The Future of Microsound?

[Gary Boggess]

I still use the MicroSound with success and pride. I've done my own comparisons... but am not sure if ProTools published specs are MEASURED and TESTED the same as was MicroSound's. I understand the differences in features, outputs and etc. But I've been challenged by potential clients about the quality of the D/A I/O.

Here is an excerpt of what I've written to potential clients who have inquired:

Gary's Comparisons between MicroSound & ProTools HD3 & other notes:

Needless to say, 100,000 tracks is a pretty good bonus. But, who cares right? ProTools is like Paris Hilton... popular.

#1) MicroSound has more useful sample rate frequencies to choose from. The highest being 48Khz... which is still considered to be more than adequate for all kinds of recording from broadcasting, orchestral recordings and etc. My conclusion is that 48Khz is still more than adequate for recordings. The benefits of 96-192Khz are academic and NOT practical... and it's like writing checks your ears can't cash. The market place will never HEAR the benefits of 96-192Khz sampling rate...especially NOT on I-Tunes!!!!

#3) ProTools may have higher sampling rates... but ProTools and MicroSound BOTH have 24-bit encoding D/A converters. That's that for that. TWENTY FOUR BIT ENCODING IS TWENTY FOUR BITS. But lets' look closer at some other factors that ARE NOT THE SAME:

a) The Krystal DSP audio card analog A/D and D/A converters provide excellent quality. The Krystal's THD+N (Total Harmonic Distortion+Noise) is 0.006%. Krystal's noise floor response below 1kHz is quite flat giving a very clear sound. (See the chart above). Now here's BOMB DROPPER:

PROTOOLS & MICROSOUND THD+N NOISE RATINGS COMPARED: THD+N=Total Harmonic Distortion+Noise

PROTOOLS INPUT THD+N> THD+N: 0.00056% (-105 dB); -1 ' @ 997(1000) Hz (Note 1: Measurement made using +4 dBu inputs or outputs) plus PROTOOLS OUTPUT>>>THD+N: 0.00056% (-105 dB); -1 ' @ 997(1000) Hz; see Note 1 >>>INPUT AND OUTPUTS ADDED TOGETHER EQUALS 0.00112

MICROSOUND THD+N> The chart shows the THD+N distortion to noise in both the input and output analog circuits TOGETHER or combined at 0.0121%. So when the channels are rated ONE at a time like ProTools rates their specs, MicroSound comes in at a THD+N for ONE input channel = really 0.006%!!! ProTools wins by 0.00038. So MicroSound comes out fairly well considering MTU nearly MATCHED ProTools TEN YEARS AGO!

The major POINT IS>>> ProTools specs are measured ONE input and ONE output channel AT A TIME where MicroSound measured theirs as a TWO CHANNEL measuring the entire card... for a actual per channel input or output 0.0015 THD+N rating each... which is just a tad higher than ProTools as of 2007. Hardly anything to argue about! And it's certainly no reason for me to go out and spend $40,000 or more... for 99,744 LESS TRACKS than ProTools total of 256! I mean... duh!

#4) MicroEditor mixing computes with 24-bit precision. Even projects using 16-bit sound files can output digitally as valid 24-bits after fades, gains and mixing, sounding better to human ears than many competitor's 24-bit sounds! So even though MicroSound is recording in 16-bit @44.1Khz... EVERYTHING; editing, fades, mixing, processing, and ALL AUDIO processing is ALWAYS HAPPENING at 24-bit, using 56-bit accumulators to ensure bit depth and bit word accuracy!

#5) ProTools advertises their "2007 FLAGSHIP" D/A I/O module to have the (Dynamic SNR) SIGNAL TO NOISE RATIO of 115 dB

From the Krystal card manual: MicroSound's ten year standard for (Dynamic SNR) SIGNAL TO NOISE is 110 dB averaged across all frequencies, not just at 1K... so again, hardly anything to argue about.

#6) ProTools bandwidth is listed at >> Sample Rate = 48 kHz, Noise BW = 22 Hz – 20 kHz unless otherwise noted

Page 210 in the MicroSound manual states bandwidth specs at @48Khz sample rate to be a reported bandwidth of 0 Hz to 23,400 KHz. Saying that "MicroSound achieves a -3db down (half-power) point at 48% of Nyquist... one of the highest bandwidths available in a computer DAW"

So much for specs... MicroSound's over sonic integrity stands neck to neck with ProTools and EXCEEDS ProTools in BANDWIDTH.

