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Is it essential to use a reamp box when reamping?
Old 6th January 2017
  #31
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Quote:
Originally Posted by E-money View Post
Thanks.

Can you describe the difference in sound quality before and after making the mod?
I did it purely to get the output to where I wanted it. However if you look here (Radial ProRMP modification | Page 4 | Ultimate Metal - Heavy Metal Forum and Community) you will see a chart that shows modded vs. stock. The one I posted is the 'V2' version of the mod.
Old 6th January 2017
  #32
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nosebleedaudio's Avatar
 

Quote:
Originally Posted by przemak View Post
Well, money
And with switching power supplys connecting grounds of computer and amplifier almost always couses hum.
It's NOT just switching supply's that cause hum due to "Ground Loops"...
From my experience a Properly designed Re-Amp box makes most amps Quieter...
Old 6th January 2017
  #33
Motown legend
 
Bob Olhsson's Avatar
 

Quote:
Originally Posted by nosebleedaudio View Post
It's NOT just switching supply's that cause hum due to "Ground Loops"...
From my experience a Properly designed Re-Amp box makes most amps Quieter...
So did the headphone feed from the console!
Old 6th January 2017
  #34
Quote:
Originally Posted by kevin nowhow View Post
I recently found some information about using buffered pedals as reampers to correct impedance mismatches.What i don't get is this:Since such a pedal sees high impedance at its input, lowering Z after outputting, isn't this the opposite of what i want to achieve(low Z line output=>high Z amp input)???
That's not quite right.

To start with, "low impedance" and "high impedance" are relative and can mean somewhat different things in different situations.

The way modern audio connections work is what is known as "bridge mode." In bridge mode a lower impedance source (output) feeds a higher impedance load (input). This maximizes voltage transfer between source and load, which maximizes gain and level, as modern audio inputs sense voltage, not current or power*. What this means in this case is that the input of a pedal does not "see" a high(er) impedance, it IS a high impedance. A guitar pickup has an impedance of around 3K ohms to maybe 12K ohms, depending. (This is "high impedance compared to a 200 ohm mic or 600 ohm line, but it's still pretty low compared to the input of an FX pedal, which may be from 50K-100K up to a meg or so. A typical guitar amp has an input impedance of 1 meghohm or greater and high quality active DI boxes may run 5 megs or greater.

Modern pedals are designed to provide a high impedance load (input) to the guitar pickup and a low impedance source (output)** to whatever the next device in the chain might be.

The idea of a reamp box is to recreate (more or less) the impedance of a guitar pickup source being seen by the (first) device in the chain as well as providing a guitar-type volume control, which, since it varies the raw output impedance of the pickup to some degree can have an effect on the operation of certain FX devices (the Fuzzface is a notable example), as well as a reduction in the raw level of the line output (much hotter than the output of a typical guitar pickup) and adjustment of the line impedance feeding the first device in the reamp chain (which might affect the operations of some devices like the aforementioned Fuzzface.

Essentially a reamp box is a passive DI of mic/line transformer turned around backwards, with a little additional circuitry to adjust the very hot output level from the interface and to emulate the guitar's volume control. The volume control emulation isn't really necessary if you're not using a vintage-style device like a Fuzzface that is sensitive to manipulation of the guitar's volume control, and most audio interfaces provide some method of easily adjusting the output level of a channel (which is something that isn't all that easy on a professional multitrack tape machine.)



* - Older audio equipment (think vintage tube stuff made before the mid '60s) often operates in matched mode, in which the source and load impedances are equally matched, usually via transformer coupling. (not all transformer coupled circuits operate in matched mode). Matched mode provides optimum transfer of power, i.e. voltage times current, which is good for driving long transmission lines such as telephone lines or the line between a downtown radio/TV studio and the transmitter located outside of town, but has no real relevance for guitar gear where lines seldom exceed 50 feet.


** - in this case the output impedance might be a low as a couple of ohms or less, or as high as a few hundred. Older, vintage pedals are more likely to have a somewhat higher output impedance than more modern ones.
Old 6th January 2017
  #35
Quote:
Originally Posted by kevin nowhow View Post
I actually stand by what you say.But thing is, it's not just sound i worry about.I've heard people saying they have fried their amps/stompboxes because of level/impedance mismatches.Others saying there's no danger whatsoever.I'm confused because of my lack of experience.I can get by with a fried stomp but an amp that doesn't belong to me...that's another story.
Those people who fried things with improper connections are probably blithering idiots who tried connecting an FX box to a speaker output. Which is something you NEVER do, unless you want to release the magic smoke that precedes a transfer of cash to your local tech.

Quote:
I have an impedance matching transformer going from low Z(600ohms) to high Z(30kohms).Still not the 1Mohms guitars love but was wondering if it can be of any use...along with careful level treatment...
With a couple of sex change adapters that should work just fine as a quick and dirty reamp box.

FWIW (and to probably confuse you even more), transformers do not actually have set impedances - their impedance is variable depending on the impedance of the circuits to which they are connected. For example, when the secondary of a tuber guitar amp that is rated for 16 ohms is connected to an 8 ohm speaker load, this changes the loading that the primary presents to the output tubes, which changes the power output of the amp. People who know about tubes can also use this effect to run an amp with tubes other than those the amp was designed for, by changing the impedance of the speaker load so that the transformer can match the tubes.

In the case of your matching transformer the Low side would be connected to your interface, which actually has a lower impedance that 300 ohms, causing the Hi side to present a source to the first FX device that would be somewhat lower than the rated 30K - which would actually be much closer to the real output impedance of a typical guitar pickup.
Old 6th January 2017
  #36
Quote:
Originally Posted by Bob Olhsson View Post
I was using a headphone feed in 1969! I think the idea of a dedicated box is absurd.
It's not at all absurd if you're the person selling the reamp boxes!
Old 6th January 2017
  #37
Quote:
Originally Posted by nosebleedaudio View Post
It's NOT just switching supply's that cause hum due to "Ground Loops"...
From my experience a Properly designed Re-Amp box makes most amps Quieter...
A properly designed reamp box has a ground lift switch that breaks the loop. So do all but the cheapest passive DI boxes. For those that don't and for line matching transformers the same can be done by lifting the ground wire to pin 1 of the XLR. You might need to check the the shell of the mic cable that attaches to the transformer does not have the shell connected to ground as well.
Old 6th January 2017
  #38
Motown legend
 
Bob Olhsson's Avatar
 

Quote:
Originally Posted by John Eppstein View Post
It's not at all absurd if you're the person selling the reamp boxes!
Old 6th April 2019
  #39
Gear Maniac
 

So an Avalon U5 active DI box won't work as a ReAmping device? I wanted to figure out why there's a passive and an active ReAmping device then. Wouldn't an active one color the tone?

You mentioned "tone", but the purpose of a passive DI box isn't for tone, care to explain that?

I think the Avalon U5 active DI box could be bypassed to turn off any coloring to the sound...I'll look into this.

Active ReAmper tool is the Radial Engineering X-Amp.

Quote:
Originally Posted by FireBros. View Post
If you have a passive DI, using adapters, just run it backwards. Obviously the better the DI, the better the tone. Unfortunately this won't work with an active DI.
Old 6th April 2019
  #40
Gear Maniac
 

Couldn't a Whirlwind Little Imp do the same thing? Or an Audio-Technica CP8201.

Quote:
Originally Posted by The Famous Yard View Post
It's not essential but it is much better. I did without for a while, then used a passive DI in reverse, but getting a dedicated reamp box (not too expensive) made for much better results. It has level control, polarity switch and earth loop and it just sounds more like a guitarist is playing.
Old 6th April 2019
  #41
Gear Maniac
 

Don't some actives could be bypassed?

Quote:
Originally Posted by John Eppstein View Post
No. No active DI works reversed. See the previous post.
Old 6th April 2019
  #42
Gear Maniac
 

Could the peavey minimax bass guitar amp work?

Quote:
Originally Posted by motone View Post
this depends very much on which amp (or fx device) you're using for the reamping ... there's a whole lot of applications where it doesn't make a difference, any amp that has inputs accepting line-level signals (and are not too sensitive when it comes to impedance / loading) can be used without a reamp box easily: Twin Reverb, JC-120, pretty much every bass amp etc etc.
just the same for the classic sansamp boxes: Tchad Blake said he does all his sansamp magic WITHOUT any reamping ...

there is however amps like AC-30s or any Matchless amp which are very sensitive and where the magic lies in the interplay between the magnetic pickups and the input stage of the amp, these definitely do need a instrument-level, hi-impedance input signal so you need a reamping device. same for fuzz boxes, especially vintage-style germanium transistor ones.
Old 6th April 2019
  #43
Gear Maniac
 

Is the Whirlwind Impad20 20db inline doable?

There's an impad30 and impad40 as well, why you chose 30 db?

So running a whirlwind imp2 passive DI using one of the inline mentioned above should work as a re-amping device?

Quote:
Originally Posted by maggotspawn View Post
I run a passive DI in reverse with a -30dB pad inline. Works fine.
Old 6th April 2019
  #44
Gear Maniac
 

Could you have skipped removal if you used the Whirlwind Lifter device?

