Starting Restore on Sonab OA 116 R

[christapher]

Hello, my name is Christapher.

While searching for some speakers for a loft with high ceilings, I picked up a pair of Sonab OA 116 R from a vintage hifi sale at a convention this weekend — a real bargain at $50. I had no idea what I was getting myself into and I'm very excited to learn about my new treasures and get them in tip-top shape.

Any suggestions on where to start?

Having not read that I should not plug them in, I've had them on for a couple of days. Listening to jazz/blues thru a 12-band EQ, the mid channel was peaking out, so I dropped all freq to the left channel but the tweeters.

I would love to do a full restore. Would it devalue the speakers if I sanded and re-stained the speakers orange to match my receiver?

Thanks for your help!

[Villee]

I don´t own OA-116 myself but few things I´m still able to say. First check that the midrange and woofer units have ok foam surrounds (does not crackle etc.). If the surrounds is NOT okay, DO NOT PLAY YOUR OA-116! This is because you have a risk at 1: to destroy your speaker units 2: you´re going to kill your amplifier!

If your foam surrounds are damaged, you can usually (if the spider is not failed) replace the old surrounds with new surrounds (but you have to centre the speaker), or you buy new speaker units for your OA-116. Unfortunately, original 5,3 ohms (bass) and 16 ohms (midrange) is not available, but you can use SilverFlute W17RC38-4ohm as a replacement for the woofer.
After you have get your woofer and midrange units restored/replaced, you should check that the four Peerless MT24 8 ohm and two 16 ohm tweeters (per speaker) is okay and have correct dc-resistance (about 7 for the 8 ohm unit and ~ 14-15 for the 16 ohm unit).Usually your tweeters should be okay, although they´re still 35 years old,so they´re perhaps not too fresh anymore. Recommended replacement is Obi T22oa.

Crossover capacitors can be tired and therefore replacing can be necessary.

Your midrange and woofer units should have "Sonab" on their dustcaps. If not, original speaker units are not there and perhaps replaced with incorrect replacements. Somebody who has more info can itemise my information a bit:)

If your speaker´s finish is at good condition, I would say you should not re-stain the speakers to orange as you are going to lower your speakers value Although if the finish is crappy you can of course do what you want, newer seen any Sonabs with orange finish. OA-116 can cost about 1000$ if they are tip top condition and have uppgraded crossover, cabling etc.

[Martin Dellstig]

A very thorough answer from Villee

If the bass and midrange are possible to restore I would recommend that.
The silverflute gives a little less as a woofer compared with the original, not a lot less but some.

Otherwise the exterior is up to you, but perhaps wait a bit with that until you are satisfied with the performance?

Best regards

Martin

[Zombie]

The OA 116 L is M U C H better...

[Martin Dellstig]

Hi again

I guess you have noticed that they come as a pair, one left and one right?

Best regards

Martin