FS: Sony Mobile ES 7547 AKA "Big Red"

[mpowered325is]

Item(s) for Sale:

For sale in great condition is a Sony Mobile ES 7547. BIG power 4ch as some of you know. Its a big case amp so you better have some room. But its worth it for the great sound quality these old Sony's produce.

This amp can do 250x4 @ 2 ohms continuously, not peak.
Also can use any ohm sub on the rear channels as it is switchable for 4 or 2 ohm and 1 or .5 ohm

100 AMP Fuse


Item(s) Description/Condition:

Exterior 9.5/10
Function 10/10


Price:

$250 shipped OBO


Shipping and Miscellaneous Item Information:

Shipping included in price from 98057


Item Pictures:
(List pictures in this section, 1st picture should be your username/date if you have less than 10 positive feedbacks with the i-Trader system or less than 10 references that you have sold to in the past. (These must be listed in your signature, or a link provided to a feedback thread listing these references)).

[Bettr n' Revrse]

Awesome amps

[mpowered325is]

Shipping alone will cost me $40 I bet. Thing is HUGE. I will post demensions up later

[mpowered325is]

Bump

[mpowered325is]

$220 shipped

[mpowered325is]

200$ shipped! BUMP

[mpowered325is]

I'm only commenting because you asked me to...

The amplifier is rated at 75W x 4 at 4 ohms and 0.04%THD. The amplifier is 0.5 ohm stable, but only for channels C/D. It accomplishes this by paralleling the output devices via relays. So rather than being "bridged", the channels are paralleled in mono mode.

The outputs are interesting devices. They're MosFets rated at 100V and 70A; a great combination. The rails are +/- 28V in "high voltage" mode. This gives you ~150W into 4 ohms.

You can see where this is going.

At 2 ohms and in "high voltage" mode, you're still at 28V rails so ~250W per channel (that's 250W x 4) is not unrealistic when playing music (as opposed to test tones).

At 0.5 or 1 ohm, the amplifier should be switched into high current mode, because you will almost certainly reach an overcurrent situation quickly at 28V rails. When switched into high current mode, the amplifier halves its rails to 14V so as not to trigger an overcurrent situation. So you're limited to the same amount of power.

So what's the point of having the 0.5 and 1 ohm capability if you don't gain anything? It's partly marketing. People see that and think "superior amplifier" when it's more "bait and switch" and "LOL..." to us engineers. You aren't gaining anything but flexibility, which is valuable in its own right - but don't go changing your woofers just because it can drive 'em.
The other part is stability. The output transistors can't drive sub 1 ohm loads without blowing up, so Sony implements some extensive overcurrent circuitry to force you to switch into another, lower voltage mode.

"High current" sounds better than "low voltage", but it's the same thing in power supply engineering-land.

Another thing - there is a sh*tload of SMD circuitry under that "sparse" board. It always kills me when some chucklehead opens a Japanese amplifier on AmpGuts.com and comments on the low parts count.

It's a solid amp. If it wasn't so huge, I'd have no problem owning one. I bet it sounds divine.

[btolenti]

What are the rough dimensions on this beast?

[Max_Power]

bump for you. I passed on one of these a while back because it was "a Sony". little did I know...

[btolenti]

Is this still available????

[mpowered325is]

Still available.......130$ plus shipping!!!!