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Noise when reamping

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Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 7:23 am

Bought the palmer daccapo.
Tried my first reamp session.
Recorded di with a miced version as well.
Then reamped by sending di to daccapo to amp to mic back into rme interface.
I find the output to amp is lower?
Also theres more noise in the reamped version than there was in initial miced version.
I am probably doing something wrong here...

Also inuse headphones out of rme babyface to daccapo. Should i then choose output 3&4 or only 3 or 4 as its mono anyway. Tried both but levels vary very much.
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Re: Noise when reamping

Postby blinddrew » Sun Sep 09, 2018 8:31 am

Yep, use output 3 or 4. The Palmer is expecting a balanced mono line level input. The headphone output is providing a stereo unbalanced powered output.
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Re: Noise when reamping

Postby ef37a » Sun Sep 09, 2018 9:12 am

I do not understand the specifications of that Palmer re-amp box?

To my mind such a box should accept a line level signal from an AI or mixer and then allow the level to be attenuated, by a pot, to suit the guitar input of an amplifier.
The input impedance of such a box should be at least 10k Ohms and if balanced, >20k. The Palmer states "600 Ohms" and such a low load will cause signal loss from many "non pro" devices and possibly distortion.

The output impedance is also given as 100k Ohms. Far too high and even a modest length of guitar cable will cause HF loss (aka "tone suck")

The box also seems to give signal BOOST? Not all all what you want.

Essentially all you need is a 10k pot in a tin and the right cables plus some means of breaking the signal earth is often needed. Messrs Orchid Electronics do it right.

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Re: Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 12:04 pm

Would it be better to use the line outs of the Babyface going into the daccapo?

Are you saying the daccapo is a bad device?
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Re: Noise when reamping

Postby Matt Houghton » Sun Sep 09, 2018 12:22 pm

He's saying that a 600 ohm input impedance is on the low side -- essentially impedance matching used to be a standard decades ago, but it is an old, outdated concept that's only used in old studio gear (eg 1176) and has largely been abandoned today. Lower input impedances are 'harder work' for your line source to 'drive'.

Either way, the Palmerexpects a mono balanced line input. So use a mono line out from your RME, not an unbalanced mono or stereo headphone feed... I believe the line outs technically have a very slightly lower noise floor than the headphone ones too. See how that works...
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Re: Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 1:11 pm

Using the balanced rme output yields as much background noise as the headphone out. The sound is alright, comparable to the original directly (not reamped) recorded guitarcab, but there's just more noise.
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Re: Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 1:35 pm

Mmm i have the impression there's already a bit of hum in the DI signal.
I use the AR133 active di. From guitar straight to DI and use the link to go to amp to have a bit of a playing feel. This recorded amp tone is great, but in the DI theres a slight hum which seems to be amplified when reamping, thus the reamped amp tone has more noise.
Am I doing something wrong in making the DI?
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Re: Noise when reamping

Postby Ben Asaro » Sun Sep 09, 2018 1:39 pm

I do not use the Palmer reamp box but --

The level of the DI track may also have a bearing on the signal:noise going through your reamp device to the guitar amp. I reamp guitars a lot (using a Radial reamp) and I find that having the DI track going from an unattenuated line out from my interface at about -10dB gives the amplifier a nice strong signal; otherwise the signal is too low and you have to compensate by turning the amp/effects up which creates more noise as well.
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Re: Noise when reamping

Postby James Perrett » Sun Sep 09, 2018 1:51 pm

Have you tried connecting the line output of your interface directly to the input of your guitar amp? Most of the time this will work - Reamp boxes are only needed when the simple solution doesn't work.
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Re: Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 5:55 pm

Think it's better now: fiddled with the AR133's ground lift and recorded the DI track hotter. Now the reamped version has about the same noise as the direct recorded amp sound. I guess guitar will aways have some noise...
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Re: Noise when reamping

Postby Guitarking » Sun Sep 09, 2018 6:43 pm

How hot do you guys usually record the guitar di track?
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Re: Noise when reamping

Postby Ben Asaro » Sun Sep 09, 2018 6:57 pm

I usually have all of my tracks peaking at -14dB.
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Re: Noise when reamping

Postby permanent_daylight » Mon Sep 10, 2018 3:46 am

I doubt its the source of the noise, but it can be beneficial to minimise headroom in the digital signal and attenuate with an analogue output control (whether that's on the reamp, interface, or perhaps a pad if not). So if you peak at -14 it would make sense to pull that track up by about 13db.

