Reamping.

[Les Cargill[_2_]]

We all know what the Reamp is. My question is: would there
be a resistive equivalent to a Reamp box that would make a
standard line out* look like a 1M ohm source impedance without
a transformer?

*say, 10K ohm

I don't think a shunt would do it. Maybe an H-pad , or L-pad ?

--
Les Cargill

[Mark]

On Oct 18, 1:37*pm, Les Cargill > wrote:
> We all know what the Reamp is. My question is: would there
> be a resistive equivalent to a Reamp box that would make *a
> standard line out* look like a 1M ohm source impedance without
> a transformer?
>
> *say, 10K ohm
>
> I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>
> --
> Les Cargill

a whatever pad you like followed by a 1M Ohm series resistor!

too simple so maybe i did not understand your question..

Mark

[Mike Rivers]

Les Cargill wrote:
>
> We all know what the Reamp is. My question is: would there
> be a resistive equivalent to a Reamp box that would make a
> standard line out* look like a 1M ohm source impedance without
> a transformer?

A 1 megohm resistor in series. But I think that if the source impedance
really makes a difference to the input of a guitar amplifier (let me
amend that to "makes a USEFUL difference") it would involve
inductance, not just resistance.

You might want to take this question to an electric guitar newsgroup.
I suspect that the folks over there may not really know more than we
do here, but they can speak more authoritatively because they're
guitar players. ;)

[Scott Dorsey]

Les Cargill > wrote:
>
>We all know what the Reamp is. My question is: would there
>be a resistive equivalent to a Reamp box that would make a
>standard line out* look like a 1M ohm source impedance without
>a transformer?

Yes, BUT:

1. You need a transformer for isolation.

2. The series inductance of the pickup affects the sound of the input
stage.

You need to have isolation, the right source reactance, and the right
level. The official Reamp box does this all with one special transformer
in a really ingenious way.

In the April 2006 issue of Recording magazine, I have a DIY reamp box
project. Total parts cost is about $50. It uses an inexpensive 1:1
transformer and some lumped sum components to achieve about the same
results without violating the Reamp patent.

I highly recommend it. I use it myself. If you write mike at recordingmag.com
he can get you a copy of the back issue for a few bucks.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Don Pearce]

On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
> wrote:

>
>We all know what the Reamp is. My question is: would there
>be a resistive equivalent to a Reamp box that would make a
>standard line out* look like a 1M ohm source impedance without
>a transformer?
>
>*say, 10K ohm
>
>I don't think a shunt would do it. Maybe an H-pad , or L-pad ?

To look like a guitar, you need an output impedance comprised of about
8kohm in series with a few Henries of inductance. Look at pickup
manufacturers' web sites for accurate information. You can do this
quite handily with some lumped components. Obviously don't forget the
capacitance of the guitar lead - the best way to achieve this is with
an actual lead.

I can't imagine a single situation where you would want the source
impedance to look like 1 Meg.

Actually, the easiest way of all to do this is to wire a guitar pickup
in series with the signal. It can be one in a guitar if you just wire
a jack in series with the signal (ie, no signal ground in the cable)
and plug the guitar in.

d

[Mark]

On Oct 18, 2:27*pm, (Don Pearce) wrote:
> On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
>
> > wrote:
>
> >We all know what the Reamp is. My question is: would there
> >be a resistive equivalent to a Reamp box that would make *a
> >standard line out* look like a 1M ohm source impedance without
> >a transformer?
>
> >*say, 10K ohm
>
> >I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>
> To look like a guitar, you need an output impedance comprised of about
> 8kohm in series with a few Henries of inductance. Look at pickup
> manufacturers' web sites for accurate information. You can do this
> quite handily with some lumped components. Obviously don't forget the
> capacitance of the guitar lead - the best way to achieve this is with
> an actual lead.
>
> I can't imagine a single situation where you would want the source
> impedance to look like 1 Meg.
>
> Actually, the easiest way of all to do this is to wire a guitar pickup
> in series with the signal. It can be one in a guitar if you just wire
> a jack in series with the signal (ie, no signal ground in the cable)
> and plug the guitar in.
>
> d

well if the original recording was made with a DI that correctly
loaded the guitar, then the effect of the guitars output Z on
frequency response (or whatever) is already recorded on the track....

