that tascam's DR78HR is better sounding isn't very surprising to me...it's a higher league then the motu's "small" line.
i would not modify gear i'm happy with, unless it would be easy and (close to) risk-free....but that being said, i have to add: Modding good designed gear to better sound is possibly easyer then try to bring a Toy to life...
interesting rapport, about listening with Big Ben. Your next step could be to build an external, ACCU-powered PSU....
i've finished one 2408, now i have changed every 2115 (input stage) and all 4580 belong to out 1-8, but not the variable Main and Headphone out's. then i did some first measures Old vs New -the result is visible, mainly less artifacts.
all in all, the OPA2134 is one to go, really better then the originals, surely NE5532 league, in my Ears the OPA has a bit better transient response and dynamics then the later.
we could do some representative soundfiles (possibly best would be from "better then CD" source, and 96k sampled...)
i would not modify gear i'm happy with, unless it would be easy and (close to) risk-free....but that being said, i have to add: Modding good designed gear to better sound is possibly easyer then try to bring a Toy to life...
interesting rapport, about listening with Big Ben. Your next step could be to build an external, ACCU-powered PSU....
i've finished one 2408, now i have changed every 2115 (input stage) and all 4580 belong to out 1-8, but not the variable Main and Headphone out's. then i did some first measures Old vs New -the result is visible, mainly less artifacts.
all in all, the OPA2134 is one to go, really better then the originals, surely NE5532 league, in my Ears the OPA has a bit better transient response and dynamics then the later.
we could do some representative soundfiles (possibly best would be from "better then CD" source, and 96k sampled...)
post samples! sounds like a challenge! ha ha. just kidding. i'll see if i have the test recordings i did somewhere when i modded my 828.
actually, modding the tascam would be really, really easy - the board layout is very nicely spaced out and there's plenty of room to work in there - actually easier than the 828 even. the ne5532s are also soic-8 and i think they have the same pin layout, but i can't remember.
an external psu would be a good idea actually. fairly simple... hmmm.... so many projects, so little time!
actually, modding the tascam would be really, really easy - the board layout is very nicely spaced out and there's plenty of room to work in there - actually easier than the 828 even. the ne5532s are also soic-8 and i think they have the same pin layout, but i can't remember.
an external psu would be a good idea actually. fairly simple... hmmm.... so many projects, so little time!
I'm thinking of moding my motu 828 (mk1). I'd like to fit in a low jitter clock like the tentlabs XO2.2
I need some advice: would it work if i left the current clock(tlc2933 ) and just input the tentlab clock to the converters (cirrus logic cs4223), it would mean that the data clock wouldn't be synched to it.
i'm thinking about that as a clock distribution dsp (the acex 1k chip) creates a lot of jitter.
the converters datasheet don't mention if the both must be aligned.
I need some advice: would it work if i left the current clock(tlc2933 ) and just input the tentlab clock to the converters (cirrus logic cs4223), it would mean that the data clock wouldn't be synched to it.
i'm thinking about that as a clock distribution dsp (the acex 1k chip) creates a lot of jitter.
the converters datasheet don't mention if the both must be aligned.
got me there. don't know. you're probably right about the acex chip being not so great at distribution - that would line up right with my experimentation. it'll be a bit of an exercise to get multiple clock signals going though. the motu stuff generates its clocks by the tlc9xxx chip (can't remember the number) which is controlled by the voltage. basically for 44.1 and multiples it's getting about 1 v. for 48 and its multiples it's getting 1.3v. that's why the bla mod has a switch on the front. the acex chip does the multiplication i think. although, if yours is a mk1, you'll only have 44.1 and 48 to deal with. that'll still mean 2 crystals with a switch, or just forsaking clocking at one of the speeds (or clocking externally for that speed).
also, be warned, my 828 started acting funny after i tried messing with the clock - it still acts funny every once in a while. bla stopped doing their clock mod for that reason, the motu gear gets unpredictable when the clock is messed with, don't know why. different things stop working randomly or behave erratically. probably due to the power supply.
