Yamaha ns-670

saltwater

saltwater

Super Member
Fellas I Just got back from the thrift and picked a pair up for cheap.. couldnt pass em up.... anyone else have these lil beuties? I know... pics right? :music: :banana: :banana:

All drivers work!!!! :yes:
 

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We picked up a pair in Santa Barbara about 12 years ago. Great sound, and very heavy.

Hey....I'm from MacComb, Ill.
 
Horrible speakers!! Slightly smaller(10 in. woofer, 2 in. dome mid) and lighter than the 690's, which are even worse speakers. I have a pair of 690's. Can barely stand to listen to them. Very poorly made, but for some reason, I have a strange sentimental attachment to them.
 
Holy sh..........t!! Did the previous owner actually scratch his ID into the front baffle?!!
 
Well i guess all of the drivers are not working..... One of the tweeters is not working..but still a great find.. ill have to investigate....
 
Maybe just a crossover issue or a loose wire. The crossovers are on the back of the speaker input terminal, so it's a snap to work on them.
 
I recently picked up a pair of NS-690II's which I had to refoam. The build quality is on the high end of the scale, and they were near mint cosmetically, but they seemed quite bass shy. I had been testing them in my garage system (Tandberg, Sansui, Yamaha, Marantz receivers in rotation) but decided to bring them into the house system to see if more huevos would make a difference. It did - my Bedini 150/150 made them sing a different tune. The Japanese like them with tube amps, but they seem to like high current SS amps. And it helps to turn down the dials on the mid and tweet. That's why they put the controls there.
 
oldskoolcool said:
I recently picked up a pair of NS-690II's which I had to refoam. The build quality is on the high end of the scale, and they were near mint cosmetically, but they seemed quite bass shy. I had been testing them in my garage system (Tandberg, Sansui, Yamaha, Marantz receivers in rotation) but decided to bring them into the house system to see if more huevos would make a difference. It did - my Bedini 150/150 made them sing a different tune. The Japanese like them with tube amps, but they seem to like high current SS amps. And it helps to turn down the dials on the mid and tweet. That's why they put the controls there.
Click to expand...

I've run my 690's with a CA-1010, then a couple of tube set-ups and currently with an Accuphase E-202 and I've never found them to be bass-shy at all. With the Accuphase they maybe have a bit too much bass on some recordings, but that's probably mostly the room they're in. I did find I had to actually back off the mid-range a bit with that amp as well to keep the mids from standing out of the texture; just tons of support down low.
 
saltwater said:
Fellas I Just got back from the thrift and picked a pair up for cheap.. couldnt pass em up.... anyone else have these lil beuties? I know... pics right? :music: :banana: :banana:

All drivers work!!!! :yes:
Click to expand...

Nice score...:thmbsp:
 
Well its not in the wiring, it all has continuity through out. its the tweet. only measuring .5 on the ohms..... where or who can repair..
 
Saltwater, I'm not sure if I'm reading/understanding your posts right, but one tweeter is not working, though it has continuity? Could be a slipped magnet; this happens often on the big Yamaha woofers when they are moved suddenly, such as when dropped during shipping.

Another, more remote possibility would be a bit of stuff (glue, magnet fragment, etc...) being wedged in the narrow space alongside the voice coil former. Very unlikely, though, especially if the driver wasn't reconed/refoamed/worked on.

I wouldn't read too much into a reading of .5 ohm resistance across a coil. Most coils don't offer high resistance, and it might be fine at that reading, unless you know that these particular tweeters should read higher. The time to worry is when you get an infinite/unable-to-read result.

If it should turn out to be a defect in the coil, though, I should add:

I don't know if those are wound the same as the coils in the NS-1000s, but if they are, a good repair will be extremely difficult. I had a discussion about this with a locally-renowned speaker repair guy, and he said that the NS-1000 and -2000 series were flat-wound with a wire that has a rectangular cross-section, not round wire like the usual VCs. The flat wires but neatly up against each other, creating a "solid" coil, and once the wires are damaged or uncoiled, getting them to go back nice and flat and smooth the way they were originally is almost impossible, and that size/type of wire is basically unobtanium.

You can use a few "fudges" sometimes, and you can re-wind them with round wire, but the results will fall short of the original.

I hope this isn't the case with your 670s, but I pass it on for whatever it's worth. I hope, for your sake, that you can get these working perfectly!
 
If you briefly send a tone directly to the tweeter and hear it then it is possible that the level control is dirty. You have to pry the back off to get deoxit in there but it is doable.
 
Arkay, Thanks for the info.. One tweeter is not working, but has cont..

i been searchin for info on these and have not come up w/ much...

I tried that merry. I cant get anything out of it.... its the tweeter...

Ive taking tweeters apart before, and i did take the screws out of this one, but it was really glued on there and i wasnt gnna pry it apart, it ooks like the two plastic dots on the front are holding it to the magnet.... but what do i know....
 
Arkay said:
If it should turn out to be a defect in the coil, though, I should add:

I don't know if those are wound the same as the coils in the NS-1000s, but if they are, a good repair will be extremely difficult. I had a discussion about this with a locally-renowned speaker repair guy, and he said that the NS-1000 and -2000 series were flat-wound with a wire that has a rectangular cross-section, not round wire like the usual VCs. The flat wires but neatly up against each other, creating a "solid" coil, and once the wires are damaged or uncoiled, getting them to go back nice and flat and smooth the way they were originally is almost impossible, and that size/type of wire is basically unobtanium.

You can use a few "fudges" sometimes, and you can re-wind them with round wire, but the results will fall short of the original.

I hope this isn't the case with your 670s, but I pass it on for whatever it's worth. I hope, for your sake, that you can get these working perfectly!
Click to expand...

Its flat wire....
 
I dont know if it's a match, but there is a Yamaha tweeter for sale on the auction site, JA-0515. Good luck and hope it's match especially if they approach the sound of my newly aquired NS-690II's:)
 
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