Zenith tube amp

Mikethenewb

Constantly Driven to Learn and Create
I just finished recapping a zenith tube amp. The radio functions work great but the turntable functions are not usable with any modern turntable due to outdated input types. How would I go about putting in RCA inputs in?
 
It is probably an input for ceramic/crystal cartridge. You would need a phono preamp for a magnetic cartridge.
 
Okay so I would need a phono preamp but even then it doesnt take the normal rca input
 

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Different model, but that's like my Zenith console amp and tuner. They do use those multi pin plugs which connect the tuner to the amp as suspected, and any external device would go through the turntable input of the tuner. The turntable input is for a ceramic cartridge but will work fine for any line level device such as a CD player, tape deck, etc.

The phono input is your one and only line level input for a single device. Any more and you would have to add a selector switch box.

You will have to figure out which wires are for the phono's left and right inputs so you can just add a pair of RCA's to the phono input on the tuner. Also, when in phono mode, the tuner turns off so you would need to know which wires to jump to keep the amp on. I don't have a schematic, but I am sure someone will come along with one.

If you want to use the amp by itself, you would need to know how to jump the wires in the molex to power it up plus know which inputs are for right and left.
 
This is the amp circuit. I have added labels to this to help you help me figure out how to make the amp work on its own. The large brown unlabeled wire is one of the power inputs to the amp, the other part of the input is labeled in white. From the fuse, you can see a labeled sky blue wire (ground?) and a labeled purple wire (power to the transformer). Some other important pieces of information are as follows: The tuner is very complicated and has a lot of tight spaces that are very challenging to work with, The amount of room to insert a switch on the tuner for different inputs is limited at best, as far as I can tell the tuner only serves as an on/off switch (can be integrated into the amp) and a radio (no one uses).
 

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I think the best thing to do first is to get the amp to turn on and working by itself. That, in and of itself, is fairly simple. I can't tell in your pic, but if the power transformer has two black wires coming out of it, those are your 120 VAC input and all you need to do is to study it and see how you can simply add a power cord to the two black wires. After you figure that out, then you can just add a switch in between the hot wire and the wall socket.

Then I would deal with the input. It is a single input from the tuner to the amp (I also own this same tuner and amp) and is a line level input. The original turntable's phono cartridge was ceramic so it is basically line level.

Since the turntable plugged into the tuner, selecting phono would have been like selecting another line level device like a cd or tape deck.

The tuner has its own built in power supply so it can run independent of the amplifier so if you wanted to keep it around, it makes for a spare tuner which works pretty well with other integrated amplifiers.

Without a schematic, you would have to look at its power transformer just like the amplifier and see if it also has two black wires coming from it. Mine is wired with a power cord and female RCA's so I can use any set of patch cords with any integrated amplifier.

If you would like, I would be more than happy to take pics of mine and show you how to wire it up......if you want to keep and use the tuner separate. :thumbsup:

My amp is pretty much in a permanent location at the moment but that wouldn't help anyway as its had all of its phenolic sockets removed and is wired with RCA jacks and permanently on when plugged into the wall. It plugs into the power receptacle on the back of a Kenwood preamp so when the preamp is turned on, it also turns the amp on.
 
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