so, just be prepared to pull out your hair every once in a while when it randomly stops working or breaks its link with your computer.
may be wise just to build an external clock if you prefer stability.
if you can borrow a good clock to sync to for a while for experimentation, that would be good. the motu's fortunately have bnc connectors. see if that'll get you results your happy with.
also, be warned, my 828 started acting funny after i tried messing with the clock - it still acts funny every once in a while. bla stopped doing their clock mod for that reason, the motu gear gets unpredictable when the clock is messed with, don't know why. different things stop working randomly or behave erratically. probably due to the power supply.
so, just be prepared to pull out your hair every once in a while when it randomly stops working or breaks its link with your computer.
may be wise just to build an external clock if you prefer stability.
if you can borrow a good clock to sync to for a while for experimentation, that would be good. the motu's fortunately have bnc connectors. see if that'll get you results your happy with.
hey smitsch,
do you know what capacitance the little white smt caps are (that bridge 1 and 2 of all the opamps). i think i fried one or two, but i don't have a multimeter that measure capacitance - nevermind that getting one of those things off to measure it is a total bugger.
anyways, if you know, let me know. i'm assuming either .1µf or .01µf.
took your advice whilst repairing and cleaning up my motu of replacing the other njm4580's - the ones that buffer the converters. too late here to test it out on the speakers, but the headphones sound nice. should have done that earlier. fortunately for me, the most recent mix of the project i'm working on sounds good to me still ; ) always dangerous making your gear sound better. it sounds better, and sounds better with the buffer opamp replaced (if you know what i mean).
i've been sticking with my ths4032 samples from TI - still sound great to me, and can't afford anything else anyways.
AT
do you know what capacitance the little white smt caps are (that bridge 1 and 2 of all the opamps). i think i fried one or two, but i don't have a multimeter that measure capacitance - nevermind that getting one of those things off to measure it is a total bugger.
anyways, if you know, let me know. i'm assuming either .1µf or .01µf.
took your advice whilst repairing and cleaning up my motu of replacing the other njm4580's - the ones that buffer the converters. too late here to test it out on the speakers, but the headphones sound nice. should have done that earlier. fortunately for me, the most recent mix of the project i'm working on sounds good to me still ; ) always dangerous making your gear sound better. it sounds better, and sounds better with the buffer opamp replaced (if you know what i mean).
i've been sticking with my ths4032 samples from TI - still sound great to me, and can't afford anything else anyways.
AT
hey Adam, hot days?
i've a cap meter, they are 10nf or 0.01uf
i've heard that WIMA makes some fine MKP types they're fast impulse (impulse stable) types, could be usefull as your THS is also very fast opamp?
then, i used paper tape (painters tape) to cover those caps's and small parts surround the opamps. Paper tape can take the heat for some time (gets darker after say 10 sek) and helps to insulate the parts who should stay....
could you possibly help me with a repair ( or replace) of a turntable bearing from Oracle Audio? Please PM me on that.
regards Mitsch
i've a cap meter, they are 10nf or 0.01uf
i've heard that WIMA makes some fine MKP types they're fast impulse (impulse stable) types, could be usefull as your THS is also very fast opamp?
then, i used paper tape (painters tape) to cover those caps's and small parts surround the opamps. Paper tape can take the heat for some time (gets darker after say 10 sek) and helps to insulate the parts who should stay....
could you possibly help me with a repair ( or replace) of a turntable bearing from Oracle Audio? Please PM me on that.
regards Mitsch
no hot days... just clumsy hands. ; )
i doubt i'll replace the caps just yet. the psu in the motu's so far beneath what it could be. that's next on my hit-list. i am clueless about psu's, but have a friend here that might be able to help me. the dream is to build an external psu that has stable and clean voltage. the voltage on my motu swings from as low as 8.5 to as high as almost 11v. so i don't even know what the intended voltage is - assuming 9v is more likely than 10v.
anyways, that's all a dream - got too much actual recording work to do to think about that right now.
the painter's tape is a great idea - thanks for that.
i'll email you about the phonograph part.
