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

[diamondsouled]

Hi,

Just wondering if it is worthwhile to change out the original horn driver in the Altec Valencia's for an 808-8A or 8B? The higher power handling of the 808's would come in handy.

Larry

[CONVERGENCE]

I would choose the 808-B over the 808-A . The B uses the Tangerine phase plug which refines the technology of proper phasing,ensuing maximum high frequency reproduction while maintaining smooth overall response. The 808 series uses a symbiotic diaphragm .The 806 is an earlier model . GPA can replace the Symbiotic with newer better diaphragm.

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[RKLee]

Ditto on CONVERGENCE reply. I had a 806-8B, and there is just not enough high end with the symbiotic diaphragm. I added an EV T350. I liked the symbiotic diaphragm because it can handle a tremendous amount of power, but to me the hi-frequency response falls off appreciable around 10kHz.

[diamondsouled]

The Tangerine was introduced in 1978 correct?

I'm fairly sure that the drivers in my early seventies Valencia's are 806-8As.

So the 808-8B was basically a professional version of the 802-8G?

I'm not sure how much difference in sound there would be switching the 806-8As for the 808-8Bs.

I'm using JBL Baby Cheeks above 6000 Hz with my Valencia's and like the sound. I plan on biamping them though so having the extra 20 watts handling capacity would be good.

I'm wondering, would the midrange be improved using the 808-8B?

By the way I have the original spec sheet for the Valencia as well as two Altec catalogs and some price lists that aren't on the Lansing Heritage Site yet. Who would I contact to give scans to for uploading?

Thanks

Larry Rowe

[4313B]

Who would I contact to give scans to for uploading?

Don McRitchie

[Russellc]

Hi,

Just wondering if it is worthwhile to change out the original horn driver in the Altec Valencia's for an 808-8A or 8B? The higher power handling of the 808's would come in handy.

Larry

The difference has already been stated by posters above. You will get the tangerine phase plug with the 808 8B. The 808 8A does not have this type of phase plug.

The "increased power" capability comes from the fact that the 808 8B comes originally with the symbiotic diaphragm and the use of a "loading" cap. This is not a capacitor, but a plastic dome like contraption that nestles in behind the actual diaphrams dome. both of these devices subtract from "high fidelity" use in the home, but add power handling for the PA type use. The symbiotic is no longer available. If you want this higher power diaphram, you must go th GPA, I believe they offer the Pascalite diaphram, which is said to sound good and have increased power handling.

I myself use the 808 8B, with removed loading cap, (which necessitates the use of slightly shorter screws, and a felt in the back of the cover...both available from GPA) and replaced the symbiotic with the GPA aluminum diaphragm. This is exactly like the 802 8G now, and I consider it the better 1 inch Altec driver, you may not.

Russellc

[Russellc]

I would choose the 808-B over the 808-A . The B uses the Tangerine phase plug which refines the technology of proper phasing,ensuing maximum high frequency reproduction while maintaining smooth overall response. The 808 series uses a symbiotic diaphragm .The 806 is an earlier model . GPA can replace the Symbiotic with newer better diaphragm.

.............

I may be incorrect here, but I also am under the impression that the 806 uses a slightly smaller (shorter) magnet as well?

Russellc

[CONVERGENCE]

I may be incorrect here, but I also am under the impression that the 806 uses a slightly smaller (shorter) magnet as well?

Russellc

The specs for the 804,807 show a Flux density of 13000 Gauss. I would presume that the 806 had a 13000 Gauss density also as oppose to the 15250 Gauss for 808 and 802.

...................................

[diamondsouled]

Thanks all,

So the 808-8B and the 802-8G are the same driver? Besides the modification to the 808-8B to make it higher power handling?

As for replacement diaphrams I've heard that there are titanium as well as aluminum ones available.

These ones on eBay are?

http://cgi.ebay.ca/Diaphragm-for-Alt...QQcmdZViewItem

Would there be any appreciable difference in midrange using the 802-8G over the stock 806-8A?

Thanks

Larry

[CONVERGENCE]

Thanks all,

So the 808-8B and the 802-8G are the same driver? Besides the modification to the 808-8B to make it higher power handling?

