HD660's

[DaveAtHome]

I have a pair of Marantz HD660 that I've had in storage for 20+ years. I bought them new in 1978. I recently looked at them and it looks like I'll need to replace the foam on the woofers. I want to get a good hifi system again, Currently don't have an amp to drive the speakers, but before I refurbish these 660's and buy an amp, I want to test them to see if they are worth restoring. I do have a set of Edifier powered bookshelf speakers, so I'm wondering if I could hook up the Marantz speakers one at a time to the active Edifier to see if the Marantz still work?

 

[turnitdown]

Sure, at low level to begin with.

 

[DaveAtHome]

The Marantz will handle 125 watts each, the active Edifier puts out 21 watts so I don't expect much volume, but I do hope I will at least be able to assess whether or not to refurbish the Marantz and get a good amp. How hard would it be to find replacement subs, midrange, and tweeters if needed?

 

[homebrew]

Worthwhile speaker to rebuild, especially if the cabinets are in good condition. They were designed by a former JBL engineer so they have a credible pedigree. In addition to the woofer re-foam, they'll probably require some crossover work. Grab some De-Oxit and spray the level controls. They would be beautiful in a vintage system paired with a Marantz 2275 receiver.

 

[DaveAtHome]

Worthwhile speaker to rebuild, especially if the cabinets are in good condition. They were designed by a former JBL engineer so they have a credible pedigree. In addition to the woofer re-foam, they'll probably require some crossover work. Grab some De-Oxit and spray the level controls. They would be beautiful in a vintage system paired with a Marantz 2275 receiver.

When you say crossover work, does that mean potentially changing electronic components? Something for an electronics tech?

 

[tarior]

If they worked when you put them in storage, there is no reason why they wouldn't work now.

 

[Dswankey]

...How hard would it be to find replacement subs, midrange, and tweeters if needed?

If needed, ascertain the parts # for each and then start searching online, Ebay would probably be your best bet.

 

[Lavane]

Don't turn the volume up very much with rotted surrounds. You don't want the coil tube bottoming out or over extending. With new surrounds they should work just fine if they were working when put into storage.
Maybe replace any electrolytic capacitors in the crossovers with either new electrolytics, or a polypropylene, foil in oil, PIO, etc film caps of your choice.

 

[homebrew]

When you say crossover work, does that mean potentially changing electronic components? Something for an electronics tech?

Changing capacitors and/or resistors isn't particularly difficult. All you need is a soldering iron and some electronic solder. And if you're re-foaming the woofers, the best way to access the crossover is through the woofer hole.

 

[DaveAtHome]

Changing capacitors and/or resistors isn't particularly difficult. All you need is a soldering iron and some electronic solder. And if you're re-foaming the woofers, the best way to access the crossover is through the woofer hole.

Hey thanks, I just tested them, one at a time, they sound fantastic, even with deteriorated foam around the woofers. the tweeter and midrange controls are working, no issues. I've got replacement foams coming for the woofers. What do you recommend for a glue? I've read that Aleene's tacky glue works. I can't wait to find a vintage receiver to hook them up. I just set up a Fluance turntable and am already upgrading to a better cartridge/stylus.

 

[homebrew]

Can't say from experience, but this should be fine:

Parts Express Speaker Repair Glue 1 oz. Bottle

Parts Express Speaker Repair Glue 1 oz. BottleSpecially formulated for gluing cloth and foam rubber surrounds to driver baskets and most types of cone materials. Also recommended for gluing paper, cloth, and felt speaker dust caps. Not intended for butyl rubber or Santoprene surrounds, or poly...

www.parts-express.com

 

[DaveAtHome]

Can't say from experience, but this should be fine:

Parts Express Speaker Repair Glue 1 oz. Bottle

Parts Express Speaker Repair Glue 1 oz. BottleSpecially formulated for gluing cloth and foam rubber surrounds to driver baskets and most types of cone materials. Also recommended for gluing paper, cloth, and felt speaker dust caps. Not intended for butyl rubber or Santoprene surrounds, or poly...

www.parts-express.com

Thanks again. Another question; I've watched some videos showing how to repair the cones, they show the inner edge of the foam being glued to the front edge of the cone. My woofers look like the foam was glued to the back side of the cones. Probably gonna be harder to get at. Do you think it would make much difference if I glued the foam to the front edge?

 

[homebrew]

Don't know why it would make a difference.

 

[tarior]

Thanks again. Another question; I've watched some videos showing how to repair the cones, they show the inner edge of the foam being glued to the front edge of the cone. My woofers look like the foam was glued to the back side of the cones. Probably gonna be harder to get at. Do you think it would make much difference if I glued the foam to the front edge?

Glue the new foams to whichever side the old ones were on.

 

[Lavane]

Glue the new foams to whichever side the old ones were on.

It can make a difference in how the woofer reacts and sounds if the surround is glues to the opposite side of the cone from how it was originally done. Gluing to the back side is more of a pain though.
Do you have a speaker repair shop not to far from you? The shop near me does nice work and is very reasonable. It shouldn't cost too much since you are supplying the surrounds. I know someone that just had a pair of I think 8" woofers that he had the surrounds replaced on for $50 at that shop.

 

[RTally]

Can't say from experience, but this should be fine:

Parts Express Speaker Repair Glue 1 oz. Bottle

Parts Express Speaker Repair Glue 1 oz. BottleSpecially formulated for gluing cloth and foam rubber surrounds to driver baskets and most types of cone materials. Also recommended for gluing paper, cloth, and felt speaker dust caps. Not intended for butyl rubber or Santoprene surrounds, or poly...

www.parts-express.com

That is just a white PVA glue with a bunch of marketing-speak. It is also expensive for what you get.

I use Aleene's Tacky Glue for refoaming. You can easily find it locally. No need to order on-line and pay shipping.

 

[Son-of-Vere]

Hey! I actually own these and they're in the rotation. Yeah, I'd say they're worth fixing up. The PO refoamed them, but I recapped them. Not the greatest foam job, but they sound ok. Very east coast sound as they are somewhat layed back, with plenty of bass. Do you still have the port plugs?, they usually get lost over the course of time...

 

[absolve2525]

I have a pair of Marantz HD660 that I've had in storage for 20+ years. I bought them new in 1978. I recently looked at them and it looks like I'll need to replace the foam on the woofers. I want to get a good hifi system again, Currently don't have an amp to drive the speakers, but before I refurbish these 660's and buy an amp, I want to test them to see if they are worth restoring. I do have a set of Edifier powered bookshelf speakers, so I'm wondering if I could hook up the Marantz speakers one at a time to the active Edifier to see if the Marantz still work?

Yes, they are definitely with restoring! I recently picked up a set of 770 which are very similar, aside from having a supertweeter. They probably have film caps for the tweeter and midrange and an electrolytic cap for the woofer. I replaced the single electrolytic and left the others, and they sounds great! I refoamed mine using Aleens craft glue. Glue the edge on whichever side they were on originally.