Rolling (replacing) Op-amps in Topping D10 DAC

[Deleted member 2944]

From the zoomed in figures I can make out 1000 on the SMD resistor, meaning it is a 100 ohm precision resistor. First three numbers are significant digits, last number is multiplier (power of ten).

View attachment 15697

If it were 1000 ohms on a 3 digit marking, it would be 102. Otherwise a 101 marking on a SMD 3 digit for 100 ohms.

Yes. Thank you for the correction/clarification.
The larger SMD resistor marked "1000" is indeed the output resistor and is a 100 ohm value. The larger size/wattage to accommodate the odd short-circuit or low resistance load the unit might experience.
The output circuit appears to be very straightforward with an Av of 11.6db, as I mentioned.
Dave.

 

[έχω δίκιο]

Thank you for that enlightening test, Amir! Although I suspected the results between op-amps would be similar, I had no idea that they would practically fall on top of each other when the graph was blown up that much.

 

[Jimster480]

The A30 also has socketed opAmps..
I have a LM4562 in mine vs the OPA2134, I did tend to prefer the sound in some specific tracks. Where it did seem cleaner.
I tried a couple different Opamps like the NE5532 and the OPA2038 (I think this is the wrong number), but the LM4562 and the original OPA2134 sounded the cleanest.

 

[Krunok]

By "other" they may mean the soldered ones and hence the one we replaced is indeed the output buffer!

I will have to open it again to test to be sure as the answer without the question asked is still a bit ambiguous @Krunok, what did you ask him exactly?

I asked him what are the other 2 soldered opamps for.

 

[Krunok]

Based on the schematic of a standard DAC output config and looking at the parts around the op-amps as well as layout I would (almost) bet my life that both the fixed op-amps are I/V converters and the roll-able component is the LPF/output stage.

You would stay alive this time, but I really wouldn't recommend making a habit of betting your life.

 

[Krunok]

View attachment 15683

@amirm, this graph looks much worse than the THD+N graph on Topping D10 web page (http://en.tpdz.net/products_detail/productId=30.html).
Is it because Topping applied A-weighting for their measurement?

Btw, the data for 1kHz on this graph (app 0.0009% at 1kHz) is also worse than the initial THD+N measurement you made with your old analyser which measured app -115dB which corresponds to 0.0002%. Why is that?

 

[solderdude]

You would stay alive this time, but I really wouldn't recommend making a habit of betting your life.

I do such on a case to case basis.

 

[Snarfie]

Thanks Amirm for the test. It gave me a good insight in possible out come. As you suggest i leave it as it is.

 

[amirm]

@amirm, this graph looks much worse than the THD+N graph on Topping D10 web page (http://en.tpdz.net/products_detail/productId=30.html).
Is it because Topping applied A-weighting for their measurement?

Yes and more so, I used 90 kHz bandwidth as indicated on the graph. Noise usually increases with frequency and that is what you see in my measurements.

In addition, if you limit bandwidth, then the harmonics of higher frequencies are cut off so the THD values there are no longer representative.

 

[amirm]

Btw, the data for 1kHz on this graph (app 0.0009% at 1kHz) is also worse than the initial THD+N measurement you made with your old analyser which measured app -115dB which corresponds to 0.0002%. Why is that?

Same reasons. How many harmonics you include determines the total THD.

In this case I wanted to make sure I captured any oscillations/out of band noise so I made the bandwidth high.

There are some differences in the instruments too and run to run variation.

 

[Speedskater]

Different Op-amps function best in different circuit configurations. So it's easy for an Op-amp roller to install a chip in a circuit that it's not happy in! So if you don't have an O-scope to check for ringing or even radio frequency oscillations, don't roll Op-amps.

 

[Wombat]

Different Op-amps function best in different circuit configurations. So it's easy for an Op-amp roller to install a chip in a circuit that it's not happy in! So if you don't have an O-scope to check for ringing or even radio frequency oscillations, don't roll Op-amps.

Plus there can be thermal issues.

