I see now i follow your aprouch. No i have not tried it yet. I was looking to replace these first three caps on the dc in. These are also low cost and color the sound.
I see in yours the 1st switch is on.. mine are all off.. what theyre for?
Theres also the LM317/LM337 voltage regulators in between the SMPS and the OP.. those also have a current limit.. Robs feedback circuit on them would steer them to max during the charge time.
Its the internal power topology what makes me think the cap reserves must be placed directly on the output stage rather than the dac's 15v input power.. at least for HP amp out
Think you have a point on that. Only reason we placed them was to compensate long dc
leads to the dave and test if it would make a difference. On the speakers i heard a difference on the utopias less. Your goal is to add some punch our goal is to remove noise, what also added some punch in the end. But you could be on to something. Not trying is not knowing. About the dipswitches i have no idea. Maybe some more comparison of other daves to see if its a production thing that from some moment in time the diswitch was altered?
You could also try my farad solution for a few days to see if that brings what you want. It improves it almost on every aspect of the dave and i can build it in for you in 15min to test it if you want.
Think you have a point on that. Only reason we placed them was to compensate long dc
leads to the dave and test if it would make a difference. On the speakers i heard a difference on the utopias less. Your goal is to add some punch our goal is to remove noise, what also added some punch in the end. But you could be on to something. Not trying is not knowing. About the dipswitches i have no idea. Maybe some more comparison of other daves to see if its a production thing that from some moment in time the diswitch was altered?
You could also try my farad solution for a few days to see if that brings what you want. It improves it almost on every aspect of the dave and i can build it in for you in 15min to test it if you want.
I forgot to measure the current drawn from it while in use
As seen on your picture the original PSU is rated 6A on 5V, 1.5A on +15V and 0.5A on -15V.. how much reserve does it have..
But i know its not about amps on tap.. its about the OP's voltage modulating with the signal caused by current draw from HP.
If i understood correctly from Rob's writngs, hes compensating the voltage to OP by measuring.
But.. how fast does this go.. and does placing a extreme low Z cap directly on the transistor power pin help.. directly so i bypass even the PCB conductor lines getting fewer resistance
Talked to mattijs he says alot of caps after the regulator in general wil not sound better. And indeed the total drop with startup could damage the regulator or not. His advise was just to use good power and maybe replace the regulators with better ones. These old types leave room for improvement. Will dig into this if we can do this. Its indeed strange to add expensive power supplys and leave an old regulator type in its place.
Talked to mattijs he says alot of caps after the regulator in general wil not sound better. And indeed the total drop with startup could damage the regulator or not. His advise was just to replace the regulators with better ones. These old types leave room for improvement. Will dig into this if we can do this. Its indeed strange to add expensive power supplys and leave an old regulator type in its place.
The caps on the right are placed after the LM regulators.
Its 2x 470uF i think in parallel for each voltage
But i cant measure this since i cant lift the PCB out.. the OP transistors are 2222A and 2907A
just overthinking it a bit but we have to seperate two issues here the clean power part. Eg. Jc farad or whatever to get rid of noise and improve stability. This has proven its upgrade bij extending bass detail etc the whole mumble jumble which also gives a bit more power to the headphones. I think due to bit more stable current in the source and more detail and bass feeling. And what you are trying to gain more peak power for the hp stage get it a bit more like the tt2.
My rough guess now is by looking at it, better regulators mayby icw some better caps on there could improve things. Only one way to find out.
You cant redesign only improve on whats there already. Japan has become great on that thought
just overthinking it a bit but we have to seperate two issues here the clean power part. Eg. Jc farad or whatever to get rid of noise and improve stability
The ' noise problem' is more due to RF pushed back into the mains affecting a (HP)amp. Rather than in the DAC.. Rob took good care of that. Bc im only listening to Daves HP out.. the latter dont have my interest. (for now)
I am wild thinking on another 'upgrade' though
Thats in using 2 network SFP's to create a dual fiber data link between HMS and dave
But each SFP has to be powered from inside Dave/ HMS to stay away from the mains RF.
SFP's are so commonly adopted and cheap optic converters.. but i need to study the electric communication side first to see if its even possible.
Im a CCTV engineer and in the past i used 5Mhz video over fiber converters.. the digital ones are useless cause they expect a CVBS signal to process digitally but the older ones modulate any signal on the light emitter. They already have BNC's by nature.
Too bad i dont have any of these at hand to test..
That explains why the difference is much bigger on my two way speaker system than on my headphones. I already noticed that indeed. I sold my utopias yesterday. I dont listen to them that much. Used them last few month for testing the lps upgrade. But everytime i have them on i think “on the speakers it sound two times better” so i hang them back in 30minutes. And my rule is if i dont use it, sell it. Got big profit on it so gonna add some solarpanels next week. Insane power prices these days mannn.
That optical idea is great, maybe rob has also implemeted an optical decoupling in his new hms. Would be a wise path to follow indeed.
One thing is for sure every senseble upgrade on the dave pays off.
Do you have the wave storm cables on your system?
You could try my cables and lps’s to see if it brings the gains you are seeking for.
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