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Need help figuring out interface cable or speaker type for a recorder

Popcorn

Apr 7, 2022
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I need to purchase an external speaker so that I can hook it up to an old Roberts Model 771X reel to reel tape recorder. The plug hole for the speaker is large like a little under a quarter of an inch for the diameter of the hole.

I don't know what type of cord plugs into that hole, and how I would connect it to a speaker? Here is a video of the tape recorder. If you go to 6 minutes and 20 seconds into the video it shows the ports that interface into this recorder. So the visual should help explain what I am talking about.


Can someone give me advice on the type of speaker I would be looking for and or electronic cords that go into the speaker port.
 

Harald Kapp

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Nov 17, 2011
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You will probably not find an off the shelf speaker/cable combination. To make one yourself should be easy:

The connectors look like 1/4'' audio jacks.
The external speakers should as far as I can deduct from online information be 8 Ω.
Any 2 wire cable should be suitable. Use cable with markings (e.g. black and white, or one wire smooth, the other rough etc.) to allow for correct "polarity". Make sure both speaker are connected in the same way (e.g. smooth to red terminal, rough to bleck terminal). The exact order is not significant, but it has to be the same on both speakers.
Solder one end of the cable to the speaker (or use the terminals if you use an enclosed speaker). Solder the other end of the cable to the audio jack. Make sure that the "polarity" also matches for both jacks (e.g. smooth to tip, rough to sleeve). Again the order is not significant but has to be the same for both connectors.

That should work, provided my assumption on the connectors being 1/4'' audio jacks is right,
 

Martaine2005

May 12, 2015
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Here is the manual and schematic. for the 720 and 770.
Looks remarkably similar to an Akai I had years ago.
Does the writing below ‘spkr’ jack say ‘minimum 6 ohms’?. So as Harald said, 8 ohms will be fine.
The jacks are 6.35mm (1/4”).
You could purchase a long guitar lead and cut in half, leaving only the speaker terminals to solder or use crimp connectors. Obviously depends on speaker placement.

Martin
 

Popcorn

Apr 7, 2022
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Thanks all. Hey Martiane it has a minimum of 8 Ohms for the speaker jack, not 6. I have the manual however I don't see specifics about the jack ports, or I don't know enough electronics terms to know what I am doing. I don't feel comfortable cutting cables and soldering. Is there anything I can buy off of amazon or ebay that could help. For example I just bought this, which would let me attach my newer headphones to the 6.35mm port. (See link below). I am wondering if there is some type of adapter that would work for a modern day speaker?

https://www.acehardware.com/departm...OkYXoyehJW1dOrroWEBoCJtoQAvD_BwE&gclsrc=aw.ds
 

Martaine2005

May 12, 2015
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You could source speakers with binding posts or speaker terminals.
upload_2022-4-9_1-33-24.jpeg

Then simply cut the guitar lead in half and terminate the open ends into the holes. No soldering required.

Martin
 
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