Focusrite ISA One v Scarlett 18i20 preamps

[biffjunior]

Hi,

So I’m looking at buying an ISA One, mainly to record bass, electric guitar and vocals, but I’m just wondering if the sound would really be enough of an improvement on the sound of the preamps in my Scarlett 18i20 to justify the cost.

I also know that it’s not possible to bypass the preamps in the 18i20, so if I were to buy an external preamp, would this be an issue?

Thanks

[Drew Stephenson]

General thinking around these parts tends to be that the order of importance goes something like this:
1, Material,
2, Performance,
3, Room acoustic,
4, Mic position(s),
5, Mic choice,
6, Pre-amps and other stuff.

The pre-amps in the 18i20 aren't shoddy so personally I'd only be thinking of improving on them if I was completely happy with everything further up the list first.

[Sam Spoons]

Edit, Drew types faster than me

How good are your monitors, mics and room treatment? If they are very good then it might be worth investing but even then decide what you feel the shortcomings of your current room and rig are then consider whether a better preamp would be the most effective way to improve. It's worth remembering that outboard preamps are usually employed for the way they add character (i.e. distortion) and if you want an accurate sound the preamps in your Scarlett are probably better than you really need.

But, even before all of that, you need to consider the source, i.e. the voice, bass, guitar sounds and, even more importantly, the song and the arrangement.

A well respected forum regular posted that, in order of importance, the things that affect your recordings are :-

1. The Composition
2. The Arrangement
3. The Performance
4. The Room Acoustics
5. The Mic placement
6. The Mic Selection

Then the mic preamp and all the rest of the electronics...

[biffjunior]

Thanks for the replies. I DI my bass and electric guitar tracks and use amp sims and cab IRs in my DAW, so at least for those 2 instruments room acoustics and mics don’t factor in. In that instance would a preamp maybe be more beneficial?
As far as vocals are concerned, where I’m living right now there’s no room treatment, but I will be moving somewhere where I intend on investing in some room treatment in the near future.

[biffjunior]

Regarding adding colour to the sound, that’s sort of what I’m after, mainly for bass and guitar parts at the moments (I won’t worry about vocals until I’ve got a better treated space). I’ve read that an ISA One is a very clean pre, so would a Warm Audio W12 or something similar be better for this purpose?

[MOF]

The ISA preamps were designed to have a very wide frequency response and be able to cope with a wide variety of impedances and have plenty of gain.
It was a desire for quality, not character principally.
https://www.soundonsound.com/reviews/fo ... sa-one?amp

[ajay_m]

If you could go back in time to, say, the 70s, where so much great music was recorded and often at very high technical quality ( eg Steely Dan ) and you took any standard audio interface now available with you, then studio engineers would marvel at the low noise level, distortion and dynamic range compared to the discrete transistor designs then available. Opamp technology was in its infancy and jfet and MOSFET devices were just starting to be marketed, with huge per device parameter variation due to difficulties in controlling the diffusion processes by which they are made.

In short, pretty much any modern audio interface offers performance way beyond the ability of the human ear to distinguish, and despite all the twaddle in hifi magazines, scientific a:b testing in a controlled environment completely trashes a lot of nonsense about perceived sound quality between amplifiers or preamps.

Speakers remain the weak link in the chain with distortion and frequency response non linearity orders of magnitude beyond the electronic bits of the chain. To a lesser extent this applies also to microphones.

Finally poor room acoustics add further colouration to the sound. So worrying about preamps is like having the cylinder head on your V8 chrome plated. It looks nice but has no impact on car performance.

Now I do appreciate there are preamps typically with transformers where there is deliberate non linearity which imparts distortion that to the human ear sounds pleasing. If this is what you want, then sure go ahead. If you want the input chain to be essentially a "wire with gain" then you can easily add distortion via plugins that will mimic that from a transformer, we have the sophisticated modelling and CPU power now to do that.

Another reason to upgrade is just that you feel inspired by your new gear. If this unlocks the creative impulse or just gives you a buzz, who am I to say you shouldn't spend money on an upgrade. Indeed I have praising my shiny new mixer on another thread which technically doesn't add any capability to what I could do but sure makes it much easier to do stuff that previously might have been an inspiration killer.

In which case just buy something from a top end vendor like RME and it'll be like easing into the leather seat of your mercedes. You won't get there any faster than my humble ford focus but the journey will be more enjoyable! (PS unfair to my car, the focus is a very taut and poised thing to drive, as many reviewers have said. But.. plastic, not leather)

[Arpangel]

Pro's of the Focusrite, it has a chunky look, a nice big meter, a fetching blue colour, and nice coloured knobs, plus a carrying handle, these are all things I would buy it for, it’ll sound good too, but that’s a given, so why not have all the other stuff? It’ll make you feel better, and anyone else that’s using it, just make sure you use really thick mic cables with it, and a prestigious large diaphragm condenser.

[tea for two]

Pro's of the Focusrite, it has a chunky look, a nice big meter, a fetching blue colour, and nice coloured knobs, plus a carrying handle,
...just make sure you use a prestigious large diaphragm condenser.

For same reasons I dig it I think it's the most attractive single mic pre. I think it will look quite fetching with the Neat King Bee condenser I just purchased.
https://www.soundonsound.com/reviews/ne ... worker-bee

Also it's approx same price used as a new Cranborne EC1.

[Arpangel]

Pro's of the Focusrite, it has a chunky look, a nice big meter, a fetching blue colour, and nice coloured knobs, plus a carrying handle,
...just make sure you use a prestigious large diaphragm condenser.

For same reasons I dig it I think it's the most attractive single mic pre. I think it will look quite fetching with the Neat King Bee condenser I just purchased.
https://www.soundonsound.com/reviews/ne ... worker-bee

They share "yellow bits"

[Wonks]

What I can't find any info on is whether the ISA One has the same dynamic range in just preamp mode as it claims to have with the optional digital board in of 119dB (or whether this is applicable to an all-analogue device).

But assuming that the ISA One does achieve a dynamic range of 118-119dB with the digital board (and that's not just the spec for the board alone and it's lower when installed in the ISA One), then passing the analogue signal through the 110dB dynamic range Scarlet preamps will limit the ISA One's full potential.

In most instances this really won't matter, but on some sources you may benefit from the extra 8-9dB of dynamic range.

One option would to be to get an ISA One with a digital output board, which would obviously bypass the Scarlett's preamps so you get the best from it.

Another would to be to move up to a Clarett interface, say the 8+, which has a measured (by Hugh) 118dB dynamic range and very similar preamps to the ISA One, though lacking the Lundahl transformer.

But as has been said several times already, you won't hear any benefit until you start working in an acoustically treated room.

[Hugh Robjohns]

Regarding adding colour to the sound, that’s sort of what I’m after, mainly for bass and guitar parts at the moments (I won’t worry about vocals until I’ve got a better treated space).

In that case, I'd be looking at a fruity DI unit or a modelling guitar pedal/processor to introduce some character... Something like the Radial HDI, perhaps as a dedicated studio DI

https://www.soundonsound.com/reviews/radial-hdi

Or my favourite catch-all recommendation, the Cranborne EC1 or EC2 (single or dual channel), or the Camden500 if you're into 500-series hardware.

It's a stunningly good ultra-clean preamp, but with adjustable colour in two different genres via the Mojo control... and it has a nice DI front end and a powerful headphone amp too.

The ISA One is a lovely preamp, but I'm not convinced it will give you the DI colour you seek. Its a bit too subtle for that.

[tea for two]

What I can't find any info on is whether the ISA One has the same dynamic range in just preamp mode as it claims to have with the optional digital board in of 119dB (or whether this is applicable to an all-analogue device).

Another would to be to move up to a Clarett interface, say the 8+, which has a measured (by Hugh) 118dB dynamic range and very similar preamps to the ISA One, though lacking the Lundahl transformer.

But as has been said several times already, you won't hear any benefit until you start working in an acoustically treated room.

This intrigued me because I was looking at an ISA One used they go for a rather attractive price (also looking at Cranborne EC1).
Guessing if ISA One requires an optional digital board to get to 119dB dynamic range then without the digital board the dynamic range is less but how much less, else there wouldn't be a need for the the digital board.
So even though I really likey the looks of the ISA One my favourite single mic pre in looks, my focus might have to shift towards the Cranborne EC1.

[Drew Stephenson]

With modern interfaces and pre-amps I'd only be looking to add an external pre-amp if I wanted to deliberately add colour. In which case I'd be looking for something designed specifically for that job - the Cranborne springs to mind as a candidate but there are others with similar features.

[Arpangel]

What I think about when I hear someone talking about wanting colour, mojo, warmth etc is, have they had these things in the past, do they have any reference points? I could make a preamp and say it had "mojo" but what exactly does that mean? in reference to what?
I think this is all stabbing in the dark looking for that magic something that will make your music sound wonderful, it’s a blind alley.

[jxnWHITE]

... when I hear someone talking about wanting colour, ... do they have any reference points?

yes they do, in my case it's my own voice, as i use pres as audio condiments in a lost cause to come up with something i can listen to.

that being said, recently picked up an EC2 and absolutely love it. already had 4 channels of heavily modded tube pres and 2 of transformer based flavor, but this is becoming a goto with a couple of JZ mics on peeps who really can sing.

the advice on song/performance/etc/etc is dead on. jmho.

[tea for two]

On the tinterweb a couple people that had both ISA One and Audient id22 computer interface say they are pretty much same as far as they are neutral colourless as they can be.
I don't have either so I can't say one way or another. I had Audient id4 mk1 of which I thought it's mic pre was as neutral colourless as such interfaces get.

If only the Audient was BRG in colour with a large VU meter also with a better headphone out.

[Arpangel]

... when I hear someone talking about wanting colour, ... do they have any reference points?

yes they do, in my case it's my own voice, as i use pres as audio condiments in a lost cause to come up with something i can listen to.

that being said, recently picked up an EC2 and absolutely love it. already had 4 channels of heavily modded tube pres and 2 of transformer based flavor, but this is becoming a goto with a couple of JZ mics on peeps who really can sing.

the advice on song/performance/etc/etc is dead on. jmho.

AH!
I think we’re opposites, I think if a voice is s**t, or anything for that matter, you should emphasise it’s s**t if you go the other way it’s always a give-away. Mark E Smith made a career out of it, and the list goes on.
An Amazon basics mic would be way too good for some people, me included, I’d use a karaoke mic plugged into a Tandy mixer, and it wouldn’t make the slightest difference to my singing abilities, or my music, in fact, if I used a U47 and a Neve preamp it’d probably sound worse, you'd hear "me" and we don’t want that.

[jaminem]

I’m not gonna get bogged down in the chain of bang for buck that’s been mentioned earlier in this thread. I agree with it.
Having said that the ISA One’s DI is the best bass DI I’ve used. It’s not coloured per se, but It does do a thing. The bass sounds really ‘solid’ and focussed through it.
I sold my original one and replaced it with an API 505 DI.
It’s just not as good
I bought another ISA One.

the converter on it sounds really good too.
It’s just quality really. It gives you a clean solid signal that responds well to eq and further processing. That’s what I really need when recording bass because It can be a tricky to get right, and if you’ve already committed to character it’s hard to undo if it’s not right.

[James Perrett]

On the tinterweb a couple people that had both ISA One and Audient id22 computer interface say they are pretty much same as far as they are neutral colourless as they can be.
I don't have either so I can't say one way or another. I had Audient id4 mk1 of which I thought it's mic pre was as neutral colourless as such interfaces get.

Audient claim to use the same preamp design through all of the iD and ASP range although the specs of the iD4 are very slightly inferior to the more expensive units. Accurate, neutral mic preamps aren't necessarily expensive to make but the skill is in the design, layout and attention to detail in the manufacturing. If the PCB designer routes a trace in the wrong place they could undo all the good design work.

