Yamaha AG Stomp - long report
Gary Hall
box/mic simulator thing for two weeks now and have found that it can
improve the amplified tone or recorded tone of a variety of
guitar/pickup combinations. One caveat is that none of the preset
patches (there are 30 preset patches and 30 user programmable patches)
are likely to produce the best results for any particular
guitar/pickup combination. One needs to be a little handy with tone
controls to make practical use of this thing. In addition to
adjusting the EQ, one needs to choose the type of mic simulation to
use (8 choices) and the amount of mic simulation to mix in with the
direct signal. (You can use up to 100% mic simulation, but 100%
rarely sounded good to my ears.)
In addition to tone controls, the thing has feedback elimination
capabilities, chorus, delay, three types of reverb, a limiter and a
tuner. The tuner is the most tempermental and difficult to use
electronic tuner that I've ever delt with. The effects seem pretty
decent. I haven't yet put the limiter or the feedback elimination to
much use. One can activate the auto feedback eliminator by stepping on
a pedal. (I've tried this, and it does indeed find the howling tone
and notch it down 20 db. That's overkill, perhaps, but probably handy
in the middle of a tune.)
The AG Stomp has four tone controls, all with a range of 12 db cut or
boost and all with a sweepable center frequency. (With the bass
control, for instance, one can adjust the center frequency of the
bandwidth to be boosted or cut from 50 hz to 400 hz.) Unfortunately,
one cannot adjust the size of the bandwidth of frequencies being cut
or boosted - and the manual doesn't specify what the bandwidth is. My
guess is that the bandwidth is pretty wide (two octaves, maybe) and
not very efficient for adding a presence peak or notching out muddy
frequencies in the bass. IMO, a Baggs Para DI will probably be more
useful for those applications.
For my purposes, the mic simulations are the most important feature of
the AG Stomp. One simulation in particular, the condenser
close-miked, worked best for me. It did wonders for the Fishman
Matrix in my Larrivee C-10, the Highlander UST in my Martin D-28, the
EMG UST in my Taylor 514C and the Seymour Duncan MagMic which I
temporarily installed in a Sigma TB1. It also improved the tone of
the Baggs LB6 pickups in three different guitars, a Baggs Hex pickup
in a Tacoma EM9C, a B-Band UST in a Tacoma ER22C and the RMC hex
pickups in a Godin Multiac.
I'd say that the mic simulation helped the RMC and B-Band pickups the
least. IMO, the B-Band UST is the most natural sounding UST to begin
with. It needs the least help. As for the RMC pickup, I really like
it's in-your-face quality for fingerpicking. (It's quack city for
hard strumming.) Too much mic simulation tends to detract from that
intimate, in-your-face quality.
Before closing, I'd like to mention two complicating factors which
come into play when comparing the direct pickup sound to the sound one
gets when adding mic simulation. The optimum EQ settings for the
direct sound and the processed sound can be quite different. I often
found myself cutting the bass and/or adding treble after adding some
mic simulation. I also noted that adding mic simulation usually
increased the preamp's output volume. (I say "usually" because adding
in mic simulation from the "nylon" settings actually decreased the
volume.) I found the change in volume made it more difficult to
compare recordings of the direct tone and the processed tone.
The AG Stomp manual claims that the mic simulations add "airiness" to
the sound. I'd just say that adding a certain amount of mic
simulation produces a rounder, more natural sounding tone. It
doesn't, however, totally eliminate all the piezo quack that comes
with hard strumming. I still find it preferable to record strumming
with a mic. With fingerpicking, on the other hand, one can get a VERY
natural sounding recording using a pickup and the AG Stomp. I suspect
that I'll be using the AG Stomp for recording fingerpicking, as well
as for live sound.
I've only had experience with two pickup/internal mic setups, but I
can say that the pickup/AG Stomp setup beats those setups hands down.
I get better sound without the mic feedback hassle.
I hope the preceeding observations will be helpful to those of you who
are curious about the AG Stomp.
Gary Hall
Gordon Lau
GC and I have to say I was impressed with the AG Stomp. I didn't care
for any of the distant mic simulators but the close mic simulators
really improved the Fishman Matrix on the Taylor 712CE I was using. I
liked the condensor the best. After fiddling with the EQ, adding some
reverb and a hint of chorus, I got a wonderful tone that I would be
very happy to record with. Didn't try the tuner or the limiter. The
EQ didn't seem to me to have a very wide bandwitdth like a shelving EQ
would have. Boosting the EQ on the Fishman OBB had more of a dramatic
effect. If the AG had adjustable Q for the tone controls (fully
parametric) and a built-in compressor, it would have everything I
could possibly ask for in a single unit.
I'm considering getting it but since it's the first of it's kind, I
wonder if other companies will come out with acoustic modeling units.
I might wait to see what develops in the next year.
GL
Frank Hudson
ah...@tusco.net says...
> I still find it preferable to record strumming
> with a mic. With fingerpicking, on the other hand, one can get a VERY
> natural sounding recording using a pickup and the AG Stomp. I suspect
> that I'll be using the AG Stomp for recording fingerpicking, as well
> as for live sound.
