Squeezebox 3 modding

[waltona]

I'm looking at getting a Squeezbox 3 and performing some mods on it. I've been reading various threads over at the slimdevices andaudiocircles forums but nobody seems to give any specifics on actual modifications. So far I've not come across any photos showing SB3 internals.

Does anybody here have any advice on what mods I should an shouldn't do?

I have a friend who is very competent with smd soldering so that isn't a prob.

Here is a list of mods I've complied so far. Any comments?

1. Swap DAC for KE version (Red-wine / Bolder)
2. Internal power supply caps:
- Dac Power: Panasonic/BlackGate Nx (Bolder)
- Dac Power: BlackGate NX-Hi-Q (RedWine)
- input power: Panasonic/BlackGate Nx (Bolder)
3. OPAMP:
- Remove (Bolder) - causes low rms o/p and phase inversion
- Replace with BurrBrown OPA2604 (Red Wine) - adds Punch
4. Output Caps:
- BlackGate NX-Hi-Q from opamp out to RCA (RedWine)
- BlackGate N with Sonicap Gen 2 bypass direct from DAC to RCA (bolder)
5. Upgrade RCAs (Red-wine / Bolder)
6. 5V external linear (Red-wine / Bolder)
7. Remove 14V feed, replace with external 12V (RedWine) (power supply to DAC/OpAmp)
8. Higher 5V input cap (low ESR) http://forums.slimdevices.com/showthread.php?t=16329
9. Disable 12.28MHz oscillator (only needed for low bitRate internet Radio)
10. Add vibration damping material to oscillator

Cheers

Al

 

[ezkcdude]

Did you check out the DIY forum over there? There are a couple of threads on modding the SB3:

http://forums.slimdevices.com/showthread.php?t=23687

http://forums.slimdevices.com/showthread.php?t=23473

 

[GaryB]

Did you check out the DIY forum over there? There are a couple of threads on modding the SB3

And there is this older thread that describes what I did:

http://forums.slimdevices.com/showthread.php?t=19822

---Gary

 

[ezkcdude]

Gary, I think your totally right about removing the op amp (from reading your posts). The data sheet for PCM1748 says Vout is 0.66*Vcc or 3.3V p-p, which is more than enough.

Have you considered tapping the I2S lines and using them with an external DAC? I'm wondering if anyone's done that, as it seems like that would be a nice solution.

 

[MarkRehorst]

Gary, I think your totally right about removing the op amp (from reading your posts). The data sheet for PCM1748 says Vout is 0.66*Vcc or 3.3V p-p, which is more than enough.

Have you considered the possibility that there is a reason there is an op-amp on the output of the DAC?

I_F

 

[ezkcdude]

Yeah, I have. I read p. 22-23 of the PCM1748 data sheet.

 

[Bas Horneman]

Have you considered tapping the I2S lines and using them with an external DAC?

John Swenson is going to do that.

 

[waltona]

Thanks for the replies. Very interesting and helpful links.

At the mo my planned mods are :

decent regulated 5V supply

remove opamp and replace coupling caps before new RCAs.

change power supply caps for panasonic FCs or blackgates with same values as originals

swap DAC to KE version

Is there anything else I should try? Has anybody tried replacing the 14V dac supply with an external regulated version?

I was also considering using a NOS dac with the modded SB3. Something like a DDDAC or Monica 2. Anybody tried this? Any comments on how these DACs compare to a modded SB3 (i.e. is it worth the extra expense)?

Al

 

[Clipper]

Yep. I saw that too.
Here is a link to Ken's post.

http://www.audioasylum.com/forums/pcaudio/messages/12621.html

 

[Clipper]

Who the hell is Ken?
I meant John!

Oops

 

[Clipper]

http://forums.slimdevices.com/showthread.php?t=14931&highlight=14v

See Post #3

The 14V line powers the DAC and OpAmp and is derived from a switcher. Red Wine Audio hack into the 14V line and use an external battery feed. I think Bolder re-route things to get a cleaner feed to the DAC internally. Maybe from the headphone amp 3.3v?

If you remove the OpAmp you won't need to worry about it's supply.

 

[waltona]

From what I can understand the 3.3V supply is derived from the external switcher and is then regulated for the headphone out.

The 14V is from an internal switcher, which is then multiplied to feed to display, then reg'd down to power DAC
the final regs are linear.

How about multiplying the nice regulated external linear 5v supply and using that for the DAC?

Al