PreSonus Firebox 24bit/96khz loopback measurments

[kipman725]

I acquired this interface cheaply and have performed some measurements to evaluate its suitability for measuring amplifier etc. https://www.presonus.com/products/firebox This is an example of a several generations old budget audio interface.

Measurement setup is with a 3 conductor jack lead input 3 and output 1L. It's worth noting that the outputs of the firebox are not diffirential and are instead 'impedance balanced' which means that the -leg is connected to ground via a resistor instead of driven. I normally use the external AC adapter to power the interface as otherwise its flaky to initialize on boot-up without it but in loop-back I can see significant AC harmonics:

Remaining tests are conducted powered from Firewire only. The optimal level for this interface in loop-back (don't know if ADC or DAC limited) is around 5.7V . Beyond this voltage the performance utterly collapses with harmonic and non harmonic tones across the spectrum. I have conducted further testing at 4V as this is close to optimal and also used in ASR testing.

Next lets compare 96kHz sample rate:

and 48 kHz:

So noise is elevated by using 96kHz sample rate even if low and high pass filtering to 20-20kHZ is used. Further tests done at 48kHz sample rate:

Low frequency test:

High Frequency test:

Results:
22.5Hz: THD = 0.0026% THD+N = 0.0054%, SINAD = 85.4 dB (noise limited)
1kHz: THD = 0.0020% THD+N = 0.0048%, SINAD = 86.4 dB (noise limited)
7.75kHz: THD = 0.0028% THD+N = 0.0052%, SINAD = 85.7dB (noise limited)

Equivalent noise input voltage at 1kHz: 172uV

Looking at other loop-back measurements it looks to be possible to get around 94 dB SINAD from modern interfaces in the same price range so this seems OK for something so cheap and old.

 

[kipman725]

Here are some RMAA measurements, not sure how to adjust this software and exactly what its doing.

But THD/THD+N seems similar, extra measurements like cross-talk also look good

 

[AnalogSteph]

Seems alright for what it is. Frequency generation seems to have a bit of a PSRR problem (and distortion worsening at 96 kHz is clearly pointing towards some issues, possibly correlated jitter which may be a layout or power-related issue), and booting requiring an external PSU may suggest some degraded electrolytics in the power section (I mean, this thing should be from the mid-2000s, when such problems ran rampant, and Presonus isn't exactly the kind of brand to use premium components).

Converter specs:
ADC: AK5384 (4ch) - DR 107 dB(A) - THD+N -100 dB - filter ultimate -80 dB - filter ripple +/-0.005 dB
DAC: AK4358 (8ch) - DR 112 dB(A) - THD+N -94 dB
So distortion seems about right, while some dynamic range was clearly left on the table.
The thing is supposedly full of MC33078 (dual) and 33079 (quad) opamps. These were common back then, but you could probably do better these days (some reverse-engineering and part value adjustment may be required to extract best performance).

Official specs for the Firebox do not seem to line up with your findings. About 5.7 Vrms is +17.3 dBu - at least 2 dB short of the +20 dBu (@0.5%) max input spec, but at the same time well above the supposed +10 dBu 0dBFS reference level. An identical SNR spec for both mic and line inputs seems suspect, too. Dodgy manufacturer specs aren't all that uncommon.

 

[kipman725]

The startup issue I think is more of a windows issue as its OK to start if I unplug it and plug it back in once the PC is booted, I have tried different firewire cards with no change. On boot it goes into displaying a red light instead of a blue light and doesn't show in device manager. I have already modified mine a bit to lower the insane headphone amp gain, probably not worth swapping the opamps in something so old though. I was thinking about getting a Motu M4 for measurements or a QA402 but the gains in performance don't seem worth it, I think I would be better off using this and just hiring a AP unit for a week if I need better performance.

Looking at the output on a multimeter I can increase the output voltage a few volts more than the point at which I see clipping so I think its the inputs that are clipping before the output.

 

[AnalogSteph]

I was thinking about getting a Motu M4 for measurements or a QA402 but the gains in performance don't seem worth it, I think I would be better off using this and just hiring a AP unit for a week if I need better performance.

It all depends on what you need it for, I guess. Acoustic measurements or an average hi-fi integrated or power amp (with suitable attenuators) should pose no major issues, and the mic input (assuming the EIN spec is accurate) should provide low enough noise to gauge the output noise of most line outs. Max levels around the +18 dBu mark also betray the unit's original price tag, more the equivalent of an Audient iD14 MkII or iD22 today.

