AlNiCo vs. Ceramic Ferrite... Observations?

[Adda]

The magnets on those Wharfedale woofers look a lot like the ones on the old GAMMAs, in fact, they seem to be of a similar design all around.

 

[kirk57]

Some good information on Alnico vs Ferrite and why manufacturers switched: http://www.audioheritage.org/vbulletin/showthread.php?4031-The-Great-Alnico-Ferrite-Debate

Thanks, that link contains some hard facts on the subject.

 

[Gang-Twanger]

The magnets on those Wharfedale woofers look a lot like the ones on the old GAMMAs, in fact, they seem to be of a similar design all around.

I've seen a few pictures of the old Gamma woofers before (Seriously-well-made stuff), but I forget, when were they made? I don't know the history of the company at all. Were they British or American? Or were they German? The frames remind me of the cast-iron platter of my Dual 1019.

 

[bowtie427ss]

You can make as powerful a magnetic motor with ferrite as with AlNiCo; pound for pound

This is true. Alnico has a higher density than ferrite impregnated mud, so a pound of ferrite magnet is physically larger than a pound of alnico.

One of the main differences between the performance of ferrite and alnico is the curie point. In many applications alnico reigns supreme in it's ability to tolerate the heating of the speaker's motor structure. As long as the temperature remains below the alnico's curie point, it's magnetic charge remains essentially stable. If the curie point is reached or exceeded, the magnet can lose strength permanently.

Ferrites on the other hand, lose magnetic energy as their temperature increases which can lead to excessive power compression. The beauty of ferrites is that once cooled, their magnetic strength returns.

Note that the most extensive efforts to cool a speaker's motor assembly are usually employed on ferrite motors as their performance is most quickly affected by heat.

 

[Adda]

I've seen a few pictures of the old Gamma woofers before (Seriously-well-made stuff), but I forget, when were they made? I don't know the history of the company at all. Were they British or American? Or were they German? The frames remind me of the cast-iron platter of my Dual 1019.

You'd never guess, they are made in Bulgaria by Vissokogovoriteli (yes I can spell that now lol), they have barely changed at all since the early 70's.
I don't know exactly when they started, but they had a full lineup of products by the early 70's, 12" BK3013A, 5" BK138A and the VLD-12 ribbons.

By the late 70's early 80's, the BK3013A got replaced by the LA1231, still with AlNiCo magnets, but with a tougher voice coil for higher power handling.
The VLD-12 got replaced by the VLD-13, both use AlNiCo magnets, but the VLD-13 different innards, but electrically, it's the same.
The BK138A was their cheapest midrange woofer, not a particularly good one.
It also came in a fullrange driver version, with the name VK138A, that driver was used in public buildings all over the USSR, so if you have been to Russia, maybe you have heard one.

At some unknown point in time, Vissokogovoriteli switched to ferrite magnets for all their drivers, except ribbons.
The only change they made to the LA1231, was give it a new motor, apart from that, it's the same driver as the older AlNiCo version.
It would be very interesting to compare the two.
They did make one last gem during the 80's, the VLDD80 AlNiCo ribbon tweeter.
It's not as linear as the older horn loaded models, but just as efficient without the need for a horn.

Vissokogovoriteli drivers are generally overbuilt, and work well, but the craftsmanship is terrible, deep scratches UNDER the paint is common, it's almost impossible to find two drivers that look exactly the same.
Doesn't affect performance though, and you won't find better bang for the buck anywhere, the VLD ribbons are some of the most linear ribbon tweeters ever made, both in terms of frequency response, but also impedance, phase response and distortion.
They are the very definition of linear.

VLDD80:

The way Vissokogovoriteli drivers made their way to Scandinavia, was through a company called Audioscan, who sold them under the name "GAMMA", as DIY speaker kits.
They also sold Nikko, Accuphase, Coral and IMF, and where hugely popular back in the 70's early 80's, no wonder with a lineup like that.

A Swedish speaker manufacturer by the name of Audiotronic, used GAMMA VLD-12 ribbon tweeters along with KEF B200 drivers.
Today that company is called Transmission audio.

German Expolinear was (as far as I know) founded by the maker of the original VLD-12 ribbons, and use an updated VLDD80 ribbon tweeter with Neodymium magnets in some of their speakers.

The LA1231 woofer got sold under the name "Giant" at some point, and some VLD-13 ribbons are called "Jordanov".

 

[Gang-Twanger]

You'd never guess, they are made in Bulgaria by Vissokogovoriteli (yes I can spell that now lol), they have barely changed at all since the early 70's.
I don't know exactly when they started, but they had a full lineup of products by the early 70's, 12" BK3013A, 5" BK138A and the VLD-12 ribbons.

By the late 70's early 80's, the BK3013A got replaced by the LA1231, still with AlNiCo magnets, but with a tougher voice coil for higher power handling.
The VLD-12 got replaced by the VLD-13, both use AlNiCo magnets, but the VLD-13 different innards, but electrically, it's the same.
The BK138A was their cheapest midrange woofer, not a particularly good one.
It also came in a fullrange driver version, with the name VK138A, that driver was used in public buildings all over the USSR, so if you have been to Russia, maybe you have heard one.

