Technics SB-6000A Restoration?

[goldswimmerb]

Hey guys, so I recently picked up a set of technics SB-6000A off of a guy for $100. He also had a Marantz 2285B listed for $50 but by the time I contacted him, that was long gone.

They're not in too terrible shape:

Im planning on cleaning up the cabinets and drivers and getting that dust cap taken care of. The grills are excellent but not pictured.

I also noticed this:
Can I just glue that on with rubber cement? or pull it entirely? It looks to be a cosmetic piece that was previously either glued to the metal outer ring or glued to the top of the outer area of foam.

And lastly, does anyone have the schematic for the crossovers? I am planning on giving them a recap but could only find the schematic for the SB-6000 model, which I am guessing is different since those look to be sealed or rear ported rather than front ported.

 

[goodolpg]

Looks like the loose part is a gasket or trim piece.
A lot of folks use Aleenes tacky glue for gaskets and refoaming. Available at Walmart, craft stores, etc.

 

[RickeyM]

Hey guys, so I recently picked up a set of technics SB-6000A off of a guy for $100...
And lastly, does anyone have the schematic for the crossovers? I am planning on giving them a recap but could only find the schematic for the SB-6000 model, which I am guessing is different since those look to be sealed or rear ported rather than front ported.

Sealed or ported probably wouldn't affect the crossover but who knows, Technics may have made a crossover change along the way
You could always open one up and get a look at the crossover that's in there.

 

[NH-MAN]

I have a similar 8 inch pair, they sound good.

 

[dzkfraser]

crossover

 

[greymatter]

I have a pair of the Sb 7000a the part hanging out on your speakers look like the surround is in need of repair or new surrounds installed . Before I would sink any money into them . I would check out the tweeters to see if they work . If not they are very hard to source , and very expensive . You might think of parting them out . The tweeters could cost you as much as 150.00 for 1 , that's if you can even find them . Just a FYI.

 

[goldswimmerb]

I have a pair of the Sb 7000a the part hanging out on your speakers look like the surround is in need of repair or new surrounds installed . Before I would sink any money into them . I would check out the tweeters to see if they work . If not they are very hard to source , and very expensive . You might think of parting them out . The tweeters could cost you as much as 150.00 for 1 , that's if you can even find them . Just a FYI.

Tweeters work great and the foam is still 100% in tact, I think that like my cerwin vegas they have a plastic piece that runs over the foam to hide the lip.

 

[greymatter]

On the 7000a there is a metal clip on them for each screw to hold the drivers in place . Not sure about the 6000 , if that's the case .

 

[larry777]

This is supposed to be the crossover for the Technics SB-6000A that I found on line. It does have 6 caps which is what shows for the SB-6000 model.
I just picked up a pair of the SB-6000A's myself about 10 days ago and was also thinking about doing a recap due to the age of the speakers. So I found this
picture of the crossover while searching for information. Some replacement caps will be big ( 68uf and 3 for each speaker ) so trying to figure out a way to fit them to the crossover may be tricky. I will be following this thread closely to see how you get along. These speakers seem to be rare especially in my area, so nice to see another member getting a pair around the same time and thinking about doing the crossovers as well.

 

[RickeyM]

You might consider mounting the crossovers for the HP & LP sections on separate boards within the speaker enclosure. That way you can give them more room and fit in those poly caps.

 

[larry777]

You might consider mounting the crossovers for the HP & LP sections on separate boards within the speaker enclosure. That way you can give them more room and fit in those poly caps.

I did think about this as an option, but was concerned if the leads from the caps would be long enough to solder in the right places. As the poly caps are normally lying flat with the leads on either end, as compared to the ones on the crossover now which are up and down due to both leads coming from the same end.

 

[dzkfraser]

I did think about this as an option, but was concerned if the leads from the caps would be long enough to solder in the right places. As the poly caps are normally lying flat with the leads on either end, as compared to the ones on the crossover now which are up and down due to both leads coming from the same end.

I recapped my 5000a's - definitely a tight fit, what you need to do is bend one of the leads down the side of the cap so it is in a radial configuration. Will need to solder extensions on the leads so you can bend them around while fitting to the board - should also cover the leads with heat shrink to prevent any possible shorting.

 

[goldswimmerb]

I recapped my 5000a's - definitely a tight fit, what you need to do is bend one of the leads down the side of the cap so it is in a radial configuration. Will need to solder extensions on the leads so you can bend them around while fitting to the board - should also cover the leads with heat shrink to prevent any possible shorting.

That's exactly what I did with my Cerwin Vega VS-120s, tight fit but worked great. It's a shame no one makes radial crossover caps anymore....

 

[dzkfraser]

That's exactly what I did with my Cerwin Vega VS-120s, tight fit but worked great. It's a shame no one makes radial crossover caps anymore....

