Hi Shaan,
I want to direct +/-16VDC battery supply at TP1&2, to drive the preamp board. I plan to deploy 18650 (each 2800mA) x 4 x 2, can you estimate how long I can play with this preamp by this battery system？
I want to direct +/-16VDC battery supply at TP1&2, to drive the preamp board. I plan to deploy 18650 (each 2800mA) x 4 x 2, can you estimate how long I can play with this preamp by this battery system？
I estimate 30+ hours if you uses series regulator not ehunt reg. And set cut off voltage around 3v per battery.
Excellent! Still don't know whether to build this as a headphone amp or as the preamp to my V4....decisions, decisions.
Hi Neal.
You can build as both. Bias it for headphone application and just connect a pair 470uF off board from TP4 and TP6 to the headphone socket (install a pair 10kohm to ground from the negative pins of the electros). Return the shield directly to GND via a thick wire. You may want to remove the headphone jack during using as preamp as the low load impedance will bring output voltage down a bit due to high current draw from preamp.
You can build as both. Bias it for headphone application and just connect a pair 470uF off board from TP4 and TP6 to the headphone socket (install a pair 10kohm to ground from the negative pins of the electros). Return the shield directly to GND via a thick wire. You may want to remove the headphone jack during using as preamp as the low load impedance will bring output voltage down a bit due to high current draw from preamp.
@shaan where can parts be bought online in India except element14/Rsdeliver these are too costly.
Dual function ... Perfect ...
Hi Shaan,
- the shield from what? May be a stupid question ...
- the same types / Voltage for the Caps like C27, C28 ?
Thanks a lot
Joe
Hi Shaan,
- the shield from what? May be a stupid question ...
- the same types / Voltage for the Caps like C27, C28 ?
Thanks a lot
Joe
Hi Joachim.
- Shield of the headphone socket. Not a stupid question at all! The shield should be isolated from chassis and routed to GND on the Preamp PCB with its own thick wire.
- 25V rated as suggested in the BOM. In fact the 10uF for preamp can be 63V rated without any problem.
- Shield of the headphone socket. Not a stupid question at all! The shield should be isolated from chassis and routed to GND on the Preamp PCB with its own thick wire.
- 25V rated as suggested in the BOM. In fact the 10uF for preamp can be 63V rated without any problem.
Update:
The good stuff has arrived! I have already assembled one of them and it is working perfectly! We're good to go!
Regarding available shipping options to different countries, I have made a list of all the countries that the boards are to be shipped (along with V4H and PSU), and will take it to the PO today to check what options among speedpost, air parcel and registered post have now become available for each country. Our extremely "smart" Govt. postal website has no update of any sort so far on this, so I will spend some quality time with the officer today and get the list updated. Will share it in the evening. 🙂
Thanks everyone for your patience.
The good stuff has arrived! I have already assembled one of them and it is working perfectly! We're good to go!
Regarding available shipping options to different countries, I have made a list of all the countries that the boards are to be shipped (along with V4H and PSU), and will take it to the PO today to check what options among speedpost, air parcel and registered post have now become available for each country. Our extremely "smart" Govt. postal website has no update of any sort so far on this, so I will spend some quality time with the officer today and get the list updated. Will share it in the evening. 🙂
Thanks everyone for your patience.
