Tin foil is a wonderful shielding agent!

Bart Nettle said:

I am looking at getting a new interface in the near future.

There are quite a few offerings and a mag shootout of of the best of the best to those pushing above their wieght would be great.

A mag article without advertizing bias (get all of them to advertize in the issue Ed! Hehe). 

What are your requirements in an interface ?

What Platform are you on, OSX or Windows ?

Shoot outs are a tough ask as there are so many areas to focus on , there really isn't a one size fits all when it comes to requirements.

Number of I/O, Mic Pre's, MIDI , ADAT I/O, etc , will it be used for live tracking or do you require better low latency and round trip performance due to using Virtual Instruments or tracking thru Guitar Amp Sims- for example. All of these can be factors , so apart from the usual audio specs, there are so many variables it would be hard to try and cover all aspects in a single shootout IMO

FWIW: I have done extensive testing on Low Latency Performance of a whole range of interfaces on Windows 7 that I have posted on various spaces around the web , but that is only one aspect , although an important one.

Peace

Hey I found this on Gearslutzs, technical stats are not my strong suite, so if anyone can explain the findings to me and to the rest of the readers that would be nice.  It doesn't have to be to dumb I understand the jargon as most would around here.  http://www.gearslutz.com/board.....hread.html

 

Oh and SVB, yea I know you were kidding, I just like to feign indignation!!!

 

Peace Ben

There are two things shown in the findings for each of the converters.

One is labelled 'Rate adj', which specifies the clock stability in parts-per-million. Unfortunately the test is assumed to take place at a constant temperature, whereas clock rates really change with temperature and are specified in ppm/K. This would then show you how much clock skew or jitter you might get as the unit warms up as opposed to cold.

The second spec is the correlation between the input digital file and the resulting file after doing 10 passes through the DAC and back into the ADC. There will be distortion  introduced from errors in both the ADC and DAC conversions and accuracy, and any analogue front end circuitry the signal may have to pass through before going back into the converter. I suspect these readings also have a temperature dependence as well.

So on the face of it Geoff, even if we factor in the heat thing, MOTU seem to be punching above their weight when it comes to jitter but the convertors maybe not.  Am I reading the specs correct???

 

Also if what you are saying is correct in terms of heat, it would be a wise thing to do if we turned our interfaces off when not in use.

 

Finally if I have read the specs correctly and MOTU seem to have better jitter but not so good convertors, which one do you think is more important in terms of specs for an interface.

 

Peace Ben

The clock frequency variations do look excellent for the MOTU units that were tested. Since we don't have a spread of units then we don't know if this is similar across the board or just a good unit. For example, the 2408 MK3 is showing 0.117ppm, which is 0.0000117%. We aren't given information as to whether the variation is a slow change, such as the unit warming up and settling from the initial measurement or whether it is jitter on a cycle-by-cycle basis, or a combination of both.

The correlation is also very good, and we don't have enough information to know if this is a single unit or an average of a spread of units or the conditions of the test. If they used the front panel connectors to loop the DAC to the ADC then it is likely that the analogue front end circuitry contributed a great deal to the signal distortion than the converters. Remember it has gone through this circuitry 10 times to get the final result.

Overall the comparison is interesting, but rather meaningless scientifically. Little detail is given as to the test and measurement methods or conditions of tests. No measuerment errors are shown and it appears to be a single unit only, which may not be typical.

As for heating effects, the MOTU units I have (896 and 896HD) all run quite hot so I usually switch them on at least 30 mins before using so they heat up and settle, rather than drift from cold to hot. Not sure if it makes a whole lot of difference since I've never taken any cold/hot measurements but the case metalwork seems to run up to about 40 C, probably about 20-25C above ambient. This is due to the linear PSU regulators using the case as a heatsink.