And when you consider that it offers:

* instant fades (unlike ProTools process of writing each fade to a file)

* accurate fade ramps (unlike ProTools' quantized group sample or step zipper fades)

* 100,000 tracks (unlike ProTools' 256 max)

* Zero occurrences of audio file corruption (unlike ProTools historic issues)

To list a few major benefits... it's just STUPID to say MicroSound can't compete with ProTools. While all my friends are STILL (one last month) loosing projects due to corruption on their $40,000 plus ProTools HD3 systems... I relax and get work done! AS for 24-bit, I don't worry about it because between microphones that top off at 16K and guitar amps that still buzz and hum, and end product increasingly selling as I-Tunes MP3s... it's rediculous to talk high sampling rates. And in according to Moultan below, we can't hear 24-bit, and if we DID we'd be hearing it at the LOW END of the dynamic range.... well below the noise floor of 90% of the listening environments and playback levels. READ THE FOLLOWING!!!!

Dave Moulton, with his son Dr. Mark Moulton, provide subjective measurement of audio systems and devices for companies such as Lucent Technologies. Moulton is a monthly columnist for TV Technology Magazine and has regularly written for Recording Magazine since 1992. http://www.davemoulton.com/index.html
Moultan says: "In fact, double blind tests often seem to show that listeners can’t reliably distinguish between 16-bit audio and 20-bit audio! When we increase the resolution of the signal to 20 bits, we don’t change the magnitude of 0 dBFS, all we do is push the magnitude of the Least Significant Bit further down toward the grunge and noise floor, so that for a 20-bit word, the LSB is equal to .012 milliVolts. We’ve increased the overall magnitude of the signal by only .18 milliVolts! Going to 24 bits from 16 bits only gains us .2 milliVolts of signal resolution!! we have a serious mismatch of reference levels here, and it unreasonably diminishes any benefit we might expect from the enhanced resolution of 20 or 24-bit digital signals, relative to our venerated 16-bit signal. Failure to reasonably manage the relative headroom of analog and acoustic realms vis-a-vis our digital signal has painted us into a serious wastage of dynamic range. It also means that the resolution benefits of 20-bit and 24-bit signals are not only hard to hear, they’re, well, inaudible as we currently do it. Uh-oh!"

Checl this data out yourself at: http://www.moultonlabs.com/weblog/more/bits_really_bits

So, I am posting to invite Admin (Dave Cox) or someone who KNOWS, how much better, if any, is the new HD3ProTool HD3 192 I/O???? Especially in the THD+noise measurements. -Gary
******************************************

http://www.digidesign.com/index.cfmi...892&langid=100
ProTool HD3 192 I/O $ 3,995.00

Overview Features Specifications Download

192 I/O, the flagship of the Pro Tools|HD interface family, is the best-sounding audio interface ever offered from Digidesign, rivaling similar products costing more than twice its price. In addition to support for up to 16 channels of analog and digital input and output, 192 I/O features a wide range of analog and digital I/O options to choose from, including 8 channels of high-definition, pristine-quality analog I/O, 8 channels of AES/EBU, 8 channels of TDIF, 16 channels of ADAT, and 2 additional channels of AES/EBU or S/PDIF digital I/O.

192 expansion cards
Along with its outstanding sonic specs, 192 I/O includes an additional I/O option bay, allowing you to add more inputs or outputs, and making it one of the most unique and flexible audio interfaces on the market. To expand the analog I/O capacity of 192 I/O, you can add either a 192 AD card, providing 8 more channels of high-definition analog input, or the 192 DA card, which gives you 8 additional channels of analog output. 192 I/O can also be outfitted with the 192 Digital card, which adds 8 channels of AES/EBU, TDIF, and ADAT I/O connections.

192 AD Expansion Card
192 DA Expansion Card
192 Digital Expansion Card

Digidesign
2001 Junipero Serra Blvd.
Daly City, CA 94014
www.digidesign.com


In designing the Pro Tools|HD environment, we didn't just stop at supporting up to 96 kHz sample rates — we decided to go all the way and support up to an astonishing 192 kHz. As the flagship audio interface for Pro Tools|HD, 192 I/O supports 192, 176.4, 96, 88.2, 48, and 44.1 kHz sample rates.

With 192 I/O, you're prepared for both working with the latest standards in the world of professional audio production as well as for the emergence of future standards. The new, higher sample rates and 24-bit resolution you get with 192 I/O mean you're able to capture every nuance of sound with the utmost clarity and precision.

