Topic: Honest Critiques of the Edirol R4

[poorlyconditioned]

If anyone is curoius I've (partially) traced the front end of the R4.  As suspected, "line in" is just an attenuated version of mic-in, so everything goes through the same pres/opamps.

Hi Richard, when I run UA-5 > R4 I use digi in via s/pdif.  I think maybe you just mean line in vs. mic in through the XLR's goes through the same pre's, as I can't imagine the signal going D>A>D...  Just want to make sure I understand you correctly.

Yes, you're right, it will be digital and no analog muck from the R4 at all.  Note that you *cannot* record any more (analog) channels, so the R4 is just a bit bucket.  24 bits, yes, but still a bit bucket.

I've been reading the few posts I see here like Brian's with interest.  I've been wondering what I would get for a 2nd pair.   What kind of mic combo's would folks consider a good "match"?     If money weren't an issue, I'd probably get a pair of 140's right now...

I don't have that much experience with different mics, aside from AT853 and AKG 391/3 that is...

  Richard

[Chanher]

Hi Richard, when I run UA-5 > R4 I use digi in via s/pdif.  I think maybe you just mean line in vs. mic in through the XLR's goes through the same pre's, as I can't imagine the signal going D>A>D...  Just want to make sure I understand you correctly.

So far, I believe all tested Edirol products turned out to NOT be bit-accurate.  I would bet that the R4 is not bit-accurate, but since nobody has tested, we don't know for sure.

Let's assume it is not bit-accurate. Run a test, maybe ua-5 > optical > jb3 (16 bit) and ua-5 > coaxial > R4 (16-bit). Compare them, maybe even post them! I predict that there will be no sonic difference.

[ford prefect]

Yes, you're right, it will be digital and no analog muck from the R4 at all.  Note that you *cannot* record any more (analog) channels, so the R4 is just a bit bucket.  24 bits, yes, but still a bit bucket.

Thanks for the clarification.  If I don't have 2 more channels available, a bit bucket with really nice level meters is fine with me.  I guess I was more commenting on the fact that the stock pre's in the R4 don't sound as good to me as the mod UA-5.  However, I won't turn down a 4 channel opportunity just because of that...

So far, I believe all tested Edirol products turned out to NOT be bit-accurate.  I would bet that the R4 is not bit-accurate, but since nobody has tested, we don't know for sure.

Is bit accurate important?  I would think the sound of the preamp is more important than the 1's and 0's.

[poorlyconditioned]

OK, I tried a second mod on the R4.  The files are at:
   www.cs.uwaterloo.ca/~mannr/R4

sample1b.flac, sample2b.flac.

They are both modded, but differently.  One is "warm" (what I showed before) and the other is "transparent" (a new opamp).  I'm really not sure if these mods even work.  Please let me know:

  - do you hear a difference?
  - what do you like better?

NOTE: These are recorded with body-worn Sennheiser MKE40 cardioids (lav mics) into a battery box.  (The same mics through a splitter.)  There is some obvious "brickwall" distortion there.  I obviously need a 3-wire battery box (or the "4.7k mod") to fix this.  I guess you should just listen to the quiet parts .

  Richard

[poorlyconditioned]

So, here are my mods so far:
Ch1:  IC1 (pre), IC2 (driver), short R8, R23
Ch2:  IC3           IC4            , short R39, R58
Ch3:  IC5           IC6            , short R65, R68
Ch4:  IC7           IC8            , short R93, R112

I replaced all the chips with AD8512.  (And I notice a difference from my previous chips, it is more "transparent"...)  Busman uses a different chip which I have not (yet) tried, but for me the AD8512 is pretty good.

The result off this is *much reduced* noise floor on all channels (try  a dynamic  mic like Shure SM57/58 to see the difference).  But it disables the Line in on Ch3/4.  Ch1/2 work for both mic and line.

Enjoy...

  Richard

[kbergend]

I've never used a stock R4, but I recently had Oade upgrade my t-modded R4 to ACM (which wasn't available when I originally bought the unit late last year) and I really couldn't be  happier with the sound I'm getting now with my 481s.  The tmod was a little dry and clinical sounding to my ears, but the ACM sounds warmer and bigger without being any less detailed -- I don't know the first thing about electronics myself, but Doug tells me this is largely due to using FETs in his ACM circuits vs. BJTs in the TMOD.  Noise is negligible even with the gain close to max.  I don't feel the need to put anything else in front of it (not that I have the world's most discerning ears at age 54), my last couple of pulls are finally sounding the way I've always wanted my recordings to sound -- that is, I can close my eyes and feel like I'm there again.    Ergonomically, the R4 itself is wonderfully simple to operate, especially after coping with the many design flaws of the Core MIC2496 > Microtrack combo I was using.  The only problem I've ever had is overloading the "line in" (attenuated mic in) circuit on channels 1 & 2 with an unusually hot board feed, so I got a couple of XLR pads to handle that eventuality.

I got the R4 mainly to do matrix without having to synch in post, but I hope to get some 482s next year and do a little 4-mic recording -- neither my Audix M1290s nor AT943s with omnis blend well with the 481s.  Dan Lynch will be running his legendary KM-150s + 4021s (united at last!) into my box for Lesh & Friends at Nokia Theater next month, I'm really looking forward to hearing what that sounds like and also finding out how my 481s sound with his Mini-Me.