[John Albert]

Hello all -

On prior recommendations of this group, I added an FMR RNP
to my setup and it works very well.

I'm wondering about adding their RNC compressor, but not
sure if it will be useful for what I'm trying to accomplish.

I record acoustic guitar, mandolin, and banjo, along with
vocals. Is there any benefit to adding a touch of
hardware-based compression to "strictly acoustic music",
while trying to preserve a [mostly] natural and uncolored
result?

I have always thought that acoustic music should be offered
the greatest dynamic range possible - although when
post-processing, I will adjust gain upward or downward
manually, note-by-note, where necessary.

Would the RNC, operating in their "Supernice mode", be worth
experimenting with?

Thanks,
- John

[Mike Rivers]

On Apr 8, 10:32 am, John Albert wrote:

I record acoustic guitar, mandolin, and banjo, along with
vocals. Is there any benefit to adding a touch of
hardware-based compression to "strictly acoustic music",
while trying to preserve a [mostly] natural and uncolored
result?

It would be OK on vocals, but I wouldn't mess with the instruments
other than maybe to try it for "mastering" after you've mixed the
song.

[Scott Dorsey]

In article ,
John Albert wrote:
Hello all -

On prior recommendations of this group, I added an FMR RNP
to my setup and it works very well.

I'm wondering about adding their RNC compressor, but not
sure if it will be useful for what I'm trying to accomplish.

I record acoustic guitar, mandolin, and banjo, along with
vocals. Is there any benefit to adding a touch of
hardware-based compression to "strictly acoustic music",
while trying to preserve a [mostly] natural and uncolored
result?

I have always thought that acoustic music should be offered
the greatest dynamic range possible - although when
post-processing, I will adjust gain upward or downward
manually, note-by-note, where necessary.

Would the RNC, operating in their "Supernice mode", be worth
experimenting with?

If you have a computer with some available DAW software, try the
compression function in software. If you like it, and you find it
useful, consider buying the RNC. If you don't, don't bother.
The RNC may do a better job than the software, but it will do a
similar thing.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Webb]

To: Mike Rivers
Hi Mike,
Mike Rivers wrote:
I record acoustic guitar, mandolin, and banjo, along with
vocals. Is there any benefit to adding a touch of
hardware-based compression to "strictly acoustic music",
while trying to preserve a [mostly] natural and uncolored
result?

It would be OK on vocals, but I wouldn't mess with the instruments
other than maybe to try it for "mastering" after you've mixed the
song.

I'd agree, but when you need a little something for compression on such
instrument tracks the rnc is a good choice. USed to use it occasionally when
playing 12 string guitar to even myself out just a bit, because my technique
isn't the best.

Regards,
Richard
use elspider at bellsouth dot net to email
.... Amazing how much tape is on a 10" reel when it's not.
--- timEd 1.10.y2k+
* Origin: Radio REscue net operations BBS (1:116/901)
--- Synchronet 3.15a-Win32 NewsLink 1.85
* Derby City Online - Louisville, KY - telnet://derbycitybbs.com

[Jay Ts]

Scott Dorsey wrote:
In article , John Albert
wrote:
Hello all -

On prior recommendations of this group, I added an FMR RNP to my setup
and it works very well.

I'm wondering about adding their RNC compressor, but not sure if it will
be useful for what I'm trying to accomplish.

I record acoustic guitar, mandolin, and banjo, along with vocals. Is
there any benefit to adding a touch of hardware-based compression to
"strictly acoustic music", while trying to preserve a [mostly] natural
and uncolored result?

I have always thought that acoustic music should be offered the greatest
dynamic range possible - although when post-processing, I will adjust
gain upward or downward manually, note-by-note, where necessary.

Would the RNC, operating in their "Supernice mode", be worth
experimenting with?

If you have a computer with some available DAW software, try the
compression function in software. If you like it, and you find it
useful, consider buying the RNC. If you don't, don't bother. The RNC
may do a better job than the software, but it will do a similar thing.
--scott

John:

I was ready to reply to your post saying "GO RIGHT AHEAD"
and use the RNC for acoustic guitar and similar instruments.

Scott: Thanks very much for beating me to following up, and
providing advice that is much more tempered.

