Impedence matching problem

[Bill Graham]

I am new to this group, so I apologize for asking a question than may have
been asked and answered many times before. I am a trumpet player, and I
would like to mike my horn and add a chorus effect to the output of the
mike, which I will then send to my 45 watt Beherenger keyboard amp and
speaker unit. I am using an Audio Technica PRO 35 R condenser mike which has
a low impedance output, since it requires a phantom power unit, and when I
put this signal into any of several chorus units, the result is very
distorted, since all these units are made for electric guitars, and they all
have high impedance inputs, as far as I know. What I would like to know is,
does anyone know of a chorus unit that can accept a low impedance input so
it can be driven by a condenser mike without distorting? Or, if not, how can
I change the mike output to a high impedance so it won't seriously overdrive
the chorus effect unit? I love the chorus effect, and it seems to me that
there must be some equipment combination that the pros use so they can sing
into, or play their acoustic instruments into a chorus effect unit without
getting a lot of distortion. Vocalists must use this effect too, and they
would have to drive those units with microphones also.
I am Bill Graham, from Salem, Oregon.

[Jay Ts[_2_]]

Bill Graham wrote:
> I am new to this group, so I apologize for asking a question than may
> have been asked and answered many times before. I am a trumpet player,
> and I would like to mike my horn and add a chorus effect to the output
> of the mike, which I will then send to my 45 watt Beherenger keyboard
> amp and speaker unit. I am using an Audio Technica PRO 35 R condenser
> mike which has a low impedance output, since it requires a phantom power
> unit, and when I put this signal into any of several chorus units, the
> result is very distorted, since all these units are made for electric
> guitars, and they all have high impedance inputs, as far as I know. What
> I would like to know is, does anyone know of a chorus unit that can
> accept a low impedance input so it can be driven by a condenser mike
> without distorting? Or, if not, how can I change the mike output to a
> high impedance so it won't seriously overdrive the chorus effect unit? I
> love the chorus effect, and it seems to me that there must be some
> equipment combination that the pros use so they can sing into, or play
> their acoustic instruments into a chorus effect unit without getting a
> lot of distortion. Vocalists must use this effect too, and they would
> have to drive those units with microphones also. I am Bill Graham, from
> Salem, Oregon.

Looks like you are a little confused. :) If I understand your situation,
it's not the impedance that is causing you problems; it is other things.

The mic needs to be plugged into a microphone preamp, which will supply
the phantom power. The easiest way for you is to use a mic preamp that
has an unbalanced, 1/4" phone jack at the output. Then you can use
guitar/instrument cable (1/4" phone plug connectors) to connect to your
chorus unit.

To avoid distortion, you need to make sure that the level out of
the mic preamp is not overdriving the chorus unit. That's all.
On most mic preamps, there is a knob you can turn to adjust that. ;-) ;-)

Jay Ts

[[email protected]]

On Sun, 22 Aug 2010 16:16:15 -0700, "Bill Graham" > wrote:

>I am new to this group, so I apologize for asking a question than may have
>been asked and answered many times before. I am a trumpet player, and I
>would like to mike my horn and add a chorus effect to the output of the
>mike, which I will then send to my 45 watt Beherenger keyboard amp and
>speaker unit. I am using an Audio Technica PRO 35 R condenser mike which has
>a low impedance output, since it requires a phantom power unit, and when I
>put this signal into any of several chorus units, the result is very
>distorted, since all these units are made for electric guitars, and they all
>have high impedance inputs, as far as I know. What I would like to know is,
>does anyone know of a chorus unit that can accept a low impedance input so
>it can be driven by a condenser mike without distorting? Or, if not, how can
>I change the mike output to a high impedance so it won't seriously overdrive
>the chorus effect unit? I love the chorus effect, and it seems to me that
>there must be some equipment combination that the pros use so they can sing
>into, or play their acoustic instruments into a chorus effect unit without
>getting a lot of distortion. Vocalists must use this effect too, and they
>would have to drive those units with microphones also.
>I am Bill Graham, from Salem, Oregon.

I think your main problem is that the mic output is too high, not it's
impedance. You need to cut down the level of the mic to match a guitars output.
Your best bet is to use some kind of mixer in between, or find a friendly tech
to make you a converter box!

I used to have level reducing jack/plug assemblies but don't know where to buy
them, perhaps you could search for level attenuators or matching boxs.

