Reamping without a reamp box ?

you SHOULD be able to but it wont be actual zero latency. Shold be passable though.

I did this with my Saffire pro 40 before I got my Countryman:

Guitar > Input 1 Saffire > Saffire OUT 7 > TS > Amp

The DAW records the dry guitar signal going in then I split the routing in the Saffire to go to the DAW and Output 7 on the Saffire. Was nearly 0 latency 1 or 2 ms max.

Using 2 interfaces you may get a bit more latency cause it needs to his the CPU first, then load up in the other set of drivers, so your probably talking 4 to 5 ms which is still tolerable

EDIT: Think I may have misunderstood your question, you have 1 interface or 2?
 
You can plug an unbalanced line out from the DAW to the amp without problems, except if you get hum you may need a transformer to break the loop. That's the advantage to a reamp box, plus the fact that you can put it by the amp and use balanced cables for most of the distance between DAW and amp, which reduces noise.

impedances and nominal voltages have to be matched for the stage that you are going into... ...the voltage generated by the guitars pickup has to be stepped down so that the nominal voltage is equal to that of the calibrated line level.

Guitar pups don't actually have a nominal output voltage. Actually the nominal signal levels don't matter, only the actual levels.

If the guitar output is greater than the line headroom, it will have to be stepped down (or padded) on the way in or it'll clip. In that instance the recorded signal will have to be stepped back up at the output to the amp.

Professional +4dBu line level doesn't clip until about 1.74 volts, so it's not often a problem. A lot of gear also has greater headroom than this, although it's nominally +4dBu you could actually swing more without clipping.

Passive DI boxes will step the guitar level down because they have to step the line-level impedance up for the guitar. An active DI can present the requisite high-Z for the guitar without stepping down the signal.

A transformer will convert the unbalanced to balanced signal and a buffer, a single gain stage designed with a specific input impedance and a specific output voltage/current gain are what is needed to ensure the strongest, cleanest signal...

Or a 1:1 transformer. The output voltage will be what you got at the input, from the guitar. You don't then need an extra gain stage, so it's cleaner.

Impedance-matched connections are not wanted here, bridged impedances are required i.e. the load impedance should be much greater than the source impedance.

A line out should be able to drive impedances of 10k or greater (although many are fine down to about 2k), and at 1Meg typically, the input impedance of an amplifier is 100 times greater than required. Even if the input triode on the amp clips and the cathode starts drawing current from the grid, the load impedance won't drop to anything near the 10k minimum.

The amp doesn't care that the output impedance of the DAW is low. Stomp boxes have low-Z output, for example.
 
Call me crazy, but how widely used reamp boxes are these days, by top producers/engineers no less, I find it hard to believe reamp boxes are just another way to get your money...
 
I have some doubts about real impedance matching, because, for example, Jensen transformers for reampers are 1:1 (JT-11P-1), with 10k impedance on both ends.
But, for me, Reamp box can cost it`s money at least by to factors: balanced->unbalanced conversion so someone can use longer cables and transformer isolation for hum reduction.
 
Guitar pups don't actually have a nominal output voltage. Actually the nominal signal levels don't matter, only the actual levels.

while guitar pickups don't have a nominal voltage itself, when presented with a load the total output can not exceed the calibrated voltage on the next stage

If the guitar output is greater than the line headroom, it will have to be stepped down (or padded) on the way in or it'll clip. In that instance the recorded signal will have to be stepped back up at the output to the amp.

You just explained to operation of DI's and Reamps, and I highly agree.

Professional +4dBu line level doesn't clip until about 1.74 volts, so it's not often a problem. A lot of gear also has greater headroom than this, although it's nominally +4dBu you could actually swing more without clipping.

While most high output pickups average from 90-110mV when plugged into a guitar amp, this can change greatly depending on the load that it is represented with. Under a lighter load, the pickup is able to produce a higher voltage and the same goes for any active gain stage's output depending on the input impedance of the next stage. Considering that the output impedance of the average guitar pickup ranges from 8k-16k and that a guitar amp averages 1M, its easy enough to say that loading a guitar pickup into a 1K load typical of mic pres and A/D converters (lower than the pickup which is very bad), you will easily have peak voltages that are beyond what 1.74v.

Passive DI boxes will step the guitar level down because they have to step the line-level impedance up for the guitar. An active DI can present the requisite high-Z for the guitar without stepping down the signal.

I never said anything contrary. in terms of using a Passive DI is that if plugged into a gain stage such as a preamp with 1K impedance, the input impedance of the DI if a 12:1 tranny was used is about 140k. Still a bit low for a guitar (actually extremely low) but better than having 1k. Active DI's can use a 1:1 and provide a high input impedance, and low out.

Or a 1:1 transformer. The output voltage will be what you got at the input, from the guitar. You don't then need an extra gain stage, so it's cleaner.

