Bobby's Dad's thread....

[laatsch55]

One thing about it BD, those 7B's will wake the F&^%&^% Maggies UP!!!

 

[derek92994]

One thing about it BD, those 7B's will wake the F&^%&^% Maggies UP!!!

There wont be no squarking crows around my house when I get that phase linear

 

[pennysdad]

.... they've just been dropped off, but it's only 11.45am. wayyyyy too early for me.
goin' back to bed for another hour, then i'll have a play.

 

[derek92994]

.... they've just been dropped off, but it's only 11.45am. wayyyyy too early for me.
goin' back to bed for another hour, then i'll have a play.

I'd find it hard to sleep if a new toy had just showed up =)

 

[pennysdad]

I'd find it hard to sleep if a new toy had just showed up =)

i need some dream time to plot a course of action.
where am i going to put these suckers????
should i have an extra sugar in my coffee when i wake up?
wot colour sox should i wear today?
these are decisions not taken lightly, and require some serious dreaming.
.... back to bed. back in an hour.

 

[derek92994]

i need some dream time to plot a course of action.
where am i going to put these suckers????
should i have an extra sugar in my coffee when i wake up?
wot colour sox should i wear today?
these are decisions not taken lightly, and require some serious dreaming.
.... back to bed. back in an hour.

Defragment your room like your hard disk, 3 sugars in coffee, blue socks with red ones on top (double), dream about sound waves.

 

[pennysdad]

Hate 'em!

 

[derek92994]

Hate 'em!

What do you hate G?

 

[pennysdad]

What do you hate G?

well, one does have a blown 'tweeter' after all, but even then, they are very space hogging.
you can't have 'em near ANYTHING!
.... but they still sound ok from the kitchen.
I'll have to put 'em aside, 'till I'm ready to open them up, and find the break in the circuit.

 

[derek92994]

well, one does have a blown 'tweeter' after all, but even then, they are very space hogging.
you can't have 'em near ANYTHING!
.... but they still sound ok from the kitchen.
I'll have to put 'em aside, 'till I'm ready to open them up, and find the break in the circuit.

Oh those planar things? Something to play with in the future. Well I'm glad to have both my 9500s amps working, sharing the pre out from the working source amp does wonders when all the line in electronics are dead on the other. Its alive!

 

[pennysdad]

Well, I opened up the suspect Maggie, and found a heap of corrosion totally covering most of the tweeter wires. Checked for continuity with my DMM, and nuthin'. Got some de-oxit and swabbed all the wiring to remove as much of the oxidisation as possible only to then find breaks all over the place.
Impossible to repair, being aluminium, so then just proceeded with stripping off all the wiring, and cleaning the mylar with some acetone. Once that was all done, I then unravelled the winding from an old broken voice coil from a JBL 2470 compression driver. The wire was almost exactly the same gauge, but "flat-milled" wire. Anyway, it would have to do. After gluing it all up (not as simple as it sounds), I checked continuity, and it was a go, measuring almost 5 Ohms. (... or was it 4, or was it 6? I can't remember now, but it was something that was 'normal', I think.) Ran a battery check with a 9V battery, and it made a noise. Hooked it up to an amp, nuthin'. WTF????? The full range stuff works fine, but the tweeters? Nuthin'. Re-checked with my DMM, fine! Did another battery test? Fine. Checked the fuse? Fine. Plugged the amp back in? Nuthin'.
I guess I'll have to open up the other one tomorrow and check to see what a working one measures up like.
Otherwise, I'm screwed...... I'll have to do it all over again except this time I'll have to find the right wire, (locally), and enough for two because I'll just have to do the other one if the amount of corrosion in this one is anything to go by.