On the reamp impedance issue mentioned, well i've built a few DIY and often having it slightly mismatched gave it some of the natural degradation that makes it sound like a guitar plugged in directly. Just my opinion, the ones i built also included a few inductors to get closer to the direct approach. Some degradation is more accurate imo.
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Re: Noise when reamping

Postby Guitarking » Mon Sep 10, 2018 6:21 am

do you mean record at -14 and then normalize?
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Re: Noise when reamping

Postby permanent_daylight » Mon Sep 10, 2018 1:27 pm

Guitarking wrote:do you mean record at -14 and then normalize?

yes. -14 would be a good digital 24-bit level for tracking.
...but what i mean is so the analogue noise of your system is minimised when sending signals out of it if you can turn down the 'post' fader. whilst increasing the volume of the bits in your pc won't change the sound or add noise. So just for reamping its just standard to send analogue equipment a hotter signal, in this case your output circuitry, reamp box, might introduce noise. having a volume control or pad in the analogue chain will also turn down noise, if your signal is just under 14db higher then you get to turn down the noise by 14db without introducing any more noise since digital faders don't add noise.

And of course the micced signal can be recorded back at -14, or whatever number your chose, i go for -12 and often a bit over, as its quite arbitrary as long as there's headroom.

A long while back when i only used a reverse DI box, i actually just stuck my guitar volume pedal between the box and the amp...perfectly suitable for a guitar level signal of course and worked pretty well noise wise (though a reverse DI altered the tone a lot)
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Re: Noise when reamping

Postby ef37a » Mon Sep 10, 2018 1:49 pm

The track level really doesn't matter. The Babyface puts out +13dBu* for 0dBFS, that's about 3.5V rms and so even if the track was down at neg 20 there would still be 350mV ish going to the amp if you used James P's idea of a simple link.

350 mV is enough to drive any guitar amplifier stupid. What is it by the way?

*Unbalanced.

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Re: Noise when reamping

Postby permanent_daylight » Mon Sep 10, 2018 2:30 pm

ef37a wrote:The track level really doesn't matter. The Babyface puts out +13dBu* for 0dBFS, that's about 3.5V rms and so even if the track was down at neg 20 there would still be 350mV ish going to the amp if you used James P's idea of a simple link.

350 mV is enough to drive any guitar amplifier stupid. What is it by the way?

*Unbalanced.

Dave.

That's in the ballpark of a guitar signal, sure..
If there's noise, lower the noise floor, worth a try.
I mean there IS noise in the signal chain, so why not lower the noise floor?
IME its the signal before the amp's input that has noise, rather than the amp receiving too little gain. Same level hits the guitar amp.
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Re: Noise when reamping

Postby John Willett » Mon Sep 10, 2018 2:47 pm

permanent_daylight wrote:
Guitarking wrote:do you mean record at -14 and then normalize?

yes. -14 would be a good digital 24-bit level for tracking.

Actually, the EBU specs say set 0VU to -18dBFS for 24-bit recording and -12dBFS for 16-bit recording.

This leaves enough for peaks (including inter-sample peaks that cannot be seen on the meter, but can still distort).
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Re: Noise when reamping

Postby ef37a » Mon Sep 10, 2018 3:34 pm

permanent_daylight wrote:
ef37a wrote:The track level really doesn't matter. The Babyface puts out +13dBu* for 0dBFS, that's about 3.5V rms and so even if the track was down at neg 20 there would still be 350mV ish going to the amp if you used James P's idea of a simple link.

350 mV is enough to drive any guitar amplifier stupid. What is it by the way?

*Unbalanced.

Dave.

That's in the ballpark of a guitar signal, sure..
If there's noise, lower the noise floor, worth a try.
I mean there IS noise in the signal chain, so why not lower the noise floor?
IME its the signal before the amp's input that has noise, rather than the amp receiving too little gain. Same level hits the guitar amp.

Noise? Shmoise! The signal to noise ratio is already fixed in the track. No matter what level, within a very large margin, you send from the Baby face it is going to be WAY cleaner than any guitar amp. Even one I know to be probably the quietest 5watter on the market!
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