Crown Macro-Tech history?

[Rhodesplyr]

I was given a non-working Crown Macro-Tech 2400 that I fixed last night: a transistor lead had broken loose from its solder pad, probably from rough handling. Other than needing a new On/Off button, replacement of a bent binding post, and, I suppose, I new air filter, it seems to be in good working order.

Based on date codes on transistors and capacitors, it looks like it's from 1988. I wasn't aware that the Macro-Tech series went back that far, and the documentation Crown has on their site doesn't give much information on version history this old. (It looks like all their documentation has been re-worked to reflect the Harman International ownership.)

When did they start making these?

David

[Mark Black]

The Macro-Tech line grew out of the Micro-Tech series, which was introduced around 1984 (according to Crown's timeline):
Crown Timeline

As I recall there eventually was a model called the Micro-Tech 1200LX which, according to a Crown tech I talked to many years ago was functionally the beginning of the Macro-Tech line.

[Rhodesplyr]

Thanks, Mark. Perhaps the oddest thing about this amp is that it has a massive power cord that looks like what you'd find coming into your house from a mains transformer ending in a plug that looks like a 240V plug, then a huge adapter for a regular wall outlet. However, it has no obvious provision for being switched to run on 240V. Was there a move at some point to run pro audio gear from larger format outlets?

[zero cool]

The macrotech 2400 can dran nearly 20 amps of current from the AC line. that is not a 240V plug but a 20 AMP plug. running this amp on standard 15 amp service will starve it for power if you push it real hard. power in = power out + losses so when you think about it...if it is 2400 watt amp...that 2400 watts has to come from someplace. plus add in a couple hundred watts in losses.

According to the power draw and thermal spec sheet http://www.crownaudio.com/pdf/amps/131509.pdf this amp is 65% efficient. and with a 50% duty cycle and 2 ohm stereo or 4ohm bridged mono(worst case) this amp will draw 1780 watts from the AC line. and figure the AC line is going to sag a bit, maybe say 100V, that's 17.8 amps all while pumping out just over 2300 BTU's!

big amps, require big power!

[Rhodesplyr]

zero, You pointed me in the right direction. I examined the plug carefully and saw it said 30 Amps. I googled it and found out that it's a NEMA TT-30 plug, a standard for plugging recreational vehicles into a power source. So, does that mean you have to go to an RV park to plug it in? ;-)

By the time this amp was working hard, any speakers I own would be smoking lumps of melted wire and bits of paper cone.

File:NEMA TT-30.png - Wikipedia, the free encyclopedia

[Enzo]

It means that, assuming the power wiring is proper, you can only operate the amp at full capacity from an outlet wired for the higher current. The adaptor allows operation from a more common outlet, but that outlet won;t have the current for full power output.

[jrfrond]

Operating and cooking large power amp like the MacroTech MA-2400 and beyond (there a MacroTech 10000! We've only seen one) requires A LOT of available power. You can do static and turn-on tests on a standard house line with an adapter plug, but these pups draw about 4-5A at idle and 15A or so inrush at turn-on.

Ironically, the larger amps (3600, 5000 & 10000) are relatively more forgiving at idle due to the power supply design, but let me tell you, there is a reason why we had our electrical system replaced and upgraded here in the shop.

[zero cool]

The last MA3600 I had in my shop. I did the rebuild and basic calibration but had to send it back to crown for the full on calibration as the AC line in my shop wont support the full power 40 amp short circuit current limit testing LOL!!!

[jrfrond]

Hence our need to run 100A lines to our power amp benches. 220V as well. On the wall under the benches, I had the electrician wire up individual outlet boxes with every friggin' high-current outlet type we could find!

[zero cool]

Hence our need to run 100A lines to our power amp benches. 220V as well. On the wall under the benches, I had the electrician wire up individual outlet boxes with every friggin' high-current outlet type we could find!

I am doing this very thing in the new shop i will be moving to in spring!!