Why does my ISA One have more noise than my Scarlett?

[mrbman]

I'm a recording noob trying to understand why my new ISA One preamp hasn't reduced the noise in my recordings.

I have a small bedroom recording setup that includes a Focusrite Scarlett 4i4 3rd gen and an SM58 (my only microphone). With this setup I am trying to record quiet acoustic guitar, but of course it requires a lot of gain from my Scarlett. With the gain knob at around 80%, the 4i4 starts getting noisy and the volume is still too low.

To get a recording with less hiss and more gain, I figured it would be fun to try upgrading to a more powerful external preamp. I bought a new ISA One and plugged it into the rear line level input on my 4i4. I expected that this setup would let me turn the ISA One up to 60-65 dB and get a cleaner and louder signal than what I get from my Scarlett's built-in preamps.

While the raw audio from the ISA One is certainly louder than the Scarlett, my recordings still have just as much noise, if not more. In fact, it seems like I get better results from my Scarlett alone by just recording at 80% gain and increasing the volume in my DAW to match the raw volume from my ISA One. I've attached a recording from my ISA One at 60 dB going into the rear line level input of my 4i4, and a comparison recording from my 4i4 at 80% gain and the volume increased to match the ISA One file. To me, the ISA One does not sound like an improvement.

Am I making an amateur blunder? Was I wrong to expect that the ISA One would let me record at these levels with less noise than my Scarlett? Many people online have shown that adding Cloudlifters and other preamps to a Scarlett can make a big difference in noise reduction, so what am I missing? If my goal was to reduce noise in this situation, should I have purchased a nice condenser microphone instead of trying to get more juice to my SM58? Would appreciate any insight from those who have more experience.

 

[Steenamaroo]

Hi there!
Welcome to HR.

I think the noise in both clips is a : acceptable and b: a computer fan.
Might be wrong but it sounds like it's got ambience on it where equipment self noise would not.

 

[mrbman]

You're right, I was recording right next to a big ATX tower with fans going. I made the same recordings far away from my PC and the noise is much quieter, so thank you.

I guess this is revealing that I don't have a good enough ear to tell whether the ISA One is improving anything for me. I definitely get much more gain from the ISA One, but I can't tell much of a difference between a raw 60 dB recording from the ISA One versus the 4i4's preamp with the volume increased in my DAW. I thought there would be an obvious difference with the SM58, but if there is, I don't know what to look for.

 

[Steenamaroo]

Ah, glad to hear that's what it was. At least it's an easy fix then.

Don't feel bad - The differences between preamps can be very subtle, particularly when just comparing one single-track recording to another.
You might find the differences are more apparent after layering up multiple tracks, or when recording different sources...Maybe bass or drums.

The 4i4 preamps are already pretty good so, to be honest, I'm not surprised the difference isn't night and day.

 

[ecc83]

Not that I can be any judge but I agree, noise levels are pretty good.

This thread shows something that people still do not believe, it is perfectly possible to make a very good, low noise pre amp for about $5 worth of components. In the last 5 years or so AI mnfcts have got their design ***t together and produced pre amps that are close to state of art, at least in terms of adequate gain and noise.

So, the ASI One might not be much quieter than the Scarlet but likely has higher ultimate headroom.

Dave.

 

[mrbman]

That's an interesting take. I did a lot of online research on the ISA One before my purchase, and many of the reviews were from 7-10 years ago.

 

[CoolCat]

You're right, I was recording right next to a big ATX tower with fans going. I made the same recordings far away from my PC and the noise is much quieter, so thank you.

I guess this is revealing that I don't have a good enough ear to tell whether the ISA One is improving anything for me. I definitely get much more gain from the ISA One, but I can't tell much of a difference between a raw 60 dB recording from the ISA One versus the 4i4's preamp with the volume increased in my DAW. I thought there would be an obvious difference with the SM58, but if there is, I don't know what to look for.

I remember when that happened here too, funny...the ATX tower fan!!
Not heard with the headphones off, but with the studio cans "ON"..yikes!
.seems funny once you realize how much every little sound is magnified.

Same thing happened slapping on heavy compression, where it raises the quiet levels to some abnormally huge noise floor, it seems.

Most of the noise floor is meaningless once the drum track and music is playing for rockpop music..... which uses slamming comps and other odd distortions on purpose. For Folk or Classical, probably a more demanding silence is needed.

As for the ISA One, I had the same results and sold it. Its an awesome built tank, it has tons of GAIN but sonically I did not hear some huge Capital Records Mastered Vocal track when I used it, versus my interface preamps.
I also spent a year or so trying different preamps and none of them did any better than the ISA One sonically. It became miniscule with transformers, tubes, IC clean, ….at least for what I thought would happen. That's a misconception I had was that a preamp would add some huge Pro Studio sound to my HR track. IMO it doesn't happen. If you find some that are FX, and intentionally add sparkle or Eq or distortion that's different. SM58...SM7b...low output....try a Cloudlifter and its about the same as a ISA 1...imo. If you don't need any gain added, because your source is loud you don't even need a Cloudlifter.