[alex]

On 23/08/2010 01:16, Bill Graham wrote:
> I am new to this group, so I apologize for asking a question than may have
> been asked and answered many times before. I am a trumpet player, and I
> would like to mike my horn and add a chorus effect to the output of the
> mike, which I will then send to my 45 watt Beherenger keyboard amp and
> speaker unit. I am using an Audio Technica PRO 35 R condenser mike which
> has
> a low impedance output, since it requires a phantom power unit, and when I
> put this signal into any of several chorus units, the result is very
> distorted, since all these units are made for electric guitars, and they
> all
> have high impedance inputs, as far as I know. What I would like to know is,
> does anyone know of a chorus unit that can accept a low impedance input so
> it can be driven by a condenser mike without distorting? Or, if not, how
> can
> I change the mike output to a high impedance so it won't seriously
> overdrive
> the chorus effect unit? I love the chorus effect, and it seems to me that
> there must be some equipment combination that the pros use so they can sing
> into, or play their acoustic instruments into a chorus effect unit without
> getting a lot of distortion. Vocalists must use this effect too, and they
> would have to drive those units with microphones also.
> I am Bill Graham, from Salem, Oregon.
>
A microphone always need a mic preamp.
the usual path is:
mic -> mic preamp -> external effects unit -> output. In this case you
can "balance" between dry and wet via the "mix" parameter on the fx unit.
If you have a mixing board you can connect the mic to a board mic input
channel, and drive the fx unit via auxilary send, then mix its output
with the help of one (or two) addictional line input channels on the
mixer. This give you much more control over the equalization, panorama
placement and even feedback.

alex

[Scott Dorsey]

> wrote:
>
>I used to have level reducing jack/plug assemblies but don't know where to buy
>them, perhaps you could search for level attenuators or matching boxs.

Shure makes nice balanced ones, part A15AS. Everybody should have a handful
of them in a drawer somewhere.

The thing is.... the mike output level is very low.... it's lower than typical
"instrument level." So the odds are that a high level into the pedal is not
the problem. It could be, and an attenuator would tell you for sure, but more
likely it's the output of the pedal that is too hot.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Bill Graham]

"Jay Ts" > wrote in message
.com...
> Bill Graham wrote:
>> I am new to this group, so I apologize for asking a question than may
>> have been asked and answered many times before. I am a trumpet player,
>> and I would like to mike my horn and add a chorus effect to the output
>> of the mike, which I will then send to my 45 watt Beherenger keyboard
>> amp and speaker unit. I am using an Audio Technica PRO 35 R condenser
>> mike which has a low impedance output, since it requires a phantom power
>> unit, and when I put this signal into any of several chorus units, the
>> result is very distorted, since all these units are made for electric
>> guitars, and they all have high impedance inputs, as far as I know. What
>> I would like to know is, does anyone know of a chorus unit that can
>> accept a low impedance input so it can be driven by a condenser mike
>> without distorting? Or, if not, how can I change the mike output to a
>> high impedance so it won't seriously overdrive the chorus effect unit? I
>> love the chorus effect, and it seems to me that there must be some
>> equipment combination that the pros use so they can sing into, or play
>> their acoustic instruments into a chorus effect unit without getting a
>> lot of distortion. Vocalists must use this effect too, and they would
>> have to drive those units with microphones also. I am Bill Graham, from
>> Salem, Oregon.
>
> Looks like you are a little confused. :) If I understand your situation,
> it's not the impedance that is causing you problems; it is other things.
>
> The mic needs to be plugged into a microphone preamp, which will supply
> the phantom power. The easiest way for you is to use a mic preamp that
> has an unbalanced, 1/4" phone jack at the output. Then you can use
> guitar/instrument cable (1/4" phone plug connectors) to connect to your
> chorus unit.
>
> To avoid distortion, you need to make sure that the level out of
> the mic preamp is not overdriving the chorus unit. That's all.
> On most mic preamps, there is a knob you can turn to adjust that. ;-) ;-)
>
> Jay Ts

Thanks, Jay. I am using a mike preamp. (I have to, because it has to supply
phantom power), but I can't drive the chorus unit directly, because when I
do, the sound is badly distorted. This is, (I think) because the mike
preamps have low impedance outputs and all these chorus pedals are made for
guitars, and take high impedance inputs. I can screw around with
potentiometers to reduce the drive power of the preamp output, but I was
hoping that someone would know of a chorus unit that was made for singers
that would accept a low impedance input. I already have a rack unit that
works OK, but it is too big to be convenient at gigs.......I am looking for
a pedal that will do the job, or one whose input I can modify to get it to
work OK.

[Bill Graham]