so when you play it back and re-amp it you don't want the effect to
happen again...

you probably have to provide a flat interface form the playback to the
guitar amp..

it is a good point to consider, if you WANT the re-amp to sound like
the original (which usually is the objective) you have to decide and
manage where this effect will take place, during the recording or
during the playback, but not BOTH.

Mark

[Don Pearce]

On Sun, 18 Oct 2009 14:02:57 -0700 (PDT), Mark >
wrote:

>On Oct 18, 2:27*pm, (Don Pearce) wrote:
>> On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
>>
>> > wrote:
>>
>> >We all know what the Reamp is. My question is: would there
>> >be a resistive equivalent to a Reamp box that would make *a
>> >standard line out* look like a 1M ohm source impedance without
>> >a transformer?
>>
>> >*say, 10K ohm
>>
>> >I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>>
>> To look like a guitar, you need an output impedance comprised of about
>> 8kohm in series with a few Henries of inductance. Look at pickup
>> manufacturers' web sites for accurate information. You can do this
>> quite handily with some lumped components. Obviously don't forget the
>> capacitance of the guitar lead - the best way to achieve this is with
>> an actual lead.
>>
>> I can't imagine a single situation where you would want the source
>> impedance to look like 1 Meg.
>>
>> Actually, the easiest way of all to do this is to wire a guitar pickup
>> in series with the signal. It can be one in a guitar if you just wire
>> a jack in series with the signal (ie, no signal ground in the cable)
>> and plug the guitar in.
>>
>> d
>
>well if the original recording was made with a DI that correctly
>loaded the guitar, then the effect of the guitars output Z on
>frequency response (or whatever) is already recorded on the track....
>
>so when you play it back and re-amp it you don't want the effect to
>happen again...
>
I thought of that just after I posted. It is all quite timely for me
as I have just done a serious guitar mod adding a super high impedance
active buffer inside the guitar and changing he tone by altering the
capacitive and resistive loading on the pickup. My SG can even perform
a very passable imitation of a Strat, but without the hum and buzz.

>you probably have to provide a flat interface form the playback to the
>guitar amp..
>
>it is a good point to consider, if you WANT the re-amp to sound like
>the original (which usually is the objective) you have to decide and
>manage where this effect will take place, during the recording or
>during the playback, but not BOTH.
>
>Mark

I can see a use for the Reamp, but it does need to be adaptable to
give the right range of tones.

d

[Les Cargill[_2_]]

Scott Dorsey wrote:
> Les Cargill > wrote:
>> We all know what the Reamp is. My question is: would there
>> be a resistive equivalent to a Reamp box that would make a
>> standard line out* look like a 1M ohm source impedance without
>> a transformer?
>
> Yes, BUT:
>
> 1. You need a transformer for isolation.
>
> 2. The series inductance of the pickup affects the sound of the input
> stage.
>
> You need to have isolation, the right source reactance, and the right
> level. The official Reamp box does this all with one special transformer
> in a really ingenious way.
>
> In the April 2006 issue of Recording magazine, I have a DIY reamp box
> project. Total parts cost is about $50. It uses an inexpensive 1:1
> transformer and some lumped sum components to achieve about the same
> results without violating the Reamp patent.
>
> I highly recommend it. I use it myself. If you write mike at recordingmag.com
> he can get you a copy of the back issue for a few bucks.
> --scott


Awesome. Thankee sai.

