Removing the 12..288MHz Crystal Mod

[S-Man]

Since my original mention of this dissapeared, along with the transporter mod thread about 10 minutes ago, I thought it worth posting this on the DIY forum.

I recently removed the 12MHz crystal from my SB3, the intent behind this is to ensure that there is no interaction between the two asynchronously running clocks which share the same HCU04 package.

I believe this improves the sound of the SB3 noticeably. The difference, to my ears, is inreased resolution and better flow and timing of the music.

This mod should be applicable to all the SB products (I only wish I had thought to do it to my SB+ when I had it), but it does mean that any source with 48Khz or 96KHz sampling frequency will not work anymore.

Anyone else tried this?
I would be interested to read your comments about the change (or lack of) to the sound quality.

[inguz]

My experience with a player that had its 12MHz crystal removed: not only did it not play 48kHz material, but actually if a 48kHz track was played accidentally, the SB output very loud white noise until physically unplugged. Just a note of caution.

[S-Man]

Yes, this is a major concern. I've just tried loads of internet radio stations until I eventually found one which uses the 48KHz sampling frequency and I got the same result as inguz.

Since this is potentially speaker destroying (thankfully I use a preamp and inguz had prepared me) anyone trying this should proceed with caution.

This is a shame becaue I think this mod provides a worthwhile improvement to the sound. I wonder if Slimdevices could prevent this in the firmware, if they so desired?

[Patrick Dixon]

This mod should be applicable to all the SB products (I only wish I had thought to do it to my SB+ when I had it)
I don't think it makes any difference to the SB+. The clock circuitry is completely different to the SB3 and the two clocks are totally separate, and individually screened in the SB+. However, there is a jumper option to disable each clock independently should you so desire.

[parrydave]

I did this when modding my SB3. Can't comment on improvement as it was one of many mods. In use, I get a loud click when moving between 44 and 48kHz files, then silence as the track plays, no white noise. I haven't tried internet radio with 48kHz.

[S-Man]

I don't think it makes any difference to the SB+. The clock circuitry is completely different to the SB3 and the two clocks are totally separate, and individually screened in the SB+. However, there is a jumper option to disable each clock independently should you so desire.

Thanks Patrick, that puts my mind at rest - obviously I would not have been able to try the mod in the SB+, but it's clear you have done the job properly anyway.

[ermine]

I recently removed the 12MHz crystal from my SB3, the intent behind this is to ensure that there is no interaction between the two asynchronously running clocks which share the same HCU04 package.


Have you actually established that this poor thing was actually enabled while playing 44k1 sources before you hooked it out?

It would seem the easiest and most obvious thing in the world for the SB syscon logic to only power up the desired crystal, once it had determined the sampling frequency of the incoming signal. I would be surprised if Slim Devices had missed that trick.

[ermine]

Fair enough - at least with the SB2 they don't do that