I put off getting an RNC for the longest time, because I was
unsure whether it could handle the transients from my electric
guitar, that I've customized heavily, and has a very clear
sound not much different than acoustic. (Don't try to make
sense of that, it won't work. ;-P)

Recently, my old compressor died, and I replaced it with
an RNC, and was amazed. I'd been reading about it for years
here in RAP, but still had no idea of how smoothly it functions.
It handles both my guitar and electric bass easily. (I can almost
hear it thinking, "Ha, piece of cake!") I'm using up to about 8
dB of compression and still liking the sound. (But usually I keep
it in the 4-6 dB range.) Previously, the most I'd gotten from
any compressor I'd tried (dbx 1066 and several audio plugins) was
about 3 dB.

Scott's idea of trying software plugins is a very good one. If
you don't have any compressor plugins yet, go to
http://kvraudio.com and search their plugin database for
free compressor ("dynamics") effects. And if you don't have any
recording software, there are free VST hosting apps there, too.
(You can turn your computer into a very classy digital effects
"pedal" for free, no joke!) And of course, see if you can get
demo versions of the commercial apps (e.g., Waves, http://www.waves.com).

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

And BTW, just so that no one gets the wrong idea, I'm *not* an
advocate of overuse of compression. I'm using 6 dB of compression
for playing live, not recording a track in a mix that will be
further compressed later in production.

And as a side note, it's possible to get amazing sustain from
a guitar using the RNC more aggressively, as an "effect" rather
than for delicate modifification of dynamics.

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Paul Stamler]

"Jay Ts" wrote in message
ng.com...

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

One oddity: it can occasionally get sibilant on vocals. If that happens,
lengthen the release time a bit and it should go away. (I haven't heard this
on other compressors, and don't know why it happens, but...)

Peace,
Paul

[[email protected]]

One thing very useful about adding a RNC to the RNP is that, with a
single cable into the insert, you can fine tune the level better than
the with the RNP alone pretty transparently. One thing (well two)
about the RNP is that in keeping the cost so low, the input gain is
fairly widely stepped, and there is no output control. So used alone
one might find that keeping a safe headroom makes for a lowish output,
because the wide step might put it lower than you'd put it
otherwise. With the RNC chained in you not only can give it the
tiniest lick of clean, barely perceptible compression, but you can
fine tune the output cleanly since its knob isn't stepped. And boost
it quite a bit, if needed.

[Julien BH]

On Apr 9, 9:47 am, wrote:
One thing very useful about adding a RNC to the RNP is that, with a
single cable into the insert, you can fine tune the level better than
the with the RNP alone pretty transparently. One thing (well two)
about the RNP is that in keeping the cost so low, the input gain is
fairly widely stepped, and there is no output control. So used alone
one might find that keeping a safe headroom makes for a lowish output,
because the wide step might put it lower than you'd put it
otherwise. With the RNC chained in you not only can give it the
tiniest lick of clean, barely perceptible compression, but you can
fine tune the output cleanly since its knob isn't stepped. And boost
it quite a bit, if needed.

That's good to know since I was planning on purchasing the RNP.
thanks

[hank alrich]

wrote:

One thing very useful about adding a RNC to the RNP is that, with a
single cable into the insert, you can fine tune the level better than
the with the RNP alone pretty transparently. One thing (well two)
about the RNP is that in keeping the cost so low, the input gain is
fairly widely stepped, and there is no output control.

While in the case of the RNP one might attribute the larger finite gain
steps and lack of output level control to low cost, in the case of pres
like the Millennia HV-3 and the Gordon this is done for different
reasons, since neither of those are truly low cost units.

So used alone
one might find that keeping a safe headroom makes for a lowish output,
because the wide step might put it lower than you'd put it
otherwise.

I've gotten over this. I try to stay far below 0 dBFS nowadays, as in
peaking no higher than -12 or so, and sometimes -20. It took me a long
time to get here and I am finally happy with and relaxed about the
sounds I'm getting in the digital audio realm.

With the RNC chained in you not only can give it the
tiniest lick of clean, barely perceptible compression, but you can
fine tune the output cleanly since its knob isn't stepped. And boost
it quite a bit, if needed.

--
ha
Iraq is Arabic for Vietnam

[hank alrich]

Paul Stamler wrote:

"Jay Ts" wrote in message
ng.com...

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

One oddity: it can occasionally get sibilant on vocals. If that happens,
lengthen the release time a bit and it should go away. (I haven't heard this
on other compressors, and don't know why it happens, but...)