> wrote in message
...
> On Sun, 22 Aug 2010 16:16:15 -0700, "Bill Graham" >
> wrote:
>
>>I am new to this group, so I apologize for asking a question than may have
>>been asked and answered many times before. I am a trumpet player, and I
>>would like to mike my horn and add a chorus effect to the output of the
>>mike, which I will then send to my 45 watt Beherenger keyboard amp and
>>speaker unit. I am using an Audio Technica PRO 35 R condenser mike which
>>has
>>a low impedance output, since it requires a phantom power unit, and when I
>>put this signal into any of several chorus units, the result is very
>>distorted, since all these units are made for electric guitars, and they
>>all
>>have high impedance inputs, as far as I know. What I would like to know
>>is,
>>does anyone know of a chorus unit that can accept a low impedance input so
>>it can be driven by a condenser mike without distorting? Or, if not, how
>>can
>>I change the mike output to a high impedance so it won't seriously
>>overdrive
>>the chorus effect unit? I love the chorus effect, and it seems to me that
>>there must be some equipment combination that the pros use so they can
>>sing
>>into, or play their acoustic instruments into a chorus effect unit without
>>getting a lot of distortion. Vocalists must use this effect too, and they
>>would have to drive those units with microphones also.
>>I am Bill Graham, from Salem, Oregon.
>
> I think your main problem is that the mic output is too high, not it's
> impedance. You need to cut down the level of the mic to match a guitars
> output.
> Your best bet is to use some kind of mixer in between, or find a friendly
> tech
> to make you a converter box!
>
> I used to have level reducing jack/plug assemblies but don't know where to
> buy
> them, perhaps you could search for level attenuators or matching boxs.
>

Yes.....Your's is the second suggestion to try this....I do have a
potentiometer box I built several years ago.....I think it has 20 K pots in
it and the input goes across the whole pot, while the output goes from the
slider to ground, so I can adjust the output from full volume to zero or
ground. I was hoping that I could find a chorus pedal that already
incorporates such a thing, but if I can't, I will probably end up using my
own kludge....:^)

[Bill Graham]

"Soundhaspriority" > wrote in message
...
>
> > wrote in message
> ...
>> On Sun, 22 Aug 2010 16:16:15 -0700, "Bill Graham" >
>> wrote:
>>
>>>I am new to this group, so I apologize for asking a question than may
>>>have
>>>been asked and answered many times before. I am a trumpet player, and I
>>>would like to mike my horn and add a chorus effect to the output of the
>>>mike, which I will then send to my 45 watt Beherenger keyboard amp and
>>>speaker unit. I am using an Audio Technica PRO 35 R condenser mike which
>>>has
>>>a low impedance output, since it requires a phantom power unit, and when
>>>I
>>>put this signal into any of several chorus units, the result is very
>>>distorted, since all these units are made for electric guitars, and they
>>>all
>>>have high impedance inputs, as far as I know. What I would like to know
>>>is,
>>>does anyone know of a chorus unit that can accept a low impedance input
>>>so
>>>it can be driven by a condenser mike without distorting? Or, if not, how
>>>can
>>>I change the mike output to a high impedance so it won't seriously
>>>overdrive
>>>the chorus effect unit? I love the chorus effect, and it seems to me that
>>>there must be some equipment combination that the pros use so they can
>>>sing
>>>into, or play their acoustic instruments into a chorus effect unit
>>>without
>>>getting a lot of distortion. Vocalists must use this effect too, and they
>>>would have to drive those units with microphones also.
>>>I am Bill Graham, from Salem, Oregon.
>>
>> I think your main problem is that the mic output is too high, not it's
>> impedance. You need to cut down the level of the mic to match a guitars
>> output.
>> Your best bet is to use some kind of mixer in between, or find a friendly
>> tech
>> to make you a converter box!
>>
>> I used to have level reducing jack/plug assemblies but don't know where
>> to buy
>> them, perhaps you could search for level attenuators or matching boxs.
>>
> See
> http://www.bhphotovideo.com/c/search?Ntt=mike+attenuator&N=0&InitialSearch=yes
>
> Bob Morein
> (310) 237-6511
>

Thanks.....That attenuator box looks pretty good.....I have to use a phantom
power unit anyway, so it won't add too much junk to what I already have to
carry.......

[Bill Graham]

"alex" > wrote in message
...
> On 23/08/2010 01:16, Bill Graham wrote:
>> I am new to this group, so I apologize for asking a question than may
>> have
>> been asked and answered many times before. I am a trumpet player, and I
>> would like to mike my horn and add a chorus effect to the output of the
>> mike, which I will then send to my 45 watt Beherenger keyboard amp and
>> speaker unit. I am using an Audio Technica PRO 35 R condenser mike which
>> has
>> a low impedance output, since it requires a phantom power unit, and when
>> I
>> put this signal into any of several chorus units, the result is very
>> distorted, since all these units are made for electric guitars, and they
>> all
>> have high impedance inputs, as far as I know. What I would like to know
>> is,
>> does anyone know of a chorus unit that can accept a low impedance input
>> so
>> it can be driven by a condenser mike without distorting? Or, if not, how
>> can
>> I change the mike output to a high impedance so it won't seriously
>> overdrive
>> the chorus effect unit? I love the chorus effect, and it seems to me that
>> there must be some equipment combination that the pros use so they can
>> sing
>> into, or play their acoustic instruments into a chorus effect unit
>> without
>> getting a lot of distortion. Vocalists must use this effect too, and they
>> would have to drive those units with microphones also.
>> I am Bill Graham, from Salem, Oregon.
>>
> A microphone always need a mic preamp.
> the usual path is:
> mic -> mic preamp -> external effects unit -> output. In this case you can
> "balance" between dry and wet via the "mix" parameter on the fx unit.
> If you have a mixing board you can connect the mic to a board mic input
> channel, and drive the fx unit via auxilary send, then mix its output with
> the help of one (or two) addictional line input channels on the mixer.
> This give you much more control over the equalization, panorama placement
> and even feedback.
>
> alex
>

