767 repair/ upgrade

I’ve had this 767 for years, found it locally in a 2nd hand shop from memory, didn’t have any cassette doors on and most of the knobs were missing. I bought what I could on eBay bit by bit to get it looking reasonable, then stuck it on a shelf in my office and left it there...

Anyway, I’ve decided it’s time to get it to actually play nicely!

Everything works, just not that well. Lights come on, tapes play fine but it sounds poor - muffled, lots of static/ crackling when you change the volume. One of the speakers has a tear in it (which had been repaired with duck tape!) and a tweeter has fallen off.

So, I’d like to start with the speakers and perhaps an overhaul of the tape decks. I’ve done lots of searching on speakers and can see people trying various options so I wondered if someone can tell me what parameters I need to stick to when looking for replacements?

I’m assuming sorting the tape decks is a matter of replacing the rubber belts and such like which have probably perished over the years, will I get away with just cleaning the heads or should they be replaced as well? Is that an easy job?

I have a 777 as well that I haven’t looked at for about 5 years. I’ll drag that out next once this one is sorted!

Any advice very much appreciated.

Heads are usually ok, make sure you get some deoxit/contact cleaner to give all pots and switches a thorough cleaning.
Often muffled sound is the heads azimuth which is simply adjusted by the left hand screw while playing a tape.
As for the speakers, I think most people struggle to get the physical size, just make sure you match the ohm rating.
Then there is always the option of having the speaker professionally repaired so you keep it original.

Welcome! Nice looking unit.

Which speaker is torn? If it's one of the JVC speakers, you should probably get rid of them anyway, because they're more restrictive than the originals. You can see on the magnets they say 8 ohms, while the originals were 4 ohms. This means they will constrain the maximum volume you'll be able to get from this.

Also, unlike the 777, I don't think the 767 originally had tweeters, so the one in your photo was probably added by the previous owner, and who knows where he got them or if they're any good.

You should be able to find original speakers on Ebay quite easily (or from a member of this forum). Or, if you're willing to lose the "vintage" look, you can use aftermarket speakers, as several members have done.

docs said:

Heads are usually ok, make sure you get some deoxit/contact cleaner to give all pots and switches a thorough cleaning.
Often muffled sound is the heads azimuth which is simply adjusted by the left hand screw while playing a tape.
As for the speakers, I think most people struggle to get the physical size, just make sure you match the ohm rating.
Then there is always the option of having the speaker professionally repaired so you keep it original.

Click to expand...

Thanks docs, appreciate the reply.

The JVC speakers don’t look like they’re original anyway, so unless I can source some of whatever should’ve been in there I’ll have to find something else to fit!

Reli said:

Welcome! Nice looking unit.

Which speaker is torn? If it's one of the JVC speakers, you should probably get rid of them anyway, because they're more restrictive than the originals. You can see on the magnets they say 8 ohms, while the originals were 4 ohms. This means they will constrain the maximum volume you'll be able to get from this.

Also, unlike the 777, I don't think the 767 originally had tweeters, so the one in your photo was probably added by the previous owner, and who knows where he got them or if they're any good.

You should be able to find original speakers on Ebay quite easily (or from a member of this forum). Or, if you're willing to lose the "vintage" look, you can use aftermarket speakers, as several members have done.

Click to expand...

The torn speaker is indeed one of the JVC ones and they’re obviously not original now you mention it!! That said this is the first of these I’ve ever opened up so wasn’t sure if maybe there was a shared components thing between Sharp and JVC... Obviously not though.

Once I get access to the For Sale section I’ll keep my eyes open for some original speakers and replace the JVC ones. Failing that it will have to be aftermarket.

Thanks for the input!

Yeah those blue ones are from a JVC M70. Good speakers, but more restrictive than the originals.

Restoration of this boombox is hard job. First, you can find speakers and clean all switches and pots.
You must remove many parts to have access to tape decks and be patient when replace belts.

Thanks again for the replies folks.

I think I’ll stick some alternative speakers in first then worry about finding a set of original ones once I’ve got everything working okay.

Can anyone advise on what restrictions there are when it comes to speaker? I’m assuming I can’t just whack anything in that fits...

This looks a great and viable alternative to the original speakers.
http://boomboxery.com/forum/index.php/topic/20617-bummed-with-the-sound-777z/page-2#entry332320

Mark1892 said:

This looks a great and viable alternative to the original speakers.
http://boomboxery.com/forum/index.php/topic/20617-bummed-with-the-sound-777z/page-2#entry332320

Click to expand...

They do look great, I think I’ll give those a go! Thanks for pointing out the thread

Splitscreenvan said:

This looks a great and viable alternative to the original speakers.
http://boomboxery.com/forum/index.php/topic/20617-bummed-with-the-sound-777z/page-2#entry332320

Click to expand...

They do look great, I think I’ll give those a go! Thanks for pointing out the thread

Click to expand...

No problem, I'm thinking of going that way on one of mine eventually 😎