The Blank Slate

I have this fantasy that Album #3 is a blank slate, with no material left over from previous sessions or unfinished projects.

In reality, I have lyrics and musical fragments that I’ve been working off-and-on over the last few years. I usually get my ideas while out cycling, and it is no trouble to pull over, whip out the iPhone and record the fragment into the Voice Memo app. Later, back in the studio, I transcribe the lyric into my notebook. Sometimes I’ll open my Scrapbook project and add another piano track with the melody.

That’s cool. On the plus side, these new songs will hopefully start out being actually sing-able in my comfortable range, as opposed to many projects in the past where the music came first and the melody second and was almost always not pitched comfortably for my voice. So that’s a good thing.

Outside of these lyric and melody fragments – some of which have expanded into pretty complete stand-alone song ideas – I still have a comprehensive library of musical ideas that date back to those Grey Lynn flat jam sessions in the 90’s, converted to mp3 from C60 tape cassette.

I still feel that this situation qualifies as a “blank slate”, as far as Album #3 is concerned. Every track is going to start with a new empty project, and not an existing one, worked on in years past and put on the back-burner due to lack of time, interest, energy, ideas, whatever.

Even “The God Program” from our current release was conceived back in 2003 and much of it laid down in 2007. (And consequently re-recorded, but that’s par for the course.)

So, I’m looking forward to never again having to sit back and listen to a newly recorded section of music, and say “dammit it just doesn’t have the magic of that older demo”.

*Record Scratch*

…Yeah. That was nice while it lasted.

Back in 2002 I didn’t have any plans to resurrect “The Prodigal Sounds” as a music-releasing entity, and instead explored some other new music ideas with the tentative goal of putting it out under another band name. I had three longish instrumental thematically-related pieces recorded in “pretty complete demo” form, but only titles for the other three or four pieces.

I’ve related elsewhere the story of how I got back on track with Prodigal Sounds and the “Fruit of the Steel Tree”, and consequent to that, this other project was shelved.

Long story short, I think I’m going to incorporate the music from this old project into the songs of Album #3, or one of them anyway. The music seems to fit. It’s worth a try.

So, will it be a concept album?

A better question, should it be an “album” at all? CDs are not selling much these days, it’s all about streaming and playlists and bullshit like that.

Personally, I prefer the idea of a curated collection of songs, rather than emitting the occasional single on some indeterminate schedule like a chunk of U-238.

So, yes, there will be an Album #3, unless I give up or expire before it is released.

And I do have a concept for it, although it is of a subtle nature. Tangential, even.

Better Late than Never

Well, at long last, album #2 has been released.

My previous release, Fruit of the Steel Tree, was my best effort to realize the music that Walter and I wrote back in the 1990’s.

This new release, The Inevitable Obscenity of Autonomous Weaponry, includes a few tracks from that same period. I’ve perhaps taken more liberties with them this time, relying on my own vision.

The other tracks are all “new” in the sense that they are based on material I wrote since Walter and I stopped collaborating on music, from 2003 to 2019.

You can find out more at the album-specific pages I created (see the The Inevitable Obscenity link in the blog top menu above).

I used CD Baby as my manufacturer/distributer and due to COVID-19 related circumstances, I’m not sure exactly when and how this will be made available to purchase. It *should* appear on Amazon at some point, and although CD Baby has closed their online store, they do have copies in their warehouse for distribution.

The physical package is nice: an eco-sensitive cardboard wallet:

image

The artwork came out nicely but I acknowledge I used a sub-optimal font point size on the smallest text. It seemed ok in the PDF but I should have realized that white-on-black in print would be harder to read. Oh well, no big deal. The information (and more!) is all available online (see link above).

Digitally, the album is now up on Spotify and probably other streaming services as well. Yay!

Okay, so the timing for this release isn’t great: as I write this, we are still under a County Public Health “Stay At Home Order” due to the coronavirus pandemic, and the economy is taking a nose-dive. Folks just aren’t going to have the disposable income (or the will to spend it) that they did a couple months ago.

Originally I’d planned for this to be out in 2019 which would have been nice, but it didn’t happen.