Thanks, Alex.....I am not using a mixing board, but I may have to do so if I
can't get decent results any other way. I am limited in how much stuff I can
carry into my gigs, so I am trying to get away with as light a load as
possible. These chorus units run all the way from $15 to $1500, so you'd
think someone would make one that takes an input from a condenser microphone
preamp box.....But the whole world seems to be built for guitar
players.....If it doesn't come from a guitar, then good luck working with
it!

[Bill Graham]

"Scott Dorsey" > wrote in message
...
> > wrote:
>>
>>I used to have level reducing jack/plug assemblies but don't know where to
>>buy
>>them, perhaps you could search for level attenuators or matching boxs.
>
> Shure makes nice balanced ones, part A15AS. Everybody should have a
> handful
> of them in a drawer somewhere.
>
> The thing is.... the mike output level is very low.... it's lower than
> typical
> "instrument level." So the odds are that a high level into the pedal is
> not
> the problem. It could be, and an attenuator would tell you for sure, but
> more
> likely it's the output of the pedal that is too hot.
> --scott

Well, I am using a Behringer 45 watt keyboard amp, and it has several
inputs. I can drive the "CD" input, which is line level.....Also, my
attenuator box is for stereo, so it has two inputs and two outputs which are
separated. So, I could attenuate both the input and the output of the chorus
pedal with it.....I will have to try screwing around some more, now that I
have some good input from you guys as to what the trouble probably is......

[Scott Dorsey]

Bill Graham > wrote:
>
>Thanks, Jay. I am using a mike preamp. (I have to, because it has to supply
>phantom power), but I can't drive the chorus unit directly, because when I
>do, the sound is badly distorted.

WAIT! STOP!

You didn't mention that before.... we all assumed you were using a phantom
supply. So now you have a preamp with a line level output going into a
pedal that expects an instrument level output.

>This is, (I think) because the mike
>preamps have low impedance outputs and all these chorus pedals are made for
>guitars, and take high impedance inputs.

It's not the impedance it's the operating level.

>I can screw around with
>potentiometers to reduce the drive power of the preamp output, but I was
>hoping that someone would know of a chorus unit that was made for singers
>that would accept a low impedance input. I already have a rack unit that
>works OK, but it is too big to be convenient at gigs.......I am looking for
>a pedal that will do the job, or one whose input I can modify to get it to
>work OK.

I don't know of any "vocalist pedals." There are lots of fine rackmount
effects units that can do a chorus. I suppose you might look into the
old Alesis Wedge or Nanoverb, which are physically very small.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bill Graham > wrote:
>
>Well, I am using a Behringer 45 watt keyboard amp, and it has several
>inputs. I can drive the "CD" input, which is line level.....Also, my
>attenuator box is for stereo, so it has two inputs and two outputs which are
>separated. So, I could attenuate both the input and the output of the chorus
>pedal with it.....I will have to try screwing around some more, now that I
>have some good input from you guys as to what the trouble probably is......

Wait... wait... now it's different again.... you didn't mention that
you were using your own amp and not feeding something to the PA guy.

Let's start at the beginning.... WHAT is your signal path from beginning
to end? Draw it out, mark the operating levels at each point.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Bill Graham]

"Scott Dorsey" > wrote in message
...
> Bill Graham > wrote:
>>
>>Well, I am using a Behringer 45 watt keyboard amp, and it has several
>>inputs. I can drive the "CD" input, which is line level.....Also, my
>>attenuator box is for stereo, so it has two inputs and two outputs which
>>are
>>separated. So, I could attenuate both the input and the output of the
>>chorus
>>pedal with it.....I will have to try screwing around some more, now that I
>>have some good input from you guys as to what the trouble probably
>>is......
>
> Wait... wait... now it's different again.... you didn't mention that
> you were using your own amp and not feeding something to the PA guy.
>
> Let's start at the beginning.... WHAT is your signal path from beginning
> to end? Draw it out, mark the operating levels at each point.
> --scott
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

It's very simple.....I have an AT pro 35R clip-on instrument mike clipped on
to the bell of my horn. This mike feeds and gets its phantom power from a
small Behringer mike pre-amp, which is just like a dozen other mike pre-amp
boxes that sell for around $30. Then, I can put its output thru a 45 watt
Behringer keyboard amplifier, and all is OK. but now, I want to add the
chorus effect to this, so I put the output of the mike pre-amp into the
input of the guitar chorus pedal, and the output of the chorus pedal into
the amp, and I get a distorted sound. So now, I am wondering where the
distortion is coming from. I suspect that the chorus pedal is not made to
accept the output level of the mike pre-amp box, and is being overdriven by
it, so that's why I posted my problem to the group. Now, I will try running
the pre-amp output through an attenuator before the chorus effect unit, and
perhaps even running the output of the chorus effect unit through an
attenuator before running it into the amplifier. Luckily, I built my own
level adjustment box several years ago, which has two channels of 20K pots
that are set up with the sliders attached to the outputs of the unit, so I
can run the input signals across the whole 20K, and pick the outputs off the
slider to send out to wherever.....It is a stereo box, so I have two
independent channels of 20K attenuation each to work with. I like the chorus
effect, and also the stereo chorus effect, but I only have one 45 watt
amplifier, so stereo will have to wait until I get one channel working
properly......Then I will duplicate my amp for the other channel.

[Ron Capik[_3_]]

Scott Dorsey wrote:
> Bill Graham > wrote:
>> Thanks, Jay. I am using a mike preamp. (I have to, because it has to supply
>> phantom power), but I can't drive the chorus unit directly, because when I
>> do, the sound is badly distorted.
>
> WAIT! STOP!
>
> You didn't mention that before.... we all assumed you were using a phantom
> supply. So now you have a preamp with a line level output going into a
> pedal that expects an instrument level output.
>
>> This is, (I think) because the mike
>> preamps have low impedance outputs and all these chorus pedals are made for
>> guitars, and take high impedance inputs.
>
> It's not the impedance it's the operating level.
>
>> I can screw around with
>> potentiometers to reduce the drive power of the preamp output, but I was
>> hoping that someone would know of a chorus unit that was made for singers
>> that would accept a low impedance input. I already have a rack unit that
>> works OK, but it is too big to be convenient at gigs.......I am looking for
>> a pedal that will do the job, or one whose input I can modify to get it to
>> work OK.
>
> I don't know of any "vocalist pedals." There are lots of fine rackmount
> effects units that can do a chorus. I suppose you might look into the
> old Alesis Wedge or Nanoverb, which are physically very small.
> --scott
Hmmm, did a quick look on the Musician's Friend
page and found several "vocalist pedals" by
TC-Helicon with XLR mic' input, mic' preamp and
phantom power.



Later...

Ron Capik
--

[Bill Graham]

"Scott Dorsey" > wrote in message
...
> Bill Graham > wrote:
>>
>>Thanks, Jay. I am using a mike preamp. (I have to, because it has to
>>supply
>>phantom power), but I can't drive the chorus unit directly, because when I
>>do, the sound is badly distorted.
>
> WAIT! STOP!
>
> You didn't mention that before.... we all assumed you were using a phantom
> supply. So now you have a preamp with a line level output going into a
> pedal that expects an instrument level output.
>
>>This is, (I think) because the mike
>>preamps have low impedance outputs and all these chorus pedals are made
>>for
>>guitars, and take high impedance inputs.
>
> It's not the impedance it's the operating level.
>
>>I can screw around with
>>potentiometers to reduce the drive power of the preamp output, but I was
>>hoping that someone would know of a chorus unit that was made for singers
>>that would accept a low impedance input. I already have a rack unit that
>>works OK, but it is too big to be convenient at gigs.......I am looking
>>for
>>a pedal that will do the job, or one whose input I can modify to get it to
>>work OK.
>
> I don't know of any "vocalist pedals." There are lots of fine rackmount
> effects units that can do a chorus. I suppose you might look into the
> old Alesis Wedge or Nanoverb, which are physically very small.
> --scott

Not all chorus effect units are the same....In fact, my Beranger 45 watt
keyboard amp boasts a chorus effect, but it is, as far as I can hear,
nonexistent. I bought a unit made by Audio Technica that sounds great when
applied properly, because my friend has one and I liked its sound, but he
uses his with a guitar, and I want to use mine with my horn. I think my
problems are just signal level problems, and all I have to do is find and
install the right attenuators.

[Bill Graham]

"Scott Dorsey" > wrote in message
...
> I don't know of any "vocalist pedals." There are lots of fine rackmount
> effects units that can do a chorus. I suppose you might look into the
> old Alesis Wedge or Nanoverb, which are physically very small.
> --scott

The one I really liked was the old Tom Scholtz "Rockman" unit. But these
aren't made anymore. The Audio Technica unit I have is pretty good.....I
just wish it had an input made for Microphone pre-amps.......As I've said
elsewhere, If you don't play a guitar, you're pretty well screwed as far as
equipment goes.......