I appreciate the report too. I'm curious on a couple of conclusions
which you mention above. Why not just use a mic when recording? In my
home recording stuff I'll occasionally run a little of an internal
pickup to a second channel to mix in for effect, but there are a great
number of inexpensive condenser mics out there and I'd think that when
recording that feedback and freedom of on-stage movement wouldn't be
issues.
-Frank Hudson
remove the "x" when replying
Web page with sound samples and the "So You Want to Buy A Guitar FAQ":
http://www.users.uswest.net/~fhudson/
David Enke
"Gary Hall" <ah...@tusco.net> wrote in message
news:6b270d07.01110...@posting.google.com...
Thanks for the report Gary.
How would you describe what the adding 'mic' to the sound is doing? You
mentioned 'air', but I wonder how this would differ from adding a little
EQ'd reverb. Is there are difference in the attack envelope, or slight
compression or limiting on the front end as well? I'm going to guess that
the effect is done with a DSP chip, and I'm a little curious what the
parameters are that are being effected. Would you say that certain aspects
of the pickup sounds are reduced in addition to what is added?
I guess it would be of interest to know if the result could be achieved by
stringing off the shelf processors together (and what they'd be), or if the
box is doing something completely new.
Sorry if I asked too many questions, but this is a pretty interesting
subject, and definitely 'on-topic'.
David Enke
Pick-up the World
www.pick-uptheworld.com
pic...@rmi.net
800-375-2656
Gary Hall
> I'm considering getting it but since it's the first of it's kind, I
> wonder if other companies will come out with acoustic modeling units.
> I might wait to see what develops in the next year.
Good point, Gordon. I sounds like the only mic simulator that either
of us needs would be the condensor, close-miked. Some company may
well come up with that, for a lot less than the $400 price of the AG
Stomp.
My Korg G2 stomp box already has good effects and a good tuner. All
I'd need is a condensor mic simulator to hook up between the G2 and a
Baggs PADI. (On the other hand, I'm beginning to become very partial
to a particular delay/hall reverb combination that I've come up with
on the AG Stomp. Guess I'll have to learn to live with the tuner.)
I forgot to mention (in the report) that the AG Stomp also helps me
get a great tone out of my Gibson Chet Atkins CE classical-electric
with a Shadow pickup. It's a 1982 model, and the electronics isn't
"cutting edge" - despite the fact that I can take the back plate off
and adjust the relative volume of each individual string. Before
trying it with the Stomp, I'd been unhappy enough with the pickup that
I'd been planning to sell it. (Darn that Stomp! My wife would prefer
that I DID sell a few more guitars.)
Gary Hall
Gary Hall
> I appreciate the report too. I'm curious on a couple of conclusions
> which you mention above. Why not just use a mic when recording? In my
> home recording stuff I'll occasionally run a little of an internal
> pickup to a second channel to mix in for effect, but there are a great
> number of inexpensive condenser mics out there and I'd think that when
> recording that feedback and freedom of on-stage movement wouldn't be
> issues.
Frank,
I'm one of those folks who prefers to record guitar and vocals at the
same time. I started recording thru the pickup (for quiet picking
accompaniments) because I had been getting a significant vocal
bleedover problem when using a guitar mic with the gain turned up high
enough to properly capture a quiet picking part. IMO, I'm getting
much better overall results from using a pickup (or a pickup combined
with a mic) to record quiet picking accompaniments.
I'm also getting better results now from mixing live (reverb,
compression and volume levels all set to taste ahead of time) than I
used to get from mixing together separate tracks after the
performance. I've found that I'd rather record the same song ten
times than drive myself nuts trying to figure out how to fix something
that should have been done right in performance. I also like hearing
what the final results will sound like (in the headphones) while I'm
doing the performance. It helps me get a better feel for it.
Gary Hall
Gary Hall
Gary Hall
>
> Thanks for the report Gary.
> How would you describe what the adding 'mic' to the sound is doing? You
> mentioned 'air', but I wonder how this would differ from adding a little
> EQ'd reverb. Is there are difference in the attack envelope, or slight
> compression or limiting on the front end as well? I'm going to guess that
> the effect is done with a DSP chip, and I'm a little curious what the
> parameters are that are being effected. Would you say that certain aspects
> of the pickup sounds are reduced in addition to what is added?
> I guess it would be of interest to know if the result could be achieved by
> stringing off the shelf processors together (and what they'd be), or if the
> box is doing something completely new.
> Sorry if I asked too many questions, but this is a pretty interesting
> subject, and definitely 'on-topic'.
David,
After receiving your questions, I went back and compared the direct
signal with the 100% mic simulation. There is indeed a difference in
the "attack envelope", as you say. With the mic simulation, you can
hear the volume swell after striking a chord.
I found that 100% mic simulation was way "over-the-top" for my taste.
I was using around 20-30% most of the time, maybe more for the
stringier sounding pickups and less for more natural sounding pickups
like the B-Band UST and the Baggs LB6. (Then again, I tend to like
the in-your-face quality of a UST.)
It also sounds like EQ changes and reverb (especially with the distant
miked settings) are involved in the mic simulations. Beyond that, I
can't even speculate on how they do it. They seem to be doing some
amazing things with the "modeling" techniques that they've developed.