--
Les Cargill

[Les Cargill[_2_]]

Mark wrote:
> On Oct 18, 1:37 pm, Les Cargill > wrote:
>> We all know what the Reamp is. My question is: would there
>> be a resistive equivalent to a Reamp box that would make a
>> standard line out* look like a 1M ohm source impedance without
>> a transformer?
>>
>> *say, 10K ohm
>>
>> I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>>
>> --
>> Les Cargill
>
> a whatever pad you like followed by a 1M Ohm series resistor!
>
> too simple so maybe i did not understand your question..
>
> Mark


This is exactly why I asked - it seemed too simple :)

--
Les Cargill

[Les Cargill[_2_]]

Don Pearce wrote:
> On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
> > wrote:
>
>> We all know what the Reamp is. My question is: would there
>> be a resistive equivalent to a Reamp box that would make a
>> standard line out* look like a 1M ohm source impedance without
>> a transformer?
>>
>> *say, 10K ohm
>>
>> I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>
> To look like a guitar, you need an output impedance comprised of about
> 8kohm in series with a few Henries of inductance. Look at pickup
> manufacturers' web sites for accurate information. You can do this
> quite handily with some lumped components. Obviously don't forget the
> capacitance of the guitar lead - the best way to achieve this is with
> an actual lead.
>
> I can't imagine a single situation where you would want the source
> impedance to look like 1 Meg.
>
> Actually, the easiest way of all to do this is to wire a guitar pickup
> in series with the signal. It can be one in a guitar if you just wire
> a jack in series with the signal (ie, no signal ground in the cable)
> and plug the guitar in.
>
> d


Well, take a look here:

http://online.physics.uiuc.edu/courses/phys498pom/Lab_Handouts/Electric_Guitar_Pickup_Measurements.pdf

They have a metric |Z| (on page 8) , which shows as approaching 1M in
cases. I just kinda figured that since stomp boxes use a shunt 1M
resistor to create a 1M input, that perhaps some symmetry applied.

Of course, Mr. Dorsey has a kit in a magazine already :)

--
Les Cargill

[Les Cargill[_2_]]

Mike Rivers wrote:
> Les Cargill wrote:
>>
>> We all know what the Reamp is. My question is: would there
>> be a resistive equivalent to a Reamp box that would make a
>> standard line out* look like a 1M ohm source impedance without
>> a transformer?
>
> A 1 megohm resistor in series. But I think that if the source impedance
> really makes a difference to the input of a guitar amplifier (let me
> amend that to "makes a USEFUL difference") it would involve
> inductance, not just resistance.
>

That appears to be the consensus. I don't understand how those things
are coupled at all then. T'aint V coupled, t'aint I coupled, sure
ain't C coupled... does this mean it's somehow induction-coupled?

> You might want to take this question to an electric guitar newsgroup.
> I suspect that the folks over there may not really know more than we
> do here, but they can speak more authoritatively because they're
> guitar players. ;)


I thought about that... actually, there's a couple guys on alt.guitar
that might actually know... *right now*, I just run a line level input
into the amp, pretty much without modification and it works pretty well.

--
Les Cargill

[Les Cargill[_2_]]

Mark wrote:
> On Oct 18, 2:27 pm, (Don Pearce) wrote:
>> On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
>>
>> > wrote:
>>
>>> We all know what the Reamp is. My question is: would there
>>> be a resistive equivalent to a Reamp box that would make a
>>> standard line out* look like a 1M ohm source impedance without
>>> a transformer?
>>> *say, 10K ohm
>>> I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>> To look like a guitar, you need an output impedance comprised of about
>> 8kohm in series with a few Henries of inductance. Look at pickup
>> manufacturers' web sites for accurate information. You can do this
>> quite handily with some lumped components. Obviously don't forget the
>> capacitance of the guitar lead - the best way to achieve this is with
>> an actual lead.
>>
>> I can't imagine a single situation where you would want the source
>> impedance to look like 1 Meg.
>>
>> Actually, the easiest way of all to do this is to wire a guitar pickup
>> in series with the signal. It can be one in a guitar if you just wire
>> a jack in series with the signal (ie, no signal ground in the cable)
>> and plug the guitar in.
>>
>> d
>
> well if the original recording was made with a DI that correctly
> loaded the guitar, then the effect of the guitars output Z on
> frequency response (or whatever) is already recorded on the track....
>

DI in question is a Samson dual channel DI - "S Direct Plus", which
claims an input Z of.... "> 1 Meg. Ohm".

http://s3.amazonaws.com/samsontech/related_docs/S%20Direct%20Plus.pdf

> so when you play it back and re-amp it you don't want the effect to
> happen again...
>

Okay ,so if you drop the line out outta the amp, no reamp box is
required?


