thrift store Dual 506

[sonicdeath]

This is my first post, so hi everybody!

I picked up a Dual 506 at a thrift store today for $15. I hooked it up to the phono input of my NAD amp and put on a record, but the output level is super low. Touching the contacts of the headshell produces hum at normal levels, and though I am by no means an expert, it seems to me that the cartridge is the most likely culprit. I think the headshell and mount is the single screw type - it has the tiniest screw on top you ever saw.

I'd love to get this turntable up and running. I'm on a very small budget, but have a large record collection I have been unable to listen to for years. All-in-One Electronics in Toronto seems to have shut up shop. I could fork out $25 for this mount - goo.gl/SQo8h , but as far as I can see it doesn't include a counterweight or even screws.

Can anyone offer me any advice? It seems I am so close to enjoying my old records, and yet so far!

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[Alec124c41]

You will find an owner/\'s manual here: http://www.vinylengine.com/library/dual/cs-506.shtml
Read it.
That tiny screw prevents the finger hook from rotating back, which releases the cartridge carrier. Clean the contacts of this with the eraser on a pencil, and the same for where they contact.

Cheers,
Alec

[sonicdeath]

Thanks Alec. That sounds like good advice. I'll give it a whirl.

[deckeda]

You have a bad ground somewhere and it's probably NOT at the cartridge if the wires there are secure. Start in reverse - check RCAs, check inside the turntable ... check tonearm.

That eBay adapter is nearly unobtanium --- get it. It lets you install normal, 1/2" mount cartridges. Cartridge screws and nuts should be easy to find from any online place like needledoctor.com The fact that the adapter doesn't come with a counterweight is irrelevant.

I bought a 506 new and for me it was a reliable, quiet machine. The cartridge yours has was made by Ortofon for Dual and together they had a love child that resulted in that proprietary mount. And the cartridge is sorta the predecessor to the Ortofon OM5, a basic model. OK but lackluster. Any replacement cartridge you might get should be low mass.

[Twinman]

Are you sure that your NAD amp has a built in phono preamp? I have a NAD amp. with an input labelled "Phono" but it a line level input. If yours is the same, you will need a separate phono pre.

Cheers, Tony

[sonicdeath]

I followed Alec's advice. Reminds me of cleaning the contacts of the Scalextric cars when I was a kid - we used an eraser for that too! Only problem now is I'm having a hell of a time sliding the damn cartridge carrier back into place! Also the contacts looked very clean, so this may not be the source of the problem.

Good thought Twinman, but I used this amp with a turntable before, so I'm pretty sure it does have a built in pre-amp. It's a 304. I had a pre-amp kicking around too and I tried it just in case, but it mostly just amplified noise.

Deckeda - oh lordy this is going to be more involved than I hoped isn't it! Ok so am I looking for continuity from the cartridge / cartridge holder back to the RCA to start with? Or to the ground lead? Help! LOL

[sonicdeath]

OK, after remembering you have to slide the wee metal part you lift the tonearm up with back to put the cartridge carrier back in, I stuck it back in, and lo and behold I have one channel! I guess I should remove it again and clean the contacts again? Maybe prize the contacts up a teeny bit so that make contact better too? So you were spot-on Alec. Thank you! Oh me of little faith!

[sonicdeath]

Still one channel. Curses. Okay. So now it is a continuity-checking job. Oh joy. And just to add a little spice to the challenge, the service manual is in German.

[Alec124c41]

Under the top deck, Dual likes to have a muting switch, that cuts any signal when the arm is at rest. It is a reed switch that might need cleaaning and/or adjustment. follow the tone-arm wires.
Use a meter to check continuity from cart to RCAs.
Cart red & green to right red center and skirt, respectively
Cart white & blue to left white center and skirt

Cheers,
Alec

[sonicdeath]

Ah, you mean the Kurzschließer! Yeah I was just wondering quite what/where that was. Thanks!

[sonicdeath]

Hmm. Continuity is good on + and - of both channels from the cartridge to the RCA while the arm is at rest or in play. Signal does not seem to be cut at all while it is at rest. I tested both channels of the amp using an alternative input to be sure and it is fine. I fear this may narrow it down to the cartridge, or is it possible for one channel of a stylus to blow?

[sonicdeath]

Just forked out for the 262-186 1/2" adapter after I noticed that there were just 2 left - there were 4 earlier today. Ugh. $33 for a wee bit of plastic! Ah well, the turntable was a steal so I shouldn't complain!

[sonicdeath]

Question: The tonearm on my 506 does not have a large screw in the middle (see my pic earlier) - just a kind of solid silver bolt. How the hell is the 262-186 adaptor going to fit? Do I have some kind of non-standard 506 tonearm?

[Alec124c41]

Don't feel too bad. I bought a new replica headshell for a Micro Seiki 707 tonearm. They were listed at $150 for a bit of plastic.

Cheers,
Alec