Recording a direct out with interface

[St. Sixtus]

The guys at the shop can't give me any useful advice, so here I am hoping some kind soul can shed some light on my problem.

I'm trying to record the direct out of my Tech 21 Trademark 60 amp. The idea was to get my 'amp sound' on tape without waking up the neighbourhood (I work odd hours).

So, I went out and bought a Roland Duo-Capture Ex thinking: "If it can do mics, it can take my amp". Apparently, it can't. Having my amp volume above the 7 o'clock mark makes the little box distort like crazy.

I've tried going XLR to XLR, going headphones out to 1/4 input, putting the input gain on its lowest point, changing Hi-Z/Lo-Z (slight improvement), changing all the settings in the drivers/Sonar X1 and REAPER. Doesn't make any difference. What sounds fine in my headphones coming from the amp's headphone out, is distorting in the Duo-Capture.


Any advice for this newbie is helpful!
Cheers


Specs:

• Amp Nominal XLR Output -20dBu
• Audio Interface Roland Duo-Capture Ex

 

[Milfje]

Could be a few things. Is the gain on your interface set too high? Does adjusting the volume on your amp affect the volume of the direct out? That way you now where in the signal chain the "direct out" is positioned. I looked up your guitar amp, and the direct out says "SansAmp". Does that mean it just sends the (Hi-Z) guitar input out of it, without going through the amp itself?

In any way, unless it isn't possible, I prefer to place a microphone in front of the amp over using direct outs or DI's. That way what I hear is what I record. A DI or direct out sound different because the guitar sound doesn't get the coloration of your (tube) amp and speaker cab.

 

[St. Sixtus]

Could be a few things. Is the gain on your interface set too high? Does adjusting the volume on your amp affect the volume of the direct out? That way you now where in the signal chain the "direct out" is positioned. I looked up your guitar amp, and the direct out says "SansAmp". Does that mean it just sends the (Hi-Z) guitar input out of it, without going through the amp itself?

The gain on my interface is at its absolute lowest setting. It's still distorting and the Peak indicator is lighting up.

The idea of the SansAmp direct out is that it simulates what the amp sounds like with the cabinet being mic'd by an SM57. The output of the direct out is the same as the amp. This means that when the amp is putting out 80dB of sound, the direct out is simulating 80dB of sound.

While I'm not a fan of cab simulation, I'm unable to hear any difference between the amp and the direct out, so it's pretty good. I can't use an actual microphone because I want to record in the dead of night in an apartment.

 

[bouldersoundguy]

If the interface's mic inputs don't have enough gain range then -20dBu may be too hot. Probably an inline 20dB pad would solve your problem.

 

[mjbphotos]

Looking at the specs, the 'DI' ouput of your amp is just a low-powered headphone output, and the inputs of your Roland are mic/instrument, so there is your problem - you need an interface with Line-In inputs (no preamps).

 

[St. Sixtus]

Looking at the specs, the 'DI' ouput of your amp is just a low-powered headphone output, and the inputs of your Roland are mic/instrument, so there is your problem - you need an interface with Line-In inputs (no preamps).

Makes sense. I was under the impression that the Roland had line-in inputs, seems I didn't do my homework properly.

In case the store pulls some crap on me and I can't return the thing, would the aforementioned transformer be an option? Also, any devices you can recommend for this style of recording?


Cheers guys, much obliged!

 

[TimOBrien]

Question: Are you using the headphone out in the back or the Sansamp Direct Out plug?

 

[St. Sixtus]

Question: Are you using the headphone out in the back or the Sansamp Direct Out plug?

Either one would work for me, but I'd prefer the Direct out XLR. Plan was to use a dummy plug to defeat the amp's speaker (as mentioned in the actual amp manual) and monitoring the Direct out through the interface. Both headphone out and Direct out (which I suspect to actually be the same dB wise) have the same distorting/peak problem though.

 

[St. Sixtus]

If the interface's mic inputs don't have enough gain range then -20dBu may be too hot. Probably an inline 20dB pad would solve your problem.

Found some new info in one of the newer manuals. They mention hooking up the Sansamp XLR Direct Out to an effects processor. A small footnote says: "Use a line matching transformer, such as a Shure Model A95UF or equivalent". So a transformer might be the way to go, right?

 

[bouldersoundguy]

Found some new info in one of the newer manuals. They mention hooking up the Sansamp XLR Direct Out to an effects processor. A small footnote says: "Use a line matching transformer, such as a Shure Model A95UF or equivalent". So a transformer might be the way to go, right?

If you're hooking up to an unbalanced line level device. Your interface has balanced mic level inputs. You don't need a transformer, you need a pad. A pad will be cheaper and better sounding than a cheap transformer for your application.

 

[St. Sixtus]

If you're hooking up to an unbalanced line level device. Your interface has balanced mic level inputs. You don't need a transformer, you need a pad. A pad will be cheaper and better sounding than a cheap transformer for your application.

I got in touch with the main computer/audio tech of the chain I bought the interface from. The guy insisted (quite vigorously) that the duo capture has line level inputs. When I asked him what caused my problems he simply said "impedance mismatch, use an XLR to jack cable to solve it". When I mentioned that I tried the headphone out with jacks his answer was, again, "impedance".

I'm not quite willing to trust this stuck up schmuck and spend yet more money on a cable that may or may not work. IF the interface has a line level input, would the headphone out connected by 1/4 jacks to the interface make it distort the way it is, and would an XLR/jack cable make any difference in the whole "impedance" story?