As for replacement diaphrams I've heard that there are titanium as well as aluminum ones available.

These ones on eBay are?

http://cgi.ebay.ca/Diaphragm-for-Alt...QQcmdZViewItem

Would there be any appreciable difference in midrange using the 802-8G over the stock 806-8A?

Thanks

Larry

Sorry can't help on that one. I used new A-7 500, A-5X, A-8, 604(612) in the early to late 70's.

.........

[diamondsouled]

Thanks Conv,

Your reference to A7's made me think of this pic from the 70's of a wall of A7's in a studio. Wouldn't want to be standing under them in a .8 on the richter scale.

Lar

[garyl]

Sounds as though there is some confussion here so lets try again.

808-8A has a circumferential metal phase plug and came with a symbiotic diaphragm and loading cap.

I am pretty sure the 808-8B came with all the same except that it had the Tangerine (Tangential) orange phase plug. Both appear to be the identical motor and also identicle to the 802-8G models.

On both the 808s you can do away with the loading caps and symbiotic frams and add the felt to the rear covers and use aluminum frams from GPA or other sources for home fidelity purposes. The loading caps is where the higher power capabilities come from!

I have all three, 802G, and 808 A&B and all with the same GPA 34647 diaphragm and can't hear a bit of difference between them.

I can attest they all sound best when run through the model 19 XO at 1200Khz with the Zobel filtering. Just changing the driver on the Velencia from an 806 to an 802/808 and not doing any updating to the XO will probably be a wasted effort IMO.
I am also not too sure there is an audible difference between tangential and circumferential phase plugs! Altec marketed them as a big step forward but I am more inclined to believe they were more of a cost saving at the time, Molded plastic Vs machined metal. I would be interested in seeing some graphs of both 808-8A and 808-8B with identicle frams and rear cover felts and suspect there really wouldn't be much difference at all!

Gary

[diamondsouled]

No confusion Gary,

Thanks for the info. Interesting how they got more power handling out of the 808-8B through adding the loading cap.

Larry

[Zilch]

The curves you seek for 802 and 806 (and others) are in this thread:

http://audioheritage.org/vbulletin/s...ad.php?t=14690

I know, it's a chore to wade through it, as I have not done the index I promised, but I and many others put a lot of time and effort into figuring out Valencias there, as, apparently, no one had previously done.

Bottom line, you're going nowhere worthwhile with Valencia without upgrading to Model 19 network, or similar, as Gary says. See also Speakerdave's synthesis of the situation here:

http://audioheritage.org/vbulletin/s...098#post187098

As you'll see in that thread, there are suitable alternatives to Altec compression drivers, as well....

[diamondsouled]

Hi Ziltch,

I do plan on upgrading the crossover, most likely putting a new three-way one together. Is the schematic for the Model19 crossover available somewhere?

I'm already using JBL Baby Cheeks with my Valencia's crossed over at 6000 Hz. so the sound is already far better than stock. I used 077's with an earlier pair of Valencia's I put together myself back in 75 and the sound was great. I used my JBL 418B guitar speakers in them lol.

I use tube amps to power these and to my ears they sound quite good. I have bypassed the crossover caps with PIOs though.

I also own a pair of the old ESS AMT-1A Monitors, as well as 4 extra sets of the Heil Transformers that I plan on using with some dipole woofer projects I have on the back burner.

Thanks for the links by the way.

I know a lot of people have written off the old horn speaker designs since the Thiele-Small parameters changed the direction of speaker design in the mid-seventies. Thing is a good percentage of the music that was recorded between 1930 and 1980 was monitored in the studio on such horn speakers so they do reproduce what the musicians, engineers, and producers were hearing when recording, mixing, and mastering. Whether that is good or bad is more a matter of taste than any absolutes; just as it is with hi-end capacitors and NOS tubes in tube gear.

To tell the truth though I wouldn't have a set of Valencias without 077s, 2404s, or an EV equivalent. The 811-806 combination just doesn't do from 800Hz to 20,000Hz justice. Not too surprising though when you cross them over at 6000 Hz as well it improves the 800Hz - 6000Hz, far less IM distortion, better dynamics.

Lar