AT
i doubt i'll replace the caps just yet. the psu in the motu's so far beneath what it could be. that's next on my hit-list. i am clueless about psu's, but have a friend here that might be able to help me. the dream is to build an external psu that has stable and clean voltage. the voltage on my motu swings from as low as 8.5 to as high as almost 11v. so i don't even know what the intended voltage is - assuming 9v is more likely than 10v.
anyways, that's all a dream - got too much actual recording work to do to think about that right now.
the painter's tape is a great idea - thanks for that.
i'll email you about the phonograph part.
AT
hey,
thought you may find this of interest, especially you jayceefr.
i have had no end of little problems since messing with the clock on my motu.
recently, i had to make it just work dependably. i had broken a leg off of the tlc2933 ic in my clumsy soldering.
so, i ordered a new one and put it in. at the same time, i removed my voltage regulator/cleaner mod - i had taken the first part of a kwak clock and put it in.
anyways, instead, i took the middle part of the kwak clock and put it in... in short, i removed the 470µf cap by the tlc2933, made a break in the line (meant removing the whole board and getting at the underside) for the 3.3v supply to the IC. also removed the cap that joined the two VCC sides of the IC (logic and vco) so that they were completely separate. then i made up a little pcb with a couple big 1000µf caps in series in place of the 470µf cap (cause i didn't have another around and couldn't find the original either, which i had removed earlier... gotta clean up around here) and the ferrite beads and 0.1µf caps to each line to separate the two and clean up the noise they might give each other.
anyways, the clock isn't amazing, but it seems a fair bit better. so you may find that a cheap and simple way to get a step up. from brief listening tests, it sounds better than having the system clocked to my tascan da78hr through lightpipe - less harsh in the high end. not a drastic difference, but mildly better.
also discovered that ALL the clock signals seem to go through the tlc2933 (meaning those from the bnc in or lightpipe or spdf) because the pin i broke was the vco out and i couldn't get it to clock to anything when it was broken.
which brings me to my last thought....
if you decide to mod the clock, i might recommend doing this: bare a bit of the conductor between the vco out and the 47 ohm resistor - enough to solder both sides to reconnect it - and make a small break there. then you can patch in whatever clock mod you make with a switch to go back to the tlc2933 clock if you need to clock externally for some reason - like smpte or an external clock.
a clock upgrade would probably help a fair bit. the tlc2933 boasts 100ps jitter in ideal conditions... not so great compared to the bla clock that uses a 1ps jitter crystal.
and finally... even just with replacing the opamps and the tiny clock mod i did (as i explained above) it sounds a lot better than it did. just for giggles, i did a comparison to my motu's headphone outs with my macbook pro's headphones out - the partially modded motu kicks the livin' daylights out of the mbp headphone out; it's a really pleasant sounding rig now. oh yeah, also i just swapped the old mic pre opamps to the headphone opamps... so they are both opa2134's, quite a decent opamp. BLA says on their site that they use it's big brother, the 4134, on their mods of the digi rack stuff. anways, [i think] they're buffered from the adc by a ths4032 [i don't have the schematics for the motu, and probably wouldn't understand them anyways... so it could be that they're being buffered by the lm833's that i haven't changed out... but i don't think so, because i think those are for driving the signals for the 'cuemix' system... but what do i know?]}. whatever, it sounds good...
speaking of bla, they have some interesting video links on their site about their mods. man, matt and his gang know what they're doing, they've really done their homework on modding the gear they mod. they do a great job and i think they're more than worth their weight for what they do. they do crazy things to the digi rack stuff... check out the videos.
though i'm sure my motu could be better, i gotta get some work done and put some of the dream mods on hold for now. besides that, got a mic to mod and an office to clean!
happy modding, thanks for all the input and sharing of information - here's to better music!
