My new-to-me 820s

Yesterday was moving day for the 820s. These belonged to my audiophile uncle - who drove off to the great sound stage (and car show) in the sky last year. He bought one of the 820s new in 1956, and the other one used about 10-12 years later. The 'new' one has the Little Maestro emblem on it, and the 'used' one is a little older and has the ALTEC decal at the top.

I will have more comments, questions, and photos soon. But to whet some appetites, here is something interesting: My uncle always said that the two sounded a bit different. One was a little better on the low end, and the other was a little better on the high end. He used an equalizer to cover it up.

When we loaded them up, I laid them on their sides. And check it out. There are a number of construction differences between the two. One in particular stands out: the 'used' one is tuned using holes - like the plans in the speaker building book. The other (the 'new' one) has an angled piece in the rear.

I should note that I once asked my uncle if one was a 820C and the other a 820A. But he insisted they were both 820Cs. Same horn, woofers, and xover. I need to remove the side covers to confirm.

I wiped off the dust and debris. Then applied some Liquid Gold wood cleaner and preservative. The 'newer' 820 cleaned up really well, though there is an area at the bottom of the grill where the dark finish has disappeared.

The 'older' 820 has more problems. Part of the right side lived next to a single pane sliding door for 30 years, and got quite a bit of sunlight. The finish is almost completely gone. Just some flakes remain.

Does anyone know what kind of dark finish Altecs of that era used? I will most likely call in a professional furniture restorer, because there are a few chips in the veneer that also need to be fixed.

Those are some sweet cabinets, and I find the reflex port differences to be very interesting!
Can you post some pics of insides? Love to see the drivers and if there are any other cabinet differences.
There is a 820 thread over on LH where many plans are posted about this and other classic corner horn cabinets.

The plans shown on Post #2 by Tom Brennan of that thread show the actual part number of the grill cloth used on the 820, so it is conceivable that the finish part number may also be mentioned in that book? I don't have the book, but I would bet someone here does (it's very well-known).

I have a copy of the Badmaieff and Davis book. (13th printing, 1978.) The final chapter is all about construction and testing techniques. Just looked and it says very little about paint - other than painting the baffle board and screw heads black like the drivers so that they don't show. They also mention coating the interior with shellac to capture dust/grit left over from construction.

The finish is not oiled. I suspect it is some sort of varnish or laquer. But I really know very little about woodworking, so really need to get a pro in. I am wondering if whatever product was used can still be purchased here in California. I know that these days a lot of people buy cabinets that are made outside of California due restrictions imposed by our (fill in the blank...) environmental laws.

I hooked them up last night. It has been at least 15 years since my uncles system was totally operational, so I haven't heard them in their full glory for a while. Man, that 'presence' really comes through! Stereo imaging is terrific. For all those woofers and big cabinets, the bass is a little weaker than I remember - but clean. Could be a problem upstream though, since I was in a hurry and just used the kids X-Box 360 HDMIed into a Sony Bravia TV as a DVD/CD source.

Quote:

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Originally Posted by wws944

... For all those woofers and big cabinets, the bass is a little weaker than I remember - but clean...

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Update: So much for being in a hurry last night. It seems I wired them out of phase... Bass is where it should be.

Quote:

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Originally Posted by wws944

One in particular stands out: the 'used' one is tuned using holes - like the plans in the speaker building book. The other (the 'new' one) has an angled piece in the rear.

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Early cabs should have holes [many small ones originally] and the fiberglass wedge since the Fs of early 803s were 50-60 Hz. Later ones dropped to around 35 Hz, so would be tuned lower with just the wedge covering a solid plate vent, which begs the question, what are the date codes? They will be 391xxx.

GM

Quote:

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Originally Posted by wws944

The finish is not oiled. I suspect it is some sort of varnish or laquer.

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Finish would normally only be listed on purchase order docs, not assembly drawings except for painted finishes.

Lacquer was the preferred coating with Ga. cabinet, furniture manufacturers until EPA stopped them in the late '70s IIRC, but no clue about Ca. other than such changes originated there.

GM

Quote:

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Originally Posted by GM

Early cabs should have holes [many small ones originally] and the fiberglass wedge since the Fs of early 803s were 50-60 Hz. Later ones dropped to around 35 Hz, so would be tuned lower with just the wedge covering a solid plate vent...

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I want to say that the older cabinet is a 820A. Except check out the photos at the following:

1953 Altec 820c

He calls it a 820C, yet it has 803A woofers and holes at the bottom. But it also has a 811 horn and 802C driver. So it seems there was an evolution - horn evolved first, then the woofers.

Think I will pull the side panels off the older one this weekend to confirm which drivers and xover it has. I bet it looks like the one above.

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... which begs the question, what are the date codes? They will be 391xxx.

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On the drivers or the cabinets? There are no numbers on the outside of the cabinets.

Right, the HF horn was switched out early on.

803A should have the lower tuned cab.

On the cabs, though in the link, that particular cab was rubber stamped, so whatever you can find: 025

GM

I took a side panel off each one this morning. My uncle was right - they are both called 820Cs. Both have 802C/H-811 horns, 803A woofers, and N800D crossover. In the older one, the components are painted dark gray, and the newer one they are Altec green.

Both have schematic diagrams on the interior of the side panel. On the older one, the drawing is dated 8/30/54 and is noted as "Issue 1" - which I would take to mean it is the first version of the 820C. On the newer one, the drawing was redone. It lists itself as "Issue 2" with a date of 2/31/55, but then also shows an 11/14/55 revision date as "Issue 3".

The 803As on the older cabinet have a date code of "3-55" and have "20409" stamped on the cones. The newer 803As have a date code of "May 1957" and have "20750" stamped on the cones. (Looks like my uncle bought it in 1957, not 1956.) I didn't see any date codes on the 802Cs or the horns.

Note in the photos that the crossover is mounted on the shelf on the earlier version, and next to the horn on the later version.