When choosing an interface, clock stability is very important since it will have a non-musical distortion effect on the signal samples (as does crossover distortion, the worst of them all). The analogue circuitry into the ADC is less important, since it is pretty easy to design a transparent amplifier these days. Mic preamps on the converters can easily be bypassed and a line level signal fed into the converter from a better or more colourful preamp if that is more desirable.

LogicprObe said:

Tin foil is a wonderful shielding agent!

HAHAHA!

Hi guys and thank you on your input.

I checked out the link on GS Dr.

The 2408, I thought it has preamps but not very good gain or is that because the inputs are only line level ins. (just checked the site and found they have 8 TRS analogue i/o plus the digital i/o. no mention of 
any pre amplification. 

Now I am just about to pick one of these up. While I have a few pre amps I was kind of under the impression it had presm as I need a few extra on the drum kit.

You know you look up and research so many different interfaces it is mind boggling.

Now I think I should go for an ultralite of even the 896.

Hey bart, I just spent the last hour writing this long essay only for the computer to tell me NO.

 

I have looked over the specs of all the units you have mentioned, the MOTU 896 has 8 preamps but they only have 53db of gain structure.  From what I have read "pro" preamps have 70db of gain structure, this is not a biggy unless you are recording classical or jazz.

 

It's true the 828 only has two preamps but both units (828&896) come with exstensive in/out options including 16 channels of ADAT.

 

I have the MOTU ultralite and they all have the same preamps, these MOTU boxes, not the highend PCI card stuff but I only use those preamps for my SM58 and as a DI, I use my Presonus Eureaka for higher quality recordings.

 

My suggestion to you if you need 8 preamps now then go for the 896 as long as you are recording rock these preamps will be fine.

 

If you have enough standalone Preamps then go for the MOTU 828, this unit only has two preamps but will let you hook in your standalone preamps at the same time and if you still needed more preamps you could get a Presonus 8in ADAT box for 500 bucks, giving you as many preamps as you need.

 

The great thing about the Motu units is you can daisychain them together, so you could hook two 828's together and have 32 channels of adat if needed.

 

If you need a couple of high quality preamps and have almost enough standalone preamps to record a band you could look at the RME USB interface, their two preamps, that they come with (they have the same amount of connectors as the MOTU 828 unit) are better quality and in fact have 65db of gain but for all intense and purpose they are about the same in quality as the MOTU units in every other way even using the same ADDA converter chips.  The RME USB interface is advertised on the FactorySound website for $1800 but they have had it as low as $1300.

 

Stear clear of anything firewire, too many risks with firewire compatibility, if you havent already noticed there has not been a single new firewire audio interface latley.

 

Contact, Factory Sound, SoundCorp and The ElectricRoom to get the best price, just start a bidding war, everyone of these companies are doing it tough so you are in the box seat.

 

I am sorry if you knew any of this stuff, let me know if you have anymore questions, am glad to help.

 

Peace Ben

Dr.Hash said:

I have looked over the specs of all the units you have mentioned, the MOTU 896 has 8 preamps but they only have 53db of gain structure.  From what I have read "pro" preamps have 70db of gain structure, this is not a biggy unless you are recording classical or jazz.

My suggestion to you if you need 8 preamps now then go for the 896 as long as you are recording rock these preamps will be fine.

 

I've recorded classical and jazz with the 896 units using only the onboard preamps. They work fine, since you don't run the inputs at 0dBFS anyway, I set peak levels at -12dBFS during performance recordings. The inputs included DI and condensor microphones, and one dynamic mic.

Stear clear of anything firewire, too many risks with firewire compatibility, if you havent already noticed there has not been a single new firewire audio interface latley.

 

Do you know why that is? Because USB has been upgraded twice to USB2 aqnd USB3 with high speed specifications. It is also much easier to design and has a wider variety of chipset options to choose from (thanks to PC land). Firewire is still alive and doing well though, with FW800 being the latest incarnation. People encountered compatibility problems with certain firewire chipsets and implementations of firewire, along with some manufacturers releasing buggy drivers. The FW protocol is better suited to audio and video interfacing than USB though.