The short release times of the RNC perform to their stated spec, while
many other comps come nowhere near the same level of nearly
instantaneous attack. This is the same thing that can have users
commenting that an RNP isn't working on their bass signals. It's
tracking the actual waveform because the attack is set way too fast.

--
ha
Iraq is Arabic for Vietnam

[Frank Stearns]

"Paul Stamler" writes:

"Jay Ts" wrote in message
ing.com...

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

One oddity: it can occasionally get sibilant on vocals. If that happens,
lengthen the release time a bit and it should go away. (I haven't heard this
on other compressors, and don't know why it happens, but...)

....entering this thread late...

The RNC is an interesting box, and a good value for the money. The control section
is exceptionally good.

It's downfall for us, however -- and the reason that I sold ours after a few months
-- is that the analog path isn't very transparent compared to other segments of our
signal chain. (We do mostly location classical and acoustic music so transparency is
generally preferred.) Even with NO gain reduction, simply having the RNC in the
signal path noticeably "dulled and darkened" what I was hearing.

How much you notice this will depend on the application, and there will be some
tradeoff in using another compressor with a better analog path, but a less-capable
control section.

In many applications, such as pop vocal or a mic'd guitar cabinet, it's not likely
you'll notice this problem -- but you might with a classical singer mic'd at, say,
six feet with a good mic and pre, or a concert harp or piano similarly mic'd -- not
that we routinely compress such sources, though occassionaly very gentle comp is
used to make such spot mics sit better with a main stereo pair.

Given the good control section, I'd like to see the RNC folks perhaps offer a model
with an upgraded analog path (for more $$$ of course).

Frank Stearns
Mobile Audio
--

[hank alrich]

Frank Stearns wrote:

"Paul Stamler" writes:

"Jay Ts" wrote in message
ing.com...

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

One oddity: it can occasionally get sibilant on vocals. If that happens,
lengthen the release time a bit and it should go away. (I haven't heard this
on other compressors, and don't know why it happens, but...)

...entering this thread late...

The RNC is an interesting box, and a good value for the money. The control
section is exceptionally good.

It's downfall for us, however -- and the reason that I sold ours after a
few months -- is that the analog path isn't very transparent compared to
other segments of our signal chain. (We do mostly location classical and
acoustic music so transparency is generally preferred.) Even with NO gain
reduction, simply having the RNC in the signal path noticeably "dulled and
darkened" what I was hearing.

Frank,

Any chance anybody overlooked that the RNC is unbalanced and failed to
take that into consideration while interfacing it with other gear?

Because the RNC is reasonably flat to far beyond what you or I can hear.

This from the specs page:

"Frequency response 10 - 100k Hz ±0.5dB @ 0dBu, no gain reduction"


I don't see how an RNC can dull and darken a signal if it is both
connected properly and operated sensibly.

How much you notice this will depend on the application, and there will be
some tradeoff in using another compressor with a better analog path, but a
less-capable control section.

In many applications, such as pop vocal or a mic'd guitar cabinet, it's
not likely you'll notice this problem -- but you might with a classical
singer mic'd at, say, six feet with a good mic and pre, or a concert harp
or piano similarly mic'd -- not that we routinely compress such sources,
though occassionaly very gentle comp is used to make such spot mics sit
better with a main stereo pair.

Given the good control section, I'd like to see the RNC folks perhaps
offer a model with an upgraded analog path (for more $$$ of course).

With respect, this has not been previously reported and has never
occurred for me while using an RNC on all kinds of signals, including
cello, viola, violin, flute, clarinet, etc., stuff that has little to do
with guitar cabinets or pop vocals.

I don't think the RNC, in and of itself, caused the problem you
perceived, unless there was something wrong with the unit you had.

--
ha
Iraq is Arabic for Vietnam

[Jay Ts]

Frank Stearns wrote:
The RNC is an interesting box, and a good value for the money. The
control section is exceptionally good.

It's downfall for us, however -- and the reason that I sold ours after a
few months -- is that the analog path isn't very transparent compared to
other segments of our signal chain. (We do mostly location classical and
acoustic music so transparency is generally preferred.) Even with NO
gain reduction, simply having the RNC in the signal path noticeably
"dulled and darkened" what I was hearing.

Hi Frank.

This hasn't matched my experience at all, so I looked up your posts
here on the topic from a few years ago. You said that you gave up
on the RNC because it was too dark (distorted) and used a dbx 1066
instead.