Yeah, looks like hell but works, gotta do what ya gotta do

 

[larry777]

I recapped my 5000a's - definitely a tight fit, what you need to do is bend one of the leads down the side of the cap so it is in a radial configuration. Will need to solder extensions on the leads so you can bend them around while fitting to the board - should also cover the leads with heat shrink to prevent any possible shorting.

What do you use for the extensions ? I checked the diameter of the 68uf solen poly caps as an example and they are aprox 1.7 inches wide and aprox 3 inches tall. With 3 of these on each crossover board in the very center, that's over 5 inches wide if they are touching each other ! Then you have the other 3 poly cap replacements and the rest of the components on the board to consider.
A separate crossover board may be the way to go for one or two or all three of these larger 68uf caps, thereby leaving room for the other cap replacements on the original board. That's why I am interested in learning what the best lead extensions would be for the better sound ? What material ? Maybe part of the lead not needed from the cap closest to the board if that gives you enough length ? This seems like a more complex crossover then you would normally see on a two way system.

 

[RickeyM]

I did think about this as an option, but was concerned if the leads from the caps would be long enough to solder in the right places. As the poly caps are normally lying flat with the leads on either end, as compared to the ones on the crossover now which are up and down due to both leads coming from the same end.

What I had in mind in this case was using separate boards with the components laid out properly not separate boards mimicking the original with radial caps standing upright. Something like this.

 

[dzkfraser]

What do you use for the extensions ? I checked the diameter of the 68uf solen poly caps as an example and they are aprox 1.7 inches wide and aprox 3 inches tall. With 3 of these on each crossover board in the very center, that's over 5 inches wide if they are touching each other ! Then you have the other 3 poly cap replacements and the rest of the components on the board to consider.
A separate crossover board may be the way to go for one or two or all three of these larger 68uf caps, thereby leaving room for the other cap replacements on the original board. That's why I am interested in learning what the best lead extensions would be for the better sound ? What material ? Maybe part of the lead not needed from the cap closest to the board if that gives you enough length ? This seems like a more complex crossover then you would normally see on a two way system.

While poly caps would be ideal, you may want to look into bipolar electrolytics, Mundorf E-caps are really nice and not that large. To make extensions, I used solid core wire about the same diameter of the cap leads. I cut off a piece of the desired length, stripped off the insulation and, soldered it to the cap lead and covered with heat shrink. If you want to use the original board you will have to get creative to get them to fit, that's why you woud need to extend the leads. Like I said, not to pretty but works. You could always make you own x-over board but you would probably need to remove the woofer to find a suitable location to place it, I doubt it will fit through the opening on the box , I think you also have to come up with some new binding posts, as, if I recall correctly, they are integral to the x-over board. although the board may detach from the posts(can't remember)
Anywho, just need to put on the old thinking cap and figger it out - have fun!
BTW, make sure you have a schematic handy for reference

 

[larry777]

Thanks for your feedback dzkfraser and RickeyM, as their is a solution in there somewhere. Those Mundorf E-caps look like a good option as well and the prices are very reasonable. Have you ever used those in any speaker builds dzkfraser and if so how were the results ? The Mundorf E-caps have a VDC rating on them. Is this the same as the V for volts on other capicators ? Mundorf also has two types of E-caps showing...….Raw and Audio Plain. Audio Plain are double the cost but must provide better quality and sound for the price ?

 

[dzkfraser]

Thanks for your feedback dzkfraser and RickeyM, as their is a solution in there somewhere. Those Mundorf E-caps look like a good option as well and the prices are very reasonable. Have you ever used those in any speaker builds dzkfraser and if so how were the results ? The Mundorf E-caps have a VDC rating on them. Is this the same as the V for volts on other capicators ? Mundorf also has two types of E-caps showing...….Raw and Audio Plain. Audio Plain are double the cost but must provide better quality and sound for the price ?

Right, VDC is the voltage rating - I don't recall which I used, weren't too expensive, a couple bucks per cap. Used on some Wharfdale W45s - I was especially impressed with the build of the caps. got them from Sonic Craft.

 

[goldswimmerb]

This is supposed to be the crossover for the Technics SB-6000A that I found on line. It does have 6 caps which is what shows for the SB-6000 model.
I just picked up a pair of the SB-6000A's myself about 10 days ago and was also thinking about doing a recap due to the age of the speakers. So I found this
picture of the crossover while searching for information. Some replacement caps will be big ( 68uf and 3 for each speaker ) so trying to figure out a way to fit them to the crossover may be tricky. I will be following this thread closely to see how you get along. These speakers seem to be rare especially in my area, so nice to see another member getting a pair around the same time and thinking about doing the crossovers as well.

Been travelling, finally got a chance to see this picture, yuck at the original caps, those lavender ones are the only ones I've ever had explode with age in amplifier environments, even a Nichicon UES would do a better job. I know everyone likes their fancy crossover caps, bud judging by the bard layout here, and wanting to avoid extremely significant mods those Nichicon Bipolars may do pretty well, especially given the original caps are 100% off of the shelf, nt meant for crossover capacitors.