its little brother.....
after some listening, I decided to try something other than passive I/V.
First thing drawing my attentiion was Rudolf's simple I/V for the 1543.
The new DAC using this active I/V was built and the sound is even better, more dynamics, more details and the background is more quiet than the original passive version.
Next I will try to improve the supply section, new BJTs, new output Caps ............ 😉
BTW, I would like to thank Rodolf for sharing his I/V design. 🙂
Cheers.
after some listening, I decided to try something other than passive I/V.
First thing drawing my attentiion was Rudolf's simple I/V for the 1543.
The new DAC using this active I/V was built and the sound is even better, more dynamics, more details and the background is more quiet than the original passive version.
Next I will try to improve the supply section, new BJTs, new output Caps ............ 😉
BTW, I would like to thank Rodolf for sharing his I/V design. 🙂
Cheers.
Attachments
Nice work!
Good luck in your adventures...
Fedde
ps. And try a passive version with 2.4k and 3.8 Vdc level!
Good luck in your adventures...
Fedde
ps. And try a passive version with 2.4k and 3.8 Vdc level!
MDlover,
Looks really nice 😎
Since my pcb's are really tight, it's hard to try some other things.
With the active I/V there are some things you could try:
Try different supply voltages for the TDA1543,
like 5V, 6V, 7V, 8V to hear if there are any differences (my guess is it will be subtle compared to passive IV)
Try different voltages on the base of the common base transistor
(try varying the 4.7k resistor setting the current through the two leds)
Increase the positive rail; this enables you increase the Vce of the common base transistor which is a good thing.
Increase the current sink, this lowers the impedance of the common base transistor
Use better transisors like 2SA970BL and 2SC2240BL
One thing I did this week was replacing the 2W (magnetic) carbon resistors is was using for Riv with some DALE RN60C's
I never bothered about resistors but this spot seems quite critical
A certain edge has gone and upper bass, lower mids improved a lot. Sounds much warmer without loosing detail.
If you're willing to do some tweaking, I would love to hear some feedback.
Could you let me know some of the voltages, currents and parts you are using, have set-up ?
After my vacations I'll implement the "not so very simple active I/V" which is DC coupled , uses better parts, has a lower impedance that the DAC will see, etc.
Will let y'all know the results of course
Looks really nice 😎
Since my pcb's are really tight, it's hard to try some other things.
With the active I/V there are some things you could try:
Try different supply voltages for the TDA1543,
like 5V, 6V, 7V, 8V to hear if there are any differences (my guess is it will be subtle compared to passive IV)
Try different voltages on the base of the common base transistor
(try varying the 4.7k resistor setting the current through the two leds)
Increase the positive rail; this enables you increase the Vce of the common base transistor which is a good thing.
Increase the current sink, this lowers the impedance of the common base transistor
Use better transisors like 2SA970BL and 2SC2240BL
One thing I did this week was replacing the 2W (magnetic) carbon resistors is was using for Riv with some DALE RN60C's
I never bothered about resistors but this spot seems quite critical
A certain edge has gone and upper bass, lower mids improved a lot. Sounds much warmer without loosing detail.
If you're willing to do some tweaking, I would love to hear some feedback.
Could you let me know some of the voltages, currents and parts you are using, have set-up ?
After my vacations I'll implement the "not so very simple active I/V" which is DC coupled
, uses better parts, has a lower impedance that the DAC will see, etc.Will let y'all know the results of course
Hi Rudolf,
Thanks for your advice.
I use 6V for the TDA1543 currently. And the I/V stage supply is around 14.2V (7808+6.2V zener), the base voltage of Q3 is around 3.3V (I use 3k3+1k5 for R7).
Will tweak this circuit and will let you all know the results.
Cheers
Thanks for your advice.
I use 6V for the TDA1543 currently. And the I/V stage supply is around 14.2V (7808+6.2V zener), the base voltage of Q3 is around 3.3V (I use 3k3+1k5 for R7).
Will tweak this circuit and will let you all know the results.
Cheers
- Status
- Not open for further replies.