At some unknown point in time, Vissokogovoriteli switched to ferrite magnets for all their drivers, except ribbons.
The only change they made to the LA1231, was give it a new motor, apart from that, it's the same driver as the older AlNiCo version.
It would be very interesting to compare the two.
They did make one last gem during the 80's, the VLDD80 AlNiCo ribbon tweeter.
It's not as linear as the older horn loaded models, but just as efficient without the need for a horn.

Vissokogovoriteli drivers are generally overbuilt, and work well, but the craftsmanship is terrible, deep scratches UNDER the paint is common, it's almost impossible to find two drivers that look exactly the same.
Doesn't affect performance though, and you won't find better bang for the buck anywhere, the VLD ribbons are some of the most linear ribbon tweeters ever made, both in terms of frequency response, but also impedance, phase response and distortion.
They are the very definition of linear.

VLDD80:

The way Vissokogovoriteli drivers made their way to Scandinavia, was through a company called Audioscan, who sold them under the name "GAMMA", as DIY speaker kits.
They also sold Nikko, Accuphase, Coral and IMF, and where hugely popular back in the 70's early 80's, no wonder with a lineup like that.

A Swedish speaker manufacturer by the name of Audiotronic, used GAMMA VLD-12 ribbon tweeters along with KEF B200 drivers.
Today that company is called Transmission audio.

German Expolinear was (as far as I know) founded by the maker of the original VLD-12 ribbons, and use an updated VLDD80 ribbon tweeter with Neodymium magnets in some of their speakers.

The LA1231 woofer got sold under the name "Giant" at some point, and some VLD-13 ribbons are called "Jordanov".

I just put every word of that in a Notepad file and stored in on my hard drive. Thanks for that. It'll come in handy. I'm thinking these might be a good way for me to explore the ribbon tweeter thing.

That said, the alnico Super 3's in my W90's are all open and clear-sounding now. The oil caps are just clobbering the Dayton poly ones on all fronts. Perhaps it's an alnico thing, where they do better with an old-school sort of capacitor (like paper-in-oil or beeswax rather than polypropylene). Who knows. What a great sound though. I can now hear the difference between these and the Super 5's. The Super 3's extend a little higher, I think, plus they have better complexity. The poly Daytons were REALLY holding them back. Made them harsh and glary compared to the way they are now. Badly IMO. And they were completely-interfering with the Fisher/W90's relationship. Wish I had taken care of that a year ago.

 

[Adda]

I just put every word of that in a Notepad file and stored in on my hard drive. Thanks for that. It'll come in handy. I'm thinking these might be a good way for me to explore the ribbon tweeter thing.

Maybe if a group of people got together, and made a group order directly from Vissokogovoriteli, you could get their attention.
I have written them once, but got no reply.
From what I have found at diyaudio.com, the drivers are almost ridiculously cheap, so shipping and import tax wouldn't be a deal breaker.

That said, the alnico Super 3's in my W90's are all open and clear-sounding now. The oil caps are just clobbering the Dayton poly ones on all fronts. Perhaps it's an alnico thing, where they do better with an old-school sort of capacitor (like paper-in-oil or beeswax rather than polypropylene). Who knows. What a great sound though. I can now hear the difference between these and the Super 5's. The Super 3's extend a little higher, I think, plus they have better complexity. The poly Daytons were REALLY holding them back. Made them harsh and glary compared to the way they are now. Badly IMO. And they were completely-interfering with the Fisher/W90's relationship. Wish I had taken care of that a year ago.

I think you'd be astonished by the VLD's if you hear them, they are quite different from anything else I have heard.
They will expose your amp though, ruthlessly, probably because they are so fast there is no "filter" apart from the crossover to smooth out any harshness from the rest of the system.
If you like them, you'll probably end up building your system just for them, as you'll quickly find that it always pays off.
The limiting factor is not the ribbons, it's the electronics.
VLD's with horns have a narrow sweet spot though.
A few crossover designs from Audioscan are readily available, so you can use that as a template, and modify it to suit your needs.
One for low SPL at 3KHz and one for higher SPL at 3.5KHz, they should be compatible with all VLD ribbons, as they have nearly identical impedance and frequency ranges.

 

[Gang-Twanger]

Maybe of a group if people got together, and made a group order directly from Vissokogovoriteli, you could get their attention.
I have written them once, but got no reply.
From what I have found at diyaudio.com, the drivers are almost ridiculously cheap, so shipping and import tax wouldn't be a deal breaker.



I think you'd be astonished by the VLD's if you hear them, they are quite different from anything else I have heard.
They will expose your amp though, ruthlessly, probably because they are so fast there is no "filter" apart from the crossover to smooth out any harshness from the rest of the system.
If you like them, you'll probably end up building your system just for them, as you'll quickly find that it always pays off.
The limiting factor is not the ribbons, it's the electronics.
VLD's with horns have a narrow sweet spot though.
A few crossover designs from Audioscan are readily available, so you can use that as a template, and modify it to suit your needs.
One for low SPL at 3KHz and one for higher SPL at 3.5KHz, they should be compatible with all VLD ribbons, as they have nearly identical impedance and frequency ranges.

Maybe for my first multi-tier system... :scratch2: