Focusrite Scarlett mono 3 - external DAC and 'phones amp question

[Wasteman]

Replacing my Early 2009 iMac with an M1 iMac means I need to reconfigure how I hook up my electric guitar for recording to Garageband.

I've already decided to get s Scarlett mono gen 3 as audio interface (before, I could just connect to the audio in on the old iMac). Previously I also used a Cambridge Audio DAC Magic to connect a Creek OBH21 headphone amp, with Grado SR125 'phones for playback.

My question; am I overcomplicating things to use the audio out on the Scarlett in order to keep the DAC and 'phones amp in use? Even if I do, is the DAC Magic still required, or will the Scarlett + OBH21 do the job just as well?

Thanks for any feedback.

 

[AnalogSteph]

I've already decided to get s Scarlett mono gen 3 as audio interface (before, I could just connect to the audio in on the old iMac).

Decent choice. The current Scarletts are long past the input clipping issues of the first generation now.

BTW, the old iMac may have had a line-level input but that doesn't mean that it would have been particularly ideal for guitar. Instrument inputs tend to have very high input impedance, often around 1 Megohm, vs. a more typical 22 kOhms for normal line-level affairs. Your guitar may have been sounding rather dull so far.

Previously I also used a Cambridge Audio DAC Magic to connect a Creek OBH21 headphone amp, with Grado SR125 'phones for playback.

Oldschool. (I would look into some parametric EQ presets for the Grados, they are hardly the definition of pure canned neutrality. Also, I imagine the old OBH21 will be a far cry from modern high-performance amps. Seems to be using 2 pcs. NE5532, so it may be an "apheared-47" style buffered circuit... serviceable and still way better than the seriously lame Scarlett output but you can get far better-performing amps in the $100 class these days.)

My question; am I overcomplicating things to use the audio out on the Scarlett in order to keep the DAC and 'phones amp in use? Even if I do, is the DAC Magic still required, or will the Scarlett + OBH21 do the job just as well?

The Scarlett headphone out with a matching adapter cable should be fine. It'll be 2-3 dB quieter than the DacMagic unbalanced out (I recommend going down ~2 dB more) but that's pretty much that. Dynamic range at a nominal 104 dB(A) is still more than sufficient for a line-level source, and with negligible output loading the critical areas of distortion and channel separation should be kept in check very well.

Note that the Scarlett Solo only has one volume dial affecting line-outs and headphones equally, the more costly 2i2 gives you an independent headphone volume dial as well. This may be relevant when using both speakers and headphones.

Your new iMac no longer has Toslink output, and the old DacMagic only supports up to 16/48 input via USB (a common restriction pre-2011 or so), so any discussion of potential performance past the corresponding limits (~98 dB(A) maximum) is pretty much moot anyway and you can seriously consider retiring it.

 

[Wasteman]

Wow. That's a very comprehensive answer and more than I'd hoped for, thank you. Absolutely right that the guitar sounded dull, so I'm really looking forward to enjoying the difference the Scarlett will bring. I also appreciate the guidance on the DAC and 'phones amp I have. Silly, but I'd failed completely to factor in their age and tech progress since. That said, Old School or not, they still sound good together :0) But you're right, I'll check out the OBH21 with the Scarlett but consider the DAC Magic as obsolete in these context. Thing is, I'm still listening to music through a Sugden Pre/mono bloc hifi so my experience of contemporary tech is somewhat blinkered. Thanks again for taking time to write such a complete response to my queries.