 

[bouldersoundguy]

The input connectors on the Roland are combo XLR and 1/4" ("jack"). The 1/4" line input has significantly lower sensitivity. Connect your XLR output to the TRS (balanced) 1/4" input of the interface using a commonly available cable. That should give you 14dB more headroom.

The nominal -20dBu output from your amp's XLR is approximate. You could be sending signal well above that level to your interface so even the line inputs might overload.

Impedance could be a problem but an XLR output should be stable into a low impedance input.

 

[St. Sixtus]

The input connectors on the Roland are combo XLR and 1/4" ("jack"). The 1/4" line input has significantly lower sensitivity. Connect your XLR output to the TRS (balanced) 1/4" input of the interface using a commonly available cable. That should give you 14dB more headroom.

The nominal -20dBu output from your amp's XLR is approximate. You could be sending signal well above that level to your interface so even the line inputs might overload.

Impedance could be a problem but an XLR output should be stable into a low impedance input.

I'm not sure 14dB headroom would be enough, I want to record what I believe lies somewhere between 70 and 95 dB (this is an approximation of the output of the real speaker, not the direct out). Could a mixer or pad between the amp and interface be the solution?

 

[ecc83]

I have been downloading manuals and trying to find level specs for the last 10 minutes, with limited sucess!

The Dua-capture does indeed have a line input on (ugh!) stereo* 1/8th" jack and the nominal sensitivity is given as -10dBV or 316mV.

The amp does not give a level spec' for the emulated output AFAICS but I found a Sansamp bass module with an XLR out nominally for feeding a PA mixer. They say it is balanced but not what the level is but a good guess would be +4dBu or 1.2volts! And therein lies the problem, you need about 12dB of attenuation to get a level match (your instincts were good, talk of "impedance" was high order bollox!) ...Simplest solution? A pot in a tin. If you can solder I can send you a diagram.

But you mentioned a mixer? Yes, this would solve the issue IMO. A $50 mixer would easily cope with the standard +4dBu level and give you a controlled output as low as you need.

Mixers tend to get a bad rep on forums such as this but in fact, after the AI, mic, cans stands and leads, a wee mixer is about THE most useful bit of kit the noob can invest in!

*This has other implications depending upon other decisions.

Dave.

 

[St. Sixtus]

But you mentioned a mixer? Yes, this would solve the issue IMO. A $50 mixer would easily cope with the standard +4dBu level and give you a controlled output as low as you need.

Mixers tend to get a bad rep on forums such as this but in fact, after the AI, mic, cans stands and leads, a wee mixer is about THE most useful bit of kit the noob can invest in!

Cheers Dave, you're the man!

While soldering isn't a problem, I'd rather go for a mixer (the more gear, the merrier right?). Since I'm not using the mixer's preamp, I'm guessing I can go for a cheap Xenyx one and not have it affect the sound too much. Hook it up XLR/¼" jack for the input, jack/jack from the mixer out to the interface's TRS-Lo-Z.

 

[bdenton]

All you need is an XLR - TRS balanced cable.

Connect the XLR end to the SansAmp output on your amp. Connect the TRS end to your Roland interface. If you are plugging into Input 1, make sure the instrument input switch is set such that instrument input is turned off.

 

[ecc83]

Cheers Dave, you're the man!

While soldering isn't a problem, I'd rather go for a mixer (the more gear, the merrier right?). Since I'm not using the mixer's preamp, I'm guessing I can go for a cheap Xenyx one and not have it affect the sound too much. Hook it up XLR/¼" jack for the input, jack/jack from the mixer out to the interface's TRS-Lo-Z.

You are very welcome.
BTW..Nothing wrong with the preamps on an X802! Better than most AI's under £150. Son has made very acceptable acoustic guitar recording with ours and an SM57!

bdenton: Unless you have personal experience of both bits of kit I think you are overlooking the 12-13dB level mismatch?

Dave.

 

[bdenton]

You are very welcome.
BTW..Nothing wrong with the preamps on an X802! Better than most AI's under £150. Son has made very acceptable acoustic guitar recording with ours and an SM57!

Dave.

bdenton: Unless you have personal experience of both bits of kit I think you are overlooking the 12-13dB level mismatch?

The Tech21 Trademark 60 has a nominal output of -20 dBu from the SansAmp XLR output.

The Roland Duo-Capture Ex has a nominal input level of -46 – +2 dBu on the TRS line inputs.

Where is there a mismatch?

 

[bouldersoundguy]

I'm not sure 14dB headroom would be enough,

Neither am I.

I want to record what I believe lies somewhere between 70 and 95 dB (this is an approximation of the output of the real speaker, not the direct out). Could a mixer or pad between the amp and interface be the solution?

A mixer might do it but the pad will be cheaper, and being just a network of resistors it will be more sonically transparent and more reliable than a cheap mixer. I would get the 20dB pad and an XLRF-TRS cable for up to 34dB extra headroom.

 

[bouldersoundguy]

bdenton: Unless you have personal experience of both bits of kit I think you are overlooking the 12-13dB level mismatch?

The Tech21 Trademark 60 has a nominal output of -20 dBu from the SansAmp XLR output.

The Roland Duo-Capture Ex has a nominal input level of -46 – +2 dBu on the TRS line inputs.

Where is there a mismatch?

Possibly this:

Measured using a -10dB 400Hz test signal with all amp controls flat, no Reverb or Boost.
Actual levels will vary with your settings.