If youre expecting, searching for some "studio sound" Compressors probably got me the most change I was looking for, as in going from sterile dry interface pre with SM58, to some "radio dj compressed studio sound". Voice Channels have all that, preamp+eq+copmpression+ maybe a gate too....or you can buy separate, ISA One>EQ>COMPRESOR....

the gang here got me to a DMP3>RNC and that was another...wow...moment, adding the RNC especially versus the interface cheap mixing board portastudio. Even going through 50 variations since, the DMP3/RNC holds up well to the others Ive tried, some $2000 pieces.

a lot of bloated marketing crap and hype out there, imo.

 

[mrbman]

As for the ISA One, I had the same results and sold it. Its an awesome built tank, it has tons of GAIN but sonically I did not hear some huge Capital Records Mastered Vocal track when I used it, versus my interface preamps.

What led me to the ISA One was that I had originally paired an older Presonus Audiobox USB with my SM58. The Audiobox preamp was almost unusable in that combination, and when I switched to the 4i4 I noticed a substantial improvement in gain and noise. I figured an ISA One with all the extra headroom would be a similar upgrade to the Scarlett. I agree that the ISA One is well built and a neat design, but it does seem like the 4i4 preamp is enough for what I'm doing.

 

[JamEZmusic]

Coolcat, ^^ Awesome post, I had my eye on that ISAone for a while. I am not too eager to break the bank now. I was wondering if it would saturate my tracks in that nice way but with the (night and day) difference over my scarlett interface pre-amps, but for the cost of it and what you said. I will hold off for a while. Cheers for saving me a ton of money.

To OP - I've had nightmares in the past trying to track in room with a noisy PC fan. I almost went through the effort of lifting floorboards to run cables outside of the room and dumping the tower out there while keeping the monitor etc in room I wanted to record in. After a lot of thinking, I decided to invest in the macbook pro instead, problem solved. Had a lot of issues for a long time with that tower PC. Those tracks I used to record are laughable because of it, funny looking back on it now. But I remember it like it was yesterday, one of the biggest setbacks I've ever endured.

 

[rob aylestone]

If you want a real test - you need to determine the best gain staging between the two devices. As the pre-amp is not a conventional audio interface, you don't have the option of using the ADAT output as the Scarlett doesn't have an ADAT digital input - so you have a choice - jack line out to the Scarlett jack line in, or you can use the XLR out to the Scarlett XLR in. The Scarlett will accept the line input happily and you turn up the gain and away you go. If you use the XLR, then the Scarlett gain will need to be down very low - in fact so low you might still find with the pad it's still too hot.

The snag is you are then stuck with the gain figure the Scarlett produces. The nice preamp cannot make it lower, because you are cascading two analogue devices. Your best setting will be minimising the noise, while benefitting from the perhaps illusional character these preamps produce. So you will need to experiment with the settings on both to achieve optimal matching by the two routes you have, XLR or Jack, or perhaps even with XLR to jack.

I suggest you make a connector up that shorts all the pins together. Then as you experiment to get the best noise figure - you swap the mic for the shorting plug, and record a short 30 second clip. This will include NO audio, but will allow the noise of the entire chain to be recorded. Label the file properly, then do the next connection idea with the mic, then do the short recording again. You can then review the recorded silence and see which is the least noisy - and therefore the best gain staging for your kit. This is practically the only way to do it. By chaining two devices, you cannot reduce the noise below the worst of the two devices. However - being frank, if your experiments to date got electronic noise mixed up with fan noise - you may have bought technology a little above your current skill level.

Personally, if you're beginning in your audio experience and can send the expensive preamp back, do it now. The Scarlett is very effective. Get used to that until your experience convinces you, you need better. Then, and only then, buy a better input system - which will be a clever preamp with built in A to D converter, or a clever preamp with a matching top quality interface.

I have never been convinced I need these devices. I very rarely need to explore the gain settings where noise is an issue on my kit. If I recorded quiet sources, from a distance, then I'd have no issues buying one - but I just don't need them, AND I've had Shure SM7B mics plugged in perfectly happily - even though it seems the internet insist a Cloudlifter MUST be used - I don't have one and have never found gain a problem.

 

[ecc83]

I agree Rob...Except! Don't sort all three XLR pins together. Short* 2 to 3 and leave 1 firmly alone. Reason?

You don't want phantom power draining down to earth as that might (unlikely but might) cause noise and anyway 'live' conductors such as those of a mic capsule are not supposed to be grounded.

I too suspect that the pre amp is in fact at least AS good for noise as the Scarlet but as you say it is difficult to devise a connection and gain staging to prove it.

*Optimally you should use a terminating resistor of 150-200 Ohms but in practice this makes but a dB or so of difference and in any case depends very much on the precise design of the pre amp's front end.

Dave.