Anyone have the specs for 2408 mkII mods, BLA-style...

[offramp]

I have two 2408 mkII's, and could really stand to upgrade them, like BLA does. Problem is, if I had the $700+ it's gonna take, I need to spend it on other things.
I'm likely quite capable of doing the mod myself, just need to know what gets replaced and with what. Anyone have the skinny on this?
(Honestly, I'd love to send them off to BLA and have them worry about it, but I need to try to take care of as much as I can, 'hands on', save some money, move forward.)

 

[deuce42]

Whilst I dont have the skinny on what they do, I did get them to mod a delta 1010 that I still sometimes use. The real important changes are the op amps in AD and DA sections. Replace those with burr browns or LM series op amps and I think you will find that is where the real thrust of the mod is. With a lot of converters, the conversion chips are pretty uniform across manufacturers but the expensive ones usually have a much better analogue section which removes the "blanket over your speakers" sound some of cheaper converters have.

I dont claim to be an expert on this or what BLA does but my guess (and its only a guess) is that the impact of the op amp replacements will have much more of an effect on sound improvement then clock mods, capacitor decouples, power supply mods etc that they also do in their mods in tandem with changing the op amps.

I liken it to modifying a mic - changing the capsule will probably be like 80% of the change in sound where as changing the circuit, tube, xformer etc may be more like 20%?

Once again this is just my experience and guess. Others may disagreee.  

 

[simonsez]

I guess they change to linier PSU too, increase the voltage feed too analog sec.(opamp), thus increase headroom. I used to not believe about benefit using audio grade coupling cap, after few month ago...i changed my mind.

 

[saxmonster]

So i know this thread is old but I wanna improve my 2408 mkII so I took the cover off and found the

Motu NJM4580 Operational Amp chips seems that there are 4 of them.  How hard do you think these will be to replace.

Should I replace them with the

SA5532AP Op. amp chips  or  AD8066 FET.

I have an email into Black Lion Audio to see if the will tell me what they use or if the will sell me a diy kit.

Here is a pic of the op amps.

 

[saxmonster]

Ok So I picked up a used 2408 MKII with the BLA mod done and I am having a hard time hearing the difference.  Maybe cause I am just too tired. 

Here is the mod that was done.

Standard Mod

New, high performance op-amp upgrade on analog inputs (mic and line) to ensure better signal quality leading up to the A/D conversion stage
New, high performance op-amp upgrade on the analog outputs (line, monitor, and headphone) to ensure better signal quality from the D/A conversion stage to the outputs
Improving the performance of the analog stage circuits makes a drastic difference for tracking, mixing, and mastering (expect amazing micro-dynamics and space)!


I have loaded some commercial CD's tracks that I know and love into Digital Performer and I am able to switch in-between the 2 units and man its hard to hear a difference.  I think there is a difference but I can't just put my finger on it.  I think the BLA one might be 1db higher in vol  but there is something else there.  What is the best way to do this?  I'm gonna load more songs in tomorrow so I will have ROCK R&B Country etc.  But What is the best way to AB them.  I have each song loaded twice on stereo tracks 1st stereo track has the song for the BLA Modded and the next stereo track has the same song for the original unit.  So All I have to do is mute the one playing and un mute the next stereo track below it playing the same song in the same spot but now going through the other original 2408.

Can't hear that big of a difference.

If I bounce a section of the song using the original unit and then another bounce using the modded unit should you hear a difference in the bounces?

 

[ruairioflaherty]

I think the BLA one might be 1db higher in vol  but there is something else there.

For converter comparisons 0.1dB of a difference in level is enough to throw the result in favor of the louder unit.  Level matching needs to be perfect or any listening tests are meaningless unfortunately.

 

[ruairioflaherty]

Sorry, double post.

 

[zamproject]

Hi

Not an A/B test but you can look(ear) at the "absolute" difference.
just re-record a song via DA-->AD loop twice, using both unit
then play both track in your DAW, one with inverted phase
Digital performer trim allow you to fine tune at+/- 0.01dB, so fine tune one track for maximum cancellation
then what do you ear?

Zam

 

[saxmonster]

So I am trying to wrap my head around this but I found something cool.

Using my original 2408MKII I made recordings  out channels 5-6 and back in channels 5-6.  I did this twice to make two stereo tracks.  When I play the stereo tracks together and flip the phase on one I get the music in both speakers but it is very soft.

See Original Vs Original Bounces

https://www.dropbox.com/sh/qo4cnexydxvwg0z/AACOxQw8-uMM8bp8BITygIbPa?dl=0

Here is the cool part.  Its very soft in the beginning but when it gets a little later in the music  the music is just coming out of the left speaker very soft though.  And then by the end of the song there is total cancelation.  I guess this is from different panning and mixing through out the song?

Then what I did is compare one of the original recordings I just made to a BLA recording.  Again using the out of 5-6 on the BLA Modded 2408mkII back into channels 5-6 of the BLA one.

See the examples in the above link. 
Beginning section is equal on both side and very soft
Middle Ssection is equal on both side and very soft
Ending is heavy on the right side and very soft

What does this all mean?  Can someone put it in english, hahahahah?
I still think I am going to return it cause I can't really tell the difference and I guess there is a bit of high end change base on the bounces and what was heard is the difference between the two units.