Altec Lansing A7's 50's model


I am thinking about picking up a pair of these speakers. They are about 40 years old and in good condition according to the pictures. Can i get some feedbacks on the following topics?

1. The sonic signature of the A7's?
2. How much they worth?
3. Can they still be serviced?
4. How are they compare with modern speakers if this is a fair question?

Thanks for your help.
Ag insider logo xs@2xginas
As a supplement to my previous post, I might mention that I "graduated" from the A7 to a pair of AR3a speakers in the early 60s, i.e. from monaural to stereo. In our psychoacoustics lab, A7s were driven by the lab standard Mac MC 60 amp, but the efficiency of the A7 suggests that was overkill. I much preferred the big 511B horn with its 500 Hz crossover to the 811B.

Although the 511B and 811B are sectorial horns themselves, the A7 isn't a LF horn design in the sense of the large corner horns in vogue in the time of monaural, e.g. those from Paul Klipsch, JBL, Electrovoice. These were mostly rear loaded LF horns designed to be placed in a corner where the walls could act as extensions of the horn. Their popularity went out with stereo, because you could rarely find a configuration of corners that would work for stereo, and taking the speakers out of the corner removed a major design parameter. IIRC, the smoothness and frequency extension of the dome tweeter of the ARs contributed to the demise of the HF horns.

I looked in the Audiogon Blue Book and didn't see anything about the early A7s, so I'd guess following the ads is the way to figure out what's a fair price.

My impression of the sound of the A7s, with over a 40 year gap, compared to my KEF Reference 104/2s, is that the A7s lack refinement. But then that was not the design goal of the A7s, spreading a lot of sound over a large area with high speech intelligibility was. Usually, A7s were hung close to the ceilings in theaters and auditoriums.

db
Dear all,
Thank you very much for your inputs. I am going to pick up a pair and let you know how they work with my class A 2A3 push pull and single ended 300B. My room is 36X40X9. The biggest issue is to pick them up in Indiana and i live in MN. The owner just dont want to deal with the packing and shipping. I got a quote from a professional mover for $700.00 and the A7's is about $1000. The total is about $1700.00.
Ginas,

You should find them a very easy speaker to drive. You haven't mentioned whether the A7s have the 811B or 511B sectorial horn. In looking over an Altec brochure from that time, I see the A7 spec is for the 811, although we had both in the lab. I hope you are aware the A7 is an industrial looking box intended to be custom finished for residential use. Their top of the line residential unit at the time was the Laguna, with two 803B LF drivers and a 511B horn with 802D HF driver. List price was $599; list price of the A7 was $299.40. By the way, one of the features mentioned in the brochure is ease of driving the speakers without the need for high powered amps.

I also have an interesting booklet by Badmaieff, Altec's chief acoustics and transducer engineer, in which he discusses speaker enclosure design principles. In my high school days, I built a few enclosures based on Altec designs and populated them with Altec drivers.

db
I own a pair of A-7's since last fall and love them. I have run them with 3/4 of a watt and 75 watts. Depending on your room size and listening habits I recommend caution in terms of power, especially if they are 16 0hm like mine. 75 watts was a pair of Blue Circle BC2 hybrid monoblocks, 3/4 of a watt ( That's right not even a full watt! )was a custom Darling amp and lastly a custom 45 SET both made by P. Townsend a retired electronics engineer/designer/extraordinaire.

These need clean low hum/noise amps. More than 2.5
milivolts from 12 feet away and you will hear it when music stops or possible quiet passages.

1. The sonic signature of the A7's? Dynamics and texture matched by few. (Tannoy?)
2. How much they worth? 700-3,500 Japanese worship A-7's
3. Can they still be serviced? Great Plains Audio http://www.greatplainsaudio.com/
4. How are they compare with modern speakers if this is a fair question?
Depends on how much care you show in amp choice and minor simple tweeks to cabinets and (damping)horn. Will exceed most modern designs in dynamics, texture, finesse and natural reproduction elegance.
My uncle owns a pair that he built in the 60's, I believe, and they are still some of the best speakers I have ever had the pleasure of listening to. His was the first truly high-end system I ever experienced. Go for it!