Focusrite 6i6 - upgrade/mod

[USchabon]

Welp, since I have a soldering kit on the way thanks to deciding to fix a monitor that died on me (and preparing to fix the second one in case it also dies, and deciding to try to fix an amp for some speakers that died a while back) I thought I might as well start planning my mod/upgrade for my Focusrite 6i6. Heheh

I came across this thread, where a user says he replaced the OPAMPS and plans to replace the headphone drivers as well.

Please don't skimp on opamps. I took apart my 6i6 today and replaced all the NJM4565 (8 in total?) with OPA2228 and LM4562 (THD+N in the order of 0.00005%), retaining only the NJM2122 and TL072 on the mic pre. Boy! The sound is so much more pristine now! The NJM4565 doesn't do justice to the 2 CS4272 converters in there!!! I would gladly pay $50 more for better opamps!

I love this unit now!!

As far as I can remember, you'd have to remove the nuts and screws on all the connectors at the rear. Remove the back panel and use a long flat head screwdriver from the rear to release the catch of the front panel before the board can slide out from the front.

On the board, you will see quite a number of NJM4565 (7 or 8 of them on the output stages if I recall correctly). I would recommend to replace them all with the LM4562 in the SOIC-8 package. They are pin to pin replacements, so it's a matter of just soldering and desoldering.

There are also several (2?) TL072 in the input stage which might benefit from the LM4562 also.

I might also consider to replace the headphone drivers (I can't remember if they were NJM4556?) with LMH6643 or AD8397. When I do get to that, I will remember to take some pictures.

A. I am not sure if the OPAMPS are the only thing that affects getting a strong and clean signal out of a microphone... but I am using microphones in my front inputs and would love to get a stronger and cleaner signal for this one mic that needs a lot of gain. So, is there a way to identify the OPAMPS for the two front XLR inputs? Might also be worth mentioning that out of the two XLR inputs the one on the far left ("01") is noticeably more noisy.

B. I am also very interested in upgrading the headphone driver/s like that user mentioned. And... I also should mention, that there seems to be an issue with the headphone output on the far right ("HP1") which is that when I lower the volume all the way, the left channel remains clearly audible. I really only need one headphone output though...

Which are the BEST components I could use out of the ones he mentions in his post?

Here are some photos. The first is too far from the unit but it covers the whole board, the second are two separate photos but much sharper.

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

Here is a link to their website: https://us.focusrite.com/usb-audio-i...s/scarlett-6i6
And a photo of the front and back panels:

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

I am I right to assume that the four MAX4477 I marked in this photo are what I need to replace to get better sound to the headphones?

I also marked seven NJM4565 which are what the other user replaced. I'll triple check if there is an 8th NJM4565 when I open it up again and order an extra just in case.

Am I missing anything else that needs to be or could be be upgraded?

[Khron]

Re: Focusrite 6i6 - upgrade/mod

An interesting exercise might be, for example, swapping opamps on only one of the input or output channels, so you can do direct comparisons. Otherwise confirmation bias WILL get you

Noisy mic input - might just be worth "wiggling" the gain pot from end to end a good few times. Not a guaranteed fix, but hell, it's free and quick

In the Saffire Pro 40 i used to have a few years ago, the NJM2122's were the actual mic preamps, from what i had managed to figure out from where the traces went. All the 4565's were handling the rest (line-level duties).

I'm slightly skeptical about opamp upgrades, and NwAvGuy's series of investigations comes to mind - http://nwavguy.blogspot.fi/2011/08/o...surements.html **cough** NJM2068 **cough**

That being said though, the good news is that at least the Focusrite engineers did their homework - i see 0603-packaged light-gray ceramic caps (NPO / C0G) in the feedback loop of all the opamps, so you should be in less danger of the replacement (higher-bandwidth) opamps breaking into oscillation.

I'd much rather start with recapping the whole thing - all those CapXons make me shiver
And i'm not a huge fan of Jamicons either, but if i had suitable replacements in stock, i'd rip those out too

Those MAX4477's i suspect are actually driving the ADC inputs. At least according to the datasheet, they're not all that shabby either - https://cdn.badcaps-static.com/pdfs/...39684215e5.pdf

Are you sure there are no (other) opamps closer to the actual headphone connectors? It's not infrequent to see SIP-packaged NJM4556's there (like i had in my Saffire, or in my current TC StudioKonnekt 48). Unfortunately that area's not visible in your photos, due to that top board with the pots there.

The headphone "channel imbalance" issue may well be down to the tolerances of the stereo pots. It's a relatively "budget" piece of gear, let's be honest

If you insist on replacing the TL072's, you'll want to use some other JFET-input opamps; those are for the DI / instrument inputs, where you want/need high impedance. LM4562 is a BJT-input opamp.

LMH6643 as a headphone driver? I wouldn't. First of all, you'll wanna check what voltages are used to supply the headphone driver opamps - if they're the more usual +/-10-15v, it's a no-go (datasheet says +/-6v or so). I recall in my Saffire the opamp supply rails were +/-7v due to the dissipation limits of the NJM2122's used in the mic preamps. Oh, and second, 50MHz GBP? That's just asking for trouble, imho

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

Thank you for your post!

I am definitely looking for educated advice and not trying to fool myself. That is why I came here instead of hoping to get info from a music forum. I thought it would be too much to ask to identify the channels, but if we can do that I would love to do one so I can test with actual recordings that I can loop back-to-back! I am gonna need your help though, as most of what I am doing here is a blind guess helped only by what I can find on forums.

