Visions of Holey-Basket Corals

[pjanda1]

Often, prior to traveling to a place, I can't help but peruse the local craigslist. I'm addicted to shopping for junk. My wife is so lucky. I'll be in Milwaukee in a couple of weeks (visiting friends), and while looking for a Brooks saddle for my bike, I detoured over to the electronics section and discovered the legendary Sony 500A reel to reel. I made a low but reasonable offer, and had a friend pick it up.

Now I sit in anticipation of new junk. With visions of Tamura transformers and holey basket coral 103A variants dancing in my head. It sounds like some of those R2R's had a different driver, and for all I know, what ever is in there is wet or blown. Still, I can't help but be excited.

What have those of you with the Holey Basket's built? I'm wondering if it would work to do a dipole with my 40-1197's. I know they'd be a little different, but would it work? Something like the BD-pipes with the Corals in front. It seems like a great use of each.

Of course, the Tamura OPT's would be perfect for driving biamped OB's (given those 600 ohm taps). I picture something like this: EliD's knocking off SE on the cheap, or the RH84.

This is all just idle speculation. What I really need to do is build something with my own drivers and get my current tube project finished. And work on my turntable, and my cd player(s). . . .

But, I'd be curious to know what folks have built.


pj
www.wildburroaudio.com

[Cal Weldon]

I use the 16 ohm version, labeled Monarch:

[Cal Weldon]

as an OB mid in a bi-amped 4 way seen here. Very nice driver.

[Brisso57]

Originally posted by pjanda1


It sounds like some of those R2R's had a different driver, and for all I know, what ever is in there is wet or blown. Still, I can't help but be excited.

What have those of you with the Holey Basket's built? I'm wondering if it would work to do a dipole with my 40-1197's. I know they'd be a little different, but would it work? Something like the BD-pipes with the Corals in front. It seems like a great use of each.

Of course, the Tamura OPT's would be perfect for driving biamped OB's (given those 600 ohm taps). <SNIP>, or the RH84.

But, I'd be curious to know what folks have built.

pj
www.wildburroaudio.com

Hi PJ,

I too have managed to snaffle holey basket's (3 pair), and 2 dead 500A decks.

I've commenced building BD pipes.

My plan for the decks is to extract the useful components and use them to build a pair of RH84's. Having two RH84's will allow me to either bi-amp the BD-pipe drivers, or else to bi-amp the pipes AND a supertweeter. See Planet10's website for Dave's commentary on BD-pipes and supertweeters.

BTW, Dave and I discovered that the holey baskets come in a number of variants, including a black-coned one! (Mine are 8 ohm, SONY-badged)

cheers

Doug

[pjanda1]

Black cones would be cool. I'll post pics of whatever I've got.

I don't think I've seen anyone biamp a super tweeter! It seems like a waste of decent sized output transformers. It would be a great use of OPT's from old consoles or radios that were biamped to begin with, as there isn't much else you can do with those. I've got a pair of tiny little OPT's from a cheap phonola AA5 amp that would be perfect. I'm also thinking of HF specific transformers from some of the higher end Magnavox consoles or some organ amps I've seen.

Let me know how those BD-pipes work out. I'm still really curious to hear opinions on building BD-pipes with mismatched 103 variants. If it would work, it really seems ideal to use one of the less acclaimed versions in the back, while saving the nicer versions for a position where you get the most out of them. I really like the idea of using these little drivers in dipoles to eliminate the need for BSC and maybe gain some efficiency.

It would be a great opportunity to build some little horns or double mouth BVR's though, provided one is suitable for the Corals.

pj

[pjanda1]

Cal,

I'm interested in the details of your design too, but I bet they are posted here somewhere. I'll search later when I've got the chance.

pj

[Piek]

Also consider this design from Niwo: http://www.rahaso.de/foren/thread.ph...ein&idx=23502&

Sound is very good with different Fe103 variants (needs a Sub).

-Micha

[planet10]

Originally posted by pjanda1
I don't think I've seen anyone biamp a super tweeter! It seems like a waste of decent sized output transformers. It would be a great use of OPT's from old consoles or radios that were biamped to begin with, as there isn't much else you can do with those. I've got a pair of tiny little OPT's from a cheap phonola AA5 amp that would be perfect.

I have some lovely little Nordmende OPTs that are destined for such an amp.

I'm still really curious to hear opinions on building BD-pipes with mismatched 103 variants.

We've tried Foster FE103A on the front & 1197 on the back. Also just upgraded the front drivers of a customers 1197 BD-Pipes to FE103eN. Works fine. I think someone also tried 1197 on the front, and the little woofer (can't recall the number off the top of my head) on the back

dave

[Cal Weldon]

Originally posted by pjanda1
Cal,
I'm interested in the details of your design too

Those were a little experiment I did without using a formula. This is what the inside looks like except that I didn't leave room to show the back panel of the cabinet. You'll have to imagine it's there.

The result tells my ears the line is too long. They are shy on bass.

[Brisso57]

I have enough Coral HB's to make the BD-pipes, but I also have 2 pair of Sanyo FE103A's. When I eventually get time I'll swap those in for a comparison.

cheers

Doug