Since the last blog post, “Final polishing” of the tracks took longer than expected because I kept finding little things I wasn’t totally happy with. This is actually an infinite process because there will *always* be things that I think I could improve, and my tastes change over time so it’s a moving target. The trick is to apply the law of diminishing returns and identify when it is time to Let It Go.

At this point, I think I chose appropriately. It’s out there now, anyway.

What’s Next

I’ve uploaded two videos on YouTube to accompany the release: A studio “play-through” for Paradigm Shift and a second one for Cathedral with “behind the scenes” text captions.

I intend to create a third video for The Toks Invade before putting the project to bed.

I’m going to be preparing a Bonus CD (well, EP maybe) with alternative versions of some of the tracks. I’ll make this available digitally via BandCamp, no physical CD for this.

Over the last couple of years I’ve been working on new lyrics and some musical ideas and it really does look like there will be an Album #3. But that’s for later.

March 2020 - The Inevitable Track List

I’ve completed recording. I’ve been mastering the tracks in Presonus’ Studio One, because it has this great “Project View” that I haven’t seen in any other software.

image

This allows me to set volume levels, frequency equalization, and cross-fades across all tracks, to ensure that they sound like a unified collection.

I still need to burn a CD and play it in a variety of locations but I think I’m close.

Next steps will be to finalize the artwork for CD duplication, and also upload to Bandcamp and/or CD Baby for distribution. This is going to be primarily a digital release but I do want some physical CDs to give to friends and family and anyone else who really wants one.

About 50% of these tracks are old music that Walter and I worked on together, and the rest is all (relatively) new.

Track List:

1. EULA (0:31)

2. Working the Paradigm Shift (8:42)

3. Listen (12:52)

4. The Toks Invade Bogland (4:57)

5. Cathedral of Hosts (3:27)

6. Enlightenment (6:06)

7. Omnipotence in 17/8  (2:58)

8. Priority Interrupt (2:07)

9. Head Crash (5:18)

10. Cathedral (reprise)  (1:12)

11. Introspection in G / Tubular DLLs  (6:57)

Tracks 5-10 are a continuous suite, so there is a choice to be made here about whether to break it up into separate tracks or keep it as one long track, for digital distribution. On an audio CD you kind of get both as it cross-fades between tracks cleanly. (usually).

I guess the right answer is “both” which is actually feasible, to have two different versions of the album up on Bandcamp. Or maybe just an additional bonus “EP” for the single-track contiguous version.

I’ll mull this over. In the meantime, stay safe folks. Don’t go viral.

Dec 2019

When the heck was my last post? October? Ouch. Well, I’ve been busy, working on the album. Much progress has been made.

Also, I’ve created a new Cakewalk Theme called “SteamPunk” to inspire creativity and in the process, written a how-to guide on theming.

Here’s a picture of the introduction to the final track on the upcoming album:

image

I realize that gives nothing away but does give an impression of the new UI theme: Slate, oiled bronze, leather, with gilt highlights.

Steampunk.sth

Young Lady's Illustrated Primer on Themeable items in Cakewalk.pdf 
(updated 03/2020 to version 0.9.5)

Back to the studio; this album’s not going to finish itself.

VIVALDI’s USB ports

Front Panel:

image

My nomenclature, from left to right: F1 – F4

Rear Panel:

image

My nomenclature, from left (top) to right (down) : R1 – R7

Type (according to XPS 8930 manual):

 ID   Description                 Speed    Connected 
 --   --------------------------  -------  ----------
 F1   USB 3.1 Gen 1 Type C         5 Gbps  
 F2   USB 3.1 Gen 1                5 Gbps
 F3   USB 3.1 Gen 1                5 Gbps
 F4   USB 3.1 Gen 1                5 Gbps

 R1   USB 2.0                    480 Mbps  Keyboard
 R2   USB 2.0                    480 Mbps  Mouse
 R3   USB 3.1 Gen 2 Type C        10 Gpbs
 R4   USB 3.1 Gen 2               10 Gpbs  Scarlett 6i6
 R5   USB 3.1 Gen 1                5 Gbps
 R6   USB 3.1 Gen 1                5 Gbps
 R7   USB 3.1 Gen 1                5 Gbps  MIDISport 2x2

Here is a report from USB Device Tree Viewer 3.3.6:

image

Quite by accident I seem to have connected the Focusrite Scarlett 6i6 to its own dedicated high-speed USB hub, which I’m guessing is optimal.

