band control. I thought the 35 DCs would be a little more turbo charged than they are right now, so hopefully spending the extra money will get it sounding better.

In your experience, does a preamp drastically alter / improve the EMG sound or does it simply offer basic EQ capabilities? What im ultimately looking for is a way to get these pickups hotter and more ''alive' sounding (and maybe shave off some of the high mid)!

I was also considering swapping out the neck for a 35P4 so the pickups arent producing similar sound. What are your thoughts on this? Is the 35P4 the same as the P but in a soap bar housing?

Thanks.

[walterw]

like i said, a "system" is just a "control" with a passive low-impedance volume and blend wired in front of it.

the EMG preamps are reasonably flat, so they're not going to really change the character of the pickups unless you boost or cut EQ.

DCs are plenty "hot" and "alive" (loud and bright, in other words) by themselves.

[SGD Lutherie]

Originally Posted by Aharon

(and maybe shave off some of the high mid)!

My experience with DC pickups is no matter how much EQ you use, you can't get rid of that tone.

They have EQ built into them to make them sound like Music Man pickups, and were originally supposed to be used in the "sweet spot".

When I mentioned to EMG that they had that annoying edgy top end when used at the bridge, they said they weren't made to be used at the bridge position! They don't work well at the neck position either.

Not my favorite EMG pickup.

[Jamie_Funk]

Originally Posted by SGD Lutherie

My experience with DC pickups is no matter how much EQ you use, you can't get rid of that tone.

They have EQ built into them to make them sound like Music Man pickups, and were originally supposed to be used in the "sweet spot".

When I mentioned to EMG that they had that annoying edgy top end when used at the bridge, they said they weren't made to be used at the bridge position! They don't work well at the neck position either.

Not my favorite EMG pickup.

I really do like the DC....but David is right - the DC was created to mimic the Stingray tone (originally for the Modulus Sweet Spot bass). It does it VERY well IMO (I actually prefer it to the MM), but to me sounds less than stellar anywhere but in the Ray sweet spot. Why EMG doesn't market it this way is beyond me.......the built in EQ curve on the DC is hard to get rid of - though in a way it isn't much different than the buit-in eq on a Stingray preamp - it's just in the pickup itself.

J

[Aharon]

This is annoying to hear after having ordered two of them. Ive been able to get good sounds out of them using a Bass POD XT but straight into the ampeg they sound pretty average.

Ive been looking at a P/J configuration but my pickup placement is bridge / neck so the P would be a little close to the neck. The bass is a maple through neck with Ash wings.