The AT Beast

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famous beagle

famous beagle

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So I remember seeing someone post about an Audio Technica RMX64 4-track a while back and thinking how cool of a machine it seemed to be. I filed it away in the "maybe someday" section of my brain. Well, the other day I came across one on CL for $65 --- mint condition, fully functional, with original box, manual, everything --- even the plastic that wraps around the unit in the box. I remember others talking about how the unit looked comparable to the Tascam 246, and with those sexy VU meters, I didn't think twice and pulled the trigger.

Times are a little tight right now, so I couldn't afford it without selling my current 4-track (a 424 mkIII), which I just did. As soon as the paypal money makes it into my account, I'll be going to pick the AT up.

However, one thing concerns me. I've since downloaded the manual and checked out the specs. Everything looks really good, but the S/N ratio is listed as 68dB with Dolby C engaged. This seems surprisingly low to me, considering its other features (including a frequency response of 20Hz to 18kHz!) and overall impressive stature.

It is a dual-speed machine, and the S/N ratio spec doesn't mention anything about that, so is it possible that spec was measured at normal tape speed?

I've been accustomed to the 85dB of my 414 mkII and the 90db of the 424 mkIII, and I'm just a little worried that I might be in for a rude awakening with regards to tape hiss.

By the way, I've attached a picture in case some of you aren't sure of the model number (this picture is not my specific machine, just FYI)

Anyone have any thoughts?

Thanks
 

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I'm not sure if the specs are with low or high tape speed. I would assume high, but the big difference is going to be the fact that the 414 has dbx...the dbx n/r accounts for quite a bit of s/n gain. I wouldn't fret though because you have to keep in mind that the s/n specs are a measurement with a specific set of parameters and don't directly translate to real-world subjective experience. I see specifications as something that can be used to pigeon-hole a device into a general performance category, or can be used to quantify or offer explanation to real-world experiences with the device, but certainly aren't the end-all definition of the device. I suspect you may have a little more noise with the Dolby C vs the dbx n/r but I bet you'll find the Dolby to be more natural sounding since it isn't a broadband commander like the dbx. Let us know what you think when you get it, and what a fantastic find for $65!
 
Thanks for the reassurance. I figured it can't be too big of a deal, because I've read several people talking about how good this machine sounded, and no one mentioned excessive noise.

I'm literally having to reorganize my studio, because it won't even come close to fitting in the space that my 424 mk III used to sit. The AT is 2 feet wide, 20" deep, and weighs nearly 50 pounds!

I'll be sure to post pictures when I get it, and of course a recording will come soon after that. :)
 
I agree with sweetbeats thoughts on the Dolby C. 68 db s:n ratio is pretty respectable and on par with an open reel two track running @ 15 ips. So as long as you record healthy levels and watch your gain staging throughout the signal chain, you should be able to make some decently hiss free recordings with it. And especially so if you're recording pop/rock type material which tends to have a narrow dynamic range anyway.

Cheers! :)
 
Holy crap--- just saw that this machine has phantom power! Didn't even know that. It'll be even more useful than I thought. I've heard the mixer sounds awesome on this thing, so I should be able to use it for additional condenser mic channels. My Tascam M-216 mixer doesn't have phantom, so I bought a two-channel PP supply. But now I'll have 8 channels of phantom! :)
 
Cool about the phantom power feature!

Kind of amazing that AT never got bigger market share with this beast as it certainly looks like a well put together unit!

I guess they made up for it with their microphone sales! :)

Cheers! :)
 
Ok, I just got it home, and everything seems to be great except the fact that the bulbs for CH. 1 and 2 VU meters aren't working. Does anyone know how to get inside and replace them?

I've taken off about 10 screws so far, and it's not giving. I was just wondering if anyone has any experience working on this deck before I keep blindly unscrewing.

Thanks
 
Congrats on taking ownership of the beast! :)

I'd imagine the odds of finding fellow owners is going to be slim.

In your opening post you mentioned the unit came complete with the box and manual. Does the manual contain service info? Diagrams, schematics, service instructions? If so, that's going to be your best resource for disassembly instructions, bulb voltages, etc.

Otherwise, I'd only suggest taking it apart as far you're comfortable doing. Remember...it's only a bulb!

Cheers! :)
 
I have the owner's manual and the spec manual, but neither one of them list parts. I haven't been able to locate any kind of service manual for the machine.

The good news is that I was able to get to the VU meter bulb and remove it. I ended up removing way more screws than necessary in the process, but I learned how the machine comes apart, which will be helpful should I need to make any other repairs. I've taken pictures to document the process, in the unlikely event that anyone else needs to make this repair on this unit. I'll post them soon.

I cannot believe how simply massive and tank-like this machine is. It's truly awesome.

The bad news is that I took the bulb to Radio Shack, and they don't carry it. So I suppose I'm going to have to do a little digging. Attached is a picture of the bulb. It was soldered in place, and there are no markings on it whatsover.

Anyone have any clue as to what it could be?
 

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It looks very similar to the ones used on a lot of Teac and TASCAM stuff, so likely a 6 or 8 volt bulb. Maybe try Mouser for it.

Cheers! :)
 
Is there a way I could measure one of the good bulbs with a multi-meter to find out its specs? I have a multi-meter and am good with a soldering iron; I'm just a little green when it comes to measuring with the meter.
 
famous beagle said:
Is there a way I could measure one of the good bulbs with a multi-meter to find out its specs? I have a multi-meter and am good with a soldering iron; I'm just a little green when it comes to measuring with the meter.
Click to expand...

Yes. Just set your meter to read DC voltage in the 0-10 volt range and put the test probes across the solder points on the meter where you removed the burned out bulb. No need to de-solder a working bulb.

It's also possible that the power to the bulbs might be simple AC juice, so change the meter over to read AC voltage if you don't get a DC reading off the bat.

And it's not the bulb you're measuring but the power supply that feeds it.

One last suggestion, once you've figured out an appropriate replacement bulb, replace all 4 with the same bulb so that the brightness and life span will be even and equal. It's silly to only change 2 and then go through the whole procedure a few months or years later.

Cheers! :)
 
Great, thanks. Would I need to read the amps as well?

The Ghost of FM said:
Yes. Just set your meter to read DC voltage in the 0-10 volt range and put the test probes across the solder points on the meter where you remove the burned out bulb. No need to de-solder a working bulb.

It's also possible that the power to the bulbs might be simple AC juice, so change the meter over to read AC voltage if you don't get a DC reading off the bat.

Cheers! :)
Click to expand...
 
famous beagle said:
Great, thanks. Would I need to read the amps as well?
Click to expand...

Yes.That would be helpful to figure out the wattage of the bulb to ensure your replacement bulbs are of a similar brightness to the originals.

You'd have to test that in line with a working bulb, which requires you to unsolder one end of the bulb and place the meter's probes in line with it, and once done, you'd then have the numbers needed to know what the wattage rating of the bulb is by multiplying the amperage by the voltage. Remember ohm's law? :)

Cheers! :)
 
Also;

If you get a negative meter reading, it means you've got the probes reversed! :D

Cheers! :)
 
On a separate note, there's going to be a serious learning curve with this machine! It's set up completely differently than the Tascams (and 414 mkII and 424 mkIII) that I'm used to! it's exciting though, because it seems as though there's just about nothing you can't do within the realm of 4-tracks.
 
Here, Here! Post some photo's for us. Hell, I am almost as excited as the Beagle!
 
I will soon, I promise. She's in pieces right now, because I was trying to get to the burned out lamps, so she doesn't look all that pretty. But I'm planning on sewing her back up tonight, and I'll get some pictures soon after that! :)
 
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