Marantz 4070 Quad Amp.

[aftershock]

Do I need a demodulator when running a marantz 4070 amp. ? I'm using a SQA-1 decoder and I operate amp. on VARI-MATRIX. Sounds great but while operating on DISCRETE sound comes out of front speakers only. No sound at all when operating on SQ-DECODER. Do I have a bad decoder ? I'm expecting a SQA-2 decoder soon in the mail. Thanks.

 

[par4ken]

Yes you need a demodulator for CD-4. The 4070 has auxiliary inputs for one or for any other discrete source.

 

[LuvMyQuad]

but having no output when switched to SQ-decoder is an issue isn't it? I assume he has the SQA-1 installed. Im not sure if the Vari-matrix actually uses the decoder module.

 

[par4ken]

but having no output when switched to SQ-decoder is an issue isn't it? I assume he has the SQA-1 installed. Im not sure if the Vari-matrix actually uses the decoder module.

He should have output on SQ if the module is installed, unless it's defective or the selector switch needs cleaning. I would check to dee if the module is in fact installed.

 

[sjcorne]

Sounds great but while operating on DISCRETE sound comes out of front speakers only.

I've got a 4070 as well and love it. Think of the discrete mode as a "pass-through" - what's being input is exactly what's being output, with no extra processing added. If you're playing an LP (stereo or quad matrix-encoded) through the internal phono preamp, you'll only get two channels out. If you engage the "vari-matrix" mode, it applies a pseudo 4-channel effect that can be adjusted using the dimension slider.

 

[aftershock]

Well I received the decoder via Ebay. SQA-1. I have a pretty good repair guy that installed the module so I do not think installation is an issue. I'm leaning towards faulty module or selector switch cleaning.

 

[timbre4]

Marantz 4140 here, if no sound from SQ position, decoder is not present or is faulty.
Also make sure no Tape Monitor function is accidentally engaged to interrupt the signal path. It's fairly easy to press a button in handling the amp and not notice it. (this would interrupt all sources)

 

[par4ken]

Well I received the decoder via Ebay. SQA-1. I have a pretty good repair guy that installed the module so I do not think installation is an issue. I'm leaning towards faulty module or selector switch cleaning.

Did he test it after installation?

 

[Sonik Wiz]

Did he test it after installation?

And you don't really need a repair guy for a consumer installation of the SQA-1 or 2 just to plug it in to the under belly of the beast.

 

[Doug G.]

And you don't really need a repair guy for a consumer installation of the SQA-1 or 2 just to plug it in to the under belly of the beast.

Early Plug-And-Play!

Doug

 

[aftershock]

Thanks for all your replies. I'm new to quadraphonic so all your input is greatly appreciated. I had the 4070 and the module Ebayed to my repair guy so he can open the unit up and give it the once over. I'm sure installation was not a problem. I'm not sure if he tested it though. Thanks par4ken. Thanks timbre4 for your imput

 

[quadsearcher]

Thanks for all your replies. I'm new to quadraphonic so all your input is greatly appreciated. I had the 4070 and the module Ebayed to my repair guy so he can open the unit up and give it the once over. I'm sure installation was not a problem. I'm not sure if he tested it though. Thanks par4ken. Thanks timbre4 for your imput

Wow, I just have to mention this, I was in repair, and occasionally someone would ask if I tested it. It felt like an attack on our integrity, and I'd reply: ____________________ "Yes! How else would I know if it worked? I couldn't give it back not working without telling you! That'd be crazy!"

 

[MidiMagic]

The vari-matrix does not need the module.

 

[skywaveTDR]

I may be wrong on this but doesn't quad discrete mean 4 channel playing from a 4 channel tape and why with a stereo input there is no rear channels? In the Sansui units I had all the decoders provided rear channels from a 2 channel source but switching to Discrete meant it was looking for the 4 channels from off a 4 channel deck.

 

[par4ken]

A stereo input to the discrete input will only output through the front channels (or back channels if that's where you connect it). Stereo inputs will play through the front channels in stereo mode or through all four if the decoder is selected. If SQ is selected and the decoder is not installed you will get no output.

 

[skywaveTDR]

OK, All my stuff has decoders in it all the time. No more room to use that stuff now days.

 

[skywaveTDR]

It is interesting to read about the strange requirement that some other equipment that I have never worked on have. No matter how long I am in this repair business you keep on learning as I tell my trainees.

 

[par4ken]

It is interesting to read about the strange requirement that some other equipment that I have never worked on have. No matter how long I am in this repair business you keep on learning as I tell my trainees.

I'm not sure what you find strange, The SQ position on the Marantz receivers doesn't produce any output without a decoder module installed. To me that is not strange.

 

[par4ken]

In case you are wondering SQ was developing rather quickly at the time the first Marantz quad receivers came out. To build in a decoder that could become obsolete in a few months or years (as other manufactures did) actually makes less sense. If I remember right the first decoder would of had no logic at all, the second front to back logic only. Finally they came out with a full logic version using the Sony chips. Then came the B version with Motorola chips.

As those receivers were bridgeable many were sold to people who were only interested in stereo, so the added expense of a decoder would of made no sense. I had a friend who had one and only ever ran it in stereo (bridged mode}.

 

[Doug G.]

Yes, at first, Marantz's approach may seem a little strange, weird, unusual, odd, curious, peculiar, bizarre, atypical, anomalous, abnormal but it was actually a good idea.



Doug