That kind of comparison also shows the kind of progress we've made since 2005... I'd think either of those would show a solid 10-15 dB higher dynamic range in loopback.

 

[Mavoz]

Hi there. Not sure if the OP is still around here! I actually have this old Presonus Firebox myself..and am using it with a 2011 era Sager NP7280 laptop (a behemoth with a desktop cpu inside it!)

I'm getting clicks and pops on large Omnisphere pad sounds...I'm wondering if the issue is this old Firebox and something like a Motu M4 would help...but also I notice the memory I have is 12gb..and it seems to be using around 10gb...

So it could also be running out of memory!

Any suggestions on whether you think the issue might be the Firebox or instead maybe memory? Thanks for any thoughts!

 

[AnalogSteph]

I actually have this old Presonus Firebox myself..and am using it with a 2011 era Sager NP7280 laptop (a behemoth with a desktop cpu inside it!)

That thing is insane. Socket 1366 (up to hexacore) plus dual MXM graphics inside a chunky 17.3" laptop weighing 6+ kg, with a 330 W power supply. I dread to think of the jet plane acoustics. Sure enough, a contemporary review suggests that it is quite the opposite of silent, though admittedly the dual GTX480M Thermis wouldn't have been helping. It's a very cool hot piece of tech, I'll give it that, but I'd probably be going nuts using one on a regular basis. (My current PC is dead silent in most cases and stashed away under the desk, with no fans under 135 mm.)

I hope the graphics are among the more modern options offered at least (idle power would have gone down with each generation), and there's some sort of hexacore i7/Xeon in there (which are on a 32 nm process and rather more efficient than the old quadcores on 45 nm). A cooling system cleanout and thermal paste reapplication on everything including the chipset (X58 is a little hottie) may already have been performed.

I'm getting clicks and pops on large Omnisphere pad sounds...I'm wondering if the issue is this old Firebox and something like a Motu M4 would help...but also I notice the memory I have is 12gb..and it seems to be using around 10gb...

So it could also be running out of memory!

That may not be helping either. What kind of ASIO buffer settings are you running? (Could you try the same using onboard audio via ASIO4All, with headphones or something?) Is there a decent SSD in there?

Have you had a look at DPC latency via LatencyMon? Some devices / drivers can be rather uncooperative. Typical areas of concern are networking including WiFi and graphics. Driver updates (or downgrades) may help.

What's CPU usage like? (Make sure to switch the graph to "Logical Processors".)

I wonder what ThrottleStop would say on such a system... I've run it on mobile Westmere dual core jobs before but never the big iron. According to the processor datasheet, C-states supported are C0, C1/C1E, C3 and C6, both core and package. I'm seeing several errata relating to package C6 in the spec update though, the last of which was only added in late 2012, after the newest BIOS for this system. I'd think having PCIe graphics would preclude anything beyond package C3 anyway, so it's probably a non-issue.

 

[Mavoz]

That thing is insane. Socket 1366 (up to hexacore) plus dual MXM graphics inside a chunky 17.3" laptop weighing 6+ kg, with a 330 W power supply. I dread to think of the jet plane acoustics.

Firstly..thanks for taking the time to reply and your interest! Yes...has been a great laptop...actually hasn't been too bad noise wise...you can hear it running...but really with headphones on or on a band situation isn't much worse than the hum of an amp!

That may not be helping either. What kind of ASIO buffer settings are you running? (Could you try the same using onboard audio via ASIO4All, with headphones or something?) Is there a decent SSD in there?

So I switchd over to headphones direct on my headphone socket...using Gig Performer with Realtek Digital Output and Asio 4All2..

it actually seemed slightly better on the clicks front...really where I notice it most is if I aggressively hold down sustain pedal....it gets swamped...if I'm 'gentle' with my use of sustain..then is fine...

Here are some graphs from the task manager...I'm wondering if it is the memory being so close to the ceiling? Will have a look at some other things you've suggested....thank you! Really the old machine still does a great job..most of the time is fine..it really is sustain pedal on big Omnisphere pad sounds that gives it quite the stress test!

 

[kipman725]

Howdy, yes I'm still here. I no longer own the firebox though its gone to electrical recycling as its internal PSU was slowly failing. I replaced it with a Tascam US HR 2x2 which I think is a decent upgrade if the reduced IO is ok for your application. In particular the US HR has enough preamp gain to be able to use dynamic mics without an external preamp.