AT
thought you may find this of interest, especially you jayceefr.
i have had no end of little problems since messing with the clock on my motu.
recently, i had to make it just work dependably. i had broken a leg off of the tlc2933 ic in my clumsy soldering.
so, i ordered a new one and put it in. at the same time, i removed my voltage regulator/cleaner mod - i had taken the first part of a kwak clock and put it in.
anyways, instead, i took the middle part of the kwak clock and put it in... in short, i removed the 470µf cap by the tlc2933, made a break in the line (meant removing the whole board and getting at the underside) for the 3.3v supply to the IC. also removed the cap that joined the two VCC sides of the IC (logic and vco) so that they were completely separate. then i made up a little pcb with a couple big 1000µf caps in series in place of the 470µf cap (cause i didn't have another around and couldn't find the original either, which i had removed earlier... gotta clean up around here) and the ferrite beads and 0.1µf caps to each line to separate the two and clean up the noise they might give each other.
anyways, the clock isn't amazing, but it seems a fair bit better. so you may find that a cheap and simple way to get a step up. from brief listening tests, it sounds better than having the system clocked to my tascan da78hr through lightpipe - less harsh in the high end. not a drastic difference, but mildly better.
also discovered that ALL the clock signals seem to go through the tlc2933 (meaning those from the bnc in or lightpipe or spdf) because the pin i broke was the vco out and i couldn't get it to clock to anything when it was broken.
which brings me to my last thought....
if you decide to mod the clock, i might recommend doing this: bare a bit of the conductor between the vco out and the 47 ohm resistor - enough to solder both sides to reconnect it - and make a small break there. then you can patch in whatever clock mod you make with a switch to go back to the tlc2933 clock if you need to clock externally for some reason - like smpte or an external clock.
a clock upgrade would probably help a fair bit. the tlc2933 boasts 100ps jitter in ideal conditions... not so great compared to the bla clock that uses a 1ps jitter crystal.
and finally... even just with replacing the opamps and the tiny clock mod i did (as i explained above) it sounds a lot better than it did. just for giggles, i did a comparison to my motu's headphone outs with my macbook pro's headphones out - the partially modded motu kicks the livin' daylights out of the mbp headphone out; it's a really pleasant sounding rig now. oh yeah, also i just swapped the old mic pre opamps to the headphone opamps... so they are both opa2134's, quite a decent opamp. BLA says on their site that they use it's big brother, the 4134, on their mods of the digi rack stuff. anways, [i think] they're buffered from the adc by a ths4032 [i don't have the schematics for the motu, and probably wouldn't understand them anyways... so it could be that they're being buffered by the lm833's that i haven't changed out... but i don't think so, because i think those are for driving the signals for the 'cuemix' system... but what do i know?]}. whatever, it sounds good...
speaking of bla, they have some interesting video links on their site about their mods. man, matt and his gang know what they're doing, they've really done their homework on modding the gear they mod. they do a great job and i think they're more than worth their weight for what they do. they do crazy things to the digi rack stuff... check out the videos.
though i'm sure my motu could be better, i gotta get some work done and put some of the dream mods on hold for now. besides that, got a mic to mod and an office to clean!
happy modding, thanks for all the input and sharing of information - here's to better music!
AT
update
just an FYI update.
ended up still having trouble even with a simple mod to the clock [to clean up the DC supply].
so, I gave up and put everything in the clock back to exactly the way it was. now i just slave it to an external clock if i'm feeling "hi-fi" hungry.
had lots of trouble with noise in my system - tried a few things in my motu, only to find out that all along my monitors weren't plugged into my power conditioner. doh. guess i won't get those hours back.
smitch, tried messing with the capacitors a bit. on my model, as it turns out, they're not .01µf bybass caps. the bypass caps on my unit are 220pf and the power caps are .47µf. by default, emphasis on the fault, i had to replace a couple of the bybass caps and power caps because i managed to destroy some of the feet/contacts for the original smd parts. so, i ended up using tantalum caps for the .47µf caps and mono caps for the 220pf caps, but only on the main outputs. not much of a difference, not worth the effort i think.
wanted to make my unit consistent, so ended up using ths4032 opamps for all of the input stages (input opamps and ADC buffer opamps). changing the the buffer opamps is definitely worth while. don't seem to have trouble with noise with those ones, all the inputs are clean and at least as quiet as the originals.