[Scott Dorsey]

Bill Graham > wrote:
>The one I really liked was the old Tom Scholtz "Rockman" unit. But these
>aren't made anymore. The Audio Technica unit I have is pretty good.....I
>just wish it had an input made for Microphone pre-amps.......As I've said
>elsewhere, If you don't play a guitar, you're pretty well screwed as far as
>equipment goes.......

Well, if you want to use a pedal in an insert of a console, the standard
box for the job is sold by Little Labs. But it sounds like you have odd
levels on both sides as well.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ron Capik[_3_]]

Bill Graham wrote:
>
> "Scott Dorsey" > wrote in message
> ...
>> I don't know of any "vocalist pedals." There are lots of fine rackmount
>> effects units that can do a chorus. I suppose you might look into the
>> old Alesis Wedge or Nanoverb, which are physically very small.
>> --scott
>
> The one I really liked was the old Tom Scholtz "Rockman" unit. But these
> aren't made anymore. The Audio Technica unit I have is pretty good.....I
> just wish it had an input made for Microphone pre-amps.......As I've
> said elsewhere, If you don't play a guitar, you're pretty well screwed
> as far as equipment goes.......
They're out there. This search comes up
with half a dozen by TC-Halicon:
< http://www.musiciansfriend.com/navigation?q=vocal+effects+pedal >

and there are others from DigiTech and Boss...


Later...

Ron Capik
--

[Jay Ts[_2_]]

On Mon, 23 Aug 2010 15:44:10 -0700, Bill Graham wrote:

> "Scott Dorsey" > wrote in message
> ...
>> Bill Graham > wrote:
>>>
>>>Well, I am using a Behringer 45 watt keyboard amp, and it has several
>>>inputs. I can drive the "CD" input, which is line level.....Also, my
>>>attenuator box is for stereo, so it has two inputs and two outputs
>>>which are
>>>separated. So, I could attenuate both the input and the output of the
>>>chorus
>>>pedal with it.....I will have to try screwing around some more, now
>>>that I have some good input from you guys as to what the trouble
>>>probably is......
>>
>> Wait... wait... now it's different again.... you didn't mention that
>> you were using your own amp and not feeding something to the PA guy.
>>
>> Let's start at the beginning.... WHAT is your signal path from
>> beginning to end? Draw it out, mark the operating levels at each
>> point. --scott
>>
>> --
>> "C'est un Nagra. C'est suisse, et tres, tres precis."
>
> It's very simple.....I have an AT pro 35R clip-on instrument mike
> clipped on to the bell of my horn. This mike feeds and gets its phantom
> power from a small Behringer mike pre-amp, which is just like a dozen
> other mike pre-amp boxes that sell for around $30.

I am wondering about this. The mic preamp is probably getting a pretty
high signal level from the microphone, since horns are quite loud.
Although I have a few brass instruments around here, I have zero
experience recording them, so I wonder if it is possible that
the signal from the mic is causing clipping inside your rather low-end
preamp. Exactly what model is that? What kind of power supply
does it use? Hopefully you are not running it off of a single
9-volt battery. ;-)

Do you have a mic preamp that will not allow you to turn the level
down to 0 (That is, -infinity dB)?

Probably you are having trouble getting the lower level of
amplification you need from the mic preamp...

> Then, I can put its
> output thru a 45 watt Behringer keyboard amplifier, and all is OK. but
> now, I want to add the chorus effect to this, so I put the output of the
> mike pre-amp into the input of the guitar chorus pedal, and the output
> of the chorus pedal into the amp, and I get a distorted sound.

A guitar pedal expects the input signal to come from a guitar
pickup, at about -10 to -15 dB relative to normal line level.

If your mic preamp isn't clipping, then you could use a volume
control pedal made for guitar to reduce the level. (I just wanted
to mention that as another possibility.) Or ...

> Now, I will try running the pre-amp output through an
> attenuator before the chorus effect unit, and perhaps even running the
> output of the chorus effect unit through an attenuator before running it
> into the amplifier. Luckily, I built my own level adjustment box several
> years ago, which has two channels of 20K pots that are set up with the
> sliders attached to the outputs of the unit, so I can run the input
> signals across the whole 20K, and pick the outputs off the slider to
> send out to wherever.....

Oh ... well, that sounds about perfect. :)

Jay Ts

[Mike Rivers]

Bill Graham wrote:

> I am using a mike preamp. (I have to, because it has to
> supply phantom power), but I can't drive the chorus unit directly,
> because when I do, the sound is badly distorted. This is, (I think)
> because the mike preamps have low impedance outputs and all these chorus
> pedals are made for guitars, and take high impedance inputs.

No, it's not because of an impeance mismatch, it's because
of a level mismatch. But you should be able to turn the
output level of the mic preamp down so that the chorus pedal
doesn't distort. Have you tried that? If not, try it.

> I was hoping that someone would know of a chorus unit that
> was made for singers that would accept a low impedance input.