I used to own a 1066, and I definitely found *that* to have a very
noticeably darkish sound, that just happened to sound good with my
guitar. When I got my RNC, the most obvious, and immediately noticeable
difference to me was that it is so clear and clean by comparison!
(In fact, I sometimes wish I had a button to press to get the low-fi
1066 sound, to use as an effect.)

We have very different applications - I don't record classical
or acoustic - but after reading your posts, I have to concur with
others who told you that you may have gotten a bad RNC.

I was curious to see the innards of my RNC to see if I could discern
anything about its design. It uses a THAT2181 trimmable VCA, that has
a very similar design to the dbx VCAs. THAT Corp. says that the
2181 is a "successor" to the dbx VCAs, and has been designed for
lower distortion, at high frequencies anyway:

http://thatcorp.com/2181-series_Trim...er_IC_Voltage-
Controlled_Amplifiers.html

In order to reach minimum distortion, it needs a trimmer potentiometer
to be properly adjusted. I have no idea if improper adjustment would
result in distortion that would be audible, but maybe you got a unit
that escaped the trimming procedure somehow. (?) That's about all I
can think of that would explain it, aside from a bad 2181 chip. Of
course, I still could be missing something ... maybe a lot.

Oh, and there other possibilities that would explain our opposite
impressions of the 1066 vs. RNC. I might have gotten a bad 1066,
or maybe our ears just work differently!

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Frank Stearns]

(hank alrich) writes:

Frank Stearns wrote:

"Paul Stamler" writes:

"Jay Ts" wrote in message
ing.com...

If you like what any of the plugins do, then I'd encourage you
to get an RNC. It's so simple and easy to use, it's almost "unreal",
and works so much better, even better than the Waves compressors
I tried out - just press the "Super Nice" button and play with
the knobs. Don't get too crazy with it, and I think you'll be fine.

One oddity: it can occasionally get sibilant on vocals. If that happens,
lengthen the release time a bit and it should go away. (I haven't heard this
on other compressors, and don't know why it happens, but...)

...entering this thread late...

The RNC is an interesting box, and a good value for the money. The control
section is exceptionally good.

It's downfall for us, however -- and the reason that I sold ours after a
few months -- is that the analog path isn't very transparent compared to
other segments of our signal chain. (We do mostly location classical and
acoustic music so transparency is generally preferred.) Even with NO gain
reduction, simply having the RNC in the signal path noticeably "dulled and
darkened" what I was hearing.

Hi Hank -

Any chance anybody overlooked that the RNC is unbalanced and failed to
take that into consideration while interfacing it with other gear?

Nope. The insert points were the typical TRS I/O unbalanced -- just what the RNC
was designed for, best I can tell.

Because the RNC is reasonably flat to far beyond what you or I can hear.

This from the specs page:

"Frequency response 10 - 100k Hz ±0.5dB @ 0dBu, no gain reduction"

Well, when I first got my old beat-up stock Soundcraft, it measured about the same
from 100 hz out to about 200K (LF was lacking due to old caps). The console didn't
start sounding open/transparent/sweet until after it got recapped, had some caps
removed from the signal path, had ICs upgraded, had a new PS with better grounding
and wiring, etc, etc.

Does freq response really tell the whole story? While basic and important, this spec
alone doesn't tell the whole story. Phase response, group delay, distortion (all
flavors), et al, also contribute a great deal to the sonics.

I don't see how an RNC can dull and darken a signal if it is both
connected properly and operated sensibly.

As I said, this was noticed with NO gain reduction, unbalanced I/O at probably -2 on
the signal peaks. The RNC also benefitted from BRAND NEW Nuetrik TRS connectors
installed at the insert points in the console.

Given the good control section, I'd like to see the RNC folks perhaps
offer a model with an upgraded analog path (for more $$$ of course).

With respect, this has not been previously reported and has never
occurred for me while using an RNC on all kinds of signals, including
cello, viola, violin, flute, clarinet, etc., stuff that has little to do
with guitar cabinets or pop vocals.

I don't think the RNC, in and of itself, caused the problem you
perceived, unless there was something wrong with the unit you had.

That's possible; but I don't think so. I need to point out that this wasn't a horrid
loss of fidelity, it was simply a noticeable loss, compared to this system on the
whole.