[MOF]

SOS are giving away the four in a box version.
https://www.soundonsound.com/competitio ... a-428-mkii

[Hugh Robjohns]

Guessing if ISA One requires an optional digital board to get to 119dB dynamic range then without the digital board the dynamic range is less but how much less, else there wouldn't be a need for the the digital board.

You're inventing a weird audio magic there T42. Adding the converter board doesn't change the performance of the analogue preamp. It just provides a digitised output.

The dynamic range of the converter chip on its own is a very healthy 119dB. This is good and means the converter is definitely not a weak link in the system.

The published specs also claim the preamp noise floor at unity gain (with a line source) is -97dBu. So if the maximum analogue output level is +24dBu then the analogue preamp's total dynamic range (with a line source) is 121dB.

Which means the converter board is well matched to the performance of the preamp, and (with a line source) the digital converters dither noise will be just fractionally higher than the analogue noise floor.

I have a feeling, though, that the standard Focusrite digital alignment sets 0dBFS at +22dBu, which means only 119dB of the preamps's dynamic range is digitised, and the analogue and digital noisefloors and dynamic range are therefore exactly the same...

However, as soon as you start dialling in hefty chunks of microphone gain, the situation changes. Not only does the preamp's own noise floor rise but the ambient acoustic noise picked up by the mic will quickly swamp any electronic noise in most practical recording environments.

The ISA One's EIN figure is -126dBu with 60dB of gain. What that means is that with 60dB of gain the preamp noise floor is -66dBu. The mic pre clips at +9dBu, so the preamp dynamic range with 60dB dialled in falls to 75dB... Lower gain would give more dynamic range, and vice versa.

Of course, it's highly unlikely that any real world recording in a project studio or on location will have a noisefloor 119dB below clipping level. You'd be doing really well to get it down to -70 or -75dBFS for that matter...

So even though I really likey the looks of the ISA One my favourite single mic pre in looks, my focus might have to shift towards the Cranborne EC1.

The EC range technically outperforms the Focusrite ISA (with a lower noisefloor and slightly greater dynamic range) ... but doesn't have the option of a digital output. In the real world, though, you are very unlikely to notice any difference in dynamic range because the acoustic environment will limit it before either preamp can.

[tea for two]

Guessing if ISA One requires an optional digital board to get to 119dB dynamic range then without the digital board the dynamic range is less but how much less, else there wouldn't be a need for the the digital board.

You're inventing a weird audio magic there T42. Adding the converter board doesn't change the performance of the analogue preamp. It just provides a digitised output.

The dynamic range of the converter chip on its own is a very healthy 119dB. This is good and means the converter is definitely not a weak link in the system.

Aaah appreciated Hugh. Happy always to be enlightened.

[tea for two]

I think if a voice is s**t, or anything for that matter, you should emphasise it’s s**t if you go the other way it’s always a give-away.
An Amazon basics mic would be way too good for some people, me included, I’d use a karaoke mic plugged into a Tandy mixer, and it wouldn’t make the slightest difference to my singing abilities, or my music, in fact, if I used a U47 and a Neve preamp it’d probably sound worse, you'd hear "me" and we don’t want that.

Tru dat. Same for me my £15 Zinghyou condenser Zoom U44 mic pres are just right for my aaardvark voice

Reason I'm probably going to get ISA One is for a project that could well sprawl years, that doesn't involve me in any shape or form rapping singing nor playing instrument through ISA One : thank heavens lol.

ISA One’s DI is the best bass DI I’ve used. It’s not coloured per se, but It does do a thing. The bass sounds really ‘solid’ and focussed through it.
I sold my original one and replaced it with an API 505 DI.
It’s just not as good
I bought another ISA One.

the converter on it sounds really good too.
It’s just quality really. It gives you a clean solid signal that responds well to eq and further processing. That’s what I really need when recording bass because It can be a tricky to get right, and if you’ve already committed to character it’s hard to undo if it’s not right.

Just what I wanted to find out. Appreciated Jaminem....some relation to Eminem