50 possible inputs and outputs (yeah... for about $35,000+ with interest)

Supports up to 16 simultaneous channels of high-definition I/O

Extremely flexible analog and digital I/O

Card option bay for analog or digital I/O expansion with 192 AD, 192 DA, or 192 Digital cards

World-class 24-bit/192 kHz A/D and D/A conversion

Comes with a wide range of digital I/O, including 8 channels of AES/EBU I/O, 8 channels of TDIF I/O, 16 channels of ADAT I/O, and 2 additional channels of AES/EBU or S/PDIF I/O
Word (1x) and Slave Clock (256x) input/output

Switchable, real-time sample rate conversion on digital inputs on the 192 Digital card, which allows easy streaming of digital signals at any sample rate

Soft-Clip Limiter that allows higher levels to disk for punchier, hotter recordings

Expansion Port that allows for direct connection of another 192 I/O or 96 I/O

Legacy Peripheral port that allows for connection of 888|24, 882|20, 1622, or 24-Bit ADAT Bridge I/Os*

* At 48 kHz or lower sample rate
Dimensions

Width: 19 in / 48.26 cm

Height 3.5 in / 8.89 cm

Depth: 15.19 in / 38.58 cm
Weight: 20.17 lbs / 9.15 kg

A/D
Sample Rate: 44.1, 48, 88.2, 96, 176.4, 192 kHz ±10%

Dynamic Range: 120 dB (A-weighted), 118 dB (unweighted); see Notes 1 and 2

THD+N: 0.00035% (-109 dB); +21 dBu @ 997 Hz; see Note 1

THD+N: 0.00035% (-109 dB); +21 dBu, 20 Hz – 20 kHz; see Note 1

Frequency Response: ±0.05 dB @ +2 dBu, 20 Hz – 20 kHz; see Notes 1 and 3

D/A

Sample Rate: 44.1, 48, 88.2, 96, 176.4, 192 kHz ±10%

Dynamic Range: 118 dB (A-weighted), 115 dB (unweighted); see Notes 1 and 4

THD+N: 0.00056% (-105 dB); -1 ' @ 997 Hz; see Note 1

Frequency Response: ±0.05 dB, -20 ', 20 Hz – 20 kHz; see Notes 1 and 3

Sample Rate = 48 kHz, Noise BW = 22 Hz – 20 kHz unless otherwise noted, Tambient = +25 C

Note 1: Measurement made using +4 dBu inputs or outputs
Note 2: ADC measured with analog input at -38 dBu @ 997 Hz
Note 3: Measured relative to level at 1 kHz
Note 4: Measured with digital input at -60 dBFS @ 997 Hz

[geezer]

....There are a lot of A-D and D-A boxes out there now that "sound good", and you will find proponents for many of them, at all price levels. I think "sounds good", however, is a highly relative term, and any given system, sync method and upstream/downstream device setup will yield different sounding results....They may all still "sound good" but will sound different, in my experience.....

That being said, I don't think there is much doubt anywhere that nearly all converters these days that sample at 96k and up are usually supererior sounding to those of the era of the MTU boxes, when, that is, they are properly and well clocked.....MTUs converters, as far as I know, are limited to 16bits and 48k (+,- their syncing range). They were/are very good sounding within these limits, very good sounding, indeed.....Some of the best sounding for that era. I have noticed, however, that when I use newer, higher bandwidth converters, I tend to notice more detail and clarity (especially in the higher frequencies) than with the converters of the earlier era, depending on the material I am feeding in.

That, of course, is the bugaboo.....On one forum I used to participate in, someone was touting a new set of converters (AtoD, I think), and I asked this question: "What converters are you using to listen to your converters?"...Noone ever answered me, but that is the issue. The whole chain matters, and how you hear it at the end of the chain will color all opinions about any other part of the chain....

So, enough philosophical theory. As far as bang for the buck and great quality, I hear more and more about the Lynx Aurora 16 channel A-D and DA, which can be gotten for a street price of around $2500. Many people are foregoing the Apogees for these, especially since the Apogees cost at least twice as much (since you buy separate A-D and D-A).....Lynx also makes an 8 channel bi-directional version of the same box for, obviously, something like half the money.

As far as the new ProTools HD I/O, my only experience with this system was producing a recording at the NPR studios last year. NPR does not use the I/O boxes, but uses the conversion in their huge Studer digital console. I could not tell you whether that was a good decision or not, but I know they probably made the decision based on supposed technical and quality considerations from their point of view. Would I agree with those viewpoints? Would you? Who knows.