I don't believe that you'll find a pedal-format unit that is
designed specifically for a line level input. Just turn down
your premap ("mess with the potentiomenters")

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[Bill Graham]

"Mike Rivers" > wrote in message
...
> Bill Graham wrote:
>
>> I am using a mike preamp. (I have to, because it has to supply phantom
>> power), but I can't drive the chorus unit directly, because when I do,
>> the sound is badly distorted. This is, (I think) because the mike preamps
>> have low impedance outputs and all these chorus pedals are made for
>> guitars, and take high impedance inputs.
>
> No, it's not because of an impeance mismatch, it's because of a level
> mismatch. But you should be able to turn the output level of the mic
> preamp down so that the chorus pedal doesn't distort. Have you tried that?
> If not, try it.
>
>> I was hoping that someone would know of a chorus unit that was made for
>> singers that would accept a low impedance input.
>
> I don't believe that you'll find a pedal-format unit that is designed
> specifically for a line level input. Just turn down your premap ("mess
> with the potentiomenters")

Of course I have done that.....It didn't get rid of the distortion. If that
was all I had to do, I wouldn't even be posting here. No, there is something
else going on, and I don't yet know what it is. My microphone works OK when
plugged directly into the amplifier.....It only distorts when I interrupt
that line with the guitar effects unit. The same mike setup works fine when
I interrupt it with my DOD gated compressor limiter, and Digitech TSR 24
effects units, but these are rack mounted units and have inputs that are set
up for line-level preamplifiers. I can't use rack mounted units for what I
am trying to do......Bring a portable set up to a dance band gig. I am
looking for a "cheap & dirty" solution.....Perhaps this (TC-Helicon Voice
Tone Harmony G )unit will do it for me.....

[Mike Rivers]

Bill Graham wrote:

> Of course I have done that.....It didn't get rid of the distortion. If
> that was all I had to do, I wouldn't even be posting here. No, there is
> something else going on, and I don't yet know what it is. My microphone
> works OK when plugged directly into the amplifier.....It only distorts
> when I interrupt that line with the guitar effects unit. The same mike
> setup works fine when I interrupt it with my DOD gated compressor
> limiter, and Digitech TSR 24 effects units

Does the chorus work properly when fed with something other
than the mic preamp? That's the one thing I don't think
you've told us yet. Maybe it needs a new battery.

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[Bill Graham]

"Mike Rivers" > wrote in message
...
> Bill Graham wrote:
>
>> Of course I have done that.....It didn't get rid of the distortion. If
>> that was all I had to do, I wouldn't even be posting here. No, there is
>> something else going on, and I don't yet know what it is. My microphone
>> works OK when plugged directly into the amplifier.....It only distorts
>> when I interrupt that line with the guitar effects unit. The same mike
>> setup works fine when I interrupt it with my DOD gated compressor
>> limiter, and Digitech TSR 24 effects units
>
> Does the chorus work properly when fed with something other than the mic
> preamp? That's the one thing I don't think you've told us yet. Maybe it
> needs a new battery.
>
Yes.....I took it to a friends house, and he plugged his guitar into
it.....It uses a wall wart, and it seemed to work fine with his set up.

[Jay Ts[_2_]]

Bill Graham wrote:
> My microphone
> works OK when plugged directly into the amplifier.....It only distorts
> when I interrupt that line with the guitar effects unit.

Aha. Well, if the guitar pedal is getting a signal above
-10 dBV, it may be clipping internally. It is running off
of a (more or less) 9V DC supply, either from a battery or wall-wart.
As a result, the maximum signal it can generate is around +/- 4.5 volts,
or about +6 dBV. If the input signal is really hot, it might be clipping
against that right at the input.

> Perhaps this (TC-Helicon Voice Tone Harmony G )unit will do
> it for me.....

I was going to suggest something similar. Rather than
chorus, you might get a better sound from a small pitch detune.

Jay Ts

[Neil Gould]

Bill Graham wrote:
> "Mike Rivers" > wrote in message
> ...
>> Bill Graham wrote:
>>
>>> I am using a mike preamp. (I have to, because it has to supply
>>> phantom power), but I can't drive the chorus unit directly, because
>>> when I do, the sound is badly distorted. This is, (I think) because
>>> the mike preamps have low impedance outputs and all these chorus
>>> pedals are made for guitars, and take high impedance inputs.
>>
>> No, it's not because of an impeance mismatch, it's because of a level
>> mismatch. But you should be able to turn the output level of the mic
>> preamp down so that the chorus pedal doesn't distort. Have you tried
>> that? If not, try it.
>>
>>> I was hoping that someone would know of a chorus unit that was made
>>> for singers that would accept a low impedance input.
>>
>> I don't believe that you'll find a pedal-format unit that is designed
>> specifically for a line level input. Just turn down your premap
>> ("mess with the potentiomenters")
>
> Of course I have done that.....It didn't get rid of the distortion.
> If that was all I had to do, I wouldn't even be posting here. No,
> there is something else going on, and I don't yet know what it is. My
> microphone works OK when plugged directly into the amplifier.....It
> only distorts when I interrupt that line with the guitar effects
> unit. The same mike setup works fine when I interrupt it with my DOD
> gated compressor limiter, and Digitech TSR 24 effects units, but
> these are rack mounted units and have inputs that are set up for
> line-level preamplifiers. I can't use rack mounted units for what I
> am trying to do......Bring a portable set up to a dance band gig. I
> am looking for a "cheap & dirty" solution.....Perhaps this
> (TC-Helicon Voice Tone Harmony G )unit will do it for me.....
>
It seems to me that you are simply overloading the input of the chorus
pedal, and the lowest output level that your mic preamp puts out (e.g. just
above "off") may still be too high for an instrument-level device. If so,
putting a pad between the mic preamp and the pedal may help.