My strategy: Provide the BadCaps community with all the photos I can and hope a consensus is reached in the thread telling me exactly what to do



Below are more photos showing everything the previous photo didn't capture due to that little board that runs along the front panel hiding stuff.

Like you predicted, I found the 8th 4665 tucked away under there towards the left in the second photo. I would really SUCK to have to replace that one, as a BUNCH of stuff would have to get desoldered in order to remove the little board, which would have to come out to be able to work on that 4665.

There are some other interesting looking components under there, which I hope you will be kind enough to decipher for me, as to my un-educated eyes they might as well be hieroglyphics.

[Khron]

Re: Focusrite 6i6 - upgrade/mod

Ehrm... What exactly would need to be desoldered, to remove the pot-board? The wiring harnesses go into connectors, on the pot-board

The knobs you can most likely pull off, which might then free up the front panel. And then there's the trivial matter of those three(?) screws, and job done

This wasn't designed by Apple, y'know, so the assembly is NOT to spite servicing

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

Awesome, that's good to know, I thought I saw some stuff that was locking it down but I think I might have confused myself.

So what are you thinking? What would YOU do to this unit if these were your areas of interest, in order:

Important:
1. Better headphone sound
2. Cleaner and more powerful signal from mics in front inputs 1 and 2
3. Cleaner signal to the monitors (using outputs 1 and 2 in the back)

Trivial:
4. Better sound in through rear inputs 3 and 4 (furthest out in the back), I am using an unbalanced signal from my TV box so kinda pointless to put effort into this, but since I don't know might as well put it out there

[Khron]

Re: Focusrite 6i6 - upgrade/mod

1. What is "better"?
2. Are you getting distortion or noise? Or should i say, more than with the same mics using another audio interface?
3. Same question as above.
4. Same question as 1.

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

1. Stronger bass drive, lower noise floor, more frequency range... anything that could be improved.
2. There is this one mic I have that I like, but I need to get to the very top of the gain on the dial to get a strong signal out of it. Up there there is some noise.
3. Only lower noise floor here.
4. I really don't know what could be improved since the signal itself comes in with so much noise that it is pretty much useless to try to improve the interface. Might be best to research about how to get a different output from the box into the interface... but not worth that much. This is just for me to watch TV while I wait for a video render to finish.

[Khron]

Re: Focusrite 6i6 - upgrade/mod

1. Maybe increase the values of the output coupling caps? Of course, within the physical limits available. Although that also depends on the 'phones you use, and obviously your ears
2. Any and all preamps WILL have some noise when you gun the gain. Is that a ribbon mic, or something like an SM7? I've heard of a doohickey called a Cloudlifter, which supposedly provides can't-remember-how-many-dB of clean gain, between the mic and the preamp input.
3. I guess some low-noise opamps should be sufficient then - but then you'd have to wonder just how much noise is added by the electronics & amps in your monitors.

[stj]

Re: Focusrite 6i6 - upgrade/mod

this thing is probably built better than your "tv box"
so start at the source and look at the tv-box output circuits.

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

1. That sounds good. So I guess capacitors DO have an effect on sound, right?
2. Not worth the investment considering I am getting good enough results already. But if there is a little to be had with a component, I am game.
3. The speakers are EVENT 20/20p

STJ, for sure, didn't think of that. If there is a simple mod that would have an effect, I am game. The box is AT&T Uverse's Motorola VIP1225. Where can I look into that. I wouldn't know where to start, as you can tell.

[Khron]

Re: Focusrite 6i6 - upgrade/mod

1. Inasmuch as the series DC-blocking output caps form a high-pass filter with the impedance of the headphones. For a certain impedance, a larger value (more uF) will yield a lower cut-off frequency
2. Any chance you can place the mic closer to the source?

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

1. Inasmuch as the series DC-blocking output caps form a high-pass filter with the impedance of the headphones. For a certain impedance, a larger value (more uF) will yield a lower cut-off frequency
2. Any chance you can place the mic closer to the source?

1. I have no idea what you just said
2. Nope. You know I guess what I want is not so much a stronger signal, but a cleaner signal towards the top of the gain.

So what are you thinking? What changes would be worth trying?

[stj]

Re: Focusrite 6i6 - upgrade/mod

STJ, for sure, didn't think of that. If there is a simple mod that would have an effect, I am game. The box is AT&T Uverse's Motorola VIP1225. Where can I look into that. I wouldn't know where to start, as you can tell.

just trace the output pins back - if they go through an electrolytic then replace it with rubycon YXF or a film cap.

[Khron]

Re: Focusrite 6i6 - upgrade/mod

What microphone(s) do you need that much gain for, though?

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

It is a Russian cardioid called Oktava Mk-012-01

just trace the output pins back - if they go through an electrolytic then replace it with rubycon YXF or a film cap.

F'yea! Easy enough

[stj]

Re: Focusrite 6i6 - upgrade/mod

foto's of the board then

[USchabon]

Re: Focusrite 6i6 - upgrade/mod

foto's of the board then

BOOM!

https://www.badcaps.net/forum/showth...712#post665712

Figured I might as well make a separate thread to keep things searchable and organized as my contribution to the BadCaps community

[budm]

Re: Focusrite 6i6 - upgrade/mod

BOOM!

https://www.badcaps.net/forum/showth...712#post665712

Figured I might as well make a separate thread to keep things searchable and organized as my contribution to the BadCaps community

That link is for your Motorola VIP1225 - (AT&T Uverse).
I thought this thread is about Focusrite 6i6.
Never mind, I see what is going on now.