 

[Mavoz]

Howdy, yes I'm still here. I no longer own the firebox though its gone to electrical recycling as its internal PSU was slowly failing. I replaced it with a Tascam US HR 2x2 which I think is a decent upgrade if the reduced IO is ok for your application. In particular the US HR has enough preamp gain to be able to use dynamic mics without an external preamp.

Thanks for that....actually you've given me an idea.. I've got a Zoom h4N...maybe I'll give that a try for testing purposes...I'm guessing I can use that as an audio interface. I'm thinking about purchasinga Motu M4....but may well not fix the issue without upgrading the laptop...but wondered if newer drivers might help with a more recent interface...I think the Presonus was from mid 2000's! Thanks.

 

[AnalogSteph]

Firstly..thanks for taking the time to reply and your interest! Yes...has been a great laptop...actually hasn't been too bad noise wise...you can hear it running...but really with headphones on or on a band situation isn't much worse than the hum of an amp!

Fair enough.

it actually seemed slightly better on the clicks front...really where I notice it most is if I aggressively hold down sustain pedal....it gets swamped...if I'm 'gentle' with my use of sustain..then is fine...

Kind of makes sense if you think about what sustain does... there's more notes (samples) to be played at once.

The default buffer setting for ASIO4All is 512 samples, so that may have been helping. You can play with that (note: the interface defaults to "easy mode" or whatever it's called, toggle that) and see what effect it has.

Here are some graphs from the task manager...I'm wondering if it is the memory being so close to the ceiling?

It does seem pretty tight. Have you already optimized memory usage by means of predictive loading (if applicable)?

I do see 8 GiB DDR3 SODIMM modules being offered for this system. 1.5 V, dual row / double sided, 1333 MHz probably is what you need.

Besides, I'd be looking out for a Xeon X5660 (or -50 or -70) perhaps, last time I checked these were super cheap and some versions of this Clevo barebone even shipped with them right from the factory. Don't forget a tube of Arctic MX4 or something if you don't have any thermal paste floating around. The Clevo X7200 service manual is available on the web, and it's all pretty well documented.

(Xeons also support registered DIMMs with substantially higher capacity, but they seem to be uncommon in SODIMM formfactor and I sort of doubt this system supports them.)

Obviously you have to know what kind of money and effort you still want to invest into the old beast. I would also price out a used portable workstation type machine from 2017/18ish or consider a Mini-ITX PC build with a portable monitor (components don't have to be new new, and GPU wise a GT1030 or even a GT710 would be fine for your application). Anything that you can easily plop 32 GiB of RAM into if need be.

 

[Mavoz]

Obviously you have to know what kind of money and effort you still want to invest into the old beast

Thanks again for all the great suggestions!

Am certainly thinking the same.. isn't worth going too far down the rabbit hole of trying to upgrade.. probably the two items I'm considering is just throwing 2 x 8gb sticks of ram in and then perhaps buying a Motu M4 (something I'd need if I go down the new build path)

Thanks for ram clarification.. I nearly ordered the wrong voltage type the other day..

Mini-ITX PC build with a portable monitor (components don't have to be new new, and GPU wise a GT1030 or even a GT710 would be fine for your application). Anything that you can easily plop 32 GiB of RAM

Thanks for this.. really helpful. I think this is the path I'm going to ultimately go down... a few users on the Gig Performer forums are having success with these kind of builds. Am searching around for what components provide the bang for buck options. (If you are aware of any excellent articles or posts on this topic am really interested) Will try and figure out something that can run a little quieter too. Thanks so much!

 

[AnalogSteph]

Am certainly thinking the same.. isn't worth going too far down the rabbit hole of trying to upgrade.. probably the two items I'm considering is just throwing 2 x 8gb sticks of ram in and then perhaps buying a Motu M4 (something I'd need if I go down the new build path)

Going from 12 to 16 gigs is not really a whole lot of an upgrade for what you pay, now is it? You'd also be losing some memory bandwidth in the process (which memory hogs tend to like)... it would take the faster memory controller of the newer 32 nm hexacore chips to make up for this, those should be about as fast in dual channel as the older ones in triple channel.

So IMHO, it only makes sense if you go with 3x 8 GiB, which obviously raises the financial stakes.

Thanks for ram clarification.. I nearly ordered the wrong voltage type the other day..