Quote:
Originally Posted by KamandaSD View Post
Remove the 3rd resistor (R3)
Remove the other two resistors (R1) (R2)
Rebridge (R1) and (R2) with some wires.
Old 9th April 2019
  #45
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Quote:
Originally Posted by slutbox View Post
Could you have skipped removal if you used the Whirlwind Lifter device?
I wouldn't know as I do not have one. Although isn't that just a ground lift? And wouldn't it act the same as the ground lift on the device itself?

Sorry I am not much more help.
Old 9th April 2019
  #46
Gear Maniac
 

Your post that I quoted you said you removed something, could you have skipped removal if you had used the product I stated?

Quote:
Originally Posted by KamandaSD View Post
I wouldn't know as I do not have one. Although isn't that just a ground lift? And wouldn't it act the same as the ground lift on the device itself?

Sorry I am not much more help.
Old 9th April 2019
  #47
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Quote:
Originally Posted by slutbox View Post
Your post that I quoted you said you removed something, could you have skipped removal if you had used the product I stated?
No.
Old 9th April 2019
  #48
Gear Maniac
 

Did you read its intended purpose?

Quote:
Originally Posted by KamandaSD View Post
No.
Old 9th April 2019
  #49
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Quote:
Originally Posted by slutbox View Post
Did you read its intended purpose?
Yes I did. The Whirlwind Lifter is simply that...a ground lift. This function is already built into the ProRMP. The idea behind modding the ProRMP is to allow it's output to be up to where I needed it to be.
Old 13th April 2019
  #50
Gear Maniac
 

How about the passive Whirlwind Director DI Box?

Quote:
Originally Posted by KamandaSD View Post
Yes I did. The Whirlwind Lifter is simply that...a ground lift. This function is already built into the ProRMP. The idea behind modding the ProRMP is to allow it's output to be up to where I needed it to be.
Old 23rd April 2019
  #51
Gear Maniac
 

any clue if an active DI box could work as a reamping tool?

"The most obvious difference is that passive DI boxes don't need to be powered. Active DI boxes require a power source, usually batteries or phantom power over an XLR jack."

So does this quote imply that an active DI box could be "passive" if not using the power supply or what?
Old 23rd April 2019
  #52
Old 23rd April 2019
  #53
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Moonwhistle's Avatar
 

Quote:
Originally Posted by Bob Olhsson View Post
I was using a headphone feed in 1969! I think the idea of a dedicated box is absurd.
Quoting just because I like this a lot.
Old 23rd April 2019
  #54
Gear Maniac
 

How so? When passive is nothing more than a lifeless box you're supposed to run signals through lol. I'd assume a dead VCR would work just as well as long as it's not powered.

Quote:
Originally Posted by John Eppstein View Post
Not really.
Old 23rd April 2019
  #55
Gear Maniac
 

What's a headphone feed?

Quote:
Originally Posted by Moonwhistle View Post
Quoting just because I like this a lot.
Old 25th April 2019
  #56
Motown legend
 
Bob Olhsson's Avatar
 

Quote:
Originally Posted by slutbox View Post
What's a headphone feed?
A headphone feed is the output of an amplifier out in the studio that would normally be used for headphones. It is fed by one of the console busses.
Old 26th April 2019
  #57
Quote:
Originally Posted by slutbox View Post
Don't some actives could be bypassed?
no.
Old 26th April 2019
  #58
Quote:
Originally Posted by slutbox View Post
So an Avalon U5 active DI box won't work as a ReAmping device? I wanted to figure out why there's a passive and an active ReAmping device then. Wouldn't an active one color the tone?

You mentioned "tone", but the purpose of a passive DI box isn't for tone, care to explain that?

I think the Avalon U5 active DI box could be bypassed to turn off any coloring to the sound...I'll look into this.

Active ReAmper tool is the Radial Engineering X-Amp.
You cannot turn an active DI around backwards. You can't use the output of an amplifier as an input. It does not work. It's like trying to sh*t through your mouth.

An active device will not "color" tone any more than a passive one will - unless the device is designed to do that. In either case it has nothing to do with the question at hand.
Old 26th April 2019
  #59
Quote:
Originally Posted by slutbox View Post
What's a headphone feed?
Shirley, you jest.

At least I certainly hope so.
Old 27th April 2019
  #60
Gear Maniac
 

Ok. An Avalon U5 has a tone knob. I guess this one is the exception, for an active direct box.

Quote:
Originally Posted by John Eppstein View Post
You cannot turn an active DI around backwards. You can't use the output of an amplifier as an input. It does not work. It's like trying to sh*t through your mouth.

An active device will not "color" tone any more than a passive one will - unless the device is designed to do that. In either case it has nothing to do with the question at hand.
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