Modifications

[sopiblack]

Hi can some of you help me. I will replace the opamp NJM 2041 with AD 8620, but where it is located on the print.

[mfieger]

sopiblack:

Squeezebox 3, it's "U1" and is near the headphone jack.

Squeezebox 2, it's "U10" and is near the headphone jack.

They both have "2041" printed on the chip.

[sopiblack]

Thank you for your help. Do you have a picture where i can see the dac, and also which capasitors, i can change to Black gate nx.

[mfieger]

I don't have a picture.
SB3: C21 and C23
SB2: C44 and C45
These are the 10uF output capacitors.

[sopiblack]

Are there someone here with good pictures of the print, i need them for modifications.

[mfieger]

I can take a picture, and post it. Do you have the current Squeezebox 3, or do you have the older Squeezebox 2? Should I mark the dac, opamp, and output caps in the picture?

[sopiblack]

Yes, and it is very kind of you, i hope i can help you another time.

[sopiblack]

I have Squeeze box 3

[mfieger]

Here is a picture (attached). The green circles are the 10uF output caps, note the black mark on the top which indicates the negative pin. The orange box is the opamp, note the dimple which indicates pin 1. The blue box is the dac.

[sopiblack]

After replacing dac i have a problem, there is no sound, i hope you can help me. Is pin 11 and 12 connected to something on the print, or not I mean is something connected to these pins.

[Amauta]

It seems nothing is conected...

[seanadams]

It seems nothing is conected...

We don't use those. Those pins indicate when the DAC is receiving all-zeroes, and can be used for driving a separate muting circuit.

[mfieger]

Check your digital output, make sure the payer is still working.
Check if adjacent pins on the dac are short circuited with solder, use a multimeter for this. Check for shorts with the SB3 powered off. Check for cold solder joints. Check the power supply voltages on the dac. Pin 5 is 3.3V, pin 6 is 5V. The negative terminal of the HUGE capacitor goes to ground. Make sure to put the probe on the actual pin of the dac, not the pad.

[gunnar]

I think I`ll do this mod. I found the DAC and op-amp at Digikey and Mouser (DAC not in stock at Mouser), but where can I get surface mount Black Gate caps? What other caps could be used? I found an alternative myself, 128 SAL-RPM from BC / Vishay, that is said to be as good as the Black Gates. Also does not age as fast. But I can`t find a source for these either. How many coupling/decoupling caps are there that would be a point to replace?

Gunnar

[sopiblack]

Check your digital output, make sure the payer is still working.
Check if adjacent pins on the dac are short circuited with solder, use a multimeter for this. Check for shorts with the SB3 powered off. Check for cold solder joints. Check the power supply voltages on the dac. Pin 5 is 3.3V, pin 6 is 5V. The negative terminal of the HUGE capacitor goes to ground. Make sure to put the probe on the actual pin of the dac, not the pad.

Hi can someone take a photo of the hole sb3 print

[Dazza]

Is there any DC offset from the Opamp anyway? is it possible to just drop the output capacitors?

[occam]

Is there any DC offset from the Opamp anyway? is it possible to just drop the output capacitors?
Yes.
No.

The opamps on both the Duet and SB2/3 are running single rail and the outputs have about a 4.5vdc offset.

[drewe181]

Here is a picture (attached). The green circles are the 10uF output caps, note the black mark on the top which indicates the negative pin. The orange box is the opamp, note the dimple which indicates pin 1. The blue box is the dac.

what voltage are those caps?

-D