Now, and at the time, I still feel the RNC is a good value. And I was pleased to
have recouped nearly all that I paid for it. However, it imparted a sonic loss that
I was not quite willing to let pass. And rather than simply never use it, I elected
to sell it.

Both a blessing and sometimes a curse of our plant is the rather startlingly
revealing monitor chain (including the room). I mean, you can hear subtle stuff here
that you'd probably not hear in most other settings.

So perhaps it seems silly to chase such subtleties and minute degradations, but I
chase them because I still believe that at the very end of the chain -- when all the
little blemishes and losses are accumulated -- there is a difference that the
average person will hear on their system. Given that to a lesser or greater degree
loss accumulations are inevitable, I try to remove each one as I find it (and as is
practical to do so). I avoid adding them unnecessarily.

Given what we do, the RNC didn't quite pass the test. Software-based compression
(Digi and Soundforge), properly set up, have been doing the job, and actually much
better than I'd expected. And I didn't have to spend big bucks for higher-end analog
comp/limiters. (It does seem that the digital domain excels with dynamics
processing, even if other areas in digital-land are sometimes lacking.)

Frank Stearns
Mobile Audio

--

[Frank Stearns]

Jay Ts writes:

Frank Stearns wrote:
The RNC is an interesting box, and a good value for the money. The
control section is exceptionally good.

It's downfall for us, however -- and the reason that I sold ours after a
few months -- is that the analog path isn't very transparent compared to
other segments of our signal chain. (We do mostly location classical and
acoustic music so transparency is generally preferred.) Even with NO
gain reduction, simply having the RNC in the signal path noticeably
"dulled and darkened" what I was hearing.

Hi Frank.

This hasn't matched my experience at all, so I looked up your posts
here on the topic from a few years ago. You said that you gave up
on the RNC because it was too dark (distorted) and used a dbx 1066
instead.

Something along those lines, though we've not used the 1066 in that application for
a quite a while now.

I used to own a 1066, and I definitely found *that* to have a very
noticeably darkish sound, that just happened to sound good with my
guitar. When I got my RNC, the most obvious, and immediately noticeable
difference to me was that it is so clear and clean by comparison!
(In fact, I sometimes wish I had a button to press to get the low-fi
1066 sound, to use as an effect.)

Interestingly, the non-GR "pass-through" on our 1066 was pretty good (better than
the RNC), but it did *definitely* start getting crunchy during GR. You can finess
around this somewhat by not getting overly aggressive with it.

The RNC did not get crunchy during GR, but it did retain that "darkness" I've
mentioned.

BOTH problems (here at least, for our applications) were solved by using dynamics in
the digital domain.

We have very different applications - I don't record classical
or acoustic - but after reading your posts, I have to concur with
others who told you that you may have gotten a bad RNC.

I was curious to see the innards of my RNC to see if I could discern
anything about its design. It uses a THAT2181 trimmable VCA, that has
a very similar design to the dbx VCAs. THAT Corp. says that the
2181 is a "successor" to the dbx VCAs, and has been designed for
lower distortion, at high frequencies anyway:

http://thatcorp.com/2181-series_Trim...er_IC_Voltage-
Controlled_Amplifiers.html

In order to reach minimum distortion, it needs a trimmer potentiometer
to be properly adjusted. I have no idea if improper adjustment would
result in distortion that would be audible, but maybe you got a unit
that escaped the trimming procedure somehow. (?) That's about all I
can think of that would explain it, aside from a bad 2181 chip. Of
course, I still could be missing something ... maybe a lot.

Oh, and there other possibilities that would explain our opposite
impressions of the 1066 vs. RNC. I might have gotten a bad 1066,
or maybe our ears just work differently!

Always possible: one man's distortion is another man's premium effect! (and vice
versa) g

I never opened the box, but I'm guessing that other aspects of the RNC account for
what I heard (assuming it was properly adjusted -- all bets are off if it had, as
you note, missed the VCA adjustment). The thing was designed to a phenominal price
point, and I don't expect it to match spendier offerings -- parts budget simply
isn't there). As noted, I was happily surprised by the control section.

In general, I've had reasonable successes taking good designs that have not been
fully realized due to parts budget limitations, and making them "come alive" by
doing pretty basic things (better ICs, caps, ground), things that while not terribly
expensive would kill a budget of many mass products. Just moving from 10 cent i/o
interface ICs to better sounding $2 ones is a deal breaker for most of the lower
price-point products. (And you can go crazy and get $6+ parts if you want.
Diminishing returns at that point, IME, and really out of sight for a mass builder.)

I didn't get into modifying this unit; figured it was SMD and possibly somewhat
fragile (from a rework point of view). About the same time, I'd gotten much better
at setting digital comps to do what I wanted, so this became less of an issue.

But perhaps you've cleared the issue: make sure the VCA is properly trimmed! Does
RNC offer a test/adjustment procedure?

Thanks,

Frank Stearns
Mobile Audio
--

[Geoff]

Frank Stearns wrote:

As I said, this was noticed with NO gain reduction, unbalanced I/O at
probably -2 on the signal peaks. The RNC also benefitted from BRAND
NEW Nuetrik TRS connectors installed at the insert points in the
console.

Starting to sound more and more like psychological effects by now....

geoff

[Jay Ts]

geoff wrote:

Frank Stearns wrote:

As I said, this was noticed with NO gain reduction, unbalanced I/O at
probably -2 on the signal peaks. The RNC also benefitted from BRAND NEW
Nuetrik TRS connectors installed at the insert points in the console.

Starting to sound more and more like psychological effects by now....

I wonder...

One of the things I noticed after opening mine up is that
the 1/4" jacks are not Neutrik. At first glance, they look
just like them, but I had to look up close to see that they
are look-alikes. According to my notes, they are made by
Cliffuk, and I think they are the T3 model.

And then it dawned on me that it might have explained why
I was having trouble with one of them. The plug wouldn't go
in without using a lot more force than with the others.
Not quite up to Neutrik standards.

Beyond that, I also wouldn't think the cheaper connectors
would influence the audio quality. And I don't
want to discuss this particular matter much more! ;-) ;-)

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Jay Ts]

First I want to say that when I opened my RNC the first time,
I was thinking that maybe some folks here might like a photo
of the innards along with some comments from me on the design.

I don't know if I'll have time and/or interest to do all that,
but I do plan to open it up again and take another look sometime
to check a couple of things I missed the first time. It's easy
to do, and I've already voided the warranty, I assume.

So if anyone would find that interesting, drop me a note (use
the link below my name) and say so. I'd just like to know if
there is interest, and if so, how much.

Frank Stearns wrote:
I never opened the box, but I'm guessing that other aspects of the RNC
account for what I heard (assuming it was properly adjusted -- all bets
are off if it had, as you note, missed the VCA adjustment).

I looked around some more at the THAT Inc. website, and read
some of the data sheet and application notes for the VCA.
There's some interesting information in there, and it looks
like if the trim hadn't been set, the distortion could end up
pretty high by audiophile standards. But, they say even if you
don't trim at all, THD will still be less than 1%. That's in
the region where trained ("golden") ears can hear it, and it
might be why you ran into problems on classical and acoustic
sources. There are other things that could cause high distortion,
but those would not appear in a good design, and they seem to
be falling over themselves helping the designers get good results.

The thing
was designed to a phenominal price point, and I don't expect it to match
spendier offerings -- parts budget simply isn't there). As noted, I was
happily surprised by the control section.

Many RNC afficinados have pointed out that it's not a match for
the really classy and expensive compressors. It's strength as
a product is that it delivers so much for so little, and that
the quality is more than sufficient to please many demanding
users -- at least for tracking many kinds of sources.

Upon studying the innards, I developed a respect for Mark McQuilken's
design skills:

- It's one thing to design something at a low quality
point to sell at a low price point.

- It's another thing to design at a top quality point
regardless of cost, and pass the costs to the customer.

But,

IMO, Mark has done something much more challenging. He has designed
for a high (but not top end) quality point, while keeping the price
well within reason. It's not easy to get the balance of that just right!
Keeping close watch over the costs while maintaining good quality
is a very complex task. It requires thinking out every part, how
much quality you can miss without it mattering significantly, in
a design with interdependent parts and complex relationships among
them. The main danger is unknowingly letting weak links creep in,
so you have to understand everything fully.

There are a few things about the RNC that I'd like done just a
little better. Like Neutrik connectors, and I'd use something
that I personally like more than TLC072's. But, Mark uses the
OP275's that are recommended by THAT, on the outputs of the VCA,
where it really matters, and the analog signal chain is otherwise simple.
From what I've figured out so far, there's not much to go wrong.

