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Refurbing a Dual 604

You are right about the quality of the top piece. I occasionally make bases out of 3/8" oak. Easy enough for you to do, but that top piece would look out of place. On some of the factory bases, the top piece, complete with dust cover retainer/tension assembly, comes off separately and can be used on a new base. Did this on my 701 [it came with a vinyl-covered flakeboard base], and the top piece easily separated from the rest. Even the bottom can be used in the project. Maybe I can take a pic if I can dig up the turntable.
 
Now that is a nice plinth. I think the one I have was trying to be like that in a twisted/demented way.
 
My Dad was a great carpenter. I have all of his tools, and a tiny fraction of his skills. You would need a radial arm saw or a much-more-dangerous table saw, and either a miter box plus back saw or an electric miter saw. And glue and color pins [have ridges and are tempered].
This turntable is flawless, but cannot compare to a 12" Dual idler unit. Not even close.

Watch your fingers !!!

 
I have most of those tools, but I have to admit I'm not good at finish carpentry. I used those tools for rough carpentry. If I didn't have so much in my queue, I might take on a plinth project such as that.
 
Trade in that framing hammer for a smaller finish hammer and purchase a blade with fine carbide-tipped teeth. You will do just fine. And if this Dual fails, the new base would fit the other 12" models, all of the three drive types. The idlers require a higher base because the motor is larger. But one thing at a time. I will try to convert you to idler in the future.
 
NoTransistors said:
Trade in that framing hammer for a smaller finish hammer and purchase a blade with fine carbide-tipped teeth. You will do just fine. And if this Dual fails, the new base would fit the other 12" models, all of the three drive types. The idlers require a higher base because the motor is larger. But one thing at a time. I will try to convert you to idler in the future.
Click to expand...

NoTransistors,

No need to convert me to an idler. My main unit is a 1226 w/M91ED. I have three other idlers in the queue (another 1226 and two 1009's). I'm only doing the 604 because I fell into it and it seems like a nice TT. I'm a charity case. I just can't overlook audio equipment in need. :)
 
Just for fun, I buttoned it up and assembled it and set the VTF and AS and started her up. Hooked it up to my Fisher KX-100 and it sounds pretty good. I'm running it with the original stylus with unknown hours on it. I'd like to get the stylus checked, but I have no idea on how to do that. Playing "Yes" right now.

It's got a low level hum in both channels. I checked the RCA connections at the amp and rotated them a few times with no change. It's got the USA style ground connection and it's going between the ground point on the amp and the chassis of the TT. Don't think the problem is with that wire. My recently restored Dual 506 is wired the same way and has zero hum. I'll check the connections underneath in the coming days and clean them. I'll also replace the RCA plugs with new ones.

What's left?
- Replace the electrolytic caps.
- Replace the stylus
- Get a dust cover
- Figure out the hum
- Figure out what that funny knob is for next to the queuing lever. The owners manual says, "Turning knob for tonearm lowering aide". I have no idea what that means.

EDIT: Also need to find the transport screws.

Here's a pic.

IMG_0694.JPG
 
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I have seen that knob before on other models. It provides indexing for 12" and 7" records when manually handling the arm.
And hum on BOTH channels- Are the wires paired correctly? White/Blue and Red/Green? And are the actual spring-loaded pins in their proper place? You do not know what the previous owner did to this thing. Is the contact plate all the way up and are the traces polished?
 
NoTransistors said:
I have seen that knob before on other models. It provides indexing for 12" and 7" records when manually handling the arm.
And hum on BOTH channels- Are the wires paired correctly? White/Blue and Red/Green? And are the actual spring-loaded pins in their proper place? You do not know what the previous owner did to this thing. Is the contact plate all the way up and are the traces polished?
Click to expand...

NoTransistors,

Thanks.

I'll pull the sled and examine the traces with a mirror and clean them as best I can. I'll check the wire colors are attached correctly at the sled and at the RCA's underneath. I'll clean the spades where the RCA cables attach underneath too.
 
If mine has a sound quality issue it is usually the contacts at the sled cart -tone arm.I remove it a few times and it is good.
 
Chubba said:
If mine has a sound quality issue it is usually the contacts at the sled cart -tone arm.I remove it a few times and it is good.
Click to expand...

Agree or at least that is what NoTransistors is getting at too. I'll be working on that tomorrow night. Thanks.
 
Ok, I found the original stylus on the big auction site and I've ordered replacements for all of the electrolytics. I also started looking at the traces in the headshell. I think I'm going to have to do deoxit on q-tips to clean the traces. Not sure how else to get that small. Now just waiting on the parts to arrive and I need to find a dust cover.
 
The dust cover will cost more than the entire turntable. On ebay, someone in Bulgaria offers fitted tailored covers.
 
NoTransistors said:
The dust cover will cost more than the entire turntable. On ebay, someone in Bulgaria offers fitted tailored covers.
Click to expand...

Yes, I was noticing that. :(

I'll see if I can pickup a parts unit with a good cover. Oops, that's kinda how I found this one! :rflmao: It's a never ending rabbit hole.
 
Amazing what you can find with a bit of luck. Last month, I snagged a good-looking Dual 1219 with flip-down Dual base and decent cover for $125 plus $17 or so shipping. As I have lost many dust covers because sellers are too stubborn to follow simple packing suggestions, this time I told seller to not pack until hearing from me, and if he does not feel the need to then follow my packing instructions, the deal is off. I hate being nasty, but he understood my reasoning. So he followed instructions, and also placed platter in its own box. He was wonderful. Nothing broke. This is how you get a nice dust cover, with a complete turntable and base thrown in for free..
 
All the parts have arrived (excepting for the dust cover) and I'm replacing the caps.

There is a X rated safety cap inside the black steel box on the circuit board with the transformer. That cap was cracked and was probably bad. I've got a few more caps to replace tonight and I should be able to give it a try to see if the hum is gone. Progress!

IMG_0709.JPG
 
Did you try to connect only the signal cable without the ground cable? In the 70's, Dual had the bad habit to ground the chassis through the signal cables. Then, if you connect the ground separate cable, ground loop for sure.

My 1019 was plagued by this fault and connecting the ground cable was the ticket for a low level hum. The tech that restored my TT simply snipped the chassis ground connections tied to the RCA's so I could use the usual ground wire.
 
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