However, we should remember that the USB port on the Scarlett is only USB 2.0. So we’re hopefully gaining some isolation or immunity from interference, but no throughput gains. Chances are we may have another device that could leverage the 10 Gbps speeds…

Diagnosing a randomly changing patch in a VST instrument

This is going to be a somewhat random post but I want to record this before I forget what I just found out.

I was playing around with Arturia’s CS80V when the patch I was playing suddenly changed: the release time increased. Also I could see the patch had changed because an asterisk appears in the patch name.

I reset the patch by selecting it in the browser, and continued playing. Suddenly, it happened again!

This time I watched the GUI of the synth to see if I could see it happen:

image

Sure enough, about a minute later the patch changed sounds and something caught my eye – a slider had changed positions:

image

Moving the slider back restored the original sound (although of course, the patch was still “changed” as far as the environment was concerned).

OK, how to diagnose this? I’ll cut a long story short and say eventually I set a track to record MIDI data from my controller, in case something funky was entering the MIDI event stream, and played a few notes.

A short time later, I had this:

image

Those vertical lines are Continuous Controller (CC) events:

image

I was recording on Track 2 and that’s three events for Continuous Controller 83 that I can’t explain.

I need to find out why my Roland A80 master keyboard is emitting these controller events. Is this new behavior, or has it always happened?

Normally they are harmless, I guess, but the default MIDI Controller mapping for CS80v  has CC# 83 mapped to this VCA envelope release time slider:

image

So that explains the phantom finger on the slider. The ones in RED have been set to respond to a specific CC#.

It’s easy enough to fix – we can use the MIDI Mapping feature in Arturia’s software instruments to load an “empty” controller mapping:

image

Now the patch remains unchanged even when I play back the track containing the controller data.

Next up, find out why the A80 is emitting those random controller values...

April 2019 Progress

So much for keeping a regular Studio Diary… where did the time go?

In my defense I will say that the 2019 brought a long-awaited, real-world landscaping project into being, and that has taken a lot of attention.

On the other hand, since the last update I have completed two new tracks:

“The Toks Invade Bogland” was finished up last year and sounds pretty good. I’ve moved on to the song sequence titled “The God Program” and just finished up the first piece in the sequence, a solo piano overture of sorts, called “The Cathedral of Hosts”.

I really wanted to be able to perform the piano part right through from beginning to end, and to record a complete single take, and I almost did it. The truth is that I did end up tweaking a few bum notes (bad velocity). This took a lot of practice!

This quiet, contemplative track contains many musical themes and motifs that are expanded on in later sections of the song sequence:



The first sound you hear is the Roland VK8 keyboard, a “virtual clonewheel” that emulates a hammond organ. I’m using a shimmery patch as a background pad.

The piano is Modartt’s Pianoteq 4, using the “D4” model. The latest version of Pianoteq is actually 6, but they’ve tweaked the piano model and replaced it with a Steinway-endorsed “Steinway D” model. I tried using the more recent versions and ended up going back to version 4, which for some reason has a nicer character for this track.

At about 1:30 you can hear the FingerFiddle IOS app with which I perform the strings (violin and cello). This is a very cool app that requires a fair amount of practice to sound decent, almost like a “real” instrument.

At 1:55 there are some “Ahhh” vocals padding out the sound, and shortly after that a Marimba that is actually a combination of another instance of Modartt Pianoteq (version 6 this time) doubled with Native Instruments’ FM8 for extra DX7-ish bite.


The new DAW is running well. Cakewalk by Bandlab, the re-branded Digital Audio Workstation software formerly known as “SONAR” is probably the most stable it has ever been, with regular updates that focus on bug fixes rather than new features, although there are some of those as well.

Recommended, as ever.

Next: taking the demo of “Enlightenment”, the second part of God Program, and turning it into a finished track.

Onward!

They don’t make them like they used to

I can’t remember exactly when I purchased my Korg EX-8000, but based on archival recordings, it must have been around 1991. It made the trip across the Pacific from New Zealand back in 1999, and it has been in storage for roughly the last decade, along with other items of equipment that I don’t have room for in my tiny studio.

