Unoffical empeg BBS

Quick Links: Empeg FAQ | RioCar.Org | Hijack | BigDisk Builder | jEmplode | emphatic
Repairs: Repairs

Topic Options
#5219 - 11/10/1999 13:59 EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM
zimmy6996
new poster

Registered: 11/10/1999
Posts: 38
Loc: USA
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]
_________________________
Chris Zimmerman - #427
[email protected]
MK.I - 00028
MK.II - 060000051

Top
#5220 - 11/10/1999 16:15 Re: EMPEG NAKAMICHI 45z VOLTAGE PROBLEM [Re: zimmy6996]
Kram
stranger

Registered: 23/06/1999
Posts: 42
Loc: Cambridge, England
When I thought I had a voltage problem it turned out that I actually had a ground problem, I wasn't earthing the outer of the phono leads at the amp end. Sorry if you've already done that, but I thought I'd mention it in case you're trying to solve the wrong problem as I was.

Anyway, if it really is a voltage level problem then you could try a voltage divider. I put one together in half an hour by cutting up an old pair of phono extension leads and wiring in a 10k linear dual-gang pot as a voltage divider. This allowed me to vary the voltage of the signal going from Empeg to head unit anywhere between 0 and the full output of the Empeg without significantly changing the impedance that the Empeg expected to feed or the head unit expected to be fed from. It didn't cure the problem in my car (as I was trying to solve the wrong problem) but it vary the voltage/volume exactly as expected when I connected it between my Empeg and my hifi in the house.

Please don't do any of this unless you're sure you know what you're doing as it may be possible to damage your Empeg if you get it wrong. Shout up if you need any help with the circuit. In a nutshell though, image that each pot has a top, bottom and middle connector. Connect the bottom to the outer of the phone from the Empeg and the outer of the phono to the head unit. Connect the top to the inner of the phono from the Empeg. Connect the middle to the inner of the phono to the head unit. Be careful not to get the wiring wrong or you could short the output of the Empeg, though I'm fairly sure I accidentally did that for a few seconds on mine and it didn't seem to do any harm.

Assuming that the voltage divider does the trick, you can make a much smaller and cheaper version by using fixed resistors rather than the pots if you have some means of measuring the values that exist between bottom and middle, and top and middle, when the pot is set up right for your system.

Cheers,

Mark.


Top
#5221 - 23/08/2000 18:57 Re: EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM [Re: zimmy6996]
mcgrant
journeyman

Registered: 28/04/2000
Posts: 84
Loc: Menlo Park, CA USA
Hey there,

I'm curious to know how the problems discussed in this thread were finally resolved, because I am considering using a NAK 45z as my head unit as well. I still listen to some stuff on tape, and the NAK's a great deal.

It seems to me that the most appropriate solution is to connect the 1V Line Out RCA jacks from the Empeg to the Aux In of the Nakamichi. Of course, the problem with that is that the docking cage doesn't replicate those outputs. So the solution is either to jerry-rig some sort of RCA plug setup onto the docking cage, or use a line level reducer on the 4V outputs instead.

Anyway, zimmy6996, if you're there, speak up! I'd appreciate it!

Thanks
Michael

_________________________
Michael Grant 12GB Green 080000266

Top
#5222 - 24/08/2000 05:22 Re: EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM [Re: mcgrant]
rob
carpal tunnel

Registered: 21/05/1999
Posts: 5335
Loc: Cambridge UK
You could connect them the other way around, if you are using an external amplifier. Otherwise you'll need a line level converter to reduce the 4V signal down to 1V.

Rob



Top
#5223 - 24/08/2000 05:35 Re: EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM [Re: rob]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
I thought there were factory-settable jumpers for the output level - or was that a Mk 1 only feature?

One of the few remaining Mk1 owners... #00015
_________________________
One of the few remaining Mk1 owners... #00015

Top
#5224 - 24/08/2000 08:53 Re: EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM [Re: schofiel]
rob
carpal tunnel

Registered: 21/05/1999
Posts: 5335
Loc: Cambridge UK
That was for the input level, on a Mk.1.

Rob


Top
#5225 - 24/08/2000 10:42 Re: EMPEG + NAKAMICHI 45z VOLTAGE PROBLEM [Re: rob]
mcgrant
journeyman

Registered: 28/04/2000
Posts: 84
Loc: Menlo Park, CA USA
You could connect them the other way around, if you are using an external amplifier. Otherwise you'll need a line level converter to reduce the 4V signal down to 1V.

I'm trying to avoid using an external amp for now...


_________________________
Michael Grant 12GB Green 080000266

Top