I mean, I've seen DDR3L-1600 sticks listed for this system... my guess is it's using 1.5 V no matter what. That's what I found on one type of laptop, while another model did not appreciate 1.35 V sticks at all and has been without working standby power since (yikes).

I think this is the path I'm going to ultimately go down... a few users on the Gig Performer forums are having success with these kind of builds. Am searching around for what components provide the bang for buck options. (If you are aware of any excellent articles or posts on this topic am really interested) Will try and figure out something that can run a little quieter too.

That I think is virtually a given, you're not likely to be seeing fans under 80 mm in a build like this and might even be using a 120 mm AIO (about the only valid usage scenario for one), though honestly I'd be erring on the side of reliability and go all air-cooled, which may be easier said than done because many smaller cases are stuffing the power supply over the board and may only leave room for very low-profile CPU coolers - I'd want enough room for a 92 mm equipped tower cooler. (There's some "flipped tower" top-blowers but mechanical stability seems sketchy in some, and in your system I would consider that aspect.) So look closely at the size / ventilation options tradeoff and think hard about how small a system you really absolutely need.

Thankfully, it shouldn't be too much of a challenge to at least halve the power consumption over the present system.

In the light of USB headaches being a reccurring theme in AMD systems and the seeming lack of heavy multithreading, I would tend towards Team Blue (plus lower idle power, which only AMD's APU models can compete with).
This is what the cheapest option with brand-new parts would look like:
You can still get a 10th gen i3-10105F and a matching LGA1200 ITX board for around 200€ around these parts, plus maybe 100 for two half-decent 16 gig DDR4 modules (I would use ordinary JEDEC-compliant DDR4-3200 CL22). Discrete graphics to avoid sharing memory bandwidth could be as basic as a passive-cooled GT1030 (about 100 brand new, though I'd look for a used option, and you could go as fancy as a dual fan GTX1650). Apparently iGPUs can make music memory hogs substantially more prone to stuttering.
A decent small tower cooler maybe 25-50 (you could opt for the plain boxed cooler to save money), case somewhere around 50 (check what kind of expansion slot options you have, low-profile or fullsize), power supply shouldn't really be any cheaper either. SSD depending on what you need, SATA doesn't save you much over M.2 these days. Maybe an additional fan still. So like, 500-ish plus SSD?
A fancier option with i5-12400F on a matching board and DDR5 memory would add maybe 250, possibly more (we're not eactly drowning in 12th gen DDR5 ITX boards). As a mid-price option, maybe an i5-11400F on a Z590 board on clearance (not that much more expensive), or an i3-12100F or i5-12400F with DDR4.

No clue when it comes to the monitor department, except that (e)IPS panels are pretty standard these days and should give an image quality at least comparable to your present screen (which appears to be a TN+Film panel with decent viewing angles and color space coverage if a very bluish native white point). I would at the very least look for higher-contrast (e.g. *VA) panel options, which would be beneficial if you're commonly performing in the dark. So would OLED, but burn-in is no joke in computer usage.

 

[Mavoz]

Thanks again Analog Steph! Appreciate all the tips. More and more I'm thinking I won't worry about trying to upgrade the older Sager...better to start thinking of a new machine.
Really the old behemoth still does a great job..I just need to be careful on the big layered pad sounds or some of the Kontakt Pianos. I'll keep researching the components of a new build. The CPU/case and mobo seem to be the good starting point..
When I do build a new system I'll go with the option of a mid range towards high...ie. buy once..buy well.

What do you think of this NZXT case? Has cooling, PSU integrated.

H1 | Compact Mini ITX Gaming PC Case

SFF Case with PSU, AIO, and Riser Card. The all-new NZXT H1 provides a beautifully small vertical chassis, maintaining full-sized GPU compatibility.

nzxt.com

Will do some more research on the other pieces. Thanks!

 

[AnalogSteph]

What do you think of this NZXT case? Has cooling, PSU integrated.

Neat case, but a tad rich for my blood, and there's no way you're going to need a 650 or even 750 W power supply with components along the lines of what I suggested (you could probably get by with 300 W fine, though stepping it up a bit is often worth it in the interest of efficiency).

Going through some ITX cases, the Fractal Design Core 500 caught my eye. It's on the bigger side fot an ITX but is fairly roomy and will take an ordinary ATX power supply (ehich doesn't get in the way of CPU cooling either), so way more PSU choices compared to SFX. Hmm, you might no longer be able to find this older model in the US, bummer. Hmm... Thermaltake Core V1 then, perhaps? And maybe an EVGA 550 GA or a be quiet! Pure Power 11 500W as a power supply.

