Re: Mic musings

["G." <gigs@xxxxxxxxxxxxxxx>]

<quote>
Date: Mon, 15 Sep 2003 08:41:26 -0400
From: Richard Hunter <turtlehill@xxxxxxxxxxxxx>
Subject: Mic musings

I've recently been trying some mods to my Crate VC-508, and have found that
mic-amp interaction is a bigger deal than I thought.

I swapped the 12AU7 preamp tube out of the Crate and put in a 12AT7.  The preamp
section puts out a much hotter signal.  The sound is great, but it's so hot that
it produces howling feedback with most of my mics.

The exception is my Labtec AM-22 computer mic.  Apparently this mic's output is
way lower than any of the others in my collection.  It also has much lower high
end output.   (Some day soon I'll have record the signal and analyze the
frequencies on this mic.)  This mic plus the 12AT7 preamp tube gives me just
what I want from the amp: a wide range of tones, all with as much or as little
tube distortion as I want.

But if I switch to a different mic, I've got to switch the preamp tube to the
12AU7 as well.  Even my astatic JT-30 puts out more signal than the 12AT7 can
handle.

I wonder if it's a good idea in general to optimize the amp to the mic?

Also note: have recently swapped the stock speaker out for a Weber.  That
speaker rocks.

Thanks, Richard Hunter
http://www.hunterharp.com
</quote>

Hey there,
  Richard is someone I look up to and respect.  I read all his public emails.
Also I have both his albums and listen to them for both inspiration and
enjoyment, and signed up for his monthly MP3 downloads.
http://www.hunterharp.com/freemus.html

On the mic/amp relationship:  I have a collection of mics so that I have
different tonal colours and distortion characteristics and have found that at
this point, combined with Holme's HC, they give me everything I want to hear
from amplified harmonica.   I can't settle on just one mic because it depends on
the mood of the song, the style, the setting and what harmonica setup I'm using.

I do believe you are right Richard.   With amplifiers that aren't designed for
harmonica microphones, I think it is useful to develop the amp towards the mic.
>From what little I've learnt from members of this list over the years, I have
come to realise that the ideal guitar amplifier is the anti-thesis of the ideal
harmonica amplifier.

  I've been lead to believe that tube amps made prior to the electric-guitar
were designed with microphones, voice, and even accordians in mind ... and ideal
for harmonica.  Apparently they could be cranked up to get the ideal natural
tube distortion, just the way we like to hear it - whatever that is.
  I guess thats why theres a harmonica tube amplifier niche market out there -
each product developed with its own set of principals, pros and cons depending
on what the buyer wants from their rig.

Regarding the Crate VC508, I have a difference in opinion about its tone to
Richard.  I know this is a very subjective area and will bow to experience every
time. But I'm going to have my say.
I bought a Crate VC508 for a very good price, it was in very good condition, and
it was an ideal size and weight for what I wanted from a tube amp.
  I had high hopes because its no secret that Richard Hunter has promoted this
model for harmonica.  I snapped it up after a quick blast before someone else
grabbed it.  I was really rooting to find a way to make this amp work for me in
its own right.

  It came with new 12AX7 and EL84 Sovtek tubes.  I read the harp-l archives
which led to a chat with Stephen Schneider.
I tried the JJ brand 12DW7 (100/40 dual factor preamp tube) with an Ei EL84
power tube that Stephen Schnider helped me obtain in an effort to warm up the
sound from the stock Sovtek tubes the Crate came with.

  With the tube swap there was a little more headroom, otherwise very little
change in tone, at least nothing substantial enough for me to recommend the swap
other than out of curiosity.   Whatever the case I found there was only a couple
of settings (least Treble, most Bass, volume high as the mic would allow, "gain"
minimum) that I'd really bother using it with.   It seemed to be a one trick
pony...  fine for jamming at home & small open mics for an enthusiast wanting to
get started with a rig.  Keeping in mind I prefer soft warmth rather than
exciting sparkling tones that bite through the mix.

I tried it with my SM57, SM58 (both through impedance convertor), my favourite
three Green Bullets with CR, CM and MC127 ceramic elements.  With and without my
Dan Echo.   I just couldn't get the warmth and tube distortion I was hoping for.

After a few weeks of giving it the ol' college try I was sadly disappointed with
it.  I had a pro player drop round at some point and out of curiousity he gave
it a blat for half an hour.... no comment.

I was much happier with its tone when I ran the mics through a Harp Commander
into it, but then the tone I was enjoying was that of the Harp Commander and not
the VC508 ... I can get the same results through a PA, my computer, my stereo,
or any solid state amp of comparable wattage which is a lot cheaper.  I was no
further ahead for this purchase.

At the end of the day I personally found the amp has a sharp/harsh quality that
was very hard to overcome which I simply don't enjoy.  I've heard a couple of
theories as to why its this way, but I don't know what the truth is.

  So for me it just didn't do it, I took it to a music store for commision sale.
Pitty.

If I was to spend the money again I'd try the Kalamazoo, or small Fender Type A
all tube amp, like the Super 60 I once had.   As it is it just underlined that I
have what I need, and I don't need an amplifier proper at the moment.  My next
amp purchase will probably be a portable PA.

Best regards,
G.