[jonwb]

I was doing some digging on the TI website and found/downloaded the PCM1748 datasheet.  For those that don't know, the PCM1748E is the DAC chip in the Squeezebox2.

It didn't dawn on me until after I had been looking around in that document for a while, that there are basically two versions of that chip.  The PCM1748E (the one in the SB2)



...and the PCM1748KE.  It looks to my (mechanical engineer) eyes that for all intents and purposes the 'KE' is a drop in replacement for the 'E' except that the specifications on the 'KE' would seem to indicate that this is a "higher end" version of the 'E'.



Which leads me to wonder... would the performance of the SB2 be "enhanced" by replacing the PCM1748E w/ the PCM1748KE?  Maybe it'd be best to do this in conjuction w/ some other mods, but frankly it appears that replacing the DAC would be pretty cheap (@ $2.93ea):



Now I realize that this is an itty bitty SMC part, but I know people that are majic w/ a soldering iron.  

Thoughts???

[JoshK]

If I were going to do such a mod, seeing that the price of said DAC is so cheap, I would snip the leads of hte current dac and desolder the pins and solder in the new DAC.  I would not try to desolder the old DAC all at one time.  Snip for sure!

[jonwb]

Snip for sure!

Makes sense to me... but like mentioned I've got an expert to do delicate soldering like this for me.  Question is... assuming the soldering is not a problem, is it a good idea?  

BTW, here is the link to the PCM1748 datasheet.

[JoshK]

I am too "newb" to be voice of reason here, but to my eyes also, it does look like it is a candidate for drop in replacement.  Is it worth it?  Who knows?

From that document it looks like it is the same DAC with tighter tolerances.

[Vinnie R.]

I was doing some digging on the TI website and found/downloaded the PCM1748 datasheet.  For those that don't know, the PCM1748E is the DAC chip in the Squeezebox2.

It didn't dawn on me until after I had been looking around in that document for a while, that there are basically two versions of that chip.  The PCM1748E (the one in the SB2)



...and the PCM1748KE.  It looks to my (mechanical engineer) eyes that for all intents and pu ...

Hi jonwb,

Nice find!     Looks like the KE version has increased SNR and Dynamic Range (6dB).  I'm not sure if it will make much difference, but the chip is cheap enough to give it a try  

I'll post my findings soon...

Thanks for the post!

[jholtz]

Hi Vinnie,

I'd be very interested to hear your opinion on this mod. I'm very curious to see if it's an audible improvement.

Jim

Hi jonwb,

Nice find!     Looks like the KE version has increased SNR and Dynamic Range (6dB).  I'm not sure if it will make much difference, but the chip is cheap enough to give it a try  

I'll post my findings soon...

Thanks for the post!

[Vinnie R.]

Hi Vinnie,

I'd be very interested to hear your opinion on this mod. I'm very curious to see if it's an audible improvement.

Jim

Hi Jim and Everyone,

If it does make an audible improvement, I will include it in my modded SB2s at no extra cost  

Regards,

[Davey]

How 'bout testing to see if it makes a 'measurable' improvement?

Davey.

[CSMR]

Why not ask the Squuzebox people? They are known for being happy to discuss aspects of their design.

[jholtz]

Now that's great customer service!

Thanks Vinnie!  

Jim

Hi Vinnie,

I'd be very interested to hear your opinion on this mod. I'm very curious to see if it's an audible improvement.

Jim

Hi Jim and Everyone,

If it does make an audible improvement, I will include it in my modded SB2s at no extra cost  

Regards,

[jholtz]

Hi Davey,

Since the spec sheet from BB says there's a "measurable" improvement, that really isn't debatable is it? The real question is, will a small improvement in specs be a "subjectively" audible improvement, which is what was the question asked in my original post.  

Best regards,

Jim

How 'bout testing to see if it makes a 'measurable' improvement?

Davey.

[Davey]

Jim,

Sure it's debatable.  The specs of the two grades are different, but that doesn't mean there would be a measurable performance difference within the larger system design.  (Which is what I was asking about.)  I think it would an interesting datapoint regardless of whether there was a subjective improvement or not.

Anyway, my question was for Vinnie and not you.

Davey.

[Vinnie R.]

Jim,

Sure it's debatable.  The specs of the two grades are different, but that doesn't mean there would be a measurable performance difference within the larger system design.  (Which is what I was asking about.)  I think it would an interesting datapoint regardless of whether there was a subjective improvement or not.

Anyway, my question was for Vinnie and not you.

Davey.

Hi Davey,

My plan is to try out the KE version of the dac and listen to it.  Honestly, I'm not interested in finding out if I can measure an improvement...I need to hear what the differences are (if any) and determine if I like them better or not.  I've heard plenty of dacs with better specs than the 1748 that I found to sound inferior.  

IMO, the 1748 in the battery modded SB2 sounds fantastic (taking the analog voltage outputs directly to the output RCA jacks).  If the KE version is even a little bit better sounding, I'll be jumping up and down    

Again, I'll be happy to install it at no extra charge if I find it is worth the effort.  If it does sound better to me, it will be in the modded SB2 that I bring to RMAF.

Regards,