 

[maxxevv]

Would a thermal couple / gun help in checking for oscillation instabilities ? Since it will induce unnecessary heat build up when that happens.

 

[HionHiFi]

I'm in need of replacing the TI OPA2134 in my D10 (from what Topping tells me anyway). I've looked at Mousers website but I can zero in on which model chip to buy, there are several variations. I know I need the socketed one, but there are several variations of that chip as well. Can someone with more technical knowledge direct me to exact chip I need to order?

The Problem:
At all bitrates and kHz I'm getting distortion through the speakers. It's like either the speakers don't like the output from the Topping D10 or the D10 is distorting the signal before outputting it.

Things I've tried:
Installed the Topping D10 drivers.
Updated the firmware.
Replaced Edifier S2000 Pro Speakers.

Details:
Serial # 1710533066

Desktop System
HP Laptop (USB) --> Topping D10 (optical) --> Edifier S2000 Pro ---|

 

[Deleted member 2944]

To just replace the existing 2134 op-amps you would want Mouser # 595-OPA2134PA.
It's not clear this is indeed your problem/issue, but it won't hurt (or cost very much) to try.
Dave.

 

[HionHiFi]

To just replace the existing 2134 op-amps you would want Mouser # 595-OPA2134PA.
It's not clear this is indeed your problem/issue, but it won't hurt (or cost very much) to try.
Dave.

Thanks for the model Dave. How would I hone in on the issue if you don't suspect the chip?

 

[Jimmy]

If your unit is not working OK and is under warranty (this is a relatively new model so probably all units are covered at this moment in time), I would suggest to try the seller or Topping to fix it / replace the unit, you shouldn't have to do the repairs yourself, besides, how do they know that the defective parts are these opamps without even diagnosing the unit?. It may also be that the output is too hot for your active speakers, try lowering the volume digitally with your laptop, if the distortion dissapears it may be that the speakers don't like 2 volt input peaks.

I'm in need of replacing the TI OPA2134 in my D10 (from what Topping tells me anyway). I've looked at Mousers website but I can zero in on which model chip to buy, there are several variations. I know I need the socketed one, but there are several variations of that chip as well. Can someone with more technical knowledge direct me to exact chip I need to order?

The Problem:
At all bitrates and kHz I'm getting distortion through the speakers. It's like either the speakers don't like the output from the Topping D10 or the D10 is distorting the signal before outputting it.

Things I've tried:
Installed the Topping D10 drivers.
Updated the firmware.
Replaced Edifier S2000 Pro Speakers.

Details:
Serial # 1710533066

Desktop System
HP Laptop (USB) --> Topping D10 (optical) --> Edifier S2000 Pro ---|

 

[HionHiFi]

Thanks for the input. I contacted the seller and he's willing to take it back. I just haven;t sent it back yet. He states there was nothing wrong with it. Topping won't deal with anyone but the original owner.

I tried lowering the volume from the laptop out to the DAC, but the speakers still distort. Oddly, they don't distort as bad o 24/44.1 material, though I still hear it.

If your unit is not working OK and is under warranty (this is a relatively new model so probably all units are covered at this moment in time), I would suggest to try the seller or Topping to fix it / replace the unit, you shouldn't have to do the repairs yourself, besides, how do they know that the defective parts are these opamps without even diagnosing the unit?. It may also be that the output is too hot for your active speakers, try lowering the volume digitally with your laptop, if the distortion dissapears it may be that the speakers don't like 2 volt input peaks.

 

[andreasmaaan]

@Jimmy according to the product page for the speakers, input sensitivity is 600mV on the single-ended inputs. I think it's likely that your distortion is coming from the DAC being too hot for the speakers.

Could you try lowering the volume on the laptop further to see if there's some point below which the clipping stops happening?

 

[HionHiFi]

I’m using the optical input, not the analog inputs. Does it still matter about the 600mV?

@Jimmy according to the product page for the speakers, input sensitivity is 600mV on the single-ended inputs. I think it's likely that your distortion is coming from the DAC being too hot for the speakers.

Could you try lowering the volume on the laptop further to see if there's some point below which the clipping stops happening?