Topic: Edirol R-44 - 4 Channel Recorder (Part Tres)

[DSatz]

OK, here are some actual measurements. Open-circuit voltage with no mikes connected, 46.8 Volts. Connect one CMC 541 mike and the voltage at the unused input drops to 46.0 Volts. Connect a second CMC 541 mike and this drops another 0.8 Volts to 45.2 Volts, which is still just fine.

Add a CMC 58 (for double M/S, perhaps) and now the voltage on the unused input is 44.5, which as I've been saying is quite OK although it implies some small (ca. 200 Ohm) non-standard series resistance between the regulated supply and the phantom resistor pairs--though that low a value wouldn't give them much extra filtering of the DC or protection from inrush current, so it's hard to imagine the motive for it.

Anyway with another CMC 58 connected to the fourth input there are no more unused inputs, so if I unscrew the connector shell and measure across the terminals I get 31.2 Volts. Now 2 mA through a 6.8 kOhm resistor gives a 13.6-Volt drop while 2.5 mA gives 17 Volts. Since even the lower of the two figures doesn't quite add up to the 43.8-ish voltage I would expect, I have to suspect that the phantom resistors are lower in value than the nominal 6.8 kOhms. And potentially (no pun unintended) that could also be quite OK--the absolute tolerance is 20% as I recall, as long as the resistors are matched within each pair to within 0.4%.

So to me it still seems that as far as the microphones are concerned, this recorder's powering is a little below its own specifications. It's probably just barely OK for running four Schoeps CMC 5--s even though the supply by that point has fallen slightly below the official standard--but can the circuit put out nearly its maximum current for an indefinite length of time without risk of failure? Unless I can find out more, I'd have qualms about running this class of equipment that way on a steady basis.

I bought the $65 extra insurance policy and I suppose I could plug in four testers and leave the unit running for a week to see whether its power supply burns out or not, but if it does burn out and the insurance won't pay for a new one ... Main thing is, though, people with even higher-current microphones such as Shure KSMs, CAD Equiteks or Earthworks should continue to use outboard phantom supplies with this recorder.

--best regards

[Ozpeter]

R-44 Ver.1.03 System Program - downloadable for a long time from Edirol - but does anyone know what this firmware upgrade actually does?  I've looked through all the R-44 threads here and I can't find a mention of it.

[krsb]

--best regards

 We have no idea what caused it.  I do know that some of the light boards I've used you MUST turn your cell phone off or leave it very far away from the desk or else it can cause a reboot of the system.  Maybe some strong RFI signal messed us up?  And how does a 744 recording four track lose it's sync in the deck....very strange.  Yet the seond set came out fine for both of us and we didn't do anything different.

Most likely completely unrelated, but your story reminded me of something. Once I was editing video in the field on a laptop with an external lacie hard disc connected via firewire. I left my mobile phone near the lacie. When the phone rang, the lacie shut down. I thought a fluke, but but being a spazz, later I left my phone again near the hard disc and again it rang and again the disc shut down (and of course I lost all my work)

Was a while ago, maybe technology has changed...

Bit of a thread jack, apologies. Back to R44 business 



cb

[mblindsey]

Pssst....:  http://taperssection.com/index.php/topic,117952.0.html

[Gutbucket]

Checking in.. finally decided to jump on the R44 train and ordered one this morning.

[dmonkey]

It is "the shiznit" (as the kids say these days). 

[danlynch]

Checking in.. finally decided to jump on the R44 train and ordered one this morning.

Ordered mine last night (Oade Concert Mod).

[Gutbucket]

^^^
Same. Too bad we didn't do this 2 weeks ago.

[cybergaloot]

From what I'm gathering, Wanee is going to look like an R-44 user's convention.

[danlynch]

So mine came in this morning and I've read through all three of these topics.  Thanks to lee for answering the power-cable question three times, and everyone else for some really useful information.

I guess my major question is the phantom issue running 4-mics directly into the R-44.  I'll be running a pair of KM-150s and a pair of DPA 4021s.  I also have the option of running the 150s into the Mini-me and connecting digitally to the R-44.

The entire discussion begun by DSatz about phantom power equations is pretty much completely over my head, so I guess the question is whether these four will power correctly.

I did run these four together once with a borrowed R-4 and the results were truly outstanding (thanks Keith).

[BayTaynt3d]

I've run 4 phantom many times without any issues that I know of (2xAKG480+2xC4).

[mblindsey]

I've run 4 phantom many times without any issues that I know of (2xAKG480+2xC4).

same here...

2 x MC930 & 2 x Naiant XT
2 x MC930 & 2 x AKG 461

--Michael

[DSatz]

Danlynch, the phantom powering of my R-44 is a little below spec when driving four transformerless Schoeps microphones, and I prefer to avoid that situation for myself. But both the Neumann KM 150 and the DPA 4021 draw distinctly less current than the Schoeps; I wouldn't worry about using pairs of those.

Is that clearer?

--best regards

[skotdee]

Anyone ever use a batterygeek 10-14-88 to power the R-44? I've read they work with the R-4 so I assume they would work with this as well. The battery is (10V~14V) 8A max current output. Im not to good with specs, I assume since the R-44 takes 9-16V/1.2A, its all good on voltage, just wondering about the 8A max current...

EDIT: after a little crash course in electricity, I've learned the difference between voltage & amperage. The voltage is the the amount of power, while amperage is how fast it flows from the battery to the device, or current. Thus, on the 10-14-88, the maximum flow of power, or current, it can supply, is 8A. Since the R-44 only requires 1.2A, this is well within the limits of that particular battery. And since the voltage the batt supplies is also within the range the R-44 accepts, this battery should work just fine. (granted one of the connector tips fits), not to mention power it FOREVER, you can't kill this thing!

Im sure you folks already know all this, but Im just all proud of myself for figuring it out.  Please let me know if Im off base here...

[danlynch]

Danlynch, the phantom powering of my R-44 is a little below spec when driving four transformerless Schoeps microphones, and I prefer to avoid that situation for myself. But both the Neumann KM 150 and the DPA 4021 draw distinctly less current than the Schoeps; I wouldn't worry about using pairs of those.

Is that clearer?

--best regards

Absolutely, thanks!