--
best,

Neil

[Mike Rivers]

Neil Gould wrote:

> It seems to me that you are simply overloading the input of the chorus
> pedal, and the lowest output level that your mic preamp puts out (e.g. just
> above "off") may still be too high for an instrument-level device.

It would seem so but "instrument level" isn't all that much
lower than nominal +4 dBu line level. I've seen more than 10
volts p/p coming off a guitar pickup. No, something's
strange and he needs to do some measurements and
troubleshooting.


--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[Bill Graham]

"Jay Ts" > wrote in message
m...
> Bill Graham wrote:
>> My microphone
>> works OK when plugged directly into the amplifier.....It only distorts
>> when I interrupt that line with the guitar effects unit.
>
> Aha. Well, if the guitar pedal is getting a signal above
> -10 dBV, it may be clipping internally. It is running off
> of a (more or less) 9V DC supply, either from a battery or wall-wart.
> As a result, the maximum signal it can generate is around +/- 4.5 volts,
> or about +6 dBV. If the input signal is really hot, it might be clipping
> against that right at the input.
>
>> Perhaps this (TC-Helicon Voice Tone Harmony G )unit will do
>> it for me.....
>
> I was going to suggest something similar. Rather than
> chorus, you might get a better sound from a small pitch detune.
>
> Jay Ts

I should get it in a few days.....I'll let you know if it works OK.

[Neil Gould]

Mike Rivers wrote:
> Neil Gould wrote:
>
>> It seems to me that you are simply overloading the input of the
>> chorus pedal, and the lowest output level that your mic preamp puts
>> out (e.g. just above "off") may still be too high for an
>> instrument-level device.
>
> It would seem so but "instrument level" isn't all that much
> lower than nominal +4 dBu line level. I've seen more than 10
> volts p/p coming off a guitar pickup. No, something's
> strange and he needs to do some measurements and
> troubleshooting.
>
I understand, but I wouldn't be at all surprised to find that a guitar could
overdrive his chorus pedal, as well. I have experienced that capability many
times, especially in post-'70s devices designed for "heavy metal" sounds.

--
best regards,

Neil

[Mike Rivers]

Neil Gould wrote:

> I understand, but I wouldn't be at all surprised to find that a guitar could
> overdrive his chorus pedal, as well.

Sure thing, just as a guitar can overdrive a guitar
amplifier, though sometimes you want that. We just don't
have enough information to know what's going on here. I'd be
happy to have him bring over his gear and I'll check it out,
or I'll fly out to visit him at $75/hour plus travel
expenses. We'll get it sorted out.

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[Bill Graham]

"Bill Graham" > wrote in message
...
>
> "Jay Ts" > wrote in message
> m...
>> Bill Graham wrote:
>>> My microphone
>>> works OK when plugged directly into the amplifier.....It only distorts
>>> when I interrupt that line with the guitar effects unit.
>>
>> Aha. Well, if the guitar pedal is getting a signal above
>> -10 dBV, it may be clipping internally. It is running off
>> of a (more or less) 9V DC supply, either from a battery or wall-wart.
>> As a result, the maximum signal it can generate is around +/- 4.5 volts,
>> or about +6 dBV. If the input signal is really hot, it might be clipping
>> against that right at the input.
>>
>>> Perhaps this (TC-Helicon Voice Tone Harmony G )unit will do
>>> it for me.....
>>
>> I was going to suggest something similar. Rather than
>> chorus, you might get a better sound from a small pitch detune.
>>
>> Jay Ts
>
> I should get it in a few days.....I'll let you know if it works OK.

I got it via UPS yesterday, and it works great.....The unit provides it's
own phantom power at the XLR mike input jack, and I am very pleased with the
effects so far. (I haven't had time to investigate all of them yet)
Certainly there is no distortion from my clip-on AT pro 35R horn mike, and
that's important, because I will probably buy a couple more of them for
other horns to play along with and they are $120 each....I am one of these
people that likes pro equipment on an amateur's budget....:^)