What makes you think that a transistor (or vacuum tube) buffer isn't clean. The whole purpose of the circuit is to provide a high input impedance and a low output impedance so that the the signal is strong (or possibly voltage or current amplified) and that the following stage is happy with the levels and impedance it is given. There is nothing about a transistor that will alter the sound nor the circuit if it was designed correctly. If you used a 1:1 tranny in a passive DI the only thing you would be doing is matching an unbalanced to balanced signal.

Impedance-matched connections are not wanted here, bridged impedances are required i.e. the load impedance should be much greater than the source impedance.

I once made the connection that matched impedances weren't indeed matched, but purposely "mismatched", and I had someone else jump my ass for it. But yes output impedance of a stage should be loaded with an impedance at least ten times great if not one hundred times greater.

A line out should be able to drive impedances of 10k or greater (although many are fine down to about 2k), and at 1Meg typically, the input impedance of an amplifier is 100 times greater than required. Even if the input triode on the amp clips and the cathode starts drawing current from the grid, the load impedance won't drop to anything near the 10k minimum.

yes, line outs can range from 10k to 47k typically, where instrument outs range from 470K-1M, no one arguing with that. Its safe to load more than not enough and the general practice at least ten times greater, if not one hundred times greater.

The amp doesn't care that the output impedance of the DAW is low. Stomp boxes have low-Z output, for example.

the amp doesn't care, as you said, when the guitar is plugged in directly, the amp is getting high impedance, when you use a stomp box, its a low impedance with a current gain (electronically speaking this makes the first stage of the amp much happier)
 
Gave it a quick try coming out of my 003. Surprisingly it sounded pretty good until I switched my pedal on.!! Then there was a hell of a lot of white noise from the amp which would make recording impossible. Shame.. :ill:

www.ascapestudios.com
 
Just a quick question:
I have a Countryman 85 that I'd like to try to use for reamping. It's my understanding that I should hook it up in reverse. The output from my interface into the microphone out of the countryman. Then out of the countryman's instrument "IN" to the input of the amp. Is that right? The countryman has an xlr male out that now needs to be an "IN" in this scheme. How does this work? Is there an adaptor or what am I missing?

Thanks in advance for helping!
 
Gave it a quick try coming out of my 003. Surprisingly it sounded pretty good until I switched my pedal on.!! Then there was a hell of a lot of white noise from the amp which would make recording impossible. Shame.. :ill:

www.ascapestudios.com

FYI - Flip the ground loop switch on your amp and get a HUM-X should solve that. I get no white noise at all.

This thread was done without a Re-amp box:
http://www.ultimatemetal.com/forum/equipment/622194-5150-tube-test-jj-ruby-sovtek-kt88-omg.html
 
FYI - Flip the ground loop switch on your amp and get a HUM-X should solve that. I get no white noise at all.

This thread was done without a Re-amp box:
http://www.ultimatemetal.com/forum/equipment/622194-5150-tube-test-jj-ruby-sovtek-kt88-omg.html

Hey cheers for the info. Unfortnately my Marshall or Peavey doesnt have a ground loop switch! I was gonna buy a reamp box in a couple of weeks but if I can do it without one that's good news!

www.ascapestudios.com
 
when presented with a load the total output can not exceed the calibrated voltage on the next stage

Umm... If you mean "can not" literally, you're wrong. If you mean it can but then it'll be clipped by the downstream gain stage, then yes. :)

While most high output pickups average from 90-110mV when plugged into a guitar amp, this can change greatly depending on the load that it is represented with. Under a lighter load, the pickup is able to produce a higher voltage and the same goes for any active gain stage's output depending on the input impedance of the next stage. Considering that the output impedance of the average guitar pickup ranges from 8k-16k and that a guitar amp averages 1M, its easy enough to say that loading a guitar pickup into a 1K load typical of mic pres and A/D converters (lower than the pickup which is very bad), you will easily have peak voltages that are beyond what 1.74v.

Actually, an active gain stage with very low output impedance will function as a near-perfect voltage source. The load impedance affects the amount of current drawn (I=V/R), but the voltage appearing at the output remains the same -- unless the current demanded by the load exceeds the ability of the output device to supply. The line out from a DAW will be like this, and should be able to drive a 10k load according to the standards.

OTOH, a very high-impedance output resembles a current source, in which case more voltage will develop across the load as its impedance increases, in accordance with Ohm's Law V=IR.

The lower the load impedance, the lower the voltage that can be developed across it for a given current, and the more current it will require to achieve a given voltage.

Loaded with only 1k, the voltage output from a passive pup will be lower than if it were loaded with 1Meg.

The other problem with mis-loading a passive pup is that the reactances in the coil form a tuned circuit, which is not independent of the load resistance. The resonant frequency drops, and the Q factor drops, as the load impedance is reduced.

Normally the biggest influence on this is the pots in the guitar. 500k pots (à la Gibson) give hotter output with more edge on the treble than 250k pots (à la Fender). But if you switch from a stomp/amp with like 2M2 input to one with 470k, a bit of the tonal difference you'd hear comes from retuning the pup resonance. Drop the load to 10k line-in or a 2k mic-pre and you've pretty much buttfucked the tone before you even consider the dramatic increase in noise.

Active pups don't have this effect because the preamp in the pup buffers the coil from the load. If EMG hadn't put the series 10k on the output of the EMG-81 you could plug it directly into a 10k unbalanced line input without needing a DI. :mad: You'd get reduced battery life due to the greater current draw, that's all.

What makes you think that a transistor (or vacuum tube) buffer isn't clean ... There is nothing about a transistor that will alter the sound nor the circuit if it was designed correctly.

All additional circuitry will increase noise. This includes passive components like transformers, and active devices also.

Both passive and active components alos increase distortion. Active devices create harmonic distortion, transformers have hysteresis effects as well as odd-order distortions created in the core.

And an active gain stage will require a power supply, which can be fun and games in itself.

All I'm saying: if you can do it without a transformer, great. If you need a transformer for hum/noise rejection, fine. But provided your line out can swing as much voltage as the guitar would output, you don't need a gain stage, and if you don't need it it's better not to bother. :)

If you used a 1:1 tranny in a passive DI the only thing you would be doing is matching an unbalanced to balanced signal.

Yeah, I recommended a 1:1 tranny for the reamp box, not the DI. A 1:1 DI for guitar would suck, only useful for synths, drum machines etc.

I once made the connection that matched impedances weren't indeed matched, but purposely "mismatched", and I had someone else jump my ass for it.

If he was asserting that matched connections are appropriate for line-level audio signals I hope you jumped his ass right back. :mad: (In a non-gay way, I mean.)

In electrical-engineer-speak "matched" impedances specifically means the input impedance is the same as the output impedance. This is not used for line-level audio, but is used for data transmission.

Usually the transmission line connecting the output and input has the same matched impedance also, to prevent ringing and oscillations. That's why RCA cables for digital signals have a specified impedance, and why normal RCA audio cables are not recommended for S/PDIF connections.

...the general practice at least ten times greater, if not one hundred times greater.

In electrical-engineer-speak this is called a bridged connection.

Bridged connections give greatest transfer of voltage, so are used for audio line-level signals.

Matched connections give greatest transfer of power, not usually required for audio except in the output of tube power amplifiers. On the subject of which...

Its safe to load more than not enough...

For line-outs and low-Z power outputs, this is correct. Not so for tube poweramps.

I know that's not what you were refeerring to, I'm not contradicting you here, just digressing.

Check out the General Electric datasheet for 6L6GC:
http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6L6GC.pdf
Scroll down to the examples for "Push-pull Class AB1 Amplifier values for two tubes". See the first two examples have the same voltage on the plates (360V) and screens (270V) and the same bias voltage (-22.5 V). The only difference is in the load impedance.

Dropping the load from 6k6 to 3k8 results in a reduction of power by nearly a third. Maximum screen current also drops by a similar degree, and plate current is increased by only about 6 percent. The power tubes are a near-constant current source.

Loading a tube amp with greater-than spec impedance actually increases the danger to the amplifier compared to connecting lower-than-spec load impedance.

This is the opposite of a solid-state hi-fi amplifier or PA amp. Which is drifting OT, but kinda worth mentioning...
 
Few things I did were:

1. Buy 2 Hum X's put one on your interface, and one on your head
2. Make sure interface and amp are on different circuits in the house or at the very minimum different outlets
3. make sure all the "grounds" on all your gear are connected properly
4. Quality guitar cables
5. Get as far away from the interface as possible with the amp and cables
6. Make sure none of your cables are "rolled up" while using them
 
Few things I did were:

1. Buy 2 Hum X's put one on your interface, and one on your head
2. Make sure interface and amp are on different circuits in the house or at the very minimum different outlets
3. make sure all the "grounds" on all your gear are connected properly
4. Quality guitar cables
5. Get as far away from the interface as possible with the amp and cables
6. Make sure none of your cables are "rolled up" while using them

Cheers bud. If I'm gonna have to buy a Hum X then I might as well buy a ProRMP! Only had problems when I turned my pedal on so maybe thats the problem?
 
hi
I've had the same white noise problem as you but figured that if I unplug my laptop AC adaptor, all the noise is gone

You should try that before buying some unnecessary gear
 
I've gotten the best results by running the DI from my interface output into a micpreamp, which has Hi-z, so i bring down the level with it, and then from the M-audio's Output into the amps guitar input, then one can just lower the guitar some dbs in the daw for cleaner sound, etc. Or raise it for more "pressure/distortion" into your amp. Cleanest solution i've found so far. Interface output/ into Countryman 58/Amp was kinda shitty. So probably only works like guys say with "passive DI's" or a micpreamp that can bring down your linelevel to hi-z --> into the amp, or of course the Reampbox ;)