[928uk] Radio Installation

[jonathan at netvue.co.uk]

Hi Graham,

 

I have the original amp and an aftermarket head unit with my own wiring from
the head unit to the cable for the original amp.

 

If the amp is grounded and the radio is grounded and the signals within both
are referenced to ground (single-ended) which is usual for such equipment,
there is no need for another 'ground' connection between radio and amp.

 

If you want to cover yourself, my advice would be to run a ground wire from
the head unit ground to the original DIN cable as you have suggested, but
don't connect it. If it all works fine without it, then leave it
unconnected. Only connect it if you have to.

 

Bear in mind that I am talking here about ground connections, as that's what
you asked about, not screens for signal wires.

Best regards,
 
Jonathan
 
 
928 GT 1991 Amethyst Metallic

 

From: 928uk <928uk-bounces at lists.928.org.uk> On Behalf Of Graham Sheppard
via 928uk
Sent: 20 January 2023 13:58
To: 928 List <928uk at lists.928.org.uk>
Subject: [928uk] Radio Installation

 

My 1989 S4 is in good original condition and I try to keep it that way. The

Toronto SQR 46 radio works well,  but the cassette not so well. I have

decided to put in a Bremen SQR 46DAB. I intend to retain the original BQB

80 amp and the loudspeakers (which I have refoamed). I have the power

connection, part 91164240000. The problem is the connection to the amp

thruogh the original lead which has an 8 din connection, while the Bremen

pre amp out has RCA plugs. I purchased an RCA to 8 DIN lead from the US

(after shipping and VAT was very expensive). Unfortunately it was wired

incorrectly for a BQB 80. Another connector, appropriate for Porsche cars

is available from Bergvill in the US, but would end up extremely expensive

after shipping etc. I have decided to make a connector, however, because of

the RCA connections on the radio there is no ground between the radio and

amp. I have looked at the wiring diagram  and it appears that the ground

for both goes to the same point. I propose to run a ground wire from the

radio ground, on the power side, to the original 8 DIN cable. Has anyone

done this or arrived at an alternative solution while retaining the

original amp?

Regards

Graham