I personally will be taking a hard look at the Lynx box when I get some money, but my views may be different than others. I know Prism and Mytek have the votes of some of the high end guys and gals, but I like the converters on my DM2000 console for a lot of things, and I've been told they sound "gritty" by some of my trusted colleagues.....I also like the converters on my TC6000 because I can hit a button and change the way they sound! ("Vintage", "Bright", "Natural", etc.)

ProTools stuff is plain expensive, too, so that always colors my thinking about anything from them.

The other thing about the newer converters for me is that it has opened up a whole can of worms about digital stuff....When everything was limited to 48k, and you kept things in 16bit most of the time, the quality considerations were markedly fewer, to my way of thinking. I miss that sometimes. There are a bunch of my old 02R mixes to Medit at 16bit that still hold up really well....They may sound a tad band-limited to me compared to some of the newer stuff, but they still hold up.....When I made the change, it took me a long time to get things to settle down to where I understand what was needed to work with the new perception of greater bandwidth and detail. I don't really want to go back, but there are days when I miss the simplicity.

.....It is definitely confusing sometimes, too. I was just listening to one of my Blues Alley albums ('92 or so) yesterday, and much more pleased than I remembered. It was recorded to a 2" with Dolby SR through my Soundcraft 600B console (that printed eq to the tracks, which was a smarter decision on my part than I really understood at the time), then mixed back through the Soundcraft to DAT in sections, and edited on the Turtle Beach 56k editing system that I abandoned for MicroSound in '94.....It sounded better than I remembered. All the A-D conversion was solely at the input of the Panasonic 3700 DAT machines I was using.....In those days, there wasn't any real CD "mastering". People were just transferring to 3/4" video decks and inserting track IDs (PCM1630?).

So, all the stuff from those days sounds quieter, but the sonic characteristics seem to hold up. Pretty interesting.....There is one album from that era that I edited mosly on Medit (with a little bit of pop and click redrawing on Turtle Beach, which Medit never did, and which Turtle Beach did well) that received a loudness boost from an early TC box. The loudness change was astounding, and sounded pretty natural, but I can hear the compression now, at least compared to the newer software and hardware boxes.

I'm not sure what all this means except that I think the Lynx box is pretty spanky, and that the quality of the converters these days has a lot going on, but kind of increases our decision possibilities again, so doesn't exactly make our lives easier.

[Rich LePage]

Ya got me on Digi specs- not sure they would tell how they measure for that matter either.

Only Digi stuff we have is an 002rack, and I nearly never use it. I did run it briefly with Audition 1.5 (an old version) using Digi's WAV (not ASIO) driver because 1.5 did not talk ASIO. Audition 2 (and 3 soon) does though.
I might mess with it as an i/o again (but Digi is XP only right now, like Waves) when Audition 3 shows up, and try to compare it to other stuff, but it's Digi's lower end anyhow.

In general, I just never liked Digi much. We bought the 002rack to be compatible with others, but that has (surprisingly) turned out to not be that big a deal for most of what we do. It has nearly never come up. We do a lot of our stuff start to finish. But many times with other work people send us elements to build with, sweeten, mix and master.
I thought being compatible would be impt with that, but nope- they just usually send "selects" and I also try to get the out-takes in case we need to use bits of them here and there.

From various friends and friendly competitors though, apparently Pro Tools compatibility is a big deal at some levels of the NYC market. Many high end ad clients bring in drives with PT sessions on them, says one guy I know who does a lot of that work. He winds up needing to have just about everything out there in terms of plug ins, etc to handle what comes in. But in reality, he does a lot of his work by taking stuff off PT and using an old NE Digital (the Synclavier folks) system that he's used for years with great success- then putting back into PT. I wonder if the clients even notice or know....


I've also heard good things about the Lynx stuff from folks whose opinion I value locally, as I value Jim's views. I'll have to give that a try too at some point.

I see Jim's another vintage Soundcraft fan. I mixed for ages on an old 800A board we still have, much modified - some non-standard EQ, whole board was re-capped, mostly new op amps too, and we added a better grade of Penny+Giles faders than it shipped with (when the original ones got noisy!)

But all those Digi specs (and all their marketing) are probably meant to drive the endless upgrade (just send $) and demand from some types of clients that you just gotta have that.

I did quite a bit of that kind of work for a long time, at various NYC studios.