> you probably have to provide a flat interface form the playback to the
> guitar amp..
>

I have one of those - a 1/4" cable. I'm just thought-experimenting,
ultimately - this works very well... amp *is* a solid state input,
and none of this applies to my (other) tube amp.

Just mixing the DI and reamped signals is very nice as it is...

> it is a good point to consider, if you WANT the re-amp to sound like
> the original (which usually is the objective) you have to decide and
> manage where this effect will take place, during the recording or
> during the playback, but not BOTH.
>
> Mark
>

--
Les Cargill

[Scott Dorsey]

Don Pearce > wrote:
>On Sun, 18 Oct 2009 14:02:57 -0700 (PDT), Mark >
>wrote:
>>
>>well if the original recording was made with a DI that correctly
>>loaded the guitar, then the effect of the guitars output Z on
>>frequency response (or whatever) is already recorded on the track....
>>
>>so when you play it back and re-amp it you don't want the effect to
>>happen again...
>>
>I thought of that just after I posted. It is all quite timely for me
>as I have just done a serious guitar mod adding a super high impedance
>active buffer inside the guitar and changing he tone by altering the
>capacitive and resistive loading on the pickup. My SG can even perform
>a very passable imitation of a Strat, but without the hum and buzz.

It doesn't necessarily work that way. There are things that happen
to the pickup due to loading, and there are other things that happen
to the input due to source impedance (which may not happen to your
DI).

The Recording Magazine project gives you the option of selecting a
purely resistive source impedance instead of the highly inductive
pickup emulator, so you can choose which of the two you like.

>I can see a use for the Reamp, but it does need to be adaptable to
>give the right range of tones.

In a perfect world, it won't give any tone, and that will be up to
the amp and the pickup.
--scott

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

[Scott Dorsey]

Les Cargill > wrote:
>Mike Rivers wrote:
>> Les Cargill wrote:
>>>
>>> We all know what the Reamp is. My question is: would there
>>> be a resistive equivalent to a Reamp box that would make a
>>> standard line out* look like a 1M ohm source impedance without
>>> a transformer?
>>
>> A 1 megohm resistor in series. But I think that if the source impedance
>> really makes a difference to the input of a guitar amplifier (let me
>> amend that to "makes a USEFUL difference") it would involve
>> inductance, not just resistance.
>>
>
>That appears to be the consensus. I don't understand how those things
>are coupled at all then. T'aint V coupled, t'aint I coupled, sure
>ain't C coupled... does this mean it's somehow induction-coupled?

The pickup is half of a transformer, with the other half of the
transformer being the strong. So yeah, it's kind of inductively
coupled, and it behaves like a transformer with a super-high-Z secondary.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Rick Stone]

Scott Dorsey wrote:
> In a perfect world, it won't give any tone, and that will be up to
> the amp and the pickup.
> --scott

That's true, and I've bought a "Reamp" a few years ago and liked it
quite a bit (wish I'd known about your project, I might have tried
making one and saved a few bucks.

One observation I have about the tone situation is that as a jazz
guitarist, I often like a pretty dark tone, which I get at the guitar
end by rolling the tone pot way back. Trouble is, now this is on my DI
track, so there's no going back if I later decide that I went too far.

