I've spokent too fast.
Both sides, each time. Yes it settles at no DC, but it takes times... New day, cold NTD1; power on: around 200mv quickly dropping to almost nothing. Maybe 2-3 minutes. Then polarity change and the DC slowly rise to say -50mV after 5 minutes. Then wait for half an hour to get no DC.
What are other experience with DC? Mind that 5mV at source is 100mV at speakers with a x20 DC coupled power amp.
I am not sure that film caps will remove any DC right at power on, wich is mandatory, kids and familly won't allow half an hour warming prior to use.
Thanks for sharing your NTD1 behavior DC-wise, hope this flaw can be sorted out so this output stage is usable.
Both sides, each time. Yes it settles at no DC, but it takes times... New day, cold NTD1; power on: around 200mv quickly dropping to almost nothing. Maybe 2-3 minutes. Then polarity change and the DC slowly rise to say -50mV after 5 minutes. Then wait for half an hour to get no DC.
What are other experience with DC? Mind that 5mV at source is 100mV at speakers with a x20 DC coupled power amp.
I am not sure that film caps will remove any DC right at power on, wich is mandatory, kids and familly won't allow half an hour warming prior to use.
Thanks for sharing your NTD1 behavior DC-wise, hope this flaw can be sorted out so this output stage is usable.
no issue
There is no "issue". Capacitors will always have to charge up before they work properly, one should not turn on sources with the amplifier in an active state to the speakers. DAC first, and turn on the amp second, then no problem. These NTD-1 output stages will take awhile to sound their best anyway, as thermal equilibrium will take quite awhile to reach (and one adjusts the bias at equilibrium), bet to leave the DAC on all the time anyway.
There is no "issue". Capacitors will always have to charge up before they work properly, one should not turn on sources with the amplifier in an active state to the speakers. DAC first, and turn on the amp second, then no problem. These NTD-1 output stages will take awhile to sound their best anyway, as thermal equilibrium will take quite awhile to reach (and one adjusts the bias at equilibrium), bet to leave the DAC on all the time anyway.
LT3042 Parallel Regulator PCB
Is the LT3042 Parallel Regulator PCB out of stock forever? Just ask because it was marked SOLD OUT in the order spreadsheet, but people skipped down and starting ordering below where the SOLD OUT ended. Not sure if it's wishful thinking from diy'ers or Opc is going to print more? Thanks in advance.
Is the LT3042 Parallel Regulator PCB out of stock forever? Just ask because it was marked SOLD OUT in the order spreadsheet, but people skipped down and starting ordering below where the SOLD OUT ended. Not sure if it's wishful thinking from diy'ers or Opc is going to print more? Thanks in advance.
I've put together a list of MOSFETs to test for transconductance at the operating point of the ES9038PRO-capable NTD1 circuit I posted awhile back.
IRL40S212
IRL40SC228
IRL60S216
IRFS7430PbF
IRFS7534PbF
IRF2204S
PSMN1R5-30BLE
PSMN3R4-30BLE
PSMNR90-30BL
CSD19535KTT
CSD19536KTT
CSD18510KTT
CSD18542KCS
I've avoided trench MOSFETs, except for the Nexperia PSMN series which claims an enhanced FBSOA, in favor of HEXFETs and a few of TIs NexFETs. Most of these are logic-level for operating with a low gate threshold voltage.
If anyone is aware of other high transconductance MOSFETs that I should add to this list for testing, let me know!
IRL40S212
IRL40SC228
IRL60S216
IRFS7430PbF
IRFS7534PbF
IRF2204S
PSMN1R5-30BLE
PSMN3R4-30BLE
PSMNR90-30BL
CSD19535KTT
CSD19536KTT
CSD18510KTT
CSD18542KCS
I've avoided trench MOSFETs, except for the Nexperia PSMN series which claims an enhanced FBSOA, in favor of HEXFETs and a few of TIs NexFETs. Most of these are logic-level for operating with a low gate threshold voltage.
If anyone is aware of other high transconductance MOSFETs that I should add to this list for testing, let me know!
I don't know if people are building OPC's boards these days, but I wanted to share my build on the NTD1.
Cooling was my priority so I've used a large case. Sound... it has no sound, it's so natural, dynamic, clean, clear, just right from top to bottom. Owen did a perfect work. Best DAC ever heard for me. My lifetime DAC. It's time for records
Cooling was my priority so I've used a large case. Sound... it has no sound, it's so natural, dynamic, clean, clear, just right from top to bottom. Owen did a perfect work. Best DAC ever heard for me. My lifetime DAC. It's time for records
Attachments
All else being equal, and given that balanced outputs give +6dB of gain, yes.
Hi guys,
after some boards like the LT304x boards got unavailable, I designed my own LT3045-boards. You hopefully will also be able to go on with your projects, and I hope, it's OK for Owen to give you guys the link to my LT3045-alternative.
Regards
Stammheim
after some boards like the LT304x boards got unavailable, I designed my own LT3045-boards. You hopefully will also be able to go on with your projects, and I hope, it's OK for Owen to give you guys the link to my LT3045-alternative.
Regards
Stammheim