that being said, the ths4032 recommends 6.8µf tantalum caps plus .1µf ceramic caps on each unit for power filtering. tried that (replacing the .47µf caps with 6.8µf), but as one of you could have likely told me, that messed with the capacitance of the whole circuit and made the outputs very muddy in the top end. so went back to the original schematic and left it at that *with tantalum instead of ceramic though).
for my mic pres and headphones i used opa 2227 opamps. don't think they're better than the opa 2134, but i had them so they got used. sound just fine. too cheap to replace them with opa2134s.
the outputs i've swapped the dac buffers to opa2131's because it's what i had, again. the actual output opamps will be opa2134's which will match the main outs now. i switched the main out opamps to the opa2134's and the DAC buffer to a opa 2227, again because i had it on hand and it sounds just fine to me.
if i were to do this all again, i'd buy a whole whack of opa2134's and replace the lot with those. primarily i would do this because they aren't as picky as the ths4032 in regards to clean power. also, i think their lower frequency (8mhz compared to 100mhz of the ths4032) would mean for less power noise issues with the converters. i'm tired of monkeying with it, and it's working now, so it'll stay as it is. especially since i often use my tascam da 78hr's converters most of the time anyways.
the opa 2134's on the main outs with the opa 2227 buffer sound beautiful.
also, you might chuckle at this. tried an A B test with the ths 4032 inputs on my motu and the inputs on a UA2192 (my motu clocked to the UA2192). they both sound different (UA2192 has more highs and less lows), but i don't think the modded ones on my motu really sound notably worse - not bad! or, my ears aren't that good! ha ha! (this coming from a guy who picked a behringer pre over a UA in a blind test once... oops!) sometimes i think i can't hear a thing. either way, i'm satisfied. i'm not gonna compete with an all discrete piece of gear anyway i slice it while using opamps. so, i reckon i'm doing just fine. it's definitely good enough to not get in the way of the enjoyment and recording of good music, which is what matters.
happy modding.
AT
just an FYI update.
ended up still having trouble even with a simple mod to the clock [to clean up the DC supply].
so, I gave up and put everything in the clock back to exactly the way it was. now i just slave it to an external clock if i'm feeling "hi-fi" hungry.
had lots of trouble with noise in my system - tried a few things in my motu, only to find out that all along my monitors weren't plugged into my power conditioner. doh. guess i won't get those hours back.
smitch, tried messing with the capacitors a bit. on my model, as it turns out, they're not .01µf bybass caps. the bypass caps on my unit are 220pf and the power caps are .47µf. by default, emphasis on the fault, i had to replace a couple of the bybass caps and power caps because i managed to destroy some of the feet/contacts for the original smd parts. so, i ended up using tantalum caps for the .47µf caps and mono caps for the 220pf caps, but only on the main outputs. not much of a difference, not worth the effort i think.
wanted to make my unit consistent, so ended up using ths4032 opamps for all of the input stages (input opamps and ADC buffer opamps). changing the the buffer opamps is definitely worth while. don't seem to have trouble with noise with those ones, all the inputs are clean and at least as quiet as the originals.
that being said, the ths4032 recommends 6.8µf tantalum caps plus .1µf ceramic caps on each unit for power filtering. tried that (replacing the .47µf caps with 6.8µf), but as one of you could have likely told me, that messed with the capacitance of the whole circuit and made the outputs very muddy in the top end. so went back to the original schematic and left it at that *with tantalum instead of ceramic though).
for my mic pres and headphones i used opa 2227 opamps. don't think they're better than the opa 2134, but i had them so they got used. sound just fine. too cheap to replace them with opa2134s.
the outputs i've swapped the dac buffers to opa2131's because it's what i had, again. the actual output opamps will be opa2134's which will match the main outs now. i switched the main out opamps to the opa2134's and the DAC buffer to a opa 2227, again because i had it on hand and it sounds just fine to me.