At this point, I’ve decided that someone else should be enjoying this 8-voice DCO synthesizer with analog resonant filters of goodness, and I should find another home for it.

Before I can do that, I have to make sure everything is still in working order.

In the case of synthesizer keyboards and modules, providing the item has been stored correctly in a cool and dry location (which of course is the case here), then the most likely problem will be that the patch and configuration memory storage has been lost due to the internal battery running out of charge.

Indeed, this was exactly the case. Upon plugging the EX-8000 into my Philmore ST-1000 heavy duty step-up power transformer, 220V output, I discover that no sound can be produced from pressing the keys on a connected MIDI keyboard, but that pushing the “A4” button on the front panel will produce a “tick”. Reviewing the parameter values, clearly we have a corrupted memory because some of the values don’t make sense, although spinning the value editor dial will soon bring them back into line.

With some tweaking I can turn the “click” into a siren or “bloop”. Progress! All 8 oscillators appear to be in good shape, providing I can restore the memory.

Alas, upon bouncing the power on the unit, all my parameter edits have been lost. The backup battery is almost certainly the culprit. Time to open her up!

Replacing the battery

1. Remove the rack-mount ears

2. Remove 6 screws holding the cover in place (2 each side, and at the back)

Apart from the power supply and the I/O boards, the two main boards of the synth are in a sandwich configuration. You can remove 3 screws and swing them up on a kind of plastic hinge:

image

You need to do this to access the battery, plum in the middle of the underside. I use a ruler to carefully prop the boards upright.

I could see some green crusty stuff around the battery which isn’t a good sign.

Okay, now the bad news here is that the CR-2032 battery is actually soldered directly into the PCB via a little bracket. You can’t just pop the battery out and replace it. The only sane option here is to remove the lower PCB from the chassis and replace the battery+bracket with a true low-profile socket.

Fortunately, this is not too difficult. I recommend taking a lot of pictures of the cables and connectors to make sure you know how they are laid out and connected.

3. Unplug all cables from the board

4. Unscrew the four screws at each corner holding the PCB to the metal brackets

WARNING: The two orange pin arrays on the bottom right are soldered directly in, they are not plugs!

image

Instead, you need to trace them to the other end, around the other side of the sandwich, and unplug the other end from the “top” board.

Then you should be able to remove the board from the unit:

image

Replacing the corroded battery and bracket is very easy if you’re handy with a soldering iron and a solder-sucker. The socket I used didn’t quite line up with the vacated holes in the PCB, but a little wire lead and some silicone caulk (and some heat-shrink) yielded a nice result:

image

After a new CR-2032 battery is inserted into the socket, and the board mounted safely back in the case with the leads re-attached (refer to those pictures you took!), and a quick test proves that any parameter change I make is retained during a power cycle. Hooray!

Restoring the default patches

Fortunately, other folks have done the hard work on finding the patches, and restoring them turns out to be more-or-less straightforward.

There’s two ways to restore patches:

  • Play a .WAV file into the tape FROM port on the unit
  • Use a SYSEX loader to load the patches in via MIDI

Tons of good information here:

After some initial trouble of getting levels set correctly, I succeeded using the .WAV file following this process:

  • Email the .wav file to myself as an attachment
  • Open the email on my iPhone
  • open the attachment
  • connect iPhone to the TAPE FROM socket using a normal stereo 3.5 mm jack lead
  • set my iPhone playback (headphone) volume to MAX
  • switch the EX8000 FROM TAPE level switch to LOW
  • switch the EX8000 TAPE switch to ENABLE
  • press LOAD
  • tap the iPhone to start playback of the .WAV file

After some flashing, the bank numeric indicator cycled through the banks, and the LED display said GOOD. Success! Those patches sound great.

Switching power supply from 230V (New Zealand) to 120V (US)

The final step in getting the Korg EX-8000 ready to leave the studio is to convert it to use a 120V mains supply voltage. When I started this process, I figured I’d need to replace the mains power  transformer but, no, it’s way easier than that! The transformer already handles multiple voltages. From the service manual:

image

Yeah, that ‘former has multiple taps on the primary side. In real-life:

image

Although you can’t see it in this image, the terminals are actually labelled with the numerical identifiers. On my unit, the mains leads (black+yellow) deliver voltage to terminals 1 and 6. According to the schematic, that matches a 240V supply, which is best match for the NZ mains voltage of 230 V.

