1 Topic by nateandrews (edited by nateandrews 2020-07-11 18:51:44)

  • Registered: 2020-03-10
  • Posts: 112

Topic: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

I've picked up a Focusrite ISA One preamp unit which is a DI as well as a mic pre.  The output signal of the DI on this unit is VERY HOT and it is fixed, no way to lower it on the ISA going out, only to compensate the signal on interface coming in.

I am connected as follows:

XLR from      DI OUTPUT of ISA          to LINE INPUT 7 REAR FF400 TRS
XLR from      MIC OUTPUT of ISA        to LINE INPUT 8 REAR FF400 TRS

The MIC is fine, more than enough gain or lack of gain as needed, very easy to dial in the right signal level with any mic I'm throwing at it.

The DI I think I may have solved but it's so borderline close to clipping if I really bash strings that I have concerns unless someone can set me otherwise.

I am opting to use the rear line inputs vs. the front inputs just to have a clean front of interface and free up the front ports for on the fly stuff I may need and because they seem to be the best suited for this specific DI output.

The DI signal from this box is fixed and VERY HOT and all I can do is make it HOTTER, I cannot tame it on the way out.

The RME MIC/LINE 1 or 2 inputs on the front even at 0dB, the signal is way too hot, not usable for this.  Insta-clip.
*QUESTION:  Does plugging a TRS cable into these 1/2 front inputs BYPASS THE PREAMPS AND MAKE IT LINE LEVEL?

The INST/LINE 3 and 4 have the PAD button but it does something to the sound, takes away balls.  I do not like to engage this PAD button and it still clips with PAD engaged.

That leaves just the rear inputs.  The only adjustments are the 3 settings for "sensitivity": Lo Gain, +4dbU or -10dbV.

The current setting I am on is Lo Gain which almost gets me there.  I have to hit my strings R E A L L Y hard to make it clip but I can make it clip if I really hammer.  I did read somewhere that RME has made it so this occasional very brief clip is OK?  Something about the inputs are not able to actually clip?  Is any of this correct?

If I wanted to put somethign in between the TRS input of the FF400 and TRS output of the DI signal to cleanly attenuate, what could be used?  I would like to have my DI signal, never, ever go about -3dBfs regardless of how hard I hit.  Every amp sim I am using wants a very fat and hot DI signal coming into it.

  • oli_w
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  • Registered: 2020-07-06
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Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

Hi. I have ISA One going to UFX+ and don't have this problem - the DI gain is usually between 1/4 and 1/2 way round. I think I've got the line input at +4dBU.

Does it clip when you go straight into the DI on the FF?

Does the impedence/Z button on the ISA One DI section make a difference?

You can also turn the guitar down a tiny bit.

Clipping before hitting an amp sim rarely sounds too bad - I'd imagine you're going for an overdriven amp sound anyway if you're hitting the strings, but I guess that may not be so.

  • Registered: 2020-03-10
  • Posts: 112

Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

I have the DI knob on the ISA one all the way down which according to the knob label, it is automatically adding +10dB right from the get go.  Pointless.

Does it clip when I go straight from guitar to INST IN 3 or 4 of the FF400 if those inputs are set to INST?  Yes, major clipping.

It wont clip if I set to LINE but that is wrong.  Even if I engage PAD on 3 or 4, I still clip.  This is with guitar going direct into FF400 IN 3 or 4 when set to INST with PAD on.  If i leave these as LINE in and bash, it will peak at -5dB.

I am using DIGICheck for all of this monitoring.  I have the MULTI CHANNEL LEVER METER up at all times and have all of the inputs I am testing through set to HARDWARE LEVEL and INPUT.

Does the impedace/z button on the ISA one make a difference?  No.

Yes, all I do is high gain.

  • Registered: 2020-03-10
  • Posts: 112

Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

This is not the "fault" of the FF400.  It's just that that ISA One DI output is REALLY REALLY hot and should have the option to attenuate what it is putting out.  I have a NEVE RNDI that I've run to MIC/LINE 1 of the FF400 and at the default stock settings on that channel the DI is totally "unclippable" in fact, I even have to engage the 10dB boost slider to bring it up a bit.  I do wish that MIC/LINE input on the FF400 had a variable input gain instead of the 10dB to start and then 1dB incredments from there.

I will have to solve this ISA DI output issue or go back to using my RNDI and only use the ISA for the mic pre.  I was hoping to use ISA for both.

  • cyrano
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Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

nateandrews wrote:

It wont clip if I set to LINE but that is wrong.

The input should be set to "line", not to "instrument". Why do you think it's wrong?

The "Instrument" setting is for direct input from a guitar. The ISA's output is line level. Far too much for an instrument input.

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  • Registered: 2020-03-10
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Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

cyrano wrote:
nateandrews wrote:

It wont clip if I set to LINE but that is wrong.

The input should be set to "line", not to "instrument". Why do you think it's wrong?

The "Instrument" setting is for direct input from a guitar. The ISA's output is line level. Far too much for an instrument input.

Cyrano.  I was referring to setting it to line when my guitar was directly plugged into FF just as an example.   When feeding it the ISA signal it is set to line.

  • Registered: 2020-03-10
  • Posts: 112

Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

After doing some researched, I ordered one of these for $38 bucks.  Will update once I get this inline between ISA One DI output and RME line input and will set it to drop -10dB.

Audio-Technica AT8202 Attenuator with 10, 20 or 30 db of Selectible Attenuation - In-Line XLR Barrel

8 Reply by nateandrews (edited by nateandrews 2020-07-13 22:17:40)

  • Registered: 2020-03-10
  • Posts: 112

Re: FF400 Line Inputs Rear, Settings, Line Level, ISA One Pre

I forgot to mention one other part that is puzzling to me.

I use DIGICHECK to watch the levels.  When I have ISA One DI output going to LINE IN 7 of RME set as +4dBu with no extra gain anywhere, the DI signal in DIGICHECK for the ANALOG 7 INPUT, set as Hardware Level, clips and goes red.  BUT, the recorded track itself on playback, peaks at -3dB.  This shows in both Cubase and in DIGICHECK for ANA1/2 Playback this -3dB peak and not going any higher.

How is digicheck reporting a clip on the way in, very obvious clip, but on playback both cubase and digicheck do not show anything above -3dB? EDIT:  This is a cubase setting about the "PAN LAW".