 

[derek92994]

Well, I opened up the suspect Maggie, and found a heap of corrosion totally covering most of the tweeter wires. Checked for continuity with my DMM, and nuthin'. Got some de-oxit and swabbed all the wiring to remove as much of the oxidisation as possible only to then find breaks all over the place.
Impossible to repair, being aluminium, so then just proceeded with stripping off all the wiring, and cleaning the mylar with some acetone. Once that was all done, I then unravelled the winding from an old broken voice coil from a JBL 2470 compression driver. The wire was almost exactly the same gauge, but "flat-milled" wire. Anyway, it would have to do. After gluing it all up (not as simple as it sounds), I checked continuity, and it was a go, measuring almost 5 Ohms. (... or was it 4, or was it 6? I can't remember now, but it was something that was 'normal', I think.) Ran a battery check with a 9V battery, and it made a noise. Hooked it up to an amp, nuthin'. WTF????? The full range stuff works fine, but the tweeters? Nuthin'. Re-checked with my DMM, fine! Did another battery test? Fine. Checked the fuse? Fine. Plugged the amp back in? Nuthin'.
I guess I'll have to open up the other one tomorrow and check to see what a working one measures up like.
Otherwise, I'm screwed...... I'll have to do it all over again except this time I'll have to find the right wire, (locally), and enough for two because I'll just have to do the other one if the amount of corrosion in this one is anything to go by.

I'm assuming you want to keep these speakers as "original" as possible? And are these the Planars?? Is tweeter replacement an option?

 

[pennysdad]

I'm assuming you want to keep these speakers as "original" as possible? And are these the Planars?? Is tweeter replacement an option?

No Derek, it's not quite like that.

These are the Magnepan SMG. This is what the wiring looks like.
The 'tweeter' is not your conventional type of arrangement.
It's comprised of six rows of wires (the bottom six pictured), which are the equivalent to a voice coil as such.

 

[derek92994]

No Derek, it's not quite like that.

These are the Magnepan SMG. This is what the wiring looks like.
The 'tweeter' is not your conventional type of arrangement.
It's comprised of six rows of wires (the bottom six pictured), which are the equivalent to a voice coil as such.

Wow, sophisticated stuff there. The joys of new toys. Thanks for posting the pic. I'm off to work shortly, mondays suck.

 

[pennysdad]

... mondays suck.

So do Sundays and Tuesdays, and Wednesdays, Thursdays, Fridays, and Saturdays.....
Otherwise, any other day is fine.

 

[laatsch55]

DAYAM BD, that's a F^%$#^, % project, have youn been successful at that before??

 

[pennysdad]

DAYAM BD, that's a F^%$#^, % project, have youn been successful at that before??

nope!
nuthin' like this....
first time for everything!

 

[NavLinear]

nope!
nuthin' like this....
first time for everything!

I read up on these guys and what a speaker. Very different than conventional ones. Below is a link to an article done by HIFI+ that shows some of the steps in making these guys:

http://www.hifiplus.com/articles/meet-your-maker-hi-fi-visits-magnepan/

Good luck G - looks like an arse scratcher of a problem.

 

[pennysdad]

I read up on these guys and what a speaker. Very different than conventional ones. Below is a link to an article done by HIFI+ that shows some of the steps in making these guys:

http://www.hifiplus.com/articles/meet-your-maker-hi-fi-visits-magnepan/

Good luck G - looks like an arse scratcher of a problem.

Thanks for that link Dennis.
Out of the 3.7635 billion pages I've read, that's the first reference to that page that I've seen.
Really interesting sh*t that.
Well, I'm happy to say that the right one is now fixed. It was my fault. I had all the wiring right, it was just my bad solder joint. Aluminium solder is quite weird, and almost doesn't stick to anything, even itself! My bad....
.... but all is good, and working fine. (for now. fingers x-ed)
Just have my baby Crown D150 powering 'em for now. I'll save the Brystons for the day I feel like popping the other tweeter thingie, and I think I'll wait for the other one to die first, before I rewire it tho', as it really is an "an arse scratcher" as you say, o' chum.

 

[NavLinear]

Nothing quite like a bad joint.

I've never used aluminum solder before - did you fluks it first?