The schematic offers both 117V and 100V terminals (3 and 4) and suggests that terminal 4 should be used by default – It would be nice to think that the Service Manual is assuming a US standard mains supply, but that’s probably not a good assumption. The Service Manual says “Tokyo/Japan” on the front page, and Mains Voltage in Japan is 100V.

In the US, it’s 120V, although it used to be 117V. Terminal 3 seems like a better choice.

The PSU board has three connectors – CN2A, CN3A and CN4A – which I disconnected to protect the rest of the unit from any screw-ups in voltage changes.

Then I tested the voltages coming out of the transformer and measured 10 VAC from Black to each of the Red wires.

On CN3A I measured 5 and 10 VDC from the center pin to each of the outer pins. That’s our baseline, our known “good” values using the 220V mains supply.

image

The CN3A lead indeed does go to board KLM-662, and according to the schematic, should be supplying 0, –5, and +5 V on pins 1, 2, and 3. (See above).

So, that matches my observations (-5 : 0 is +5; and –5 : +5 is +10).

At this point I performed some soldering: Moving the black lead from pin 1 to pin 3 on the primary side of the transformer; and also replacing the mains socket from the proprietary 2-pin KS-17 to a more common IEC standard appliance socket.

See: http://www.dw8000.com/projects.html

Once that is done, it was time to plug into the regular US mains and re-test those voltage readings. Excellent, all looked the same as before. Could it be this easy?

Apparently, yes. I’ll run it for a while on 120V in my studio, and see if anything blows up. Either I’ll fall back in love with this sound module, or I’ll see about putting it on CraigsList or something.

VIVALDI is the new ROSSINI (Part 2)

In which we upgrade our DAW and experiment with PCIe-PCI adapter cards.

ROSSINI has four internal hard drives:

  • C: (SSD 256G) OS and applications
  • D: (SSD 256G) audio projects
  • E: (HD 1TB) backups, rips, temp
  • H: (HD 600G), mp3 library; leftover stuff from the last DAW migration 8 years ago

Every time I upgrade my DAW I end up with a new primary OS drive and then I move over the drives from the older machine. ROSSINI was the third generation, and only some of the drives are transitioning to VIVALDI. E: and H: still have gobs of free space.

VIVALDI has a 512 GB SSD as the primary drive (it's a tiny thing mounted directly on the motherboard!) and room for three additional full-size drives.

First up, some file management to back up the contents of D: to H: and also put everything I'll need (installers, product keys, license files, sound libraries) on E:.

Then, D: and E: transferred cleanly into the new chassis:

image

I also upgrade the power supply, replacing the no-brand Dell 450W unit with a brand new SMART 600W from Thermaltake. I purchased this from PC Plus in town. Support your local retailers, guys.

(I always upgrade the PSU in my DAW computers, but this time I had an additional reason that I'll get to later.)

There's a free bay on the bottom left, but I'll keep C: and H: in ROSSINI for now to serve as a backup machine for now, and eventually as a perfectly serviceable general-purpose PC. (The 4-core i7-920 is no slouch, really, and it has 16 GB RAM.)

Next Step: Powering up; cleaning up the Windows 10 Pro default installation (I can't believe the number of options you have to disable to make it bearable); and installing my suite of audio applications, VSTs, and libraries.

That took about a full day.

Now it's time to see how the Focusrite 6i6 USB 2.0 audio interface performs (see previous post for details of testing in ROSSINI):

Computer: VIVALDI
Interface: Focusrite Scarlett 6i6 USB2.0
 

Buffer Size ASIO Reported RTL Measured RTL
----------- --------------------- ------------
256 25.5 ms 1102 samples 0.037 sec
128 13.1 ms 578 samples 0.020 sec
64 8.2 ms 362 samples 0.013 sec

The RTL latency tested out exactly the same as ROSSINI! I was expecting better performance but it seems that RTL is not affected by processor speed or core count.

However, if you recall, playback of a large project on ROSSINI at 256 did result in clicks and pops. On VIVALDI, the same project played back smoothly at 128 but started clicking at 64.

