This'll be fun: Signal Path Question: How would you route it?

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Q-Eight

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Since 2002/2003
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Hypothetically speaking, say you have a Pioneer QX-9900 with Pre-Amp outputs.
Now say you have twin Pioneer SG-9500 equalizers.
Add to the mix a Teac 4-channel Dolby box.
Finally, two DBX 118 Companders.

What would be the proper routing and/or how would you want the signal processed?

Receiver to Equalizers to Companders to Dolby back to Receiver?


And why do I see buying a whole truckload of RCA cables in my future?
 
Hypothetically speaking, say you have a Pioneer QX-9900 with Pre-Amp outputs.
Now say you have twin Pioneer SG-9500 equalizers.
Add to the mix a Teac 4-channel Dolby box.
Finally, two DBX 118 Companders.

What would be the proper routing and/or how would you want the signal processed?

Receiver to Equalizers to Companders to Dolby back to Receiver?


And why do I see buying a whole truckload of RCA cables in my future?

First impression, Dolby goes with the tape, EQ before it could change it's action. Ditto compander. So, pre-out to Dolby to Compander to EQ and back into main-in.
I haven't tried a compander in many years, maybe EQ correction before it would give it more to "latch onto". So, second guess, pre->Dolby->EQ->compander->main.
 
Agree with either:
pre->Dolby->EQ->compander->main
or
pre->Dolby->compander->EQ->main
as above.

Recommend you find a source that is particularly problematic (one presumes there are issues you are trying to address/correct with the EQ & compander) and make new recordings with each configuration, then compare. The process will be a bit of a hassle, but the results could potentially be quite different.

Ideally both the EQ and Compander have bypass settings so you can have a cleaner path if desired. That is alot to add to the signal path for things that do not need it!
 
Hypothetically speaking, say you have a Pioneer QX-9900 with Pre-Amp outputs.
Now say you have twin Pioneer SG-9500 equalizers.
Add to the mix a Teac 4-channel Dolby box.
Finally, two DBX 118 Companders.

What would be the proper routing and/or how would you want the signal processed?

Receiver to Equalizers to Companders to Dolby back to Receiver?


And why do I see buying a whole truckload of RCA cables in my future?

What are you after?

Ideal audio path is: Source -> nothing -> destination

You have two categories of processors here: The dolby system and then more standard tools of EQ and a compressor/expander.
The dolby system is made for a specific application while the others are more open ended tools for altering frequency and dynamics balance.

Are you using this as two systems?
Tape deck -> dolby decoder would be one system. The output from this system would go to the monitor preamp.
The EQ and dynamics would be general tools for whatever is needed. If they are intended for the tape deck chain, then between the dolby decoder and the monitor system preamp.

Or...
Are the EQ and dynamics intended to be used to "work" the dolby decoder? If you were intending to try to use these to alter the way the dolby decoder worked to give you a degree of control over the decoding process then you would patch them between tape deck and the dolby decoder and experiment.
 
I suppose my ultimate goal is simplicity. I have a Quad 8-track deck, and a Quad Reel, neither have on-board Dolby. Thus, the need for the Dolby box. However, the Dolby only has ONE tape input (the other being a line input). Currently, only the 8-track passes through the Dolby but I'd like for the reel to be able to use it as well. That's why I want it built into the chain so that the switching mechanism becomes the receivers tape loops, both outputting to the one Dolby box. The Dolby box also has a multiplex filter which would be interesting to see how it compares to the on-board filters in the 9900 (which, are, sub par to my ears).

I may have a line on some Companders on the cheap and I've been told they can help breathe new life into older recordings. Mostly I'm just curious to play with them but also the DBX 118's have a strange port on the back called a "Quad Coupler" and I'd like to see what that's all about. The Manuals state it's for Quad use but doesn't go into a whole lot more detail.

Part of me just wants to collect vintage audio gear and make the stereo stack look that much more impressive. ;)
 
Please don't :flame me!:yikes:couch My solution to your problem, and mine, was to buy two DBX 200's (DBX 007 in Japan) and use them for my three tape decks, DBX NR and Dolby NR on a tape loop. On my receiver it allows me to use the second tape loop as an auxilliary or tape input for testing and my auxilliary is connected to a Zektor 5.1 switch for an outboard CD4 demogitator (tm Quad Linda), Oppo Blu Ray, and anything I want to put on the other two inputs as needed for testing or comparison. :mad:@: This almost gives me the flexibility I want. Now, if I could just get a stronger back for the lifting of components that are twice the weight of stereo.
 
I should have mentioned that my three decoders, SQ, QS and EV4 are also on the DBX 200's and you can hook up the EQ's as well instead of two different NR systems. I have a rudimentary EQ in my JVC receiver, so adding one wasn't a priority for me.
 
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I suppose my ultimate goal is simplicity. I have a Quad 8-track deck, and a Quad Reel, neither have on-board Dolby. Thus, the need for the Dolby box. However, the Dolby only has ONE tape input (the other being a line input). Currently, only the 8-track passes through the Dolby but I'd like for the reel to be able to use it as well. That's why I want it built into the chain so that the switching mechanism becomes the receivers tape loops, both outputting to the one Dolby box. The Dolby box also has a multiplex filter which would be interesting to see how it compares to the on-board filters in the 9900 (which, are, sub par to my ears).

I may have a line on some Companders on the cheap and I've been told they can help breathe new life into older recordings. Mostly I'm just curious to play with them but also the DBX 118's have a strange port on the back called a "Quad Coupler" and I'd like to see what that's all about. The Manuals state it's for Quad use but doesn't go into a whole lot more detail.

Part of me just wants to collect vintage audio gear and make the stereo stack look that much more impressive. ;)

"the Dolby only has ONE tape input (the other being a line input)"
What is different about the "tape" input? "Tape" inputs ARE line inputs normally. I would expect an input that is truly different from a standard line input to be expressly labeled in a unique way. Labeling a non line level input "tape input" would be incorrect. Is it possible to find a manual that describes what the original intended use was?

The most correct solution would be an input switcher for the Dolby unit to allow use from multiple sources. I'd be concerned with the fallout from connecting two inputs in parallel from possible impedance issues. Expressly since this is to be used to decode a dolby signal which is shockingly level dependent.

Now if some of this is experimental or just for amusement purposes then all good. Being critical, I'd look to avoid any unnecessary connections and/or preamp stages from source to destination. For analog domain noise reduction decoding, I'd want to at least be able to start with everything in calibration and only introduce experimentation after trying 'by the book' first.
 
It's my understanding that the "Tape" input runs it through the Noise Reduction circuitry where the "Line" input runs it through both Dolby and Multiplex filters for FM reception.
 
I would think that the Quad Coupler input is to lock the Compander functions together between the 2 units so that they Compress/Expand all 4 channels by the same amount or you could end up with some strange 'noise pumping' effects where say the Rears become 'louder' with respect to the Fronts.

Mostly I'm just curious to play with them but also the DBX 118's have a strange port on the back called a "Quad Coupler" and I'd like to see what that's all about. The Manuals state it's for Quad use but doesn't go into a whole lot more detail.
 
Yeah, the quad coupler would be sum all 4 channel's inputs to trigger the detector for quad program use in the same way a stereo coupler would sum the 2 channels (in a single 2 channel unit) together for stereo use.

Fair enough if the 2 inputs are wired to different stages of the device as well.
 
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