That kinda client will jump whenever the place down the block gets the next upgrade of newest/latest. A lot of studios in NYC tried to cater to that market-- and few managed to do it with much success, though some did ride the endless new/improved cycle for a while. (prob they had rich investors! - in fact I know some did.) To me that's more the hotel biz than the audio biz.

We try to attract clients where it's more about the end result, not how we got there. I'm sure that's true of most of us Medit folks.

[Gary Boggess]

is a talented user.

The end result IS what it's all about. All the AES hypesters and the MIX magazine advertisers can blab on endlessly about this spec and that spec.
I always say... it's NOT about what you have, it's what you can do with it.

I usually express it like this:
Go ahead... you can go buy Tiger Woods' clubs... but can you play HIS game with them? Sure enough, he could BEAT YOUR _SS WITH YOUR CRAPPY OLD SEARS CLUBS!!!! Even if with a significant handicap!

I've seen many great musicians play very well on standard instruments. It always kills me when some of these guys come in the studio with a ie: $3700 hand made bass... but can't play a decent bass line to save their life.

[Rich LePage]

Totally true, indeed. My original mentor in all things audio
was/is Les Paul, and he sure proved that well enough!
I've heard stuff he did in the late 30s, disc to disc to
disc (like 4th or 5th generation, adding more parts
each time- the hard way!!) and for their time, they
sound damned good. Of course he was using a recording
lathe he built -- using an old Cadillac flywheel!! (not kidding).


Just talked w/him yesterday, his "home studio" (probably the
ORIGINAL home studio!!) is near here. We go back a lotta
years, I grew up with one of his sons. And that's
where my audio fate was sealed early on...

He still plays in club in NYC one night a week when he's up to it,
at age 92+ -- and he packs the place, too. They did a nice
American Masters on him that was recently on PBS, catch
a re-run if you can.

[Gary Boggess]

Well... you can tell Les I said he was recording as good as 224-bit back in the 40's... because he actually HAD SOMETHING to record. What good is 24-bit in most sessions today? Might as well be at 0-bit because these so-called musicians today aren't 1-bit of good compared to the MAJORITY of the artists, writers and musicians in Les Paul's early years.

[geezer]

I agree totally with the concept that the operator is the key.

I have never like PT/digidesign much, period, but I thought the tracks I recorded at NPR (PT HD) sounded pretty good there, though maybe a little more suspect when I got home. Being HD, I could never use their session data (totally encrypted), but, also being HD, I can walk away with Broadcast Wave files wish plop down just fine in almost any other system.

Earlier (TDM) PT sessions can be readily translated by some EDL software I have, so there really is no longer a big compatability issue unless you are locked into plugins and mixes on an HD session that noone is willing to translate backwards for you (which is obviously what Avid/Digidesign is hoping for).

People do say that HD sounds better than TDM, and I usually was able to hear problems with TDM mixes I heard.....However, one of my longest friends and musical colleagues who mixed his last couple of albums at home (stellar sounding) and mixed his daughter's hit album in Canada (she's like no. 2 there) makes his TDM system sound just fine. Really sweet, really pro......It should be noted, however, that he is not using the mix buss in PT world, but bringing stems out to a Mackie D8b. That still seems to be the key: summing it externally......Anyway, the Canadian branch of Universal that his daughter is on was pretty freaked out by how good it sounded. I was thoroughly impressed myself.

Soundcraft: That mixer (a 600B I bought in 1985) probably only has a market value of $500. or most likely less. Amazing. I sold it with all the patchbays and direct out mods for $1,100. around 1999 or 2000, then bought all the patchbays, cabling and external direct out amps back for something like $500-$600........I have an open search function on ebay for Soundcraft stuff, and am always anguishing about whether I should buy one of the boards that comes up, but haven't gotten the courage to do it yet.....Listening to that old Stanley Turrentine album of mine that I was talking about in the earlier post has really gotten me thinking.....plus I did a little acoustic, non digital sound job about a month ago that reawakened something in me......I don't know........I can't give up the automation, and my DM2000 sounds great and is capable of a bigger sound than that 600B, but I am definitely thinking things through yet again...

My fond remembrances are always chastened by the looming maintenance issues with analogue consoles....aargh!

[Gary Boggess]

Without going into here too deep... I was utterly shocked at what happened to my old TASCAM Model 5A mixing console here. Mixing... err... I use it more for monitoring... although the keyboards and mics go through it to the MicroSound via a APHEX 124A -10 to +4 box.

