Not yet, next week