if i were to do this all again, i'd buy a whole whack of opa2134's and replace the lot with those. primarily i would do this because they aren't as picky as the ths4032 in regards to clean power. also, i think their lower frequency (8mhz compared to 100mhz of the ths4032) would mean for less power noise issues with the converters. i'm tired of monkeying with it, and it's working now, so it'll stay as it is. especially since i often use my tascam da 78hr's converters most of the time anyways.
the opa 2134's on the main outs with the opa 2227 buffer sound beautiful.
also, you might chuckle at this. tried an A B test with the ths 4032 inputs on my motu and the inputs on a UA2192 (my motu clocked to the UA2192). they both sound different (UA2192 has more highs and less lows), but i don't think the modded ones on my motu really sound notably worse - not bad! or, my ears aren't that good! ha ha! (this coming from a guy who picked a behringer pre over a UA in a blind test once... oops!) sometimes i think i can't hear a thing. either way, i'm satisfied. i'm not gonna compete with an all discrete piece of gear anyway i slice it while using opamps. so, i reckon i'm doing just fine. it's definitely good enough to not get in the way of the enjoyment and recording of good music, which is what matters.
happy modding.
AT
Update the other
here i'm with my finished Motu 2408mk3's:
one unit has new BB opa2134UA on on all ins and outs, (differential amp and DAC Buffers) and sounds much better now, i would say it is a new interface now, easy to hear that it's a lot less grainy and more precise now, i like it now!
second unit is more experimental: DAC and ADC buffers are all AD8620, and outs are also BB OPA2134. Inputs are 1-4 OPA2134,5-6 are AD8620, 7-8 the original NJM2115. the AD's as Buffer is a good step forward, now, even the input with the cheap NJM ops sounds better now, more drive and punch then before, and the 5-6 ins are precise and open sounding.
the whole mod's price is some hours sodering and 90$ for the op-amps...but now i have usable, musical units, not anymore things that smell like semipro...
here i'm with my finished Motu 2408mk3's:
one unit has new BB opa2134UA on on all ins and outs, (differential amp and DAC Buffers) and sounds much better now, i would say it is a new interface now, easy to hear that it's a lot less grainy and more precise now, i like it now!
second unit is more experimental: DAC and ADC buffers are all AD8620, and outs are also BB OPA2134. Inputs are 1-4 OPA2134,5-6 are AD8620, 7-8 the original NJM2115. the AD's as Buffer is a good step forward, now, even the input with the cheap NJM ops sounds better now, more drive and punch then before, and the 5-6 ins are precise and open sounding.
the whole mod's price is some hours sodering and 90$ for the op-amps...but now i have usable, musical units, not anymore things that smell like semipro...
Attachments
Has anyone tried replacing teh AK4528's with the AK4602A'?
They are close to being compatible, the 4620 has 2 extra pins that would stick over, they are flag out pin. Same codec, everything else lines up
AKM Semiconductor, Inc.: Digital Audio - CODEC - AK4620A
It has slightly larager SNR spec on both sides.
They are close to being compatible, the 4620 has 2 extra pins that would stick over, they are flag out pin. Same codec, everything else lines up
AKM Semiconductor, Inc.: Digital Audio - CODEC - AK4620A
It has slightly larager SNR spec on both sides.
Long time not heard about some Motu Mods?
I have a new one - IF (....) you beleave in Jitter:
There is the PCI/ PCIe 424 (X) Card, and all Versions produce the internal clock signals/ samplingrate (for the Interfaces), with the 64Mhz Crystal oscillator - A Friend sugessted me to power this with an external, Ultra low noise "shunt voltage Regulator" - Tent labs and others offer them. So, my pci Card für the Motu (2408 MK3 and others) got it's Crystal removed, just to install the new "ULN" voltage Regulator (3.3V) to it, and put it back - one Pin isolated on the PCB - the soucre is now the +12V Pin on the PCI socket, and the tentlab 3.3V shunt feeds the Oscillator - this little mod is so good, all motu users should go for it...it's about 80us$, and the most difficult part is to remove the crystal ( make a Special 4-Pin tool just for unsoldering, or do it with 2 Irons and 2 Persons) - once installed, there is more Music. Precision, Bass, everything gains, and it's not a tiny step, it's remarkable from Minute one - i'm sure, even if the Interface has ist original cheap opa's.