Solution: we put the exact same tone pot I use in my guitar into a
project box and place it AFTER the DI (and BEFORE the amp of course).
That way I can monitor with my dark amp tone while recording, while
still sending the non-rolled-off tone to the DI. If later on I decide I
want more highs, we can get it when mixing, or send the whole thing back
out through the Reamp -> tone-pot -> amp and have another go at it.

Rick Stone
email:
website: www.rickstone.com
epk: www.sonicbids.com/rickstone
Other sites: www.myspace.com/rickstonemusic
www.facebook.com/rickstonemusic www.reverbnation.com/rickstone
www.youtube.com/jazzand www.cdbaby.com/all/jazzand
http://jazzguitarny.ning.com

[Mike Rivers]

Mark wrote:

> well if the original recording was made with a DI that correctly
> loaded the guitar, then the effect of the guitars output Z on
> frequency response (or whatever) is already recorded on the track....
>
> so when you play it back and re-amp it you don't want the effect to
> happen again...

The purists will tell you that the complex impedance of the source
feeding the amplifier will make a difference in how the amplifier
performs, so that's the reason for the juju.

On the other hand, it's all artificial anyway. I always thought that
the idea of re-amping is so that you could fool around with amplifier
settings, mics and mic positions, and different amps after the guitarist
has recorded his part. So I would think that there really isn't anything
in the way of a sound that you couldn't get that you really cared about
with all those other parameters at your disposal.

I doubt that anyone realistically expects to re-create the exact sound
of a particular guitar plugged into a particular amplifier. If that's what
they wanted, they would have just recorded it, even if it meant working
at a time when it wouldn't wake up the neighbors.

[Don Pearce[_3_]]

On 18 Oct 2009 18:17:17 -0400, (Scott Dorsey) wrote:

>>I can see a use for the Reamp, but it does need to be adaptable to
>>give the right range of tones.
>
>In a perfect world, it won't give any tone, and that will be up to
>the amp and the pickup.

Electric guitars don't work that way. They aren't like a mic where the
object is a flat response. A guitar's interaction with the lead and
amp IS the tone. That is why single coil pickups are tonally totally
different to humbuckers - the far higher resistance and inductance of
the latter.

d

[Don Pearce[_3_]]

On Sun, 18 Oct 2009 18:02:44 -0400, Les Cargill
> wrote:

>Don Pearce wrote:
>> On Sun, 18 Oct 2009 13:37:38 -0400, Les Cargill
>> > wrote:
>>
>>> We all know what the Reamp is. My question is: would there
>>> be a resistive equivalent to a Reamp box that would make a
>>> standard line out* look like a 1M ohm source impedance without
>>> a transformer?
>>>
>>> *say, 10K ohm
>>>
>>> I don't think a shunt would do it. Maybe an H-pad , or L-pad ?
>>
>> To look like a guitar, you need an output impedance comprised of about
>> 8kohm in series with a few Henries of inductance. Look at pickup
>> manufacturers' web sites for accurate information. You can do this
>> quite handily with some lumped components. Obviously don't forget the
>> capacitance of the guitar lead - the best way to achieve this is with
>> an actual lead.
>>
>> I can't imagine a single situation where you would want the source
>> impedance to look like 1 Meg.
>>
>> Actually, the easiest way of all to do this is to wire a guitar pickup
>> in series with the signal. It can be one in a guitar if you just wire
>> a jack in series with the signal (ie, no signal ground in the cable)
>> and plug the guitar in.
>>
>> d
>
>
>Well, take a look here:
>
>http://online.physics.uiuc.edu/courses/phys498pom/Lab_Handouts/Electric_Guitar_Pickup_Measurements.pdf
>
>They have a metric |Z| (on page 8) , which shows as approaching 1M in
>cases. I just kinda figured that since stomp boxes use a shunt 1M
>resistor to create a 1M input, that perhaps some symmetry applied.
>
>Of course, Mr. Dorsey has a kit in a magazine already :)

Yes, that is exactly what I was expecting - a fairly high Q resonance.
You can't simulate that with a resistor. It has to be the right
inductor plus capacitive loading.

d