Yeah I know... your probably saying TEAC??? GEESH!!!!

Well... I was in a decision last year to replace it or improve it. After reading... studying and really tearing into what mods could do, I chose to mod it.
I rebuilt the power supply, better caps, all new regulators, external transformer... and better grounding internally... w/12ga stranded throughout.

Then I removed all of the op-amps, and used a mix of 5532's, TLO72's and Burr Brown 2604's. Why three types? Sound. They all have a sound.
It's not an EQ difference in sound... it's more how they handle complex
waveforms. Tones all passed the same way... but with music, each chip
responded differently. My thought was, since they all do have a sound, it doesn't makes good sense to USE ALL OF THE SAME op-amps.
I figured, if I had a lense filter that was very slightly pink, 15 of them
would be RED! And so, I thought mixing op-amps was similar. I chose these
three chips because I took consenus on the web by designers... about which
chips they preferred. The TLO72's were chosen because they had a overall
brittle sound... and were easy on the power supply. The 5532's were popular peformers, stable, handle wide variety of input impedences and sounded tube like and low noise footprints. The OP2604's for their high output peak safety, low noise, and warm low end friendly sound. Together... they sound awesome!
For the short story, I tested each... and ended up putting the 5532's on the inputs, the TLO72's in the middle ciruits and the 2604's on all of the outputs.
I also replaces all of the signal path caps with Panasonic FC series audio caps.
And then replaced all of the audio path resistors with metal film resistors.

The end result? Incredible. It was like a veil dropped. It was a lot of work, but a fraction of the cost of replacing the board, and rewiring the harness and patchbays. Noise dropped significantly, and the sound is (to my ears) very warm, defined and clean.

Yup... I've used Neve consoles, SSL, Euphonix... and Soundcraft... but after this experience... I wonder why most boards use all of the same op-amps???
They clearly HAVE a sound... and if you pass your audio through 30 of the SAME op-amps... you've got a very COLORED end result. I would same my approach appears to blend and balance it all out some. At least, it makes some logical sense.

[Gary Boggess]

Without going into this too deep here... I was utterly shocked at the improvement mods made to my old TASCAM Model 5A mixing console. Mixing... err... I use it more for monitoring... although the keyboards and mics go through it to the MicroSound via a APHEX 124A -10 to +4 box.

Yeah I know... your probably saying TEAC??? GEESH!!!!

Well... I was in a decision last year to replace it or improve it. After reading... studying and really tearing into what mods could do, I chose to mod it. I rebuilt the power supply, better caps, all new regulators, external transformer... and better grounding internally... w/12ga stranded throughout.

Then I removed all of the op-amps, installed sockets, and used a mix of 5532's, TLO72's and Burr Brown 2604's. Why three types? Sound. They all have a sound. It's not an EQ difference in sound... it's more how they handle complex waveforms. Tones all passed the same way... but with music, each chip responded differently. My thought was, since they all do have a sound, it doesn't makes good sense to USE ALL OF THE SAME op-amps.

I figured, if I had a lense filter that was very slightly pink, 15 of them would be RED! And so, I thought mixing op-amps was similar. I chose these three chips because I took consensus on the web by designers... about which chips they preferred. The TLO72's were chosen because they had a overall brittle or digital/edgy sound... and were easy on the power supply. The 5532's were popular performers, stable, handle a wide variety of input impedances and sounded warm or tube like and had a low noise footprint. The OP2604's for their high output peak headroom, low noise, and warm low end friendly sound. Together... they sound awesome!

For the short story, I tested each... and ended up putting the 5532's on the inputs, the TLO72's in the middle circuits and the 2604's on all of the outputs. (I did use two 2604's on two inputs for variety). I also replaced all of the signal path caps with Panasonic FC series audio caps. And then replaced all of the audio path resistors with metal film resistors.

The end result? Incredible. It was like a veil dropped. It was a lot of work, but a fraction of the cost of replacing the board, and rewiring the harness and patchbays. Noise dropped significantly, and the sound is (to my ears) very warm, defined and clean.

Yup... I've used Neve consoles, SSL, Euphonix... and Soundcraft... but after this experience... I wonder why most boards use all of the same op-amps??? They clearly HAVE a sound... and if you pass your audio through 30 of the SAME op-amps... you've got a very COLORED end result. I would say my approach appears to blend and balance it all out some. At least, it makes some logical sense. Would I like to own a Neve or similar console? Sure.
But mine has paid for itself over and over again since 1977!!!!!!!