It's my understanding that devices like the Roland VG-88 and the Boss
WP-20G Wave Processor enable the guitarist to play synth-type sounds
without the synth-type tracking delays or the synth-type loss of
dynamic nuance. (That's reason enough to hang onto my Godin Multiac.
The guitar synth was a bit of a let-down, but who knows what they'll
come up with next.)
I wish that I could shed more light on the modeling thing, but I'm as
clueless as most other folks. I just know that the AG Stomp is "for
real" and improves my amplified sound.
By the way, David, I appreciated reading your post about the
difficulties of installing the PUTW #27 in a Taylor 314. Sooner or
later, I plan to put one in my 314CE and run it stereo with the Baggs
LB6 that's in it already. (We pulled out the Fishman pickup and
unhooked the preamp.)
Later,
Gary Hall
Tom Loredo
Hi folks-
Gary and Gordon---thanks a lot for writing up your impressions! I'm
very curious about this box myself. I have Yamaha's DG Stomp (electric
guitar preamp), and they sure did their homework on that one. I like
it a lot.
David Enke wrote:
> I'm going to guess that
> the effect is done with a DSP chip, and I'm a little curious what the
> parameters are that are being effected. Would you say that certain aspects
> of the pickup sounds are reduced in addition to what is added?
> I guess it would be of interest to know if the result could be achieved by
> stringing off the shelf processors together (and what they'd be), or if the
> box is doing something completely new.
I don't know the AG Stomp processor is doing, but one can make an
educated guess. 8-) I mentioned this in another thread---this is an
idea whose time has come and which is being studied by others as well.
In particular, if you'd like to learn the details of one implementation,
some Finnish researchers associated with the B-Band folks give a detailed
description of their first attempts to use DSP to recreate a mic-like
tone from a B-Band UST pickup signal in the Journal of the AES. The
article is "DSP Equalization of Electret Film Pickup for the Acoustic Guitar"
from the December 2000 issue; I'll copy the abstract below. The way
they do it in the article is very instrument-specific. One takes the UST
signal from the guitar and a signal from a good mic positioned where
you want it, and then uses fairly straightforward DSP to reproduce the
main features of the mic signal from the UST signal. It is hard for
me to see how this can successfully be made "generic" as it must be
in the AG Stomp. But that's why the Yamaha engineers are working at
Yamaha, and I'm studying stars! 8-)
I don't see how one could accomplish this kind of thing with
off the shelf processors. A much more generic filtering capability
would be needed than is implemented in any processors I'm aware of.
Peace,
Tom Loredo
~~~~~~~~
DSP Equalization of Electret Film Pickup for the Acoustic Guitar
Matti Karjalainen, Vesa Valimaki, Henri Penttinen, and Harri Saastamoinen
The sound quality of a guitar's bridge electret film pickup does not
match that of the instrument's acoustic sound. To enhance the
instrument's pickup sound and to simulate its acoustic attributes,
the authors have applied digital signal processing to recreate
its acoustic sound characteristics. If the equalizer uses a
programmable digital signal processor, additional features such as
various sound effects or a reverberation function can be added easily.
Adrian Legg
(in message <3BE6F29D...@astro.cornell.edu>):
>
>[...]I have Yamaha's DG Stomp (electric
> guitar preamp), and they sure did their homework on that one. I like
> it a lot.
Tom, I wondered if you notice any bandwidth loss going though that ?
Tom Loredo
Hi Adrian-
On the contrary, it seems to me to have too much high end. I tend to
have to keep the presence control quite low. Even so, there is something
a little fishy (unnatural) going on in the high end that I might again
characterize as there being too much energy up there, though it's more
complicated than that. I hear the same kind of thing in other modelers---
something not quite as smooth sounding in the tone at the high end compared
to a real electric guitar amp. This is for overdriven sounds, by the way.
Clean sounds are quite clear to my ears.
I hasten to add that I am not a purist when it comes to electric guitar
tones, largely out of necessity. I've spent my whole adult life in
apartments where playing loudly through an amp was simply not an option.
So my ear doesn't have a ton of "training" in that regard. The modelers
are a really great step forward for folks in this kind of position!
Given the basic specs of the DG Stomp (20 bit A/D/A, 48 kHz sampling
rate), any bandwidth problems would have to be due to properties of
the algorithms rather than the hardware, I would think.
Peace,
Tom Loredo
Marc Benigni
company you keep.
Key question regarding the AG-Stomp: has anyone heard whether Yamaha
has any intention of releasing a rack-mountable version? I'm looking
for something to complement a POD Pro in a portable (rack bag)
solution I use with dual-out mag/piezo guitars.
If not, any good ideas for an acoustic preamp, 1U rack mountable, with
compression/ limiting, EQ & notch, reverb?
I'm new here, so let me also thank you for any help in advance...
-Marc
robohop
> Great info here. And was that *the* Adrian Legg? Intimidating
> company you keep.
Adrian's only intimidating if he opens for you .....
best,
rob anderson
Wayne
Thanks, Wayne
"robohop" <rj...@ix.netcom.com> wrote in message
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