And I actually like TI's TLC op amps a lot, it's just that the
072 isn't my personal favorite.

Here's a really good example of the design: the VCA comes in 3
grades: A, B, and C. the difference is mainly that A has the
lowest distortion spec and highest price, while C is on the other
end. Mark chose C and saved a few dollars. That might sound horrible
to people here, but you have to consider the the distortion
spec (typical): A is 0.0025% and C is .005%. Both are really low!
And almost equally inaudible.

Now for the prices: I just checked at Mouser.com, and the
A-grade part is about $10, while the C-grade part is about
$5 (in single quantity). There are two 2181s in the circuit.

If you really think you need the A part, I suppose you
can buy a couple and test your soldering skills. Not me!!!

I wonder about using the A/D converters onboard
the microcontroller to sample the signal for the control
circuit, but IIRC, Mark said once (either in RAP or in an
email to me) that because the control is all digital, that
part of the signal chain either doesn't matter so much or can easily
be worked around in software. I can't be critical of this, since I don't
know enough about how the circuit works to say that doing
that would be a limitation. I do not have a schematic.

One thing I'm really unsure about is the capacitors. I didn't
see any Vishay/Sprague or Panasonic polypropylene caps. Mark
might have used a DC-coupled signal chain (not easy). And I
hope he didn't use SMD caps in the signal chain. I wasn't thinking
of this when I had the case open, and that's one of the things
I want to look at more closely. (With no schematic and a
multi-layer PCB, I might not get far.)

I was really interested in other things, like what microcontroller
he chose, and also which VCA. And how he spec'd the inputs and
outputs at ~22.5 dBu when the power supply is a 9VAC wallwart.
(There are +/- 15 VDC regulated supplies for analog, and a +5
VDC regulated supply for the digital section.)

The whole thing uses far too few parts to look like it works,
and IMO is a very clever design. While studying it, I kept mentally
adding up parts costs and realizing how he was able to keep the
final price under $200 while still using components of good quality.

All that, and the guy does microcontroller programming too.
Is that real? Must have had help.

In general, I've had reasonable successes taking good designs that have
not been fully realized due to parts budget limitations, and making them
"come alive" by doing pretty basic things (better ICs, caps, ground),
things that while not terribly expensive would kill a budget of many
mass products.

Same here. I like unsoldering op-amps and inserting sockets and
better op amps. Honestly, I've never noticed much difference.
I probably should go for the coupling caps first!

I didn't get into modifying this unit; figured it was SMD and possibly
somewhat fragile (from a rework point of view).

Correct regarding SMD. As I indicated above, I wouldn't touch it.

But perhaps you've cleared the issue: make sure the VCA is properly
trimmed! Does RNC offer a test/adjustment procedure?

You'd have to ask. I assume they offer repairs. Mark McQ seems very
fair, and if it's obvious it's his/their fault, maybe he would extend
the warranty. Can't speak for him, though.

If you want, you can look over the design info at the That, Inc.
website (I already provided the URL), and do it yourself. I haven't
read that yet, so I don't know what equipment is involved, or
the difficulty. Seems like it can't be too complicated, because
the idea is that every one gets trimmed on the assembly line.

If you have a signal generator and THD analyzer, hey, just run
a signal through it and turn the screws until the THD is minimized.
Simple, right? :-) Feel lucky?

I was **lightly** considering that as a way to intentionally get
some dbx-style "color" into the sound. (But I'm scared to;
I might not be able to get the original back, which would
really suck.)

If I were the manufacturer, I'd really want that "dark sound"
unit back to give it a full checkout, because it might be
a manufacturing defect, that could also be symptomatic of
a production problem that needs attention.

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Scott Dorsey]

Jay Ts wrote:

Beyond that, I also wouldn't think the cheaper connectors
would influence the audio quality. And I don't
want to discuss this particular matter much more! ;-) ;-)

They could, if they have a layer of corrosion on them and aren't making
good solid contact. There's a BSTJ journal from the thirties about
parasitic copper-oxide rectifiers being generated by corroded 1/4" phone
plugs, even. Modern plating makes this less of an issue, but contact
plating can wear down and expose the phosphor-bronze underneath.

It's interesting... you can get a couple percent harmonic distortion added
because of the nonlinearity of the junction. Wiggle the connector and it
goes away....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."