Acoustic Technologies M-400

derek92994

Veteran and General Yakker
Joined
May 1, 2013
Messages
7,537
Location
Australia
Tagline
Those who enter the man cave will get WOPLed
Had this sitting for several years, freebie from a friend.
Went over it tonight and its doing a good job driving the mids/tweets. Sounds clean.

Acoustic Technologies M-400

120wpc @ 8 Ohms
220wpc @ 4 Ohms

Outputs

Left:
2x Hitachi K176
2x Hitachi J56

Right:
2x SM ECF20N16
2x SM ECF20P16

DC Offset
Left: 3.0mV
Right: 7.0mV

(Edit) Rail Voltage: 108 Volts, Caps are in series.

Filter Caps: 2x Asuno 75v 8000uF

Feb 1987 Date on both Side?/Backplanes

IMG_6197.JPGIMG_6201.JPGIMG_6198.JPGIMG_6199.JPGIMG_6200.JPGIMG_6192.JPGIMG_6193.JPGIMG_6195.JPGIMG_6196.JPGIMG_6202.JPG
 
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XLR for speaker outputs?!?! That seems like a very bad idea. Hook it up to the input of another power amp!!!!!!
Yeah Im currently in the process of making a cable to go from the speaker outs to the inputs of the WOPL :evil4:
 
The flux capacitor lives . . . .

Seriously, though, you might want to consider a refit to Speakon. I seem to recall that they migt be the same size . . . Not a terribly high powered amp, but certainly can't hurt.
 
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The flux capacitor lives . . . .

Seriously, though, you might want to consider a refit to Speakon. I seem to recall that they migt be the samemsize . . . Not a terribly high powered amp, but certainly can't hurt.
Thanks Tim
I have never used or had anything with XLRs, so this is new to me. A lot of DJ gear used XLR for speaker outputs, its a rough ol’ DJ amp.
I can understand the concern though, it seems that XLR is more for line level signals.
 
I've been in the pro audio world since 1983, and have never seen XLR on speakers. EP5 is common, and it looks like an oversize XLR, but not XLR. Then again, the DJ community has been "doing it wrong" for pretty much thier entire existence . . . Prior to speakon, it was EP5 (Multi-way) or often twistlocks. XLR just doesn't have the current rating, and cross compatible input and output connectors is a massive failure looking for a place to happen . . . OTOH, EP5 was common on such beasts as the Clair S-4 . . . (In the day of the phase 700's as well!)
 
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I've been in the pro audio world since 1983, and have never seen XLR on speakers. EP5 is common, and it looks like an oversiae XLR, but not XLR. Then again, the DJ community has been "doing it wrong" for pretty much thier entire existence . . . Prior to speakon, it was EP5 Multimway) or often twistlocks. XLR just doesn't have the current rating, and cross compatible input and output comnectors is a massive failure looking for a plaxe to happen . . .
Those connectors I saw on DJ equipment here in Australia could well have been EP5.
 
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I do believe the speakon connectors can be had in that XLR mount form factor.

They’d drop right in.

Agreed. The last mixer I owned used speakons or something very similar for balanced line level inputs so they could take either XLR or balanced 1/4" jacks. Exact size as a regular XLR.
 
I've been in the pro audio world since 1983, and have never seen XLR on speakers. EP5 is common, and it looks like an oversiae XLR, but not XLR. Then again, the DJ community has been "doing it wrong" for pretty much thier entire existence . . . Prior to speakon, it was EP5 Multimway) or often twistlocks. XLR just doesn't have the current rating, and cross compatible input and output comnectors is a massive failure looking for a plaxe to happen . . .

I see the average current rating for XLR's can handle 15-20 amps, so they look fairly robust and yes, when building ALL cables, attention must be paid to "Pin Out" configs..... Even a lowly speaker wire can cause havoc if placed incorrectly. XLR is as robust as the next.
 
I've been in the pro audio world since 1983, and have never seen XLR on speakers. EP5 is common, and it looks like an oversiae XLR, but not XLR. Then again, the DJ community has been "doing it wrong" for pretty much thier entire existence . . . Prior to speakon, it was EP5 Multimway) or often twistlocks. XLR just doesn't have the current rating, and cross compatible input and output comnectors is a massive failure looking for a plaxe to happen . . .

Seven or eight years ago a friend was given a pair of Wharfedale E90 Pro speakers. They originated from someone who I knew as well and wound up giving me the Akai integrated amp which he used with the Wharfedales. He offered the speakers to me first but I passed. Years before that, I was employed by an electroncs chain, a Wharfedale dealer, and I was familiar with E90's (didn't like them). I was however, unaware of there being a "Pro" version.

They had a handle on the back and castors on the rear corners so they could be wheeled around plus they used XLR jacks for the speaker connections.

Lighting for the photos was poor and the conventional speaker wire jammed into the XLR sockets was my way of assesseing whether the speakers were working or not. I had no knowledge of what the original purchaser used to connect them to the Akai amp as it just had garden variety speaker connections. I suspect he was provided with an XLR cable with the speakers but he may have jury rigged something as I did.

E90 4.JPGE90 6.JPG
 
I see the average current rating for XLR's can handle 15-20 amps, so they look fairly robust and yes, when building ALL cables, attention must be paid to "Pin Out" configs..... Even a lowly speaker wire can cause havoc if placed incorrectly. XLR is as robust as the next.

Depends on pin count though . . .
 
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