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View Full Version : ALTEC A7 Necessary Tube Amplifier?



oldbrowndog
06-29-2014, 05:49 PM
Hi All,
Just another question for anyone with knowledge on the Altec A7..

I am looking at a Mcintosh MC240 to use with the A7 (my setup is 16ohm) & wondering if it will have enough juice to run them to a decently ear shattering volume.. Should i so chose?

Or would it be better to wait for a MC275 to show up?

10 Watt Street
06-29-2014, 07:27 PM
A pair of McIntosh MC-30 is more than needed and preferred. Otherwise a nice EL84 PP amp.

robertbartsch
06-30-2014, 04:54 AM
I've owned at least one pair of these for +45 years or so....

They were designed in a time where "big power" was 50 watts... so they have very high sensitivity and don't need much....

I have experimented a tad with these including different boxes, different crossovers, bi-amping, etc.

Frankly, I favor the original factory set-up driven by a fairly large solid state amp of at least 150 watts per side.

oldbrowndog
06-30-2014, 05:13 AM
Seems like some contrast in those responses, not sure i understand how you can say they are highly sensitive speakers that were built in a time where 50w was huge & then say 150w a side is better..
& regarding the MC-30 thats 30w a side correct.. I guess what your saying is the MC240 is overkill? Its only 40w a side...

Bobecca
06-30-2014, 05:24 AM
Hi All,
Just another question for anyone with knowledge on the Altec A7..

I am looking at a Mcintosh MC240 to use with the A7 (my setup is 16ohm) & wondering if it will have enough juice to run them to a decently ear shattering volume.. Should i so chose?

Or would it be better to wait for a MC275 to show up?

Is this the one you have?

http://www.alteclansing.net.pl/pliki/user_manual/A7_Manual.pdf

If it is, then I would go for a MC275:D or 2 in monoblock per side:applaud:

oldbrowndog
06-30-2014, 06:24 AM
Hi, No i am building my own A7 cabinets & installing a 16ohm setup including 416-16z woofers/ 806a compression driver & 811 horns with a custom upgraded N800f crossover.

Thats a pretty expensice setup yr recommending there.. I am pretty sure the A7 being as efficient as it is wouldnt need quite that much juice.. Not that it wouldnt handle it, but within reason..

I guess i just want to know if a MC240 will do a good job as i have an option to buy one..



Is this the one you have?

http://www.alteclansing.net.pl/pliki/user_manual/A7_Manual.pdf

If it is, then I would go for a MC275:D or 2 in monoblock per side:applaud:

robertbartsch
06-30-2014, 08:08 AM
well, they can get loud with a small amp, say 30 watts per side. However, they shine when driven with a larger solid state amp.....

what is conflicting about that?

These were the industry standard for movie houses for many decades. When they were designed, solid state amps had not been developed so these were driven with modest sized tube amps.

I always admire their high sensitivity and dynamic range.

speakerdave
06-30-2014, 08:19 AM
The MC240 will do a good job. (Some people prefer the MC30 because it has a tube rectifier.)

If your listening level is consistently quite moderate you can listen to those speakers forever with very little power. But robertbartsch and Bobecca are also correct in that the additional headroom of a 200 watt amp will reveal to you a whole new dimension of what those babies can do. In my experience with both Magnificents and 604's the spl at which the speakers are designed to be used and the loudness level at which many recordings come alive will both benefit from the larger amp.

Bobecca
06-30-2014, 01:43 PM
Hi, No i am building my own A7 cabinets & installing a 16ohm setup including 416-16z woofers/ 806a compression driver & 811 horns with a custom upgraded N800f crossover.

Thats a pretty expensice setup yr recommending there.. I am pretty sure the A7 being as efficient as it is wouldnt need quite that much juice.. Not that it wouldnt handle it, but within reason..

I guess i just want to know if a MC240 will do a good job as i have an option to buy one..

Ok, I see.

I would choose the MC275 if you ask me. But I think that the MC240 is good enough if high SPL is not the goal.

oldbrowndog
07-02-2014, 04:18 AM
Great stuff all, much appreciated.. Will have to do some testing with various amps I guess to see what works. cant hurt to buy an MC240 if its a good price anyway..

audiomagnate
07-03-2014, 09:51 AM
I had a pair about 1000 years ago. I think a DCX 2496 with solid state on the woofer and tubes on the horn would make them sound damn good.

Lee in Montreal
07-03-2014, 09:57 AM
I had a pair about 1000 years ago. I think a DCX 2496 with solid state on the woofer and tubes on the horn would make them sound damn good.


+2

A digital x-over would allow to nicely shape the bass. Not having a passive filter between the amp and the woofer will also help.
And I would use the passive filter to the mids directly from the pre-amp, keeping sound pure.