Bottom line: It appears I could use the external USB 2.0 Focusrite 6i6 on VIVALDI and get almost the same RTL performance as the ECHO Layla 3G internal PCI card on ROSSINI. I'd call it acceptable.

But we're not done yet. A few days earlier, a timely post from John Kenn on the Cakewalk SONAR Hardware forum suggested an interesting alternative: using a PCIe -> PCI adapter card. Perhaps we could use the ECHO Layla in VIVALDI after all?

Checking the specs on the Layla PCI card: it's a half-height/low profile universal voltage PCI card (3.3V/5V).

Worth experimenting with, I think. Ahead of time, I ordered this PCI Express to PCI Adapter Card from StarTech.com for $60, and it arrived just before VIVALDI was shipped:

image

One catch: I needed a spare molex power connector to supply additional voltage to the adapter card. The generic PSU in the new XPS 8930 did not have any molex leads!

No problem. I was going to upgrade the PSU anyway, I'd just make sure I got one with standard molex as well as the usual MB, FAN, and SATA connectors. The SMART 600W from Thermaltake fit the requirements.

The adaptor card fit snugly into a spare PCIe x4 slot on the motherboard:

image

It's sufficiently distant from the GPU fan that I don't think there'll be an issue there. (I don't plan to drive the GPU too hard anyway).

The ECHO PCI card piggy-backs on to the adapter card without trouble:

image

In the picture above it looks as though the PCI card is having trouble sitting firmly in the PCI socket, but that's on me - when I took the photo I hadn't firmly located the two cards together. It's tight, but they mate well together without using excessive force.

In fact, I recommend connecting the two cards together outside the chassis and then inserting them as one unit into the PCIe slot.  Just for kicks, I'll show you the result:

image

Yeah, that's not going to work as-is. The full-size back plate on the ECHO PCI card is going to have to be modified, or...

The solution is to remove the back-plate from the PCI card, and swap the back-plate on the adapter card with an alternative one that ships with it:

image

Without a back-plate of its own, the PCI card has more movement than I'm comfortable with, but luckily there's a lip on the alternative back-plate that the card can rest against, and a convenient hole in the card that I could use to hold the PCI card in place using a little bolt with washers on either side.

Nice, just like a bought one.

Final assembly:

image

Not bad.

Power up; install ECHO drivers (they still work well in Windows 10 despite only being certified for Windows 7).

Works perfectly. Measurements are IDENTICAL to ROSSINI:

Computer: VIVALDI
Interface: ECHO Layla 3G PCI via PCIe adapter

Buffer Size ASIO Reported RTL Measured RTL
----------- --------------------- ------------
256 13.7 ms 602 samples 0.015 sec
128 7.8 ms 346 samples 0.010 sec
64 4.9 ms 218 samples 0.007 sec

That's fantastic. Thanks John Kenn for the suggestion to investigate PCIe-PCI adapters. Apparently they work.

VIVALDI is the new ROSSINI

This little piggy, thinks he deserves an(other) upgrade. - The Prodigal Sounds, "The God Program"

"VIVALDI" is the name I have given to my new Dell XPS 8930 tower. It's a i7-8700 6-core processor with 32 GB RAM because, why not.

It replaces - or will replace - "ROSSINI" which is a Dell Studio XPS 9000, with an i7-920 4-core 8 GB RAM (recently upgraded to 16 GB).

Long-time readers will be experiencing deja vu at this point.

image3

PCI or USB? Or Firewire?

ROSSINI has been super-stable for me over the last 8 years with a PCI-buss audio interface from ECHO, the Layla 3G. 8 inputs, 8 outputs, SPDIF I/O and MIDI... it's the perfect interface for me.  Ideally, I'd just move the audio card over to the new computer, along with the hard drives.

However, the new boy does not have a PCI card slot. (Good luck finding a modern motherboard that has one!) It only has PCIe, which are smaller and not plug-compatible with the older standard.

I could go on a rant here about how it's been a long, long time since computer hardware companies gave a damn about backward-compatibility... but nobody's got time for that.

I was prepared to say goodbye to my beloved Layla, if only I could find an alternative that worked. Not being able to afford a PCIe based interface from RME, I decided to experiment. USB 2.0-based audio interfaces are super-popular right now, because they are relatively cheap, and computers have become fast enough to handle the overhead of pushing the bits around.

