My installation consists of the EMPEG and a NAKAMICHI 45z head unit. I want a normal head unit as well, because I still want the ability to use CD's, and I like to have a quality AM/FM radio. I also like having a real head unit with an easy to use volume control.

In my situation, I am using the NAK unit as my main unit, and I have the EMPEG connected to the NAK via the NAK's AUX input. The problem I am having is this, the NAK AUX input is only a 1v input, and the EMP is a 4v. Therefore, the EMPEG overdrives the NAK and it distorts the music. If I hook up the EMP to the NAK via the 1v RCA's on the back of the EMP which you would normally use to connect to you home stereo system, it works perfect.

So my question is this, is there a way to lower the EMP's outputs from 4v to 1v via either the EMP unit, or something you can put inline with the EMP CAR OUTS in order to lower that voltage from 4v to 1v?

Any ideas?

Chris Zimmerman
Simple Dialup - Owner
[email protected]

Try a divider network between the empeg's outputs and the nakamichi inputs: I've not done the sums in my head, but this should work ok, assuming a high input impedance in the head unit.

empeg output (center) -> 5.6k -> nakamichi input (center) -> 1.8k -> empeg ground (shield).
Obviously you also need to connect the ground of the empeg to the nakamichi ground. Does the unit work ok if you turn the empeg output down? If it doesn't, then the problem is elsewhere (eg: have you tried fitting the grounding leads to the Nakamichi input and grounding them to the Nak's case?)

Hugo

Hugo,

I really don't understand what you are saying here ...

I have turned the volume down, and yes, if you turn it down, it works out much better, however, by turning the volume down, then the normalization between the head units CD/RADIO and the AUX IN are totally different. In other words, I have to crank up the head unit to almost 75% or 80% when using the EMP to get the same volume that I can get at 50% when playing from the head units CD/RADIO.

Like I say, I am sure it is a case of the output voltage being too high on the EMPEG. When I hooked up my AC power cable to the empeg, and then use the 1v outputs on the back of the empeg to connect to my NAK, I can set the EMP to 0db, and everything works awesome.

One idea that I had was to use a PHOENIX GOLD PDL1 Line Driver. I was thinking that maybe that device would work correctly. Has a variable control on it to change the output voltage up to 8volts. However, I don't know if the input voltage is 4v, if you could reduce it to 1v with this device.

Any other ideas?

Chris Zimmerman
Simple Dialup - Owner
[email protected]

This is very strange: the 4v output will be at 1v level when set to -6db (approximately - 3dB down is a halving of the output level, voltage wise). A 4v output means that the peak voltage is 4v - there's nothing magic about 4v when compared to 1v, just that the signal is 4x as large.

From what you've said it sounds more like a grounding problem - did you try the grounding leads?

Hugo

Hmmm... You have an interesting point. From what you are saying, then at -6db, the unit should play just the same as when it is hooked up via the 1v outputs on the back of the empeg.

What do you mean the grounds? I did not do the installation myself, so I am not completely familiar with what you are asking. What cables should I be checking?



Chris Zimmerman
Simple Dialup - Owner
[email protected]

The empeg comes with 2 sets of short male-female RCA leads, with a shared ground connection between each left-right pair.

If you still have both of these in the box, then they didn't use them :)

These may well need to go between the empeg line-out and the nak line-in, with the grounding flying lead being connected to the nak's ground point/casing.

Definitely worth a try - ask your installer if they tried this.

Hugo

Hugo,

Okay, I found the MAJOR source of the problem. The front left/right lines are being used to connect EMPEG to NAK. That should be fine, the problem was in the rear connectors on the EMPEG. The rear right must be defective on the slide. Twisting the connector cause the distortion to increase, and go away ...

I cut the defective connector off, as well as the rear left connector, and capped them off. No need for them anyway.

Now I run the EMPEG at -6.5db, and it sounds pretty good. However, I can still notice a difference between using it this way, and using it with the 1v out on the back of the empeg. Granted, it sounds good now, but it still seems to have a little bit of distortion.

I looked at the connection between the empeg on the nak. Right now, the female left/right lines that come directly from the emp sled, and the femail left/right lines that come from the nak aux in, are connected by 2 gold male/male connectors. There is no common ground wire comming off those male/male connectors, so obviously they were added by the shop.

I do not recall ever seeing any extra cables in the box. My unit was 00028. Maybe I didn't receive anything extra? Am I missing something?




Chris Zimmerman
Simple Dialup - Owner
[email protected]

All units go out with these cables - they would have been at the bottom of the box.

Hugo

Hugo,

Well, we conjured up a ground today to ground the left/right to the case. It didn't make any difference. BTW - I talked to my shop today. And they did not have any cables for this application.

Okay, that aside, I did take a look at lowering the volume even more. What I did come up with today was that if I lower the volume to -16db, it does sound excellent, with no distortion.

I am assuming that at this point, the old possible explaination is that it is due to the 4v outputs on the EMPEG.

I have talked to Phoenix Gold, and they make a PDL1 Line Driver. It will take a signal and boost it up to 8v, or atinuate it down to .1v. I am going to try one of those inline between the EMPEG and the NAK today to see if that works.

Any suggestions on this?



Chris Zimmerman
Simple Dialup - Owner
[email protected]

No, grounding cables aren't standard in car audio installations (but as we supply them this shouldn't be an issue) - but then again, feeding the output from the empeg into another head unit isn't too unusual either (Kram has a Philips navigation system in one car and an Alpine multimedia system in the other with no problems once the grounding was correctly done, and Steve, the business director here has his empeg feeding into a Sony CD head).

It still sounds like a grounding problem, but by all means try the line driver. You may need to ground the outputs of the empeg to the line driver case - basically, your mileage may vary.

Hugo