[Ferbose]

At one point, after dropping thousands of dollars into my audio system, I would have never expected that a $20 gadget could transform my conception of hi-end audio. But a $20 little box I bought on Ebay actually took my speaker and headphone systems to a higher level, and forced me to think deeply about what the word "stereo" actually means.

The gadget is Dynaco QD-1 Series IIL, a passive box to perform ambience extraction, turning stereo audio into five-channel surround. The device was originally marketed by Dynaco in the 70s, called QD-1 Quadaptor. Later, series IIL was released, but went out of production in the late 90s. For more about Series IIL, please refer to this article on Enjoythemusic.com

Since QD-1 was made way before I was born, and discontinued even before I got into hi-end audio, I think it would be foolish of me to start a review thread on it. Instead, I decided to start an appreciation thread. If you have enjoyed using QD-1, please chime in and discuss your experience with it. If you are still using it today, please share your thoughts on why this little box remains relevant and valuable today, in the age of surround sound and digital matrix decoders like ProLogic II. I, for one, strongly believe QD-1 is an indispensible part of my system.

 

[rickcr42]

Seconded !

Do a search man.Been touting mine for five years and actually gave my $1,500 surround sound receiver to my kids the day I purchased mine and never looked back since

 

[rickcr42]

BTW-if you have a good system take the advice in the ETM article and hook the device up in parallel with your main front speakers so when it is "off" there is zero connection to your stereo system instead of having your main speakers go through the device.
Signal purity and only what you need at the time

 

[Ferbose]

Quote:

Originally Posted by rickcr42 BTW-if you have a good system take the advice in the ETM article and hook the device up in parallel with your main front speakers so when it is "off" there is zero connection to your stereo system instead of having your main speakers go through the device. Signal purity and only what you need at the time

Yes, that is what I do.
I have two seperate intergrated amplifiers driving front and rear speakers.
Master volume control is via PreSonus Central Station.
I now listen to all my music with Dynaquad, and it can add surround effects for movies, too.

 

[Ferbose]

Bump...

Too bad Dynaquad is not getting any love these days.

Truly the best $20 tweak--not only works, but can transfrom a system.
Looks like most people pay no heed to the (lack of) ambience issue in stereophonic recordings, which was already familiar to audio engineers before WWII.

 

[AlanY]

Have you tried any of the modern ambience extraction systems? Logic7, Trifield, or DPLII/IIx? Some people swear by them and do all their listening this way.

 

[Ferbose]

Quote:

Originally Posted by AlanY Have you tried any of the modern ambience extraction systems? Logic7, Trifield, or DPLII/IIx? Some people swear by them and do all their listening this way.

No.

Modern ambience extraction are almost always built into solid-state receivers or surround processors, and work in the digital domain. This restrcits what DAC and preamp one can choose. Dynaquad is more compatible with a purist two-channel system.

 

[AlanY]

Aren't you at least curious? In my mind, the QD-1 itself can hardly be thought of as a "purist two-channel" device anyway. It's just analog instead of digital.

You could always send a pure, unprocessed analog signal to the front two channels and just use a Logic7/Trifield/DPLII processor for signals going to all the other channels. That would be a pretty decent purist approach.

Anyway, I can't comment because I only have a stereo speaker rig, but if you like the QD-1 it might be fun to try more modern and sophisticated ambience retrieval systems.

 

[Ferbose]

Quote:

Originally Posted by AlanY Aren't you at least curious? In my mind, the QD-1 itself can hardly be thought of as a "purist two-channel" device anyway. It's just analog instead of digital. You could always send a pure, unprocessed analog signal to the front two channels and just use a Logic7/Trifield/DPLII processor for signals going to all the other channels. That would be a pretty decent purist approach. Anyway, I can't comment because I only have a stereo speaker rig, but if you like the QD-1 it might be fun to try more modern and sophisticated ambience retrieval systems.

Once you choose the digital ambience enhancement method, you lose your choice over the DAC and the preamp in your system, and the possibility of having tubes at these stages. That is why Quadaptor remains an attractive alternative.

 

[rickcr42]

Quote:

Aren't you at least curious? In my mind, the QD-1 itself can hardly be thought of as a "purist two-channel" device anyway. It's just analog instead of digital.

and that is entirely the point of the device.All other methods are sent through a combination of ADC/DSP/DAC so everything passes through and is colored by these additional steps while the QD-1 is a pure analog device that adds zero to the main front speakers and nothing not present to the others.

What DSP adds is steering logic and electronic delays but for me personally I would rather use actual physical delay by spacing the speakers away from the main listening area over an electronic emulation of this which is exactly what the delay does.

One can be spectactual but never natural,the other is always natural (no croakiness added to voices for instance) and has the potential to be spectacular enough to match an actual movie theater sound system which in reality has its roots in the wide left and right channels with a L/R mix dialog channel and multiple speakers fron front side to rear side.

not for everyone but until I am stuck with a purely digital signal path i am not adding extra conversion stages between the source and speakers if i don't need to and i don't