Now, with modded clock's, Opamps and better caps for the analogue PSU Part, my Motu Setup compares to the big Avid line, RME, Apogee whatever..come in with you SOTA- gear, i'm sure there is little Air on Top. External clocks are still above, sure there is allways something better - but not that much that it rules anylonger in production workflow. And the best of it: you still have the Option to choose the clocksouce you like, and all Software- Options stay the same (like automatical switching samplerates in wavelab......)
if you have the skills, or know someone who has, it's a nobrainer....i should start a business out of this experience
from my experience, if you go for them, check if they need more Power - if so, be warned, the 2408's PSU has only little reserves...8W more and voltage Drops. And: Pin- compatible, yes, but how about protocols, spec's...if you read the Bla- comments, the AK 4528 seems to be a good device used allover the industry - they also start with analogue parts & clock...
I have a new one - IF (....) you beleave in Jitter:
There is the PCI/ PCIe 424 (X) Card, and all Versions produce the internal clock signals/ samplingrate (for the Interfaces), with the 64Mhz Crystal oscillator - A Friend sugessted me to power this with an external, Ultra low noise "shunt voltage Regulator" - Tent labs and others offer them. So, my pci Card für the Motu (2408 MK3 and others) got it's Crystal removed, just to install the new "ULN" voltage Regulator (3.3V) to it, and put it back - one Pin isolated on the PCB - the soucre is now the +12V Pin on the PCI socket, and the tentlab 3.3V shunt feeds the Oscillator - this little mod is so good, all motu users should go for it...it's about 80us$, and the most difficult part is to remove the crystal ( make a Special 4-Pin tool just for unsoldering, or do it with 2 Irons and 2 Persons) - once installed, there is more Music. Precision, Bass, everything gains, and it's not a tiny step, it's remarkable from Minute one - i'm sure, even if the Interface has ist original cheap opa's.
Now, with modded clock's, Opamps and better caps for the analogue PSU Part, my Motu Setup compares to the big Avid line, RME, Apogee whatever..come in with you SOTA- gear, i'm sure there is little Air on Top. External clocks are still above, sure there is allways something better - but not that much that it rules anylonger in production workflow. And the best of it: you still have the Option to choose the clocksouce you like, and all Software- Options stay the same (like automatical switching samplerates in wavelab......)
if you have the skills, or know someone who has, it's a nobrainer....i should start a business out of this experience
from my experience, if you go for them, check if they need more Power - if so, be warned, the 2408's PSU has only little reserves...8W more and voltage Drops. And: Pin- compatible, yes, but how about protocols, spec's...if you read the Bla- comments, the AK 4528 seems to be a good device used allover the industry - they also start with analogue parts & clock...
here they are - the unit is in daily use, everything perfect. What you see is a "tentlabs" 3.3V shunt Regulator, conected to Vcc of the XO, feeded by +12V tag on the PCI-Slot.
Attachments
This is the topology on the Motu 24I/O (and others) input buffers for the ADC
I traced it and then found a similar schematics on the web.
After reading the entire thread again, i come to the conclusion that some people are confused about the function of the opamps. One of the 3 opamps for each pair of channels is a dc servo, not a dac buffer.
I traced it and then found a similar schematics on the web.
After reading the entire thread again, i come to the conclusion that some people are confused about the function of the opamps. One of the 3 opamps for each pair of channels is a dc servo, not a dac buffer.
An externally hosted image should be here but it was not working when we last tested it.
BTW: if you want me to make you this Mod on your PCI, PCI-X or PCIe 424Card, there are possibilities.
There is also a moded PCI or PCI-X available for direct Exchange, if someone is interested.
Price: is the 3.3V Tent shunt Regulator & 1 hour of work (70 USD) & shipping - a nobrainer.
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