I found a good price on a mid-range USB 2.0 device, the Focusrite Scarlett 6i6, 2nd Gen. They've had pretty good reviews, but I still didn't really have an understanding of the relative real-world performance between modern USB-based and PCI/PCIe interfaces.

"Performance" can mean several things in the context of digital audio interfaces:

  • digital-to-analog conversation accuracy
  • signal-to-noise ratios (noise or hiss generated in the analog circuitry)
  • data transfer latency (how fast can you get audio in and out of the computer?)

DAC quality is probably the least of our problems, it's kind of a solved problem at any reasonable level of affordability.

S/N ratios are interesting because you definitely get what you pay for, especially when amplifying low input levels (such as required of microphone pre-amplifiers). That's why you'll see advertising blurbs talk about how "best in class" the mic-pres are on interfaces that offer such features, but no-one really cares about the DACs.

For my purposes, the ECHO Layla's two microphone inputs have done me just fine, and this is from an interface that was introduced back in a time when having any mic pres  at all was a big deal, let alone who designed them or what the specs were.

I'm really only interested in measuring and comparing the total "round-trip" latency (RTL) of the interface: How much of a delay is introduced by the analog input and output circuits; the Digital to Analog conversion stage, and how the bits are pushed through the buss, in and out of the CPU and hard disks?

There's more than one way to skin this particular cat (ASIO? WASAPI? WDM?) , so to keep things manageable, I'm comparing two ASIO interfaces, and just varying the buffer size to see what we get. (smaller buffer size = shorter delay; larger buffer size = longer delay but more stability)

Before I took ROSSINI apart, I took some measurements. The ASIO driver can report the latency to the audio software but you can also measure it by feeding an output of the interface back into an input; recording a transient (i.e. a snare hit) and then measuring the delay between the original audio clip and the resulting recording. By swiping in the time-line in SONAR/Cakewalk,  I can read off a measurement in seconds:

image8

Results:

Computer: ROSSINI
Interface: ECHO Layla 3G PCI

Buffer Size ASIO Reported RTL Measured RTL
----------- --------------------- ------------
256 13.7 ms 602 samples 0.015 sec
128 7.8 ms 346 samples 0.010 sec
64 4.9 ms 218 samples 0.007 sec



Interface: Focusrite Scarlett 6i6 USB2.0

Buffer Size ASIO Reported RTL Measured RTL
----------- --------------------- ------------
256 25.5 ms 1102 samples 0.037 sec
128 13.1 ms 578 samples 0.020 sec
64 8.2 ms 362 samples 0.013 sec


Some observations:

  • The measured RTL delay is slightly more than what the ASIO driver is reporting;
  • It takes the USB-based 6i6 roughly twice as long to push audio data around the loop than the PCI-based Layla3G.

Conclusions:

  • Perhaps there's another layer of processing outside of what the driver can measure. Disk read/write?
  • 11 ms is right around the point at which the delay is imperceptible to humans, and in order to get that on the Focusrite 6i6 I would have to reduce the buffer size down to an unstable level.

A less scientific test was next: I tried loading up one of my projects and playing back through the Focusrite 6i6. Even at a buffer size of 256 , I was getting a regular click or stutter every 8 seconds or so. However I have to acknowledge the caveat that this was not a normal configuration - i was reading the project data from a different location than normal:  H: drive is spinning-metal hard drive and not my usual D: SSD audio drive. So I am not drawing any conclusions from that test. It would have been nice if it had played back flawlessly under those conditions, though, wouldn't it?

Next step is to see how the USB-based interface performs in the new DAW, with substantially more CPU power available to it. My understanding is that a higher-powered CPU will affect the performance of a USB-based interface more than a PCI- or PCIe-based one, due to the different amount of work performed in software for USB vs. the PCI architecture.

This one's down to me! Please accept my apologies for this - I'll see to it that the developer responsible for this happening is given 20 lashes (but only after he or she has fixed this problem).

I'll answer the mail as soon as I can.

Ooops! An unexpected error has occurred.This one's down to me! Please accept my apologies for this - I'll see to it that the developer responsible for this happening is given 20 lashes (but only after he or she has fixed this problem).tv izle