I have been looking at my mini DSP HD10x10 again recently noticed the A>D chips 5366 https://statics.cirrus.com/pubs/proDatasheet/CS5366_F5.pdf seems to use Tantalum 47uf caps around all the supplies. Very different to the D>A 4528 chip https://statics.cirrus.com/pubs/proDatasheet/CS42528_F3.pdf
I have added some local capacitance to the D>A 4528 and this did seem to improve performance. I wonder if swapping out or piggybacking the 47uf caps might be worthwhile (I understand they are usually Low ESR).
I have added some local capacitance to the D>A 4528 and this did seem to improve performance. I wonder if swapping out or piggybacking the 47uf caps might be worthwhile (I understand they are usually Low ESR).
Strange thread title as it is neither about a DAC nor the PCB layout?! Maybe not changing anything in the ADC section is the best recipe as decoupling seems to be done adequately with ferrite beads, ferrite coils and caps. That is way above average.
Cleaning the PCB seem worthwhile as there is solder debris at places.
Cleaning the PCB seem worthwhile as there is solder debris at places.
There's always the option to do nothing. Most people seem to adopt this strategy for most things in life
Being in the other camp I also just know when not to do anything useless. Cleaning the PCB is not doing nothing 🙂 If a device is designed by competent engineers sometimes fiddling around won't make the device any better (except a confirmation bias to have done something useful).
If there is dissatisfaction maybe looking at the analog input section could be an alternative. Not familiar with this device but I have seen quite some ADC circuits with opamps being fed only 5V and such with quite lousy regulators or even tiny SMPS. The clock circuit is also a good one to check.
It would be good to check with an oscilloscope how (un)clean the supply pins of the 5366 are. Knowing is better than guessing.
If there is dissatisfaction maybe looking at the analog input section could be an alternative. Not familiar with this device but I have seen quite some ADC circuits with opamps being fed only 5V and such with quite lousy regulators or even tiny SMPS. The clock circuit is also a good one to check.
It would be good to check with an oscilloscope how (un)clean the supply pins of the 5366 are. Knowing is better than guessing.
Last edited:
I can get my isopropyl alcohol and swabs out, I will next time its apart. I have been attempting to minimise the impact of A>D and D>A and although this is only for subwoofer use, I have been made very aware how much of a compromise this can be. Over the last 12+m I have been experimenting a lot in a number of areas with limited electronics skill but slowly growing knowledge. I qualified as an automotive engineer and have limited electronic knowledge, but a lot of audio listening experience and have spent years A-Bing different equipment. So when my options are limited or closed experimenting and DIY becomes a very interesting option. Not much readily available for 8 channel A>D with EQ and timing etc then D>A. I might move to a more professional solution, but this will be yet another learning curve and it is only for 4 subs running up to 65Hz in a cinema set up
Adding some local capacitance to the Opamps made a worthwhile improvement in dynamics and swapping the SMD electrolytic for lower ESR and higher capacitance made a difference. Also experimentation with different LPS supplies was worthwhile too
Regarding clean are you referring about to solder quality, debris or noise when measuring the voltage in supply. I can see pin 33 but I am definitely not brave enough to attempt to put a needle on that tiny pin even if I had a scope
Adding some local capacitance to the Opamps made a worthwhile improvement in dynamics and swapping the SMD electrolytic for lower ESR and higher capacitance made a difference. Also experimentation with different LPS supplies was worthwhile too
Regarding clean are you referring about to solder quality, debris or noise when measuring the voltage in supply. I can see pin 33 but I am definitely not brave enough to attempt to put a needle on that tiny pin even if I had a scope
Only measuring what really happens should be leading in doing any changes. Trial and error and assumptions won't cut the cake. This section of the device has tantalum capacitors which are quite OK with regards to ESR and ESL. You could try to find the brand and specifications. There is a high chance adding TH parts in parallel will deteriorate measured performance. The tantalum caps seem to have been paralleled with ceramic caps already.
Yes, despite the propaganda LPS still outperform SMPS in many audio applications but discussion about this most of the time ends up in a holy war. Those that have the equipment to measure and see what happens do know what is the best option.
There are many test points so I am confident the supply pins have one as well. Just look up the service manual.
Yes, despite the propaganda LPS still outperform SMPS in many audio applications but discussion about this most of the time ends up in a holy war. Those that have the equipment to measure and see what happens do know what is the best option.
There are many test points so I am confident the supply pins have one as well. Just look up the service manual.
Last edited:
Jean-paul, tks I think they are Kyocera AVX https://www.mouser.co.uk/datasheet/2/40/TLJ-2401096.pdf but I cant yet match the ID number and it doesn't seem to have the A symbol noted in the description
Any idea where I get hold of a service manual ?
Any idea where I get hold of a service manual ?
Can't see the caps clearly enough to see the brand but they seem AVX which are fine. Since they are bypassed with ceramic caps it would seem normal to choose not too low ESR tantalum caps. Please don't make the mistake to replace the tantalum caps for ultra low ESR types! Also pay attention to the voltage regulators and how things are done.
If you want to change something it can be an idea to replace the ceramic caps for better SMD types. Anything lower than X7R is non optimal IMHO. SMD PPS (film) caps in the same size and the same or higher voltage ratings could be an improvement. Still measure the test points to check if the supplies are clean. It makes no sense to just do something and through hole parts have no place in this application.
No I don't know where to find a service manual but I am sure you can google just as fine as I can 🙂
If you want to change something it can be an idea to replace the ceramic caps for better SMD types. Anything lower than X7R is non optimal IMHO. SMD PPS (film) caps in the same size and the same or higher voltage ratings could be an improvement. Still measure the test points to check if the supplies are clean. It makes no sense to just do something and through hole parts have no place in this application.
No I don't know where to find a service manual but I am sure you can google just as fine as I can 🙂
Last edited: