Topic: Marantz ACM671 vs. Concert Mod 661

[Since85]

Hi,

Just wondering if anyone has a concert mod 661 who previously owned an ACM671. I would really like to downsize, but do not want to lose "all in one" sound quality. Is there much of a soundstage, s/n ratio, transparency loss between the machines? Anything else to consider?

Any insights appreciated, thanks!

[datbrad]

I have a PMD670 as well as an Oade WMOD 661, and I am familar with the PMD671 through friends that own them.

Biggest differences: PMD671 has -10 db sensitivity unbalanced RCA line inputs, PMD661 has mic/line switchable balanced XLR inputs. This gives you two advantages, a +4 db sensitivity balanced line input, and Doug's performance upgrades improve both mic and line sources, as opposed to only improving the mic in on the PMD671.

The PMD671 has digital in and out, and the PMD661 has only a digital in. Unless you require a way to output digital for a patcher, this is not a big limitation on the PMD661, IMO.

The PMD670/671 has a weak internal battery solution. The sleds can have contact problems from jostling the bag, causing premature low battery indication or total unit shutdown. The PMD661 can run for many hours with just 4 rechargable AAs, and because the batteries seat directly into the recorder, jostling the bag or the recorder itself will not impact the battery contact.

The PMD671 has a margin indicator with a reset, so you can check how high your levels were hitting while you were away from the rig, for example. The PMD661 does not have this feature.

Lastly, the PMD661 is more than half the size and weight of the PMD671. I am sure there are other differences I have failed to mention, so anyone else please chime in.

I love carrying a smaller recorder in a smaller bag. My PMD670 has been relegated to the role of DAT transfer device to archive them on wave files since I moved to the PMD661.

Good luck!!!

[Since85]

Thanks for the very good info DatBrad! Most appreciated.

However,

I am JUST curious about recording quality if using each unit as an "all in one" (i.e. just using the deck to power the mics directly w/o any preamp). I do not want to sacrifice size of recorder for a loss in quality in dynamic range, soundstage/imaging, etc...

So, looking for direct field experience in comparing the ACM671 TO THE 661 concert mod just comparing recording quality if one were to use the same microphones.

Thanks!
 

[twatts (pants are so over-rated...)]

Here is a conversation I recently had with Doug concerning the HD HD-P2 vs ACM HD-P2 mods (Oct. 18, 2009):

Hey Doug,

I own an ACM HD-P2 that I got from you a couple of years ago.  I love
the machine BTW, it makes great tapes...

I'm wondering if and how an HD mod might be different or might be able
to improve my ACM HD-P2???

Thoughts from you would be appreciated...

Thanks!

Terry Watts

Hi Terry, the HD is basically a refinement of the ACM MOD. It is based on brand new chips that were not available at the time I did the ACM. If you are recording amplified music with high output mics,  the difference would be minor.  They both have great detail and an impressive 3D image so I am not sure it would be worth the money to switch yours over to an HD.
I hope this helps...Doug

Not sure if this will help you, but you could just email Doug and ask him.  More than likely he'll try to pump you for the more expensive mod (any business person would do so), but you'll get a better idea of what he offers compared to what you need...  If you want milk, go to the cow.

Terry

[datbrad]

Thanks for the very good info DatBrad! Most appreciated.

However,

I am JUST curious about recording quality if using each unit as an "all in one" (i.e. just using the deck to power the mics directly w/o any preamp). I do not want to sacrifice size of recorder for a loss in quality in dynamic range, soundstage/imaging, etc...

So, looking for direct field experience in comparing the ACM671 TO THE 661 concert mod just comparing recording quality if one were to use the same microphones.

Thanks!
 

I don't know of any comps between the 661 and 671 like you suggest.

I can't imagine there is much difference between a concert mod 671 and a concert mod 661, since Marantz uses the same AD chips in both units, and Doug upgrades the input capacitors and opamp chips in both units.

I think the form factor and feature set differences I described are going to be the main distinctions between the 2 units.

[JasonSobel]

this is a good comparison table, and it focuses exclusively on the "mic-in" on all decks.
http://www.avisoft.com/recordertests.htm

Even though this just looks at stock units, it shows that the PMD-661 is very similar to the PMD-671 as a stock deck.  I would imagine that the concert mod PMD-661 is very similar to the ACM PMD-671 in terms of sound, though unfortunately, I don't have a direct comp either.

[Since85]

Just wanted to say "thanks" to you guys for being part of such a helpful community here! If anyone else has any insight, it would be most welcome.
 

[caymanreview]

The PMD670/671 has a weak internal battery solution. The sleds can have contact problems from jostling the bag, causing premature low battery indication or total unit shutdown. The PMD661 can run for many hours with just 4 rechargable AAs, and because the batteries seat directly into the recorder, jostling the bag or the recorder itself will not impact the battery contact.

from all ive read, which was every single thread I could find on the 671 when i got it, this was just a couple isolated people i think. (please correct me if im wrong, been awhile since i read those threads) i think i read that at least one guy had a faulty battery sled and a new one corrected his problem. not sure why a unit would be jostling around enough while recording to dislodge a sled like that or cause problems

i run my 671 on internal rechargeable energizer 2500mah nimh AA's. i run phantom all the time and i get 5.5-6+ hours @ 24/48. i havent tested it at 24/96 yet but i will because ive been running that recently

my battery sled fits snug and slips solidly right into place, even after swapping the AA's after every set (not needed, just a safety precaution). it doesnt move at all once in the unit, nice and tight

one thing i really do not like about the 671 is the gain knobs. i absolutely hate the knob within a knob setup. ive gotten used to it, but it still sucks

i actually prefer the size and layout of the 671 alot more than the 661. to me the 661 is kind of awkward in that area. i like to be able to see the actual display for things like track time, peak level, and battery meter while im recording.

[mosquito]

I can't compare for the original question, but...

IIRC with a non-mod 671 and recording 24/96 I get about 3 hours of recording time with internal alkaline batteries and about 2:15 with 2500 mAh NiMH batteries, both using phantom power.