WOW, what a beauty! Congrats
Show us your gear!
- Thread starter quadanasaziland
- Start date
Help Support QuadraphonicQuad:
Here is a Hitachi SP-2921. I have not found much information on this unit. While this is a quad piece of equipment, other than being able to play 4 channel 8 tracks, it is otherwise almost purely just a 2 channel receiver. I think from the tuner or inputs, the only quad sound is from a matrix system. As you can see, the back panel connections are very sparse. It doesn't even have a phono input. The rec/play tape connections are 2 channel only. The remote speaker outputs are for 2 speakers only. I always look at a receiver with rca jacks for speaker connections as an indicator of low to bottom of the line equipment. It only has stereo output for headphones. When you insert a stereo 8 track a 2 lights up, or a 4 if the cassette is 4 channel. It uses 4 separate volume controls. It has a unique tuning system. When you pull the tuning knob out, the knob acts as a slider, and you can quickly scan from one end of the dial to the other in an instant. When the knob is pushed in, it rotates cw or ccw to move the dial pointer and fine tune in the station. I suspect it is less than 10 wpc. If anyone has info or suggestions on where to look for some on this unit, I would appreciate that.
I have included a pair of quad headphones. For some reason I can't remember, I never had a pair of quad phones in the 70's. These are Panasonic 44 Series phones. I saw them at an estate sale and snatched them up.
I have included a pair of quad headphones. For some reason I can't remember, I never had a pair of quad phones in the 70's. These are Panasonic 44 Series phones. I saw them at an estate sale and snatched them up.
Last edited:
This is my Realistic QTA-770. Sold 1975-1976. 60 wpc stereo, 25 wpc quad. This is one of Realistic's best 4 channel receivers. It has some unique features, although I am not acquainted with them all as I cannot find an instruction manual, only service. It has a midrange tone control, and all three tone controls are split between front and rear. The volume controls are little unusual. There are two sliders for front and rear volume, and then two balance controls, one front and one rear. It has a cool tuning arrangement. When you touch the tuning knob, the tuning meter backlight turns from green to yellow. After a station is tuned in and you let go of the knob, the light turns back to green, and the station is locked in. They refer to it as "AUTOMAGIC". A unique feature is the "AUDIOROTOR". For every 90' turn of the knob, the channels rotate 90'. So left front becomes right front, right front becomes right rear, right rear becomes left rear, and left rear becomes left front. If turned cw, the channels rotate cw, and if turned ccw, the channels rotate ccw. No matter what direction you are facing, by the twist of a knob, you can have the channels correctly oriented. It has a "QUATROVOX" mode, which I assume is four channel matrix from a two channel source. It has a "STEREOMAX" mode, which I am not sure of it's effect. The front speaker rear panel outputs are available by screw post or RCA jack. It is set up for a CD-4 turntable. There are two lights to indicate if the signal from the turntable is stereo or CD-4. It has an FM det jack, and a hi/lo level switch for the turntable input. After my Marantz quads, I consider this to be my third best quad receiver.
Last edited:
Soundfield
1K Club - QQ Shooting Star
Not entirely unique, Sansui had a speaker "Direction" control on a lot of their early equipment. Here is the front panel of the QRX5500A for example-
I can't imagine many people would have found any use for such a control which I guess is why it died out.
That’s what I thought when I first figured out what that knob did.
abby normal
Active Member
stereomax bridges the front and rear amps to double the output power. at least in theory.
My Sansui QS-800 has the "Direction" control. The 800A also has it.
Well, it would’ve come in handy if you run an un-edited “A Space In Time” through it (but then, wouldn’t the corners still be crossed)
I have two of these Marantz 2440 Adaptor Amplifiers. Made 1972 - 1976. Rear speaker amps rated at 20 wpc. Retail $299.95. These are meant to convert any two channel stereo into quad. Connections are made using the stereo's tape in/out jacks. Once connected, the stereo's volume was set so that front and rear sound levels would be close to each other. Volume levels for all four channels were then set by the master volume control and triple balance controls on the 2440. Once the balance controls were adjusted, the master volume was all that was needed to adjust volume through all four speakers. Two channel equipment was hooked up to the stereo, and four channel ( R2R, 8track, etc) to the 2440. As with stand alone Marantz quads, it uses a plug in four channel decoder, and can accommodate the Marantz wired remote. The bass and treble controls affect the rear channels only. Two sets of speakers can be used. If four channel headphones are used, the front jack connects to the stereo, and the rear to the 2440. It can convert any two cannel source into synthesized quad. The four VU meters monitor all four channels. Because the 2440 face approximates the Marantz stereos of the era, when paired together they look very handsome, especially when both were wearing the optional wood cabinets. Of course, they could be used with any manufacturer's stereo. I had one back in the day, paired with a 2270. I had the remote, and the nice thing about that was that the remote's volume level is dependent on the master volume level. If the master was at 50%, that was the limit the remote could go. If you set the master at 25% and handed the remote to someone, even if they put the remote's volume at 100%, that would equal the 25% the master was set at. Nice equipment saver. I got to tell you, being able to adjust volume from the couch, way before remote controls became commonplace, was quite the luxury.
Last edited:
Wern't you one of the Fabulous Furry Freak Brothers? Where are the other guys?
I got well paid to put a hit on them. ☠
Great picture. Thanks for sharing it. Did you have a remote? Were you using the TV rabbit ears for the stereo’s antenna? I was listening to SQ vinyl and a Detroit FM station (WWWW) broadcast in SQ for a few years.
No remote but yes the rabbit ears were for FM reception. I was in a basement level apartment and good strong stereo reception, even in inner city Chicago, could be a problem
furui_suterioo
Quad & 70s Enthusiast
Got this Alpine 4006 "Multi Director" car joystick balance control today:
It only has 2ch input, but maybe I can change that.
It only has 2ch input, but maybe I can change that.
JediJoker
Audio Engineer/Enthusiast
I am confused. You say it only has two channel input, but it controls four speakers. Does it split the two channels into four? It’s a very cool looking piece of gear
I was wondering that also, but since it's for a car, maybe just split between stereo Front and Rear speakers for balance
If it has a two channel input, and then splits that into output for four speakers, the possibility of turning it into a quad balance Control are about zero
furui_suterioo
Quad & 70s Enthusiast
Probably, but I assume that maybe it is splitting the 2ch input at some point, so maybe that could be tapped into, there is a service manual for it online. I've also been thinking maybe I could connect it to quadraphones for pseudo-quad somehow, maybe combine the front outputs with reverse polarity of rears, then to the y-splitter, so when I push the joystick back it would go to the rear drivers because they are already in reverse-phase? Could this work?
Similar threads