Here's a fairly no-frills example config:

PCPartPicker Part List

CPU: Intel Core i5-12400F 2.5 GHz 6-Core Processor ($174.99 @ B&H)
Motherboard: ASRock H610M-ITX/ac Mini ITX LGA1700 Motherboard ($133.99 @ Newegg)
Memory: TEAMGROUP Elite 32 GB (2 x 16 GB) DDR4-3200 CL22 Memory ($87.99 @ Newegg)
Storage: Samsung 970 Evo Plus 500 GB M.2-2280 NVME Solid State Drive ($49.99 @ B&H)
Video Card: Asus GeForce GT 1030 2 GB Video Card ($89.99 @ Amazon)
Case: Thermaltake Core V1 Mini ITX Desktop Case ($59.99 @ Amazon)
Power Supply: be quiet! Pure Power 11 500 W 80+ Gold Certified ATX Power Supply ($69.90 @ Amazon)
Total: $666.84
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2022-07-21 22:08 EDT-0400

You could save maybe 70 bucks with a 12100F or spend 50ish on a decent cooler (the boxed cooler is just about adequate but that's it). Yes, that's a very basic board, you could no doubt also spend up to 300 on that. Either way, it would be running circles around your current system.

 

[Mavoz]

Neat case, but a tad rich for my blood, and there's no way you're going to need a 650 or even 750 W power supply with components along the lines of what I suggested (you could probably get by with 300 W fine, though stepping it up a bit is often worth it in the interest of efficiency).

Going through some ITX cases, the Fractal Design Core 500 caught my eye. It's on the bigger side fot an ITX but is fairly roomy and will take an ordinary ATX power supply (ehich doesn't get in the way of CPU cooling either), so way more PSU choices compared to SFX. Hmm, you might no longer be able to find this older model in the US, bummer. Hmm... Thermaltake Core V1 then, perhaps? And maybe an EVGA 550 GA or a be quiet! Pure Power 11 500W as a power supply.

Here's a fairly no-frills example config:

You could save maybe 70 bucks with a 12100F or spend 50ish on a decent cooler (the boxed cooler is just about adequate but that's it). Yes, that's a very basic board, you could no doubt also spend up to 300 on that. Either way, it would be running circles around your current system.

Thanks for that! Appreciate the speccing out of some components..gives me a good idea.. The case is a really interesting one...as I'm trying to figure out something to make that fairly portable..ie. something I can gig with and move easily enough + also fit in a deskspace at home.. I saw someone in a thread somewhere figure out a 'rackspace' build. Then there is a thread over here at Gig Performer about some suggestions. https://community.gigperformer.com/t/small-form-factor-windows-machine-ruminations/8524/46

I guess either way a case like the one you mentioned won't be too heavy...so it is more about physically fitting it. (A thinner one could potentially hide behind or underneath a monitor) Anyway much to mull over...sounds like "ITX" is the best balance in size/performance...versus some of the NUC style Vesa mount solutions...that I guess give issues with performance + noise . (Monitor wise I'm good to go with a custom 22" lcd screen mounted to a music stand!) Thanks...will have a good look through what you've listed!

 

[AnalogSteph]

It'll be a matter of finding a compromise between size and component layout that suits you. In the smaller cases you'll often have the issue of the power supply being perched above the board, requiring low-profile CPU cooler gymnastics. Some models of cooler literally are just hanging on by their heatpipes, and I would want something a tad more sturdy for a rig that would be getting dragged around a lot, so that's another thing to consider. These small systems certainly don't make building any easier.

 

[Mavoz]

Thanks again! Am starting with a new audio interface... Motu M4... will see how that goes in the Sager.. and then proceed from there!

Thanks so much.

 

[Mavoz]

Well just an update here.. Motu M4 arrived.. and on first go I still had clicks pops.. horrible distortion... and I thought this is a disaster! Then I restarted.. swapped out USB cable... Turned off monitoring on 1 & 2.. and something in that mix made it all go away.. and it is now running beautifully.. with no clicks pops etc The theory is that my old Presonus driver has probably just got too long in the tooth! Will see how we go over coming days.. but so far an upgrade to a new interface has done the trick and my old faithful Sager still lives! (While my equally faithful Firebox has sadly gone into retirement!) Thanks for all the advice!