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Zenith 49CZ852, 49D856, and 49D972 Driver Questions

Isaac C.

Isaac C.

Cat Hoarder
Hello everyone, I recently acquired an early 1960s Zenith stereo console. It has the drivers listed above. I have a few questions. Firstly, as anyone familiar with the 49D856 (right) and 49D972 (left) drivers? Secondly, does anyone know what the capacitance value of the capacitor attached to the 49D856 is as I am not familiar with vintage paper capacitors? I measured the impedance of all six drivers, the 49CZ852s measured at roughly 6 ohms while the 49D856s measured at roughly 4 ohms, and the 49D972s measured at roughly 40 ohms. Why would the 49D972 measure at 40 ohms? Finally, would a 47 watt per channel rated for use with 8 ohm speakers be able to safely drive these speakers. One last note, all three speakers share the same negative wire (middle wire) while the 49CZ852 has its own positive wire (right wire), and the 49D856 and 49D972 share the same positive wire (left wire). These then connect at a radial style plug on the back of the cabinet. Any help would be appreciated.
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The old cap should be marked. Did you take the 972 out of the circuit
to measure it?

You're probably not going to get much feedback. If you browse topics
here, these are drivers people just haven't focused on.

Draw out the wiring, maybe that will give you an idea of how to connect
them to your amp. It's plenty powerful to run these speakers. If the console
was originally a tube system, they're probably limited to ~8-15 watts.
 
RxDx said:
The old cap should be marked. Did you take the 972 out of the circuit
to measure it?

You're probably not going to get much feedback. If you browse topics
here, these are drivers people just haven't focused on.

Draw out the wiring, maybe that will give you an idea of how to connect
them to your amp. It's plenty powerful to run these speakers. If the console
was originally a tube system, they're probably limited to ~8-15 watts.
Click to expand...
Yeah I measured each driver separately unplugged from the wiring. I also took the capacitor off and there isn't a capacitance marking to be found.
 
Don't know about your measurement.

On the cap, you could start with 4 or 6uf, and see how it sounds.
 
RxDx said:
The old cap should be marked. Did you take the 972 out of the circuit
to measure it?

You're probably not going to get much feedback. If you browse topics
here, these are drivers people just haven't focused on.

Draw out the wiring, maybe that will give you an idea of how to connect
them to your amp. It's plenty powerful to run these speakers. If the console
was originally a tube system, they're probably limited to ~8-15 watts.
Click to expand...

Haven't focused on?! Where have you been? That woofer series is the rage in OB's. I'd put something around 4 uF for mid and around 2uF for the tweeter. 47 watts is way too much power for these drivers. My 49cz802's are blistering at 3 watts.
 
Son-of-Vere said:
Haven't focused on?! Where have you been? That woofer series is the rage in OB's. I'd put something around 4 uF for mid and around 2uF for the tweeter. 47 watts is way too much power for these drivers. My 49cz802's are blistering at 3 watts.
Click to expand...

Yeah I did some searching prior to posting and found a lot on the 852s but wasn't sure about the midrange and tweeters.
 
Son-of-Vere said:
Haven't focused on?! Where have you been? That woofer series is the rage in OB's. I'd put something around 4 uF for mid and around 2uF for the tweeter. 47 watts is way too much power for these drivers. My 49cz802's are blistering at 3 watts.
Click to expand...

Son of Vere is correct. The large Zenith 49CZxxx are very popular in the OB scene. Some of them are so good that people run them full range and very satisfied with the sound.
The thread "Open Baffle Epiphany" in the "Speakers" forum contains lots and lots of info. You might want to check it out.
 
I run my Zenith 49cz852 open baffle with subwoofer for low end support and the power is coming from a fisher sa300 (peachtree decco 65 as preamp). While I have the 30 wpc fisher dialed back I wonder if they would sound better with an 8-15wpc amp?
I do enjoy the ability to listen to any genre and loud if I choose. I think speakers are the key component and these zenith are the best I've had in my house and they can image extremely well. Another happy owner of these old zenith drivers. Open baffle with these is probably a good place to start and if you dig them then U or H frames, a sub, a tweeter are options to build your ideal set up. IMHO
 
Like most of the other replies the 49CZ852s are the real deal. The amp in the console is probably a 5G29, single ended EL84 tube amp or a close variation. Have the amp rebuilt and use it to power the 49CZ852s in open baffles. This combo is hard to beat without spending major $. Be aware the 49CZ852s have probably set unused for quite a few years. They will need quite a few hours on them to loosen up before they start to sound good.
 
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