Using 808-8As or 8Bs in Altec Valenica's

[garyl]

Yes Zilch, the info is in the thread but we never did any testing like I am asking about.

The 802-8G, 808-8A and 808-8B all have the same motors with the one exception being the 808-8A has the circumferential metal phase plug while the 802-8G and 808-8B have tangerines.

It would have been nice, while we were at it, to see if the phase plugs really made much difference at all. I could have sent a pair of the 8As at the time but just figured you had enough on the plate with all the various drivers you were testing.

I am not sure about the function of the loading caps but it sure looks to me like they allow for higher power handeling by protecting the diaphragm from overextension. Kind of like a backer plate right behind the dome keeping it from going too far. When you remove the cap and add the felt to the rear of the cover it sounds a bit smoother yet leaves the diaphragm unprotected from behind if you overpower it.

I have seen the tiny flat wire leads both broken (NOT BURNED AT ALL) from what I suspect is too much extension and burned right off from what I expect is too much power.
The new GPA frams have the leads routed different and they appear to be stronger and with no 90 degree bend.

Gary

[spkrman57]

802 - aluminum diaphram
808 - same driver w/symbiotik diaphram

806 - aluminum diaphram - smaller magnet version of 802 w/2db less effeciency
807 - same driver w/symbiotik diaphram

Later 800 series and most 900 series(800 - alnico/900 - ferrite magnet) had "tangerine" phase plug. Earlier units have "circumferential" phase plug.

Ron

[Zilch]

It would have been nice, while we were at it, to see if the phase plugs really made much difference at all. I could have sent a pair of the 8As at the time but just figured you had enough on the plate with all the various drivers you were testing.

I forget what all I had here now, actually.

In any case, it was obvious to me that the tangerine phase plug majorly advanced HF extension over the earlier Altec annulars. I also found, for what reason I never determined, that the old "equivalent" JBL LE85s with original aluminum diaphragms did a better job than either of them, both in extension and uniformity, at least insofar as the measurements were concerned.... :dont-know

[diamondsouled]

I forget what all I had here now, actually.

In any case, it was obvious to me that the tangerine phase plug majorly advanced HF extension over the earlier Altec annulars. I also found, for what reason I never determined, that the old "equivalent" JBL LE85s with original aluminum diaphragms did a better job than either of them, both in extension and uniformity, at least insofar as the measurements were concerned.... :dont-know

This was with the JBL lense correct?

Lar

[Zilch]

This was with the JBL lense correct?

Lar

No. I clamped the JBL drivers to the Altec horns for testing. They're not my horns, and I had no authorization to drill the requisite additional mounting holes in the flanges.

Results are in the Valencia thread, as is the M19 schematic you're looking for....

[diamondsouled]

Results are in the Valencia thread, as is the M19 schematic you're looking for.... [/quote]

Thanks Zitch!! I didn't look through all the posts in that thread yet.

Larry

[diamondsouled]

Whoa that's a long thread!!!

Took me a couple hours to get to the Model 19 Network, lol!!!

Course I was reading all the interesting stuff about the Valencia and Model 19 drivers and horns.

I still have to read from page 25 on, tomorrow.

Thanks again Ziltch

Larry

[garyl]

I forget what all I had here now, actually.

In any case, it was obvious to me that the tangerine phase plug majorly advanced HF extension over the earlier Altec annulars. I also found, for what reason I never determined, that the old "equivalent" JBL LE85s with original aluminum diaphragms did a better job than either of them, both in extension and uniformity, at least insofar as the measurements were concerned.... :dont-know

LOL, I have no idea how you got half of the testing done with all you had on that plate Zilch!

To recap what I remember of it, You had Altec 811B Velencia horns and a few Altec 806 Velencia drivers with Velencia XOs both stock and with upgrades.

I sent a pair of Altec 802-8Gs fresh from GPA after recharge and new frams. Another friend sent a pair of stock 802-8Gs with alnicos flux unknown.

You also had a number of other non altec drivers. BMS 4550 and 4552 shined the brightest!

My 802-8Gs did OK but fell off pretty fast after around 12-14K.

The only comparison we seemed to have missed is in checking the response of Identicle drivers and diaphragms but one having the tangerine, 802-8G and the 808-8A having the metal phase plug.

I just don't believe the tangerine phase plug does all that much and it would have been nice to find out if the hype is fact or fiction.

At the auctions you can buy the 808 with metal phase plug for about half the price as the identicle driver with the tangerine! You already proved the BMS does a fine job and can be had for less!

Here is an 808 and 802, identicle in every way except for the plugs.






Gary

[diamondsouled]

Hi Gary,

Was the same phase plug used in all 808-8A's because the picture used in the spec sheet for the 808-8A doesn't seem to correspond to your photo of the plug with the three crescent slots.

[Zilch]

Was the same phase plug used in all 808-8A's because the picture used in the spec sheet for the 808-8A doesn't seem to correspond to your photo of the plug with the three crescent slots.

Yes it does. The three crescent slots comprise the innermost of two concentric "rings" shown in cross section in the brochure....

[diamondsouled]

Thanks Ziltch,

Kind of hard to picture from the side view cutaway, lol.

Read through the 57 page 850 odd post thread, lots of good info!

Lar

[Zilch]

Read through the 57 page 850 odd post thread, lots of good info!

You can tell we had a bunch of fun doing it.

Some rainy weekend, I'll do the index....

[SMKSoundPro]

I am SO thrilled that what was accomplished by the Val thread is of some use to others!

The BMS fix was smooth, and was thrilling to hear. The ZilchLencia's were alot of fun for Lisa and I to experiment with. It really did't cost too much and we know the old Vals were the better for it.

I have not heard too much from the original owner of the vals, but I am sure they will turn up again, here in Anchorage. That somebody will find my name inside and call. Its happened before.

If they fell back in my lap, I would keep them. They were Keepers!

All that being said though, I really like my L200b's with the double 2245-18's subs underneath! I still need to add the 2405 slots. I was kind of thinking to add a small enclosured 2123 10" in the middle (like Miss Heather's) and then triamp the whole deal. It really sounds good up here!

Good luck with your Altec Valencia adventure. The only thing that I did not get a chance to do was to stiffen the box. I wanted to put a brace in from baffle to back. The box sure vibrated, alot.

Hope all is well with everyone.

Thanks.

Scott.

[diamondsouled]

Hi Scott, Ziltch, and all,

Not only useful but like a good page turning novel.

Is it my imagination but is the consensus here that the 2405-077 is superior to the 2404 baby cheeks?

Having not had a pair of 077s around for a long time it seemed to me on first listening to the baby cheeks that they were quite similar but perhaps a little less directional than the 077s. The 077's are a lot rarer than baby cheeks, sooo.

They are basically the same driver with a different lense though, correct?

Lar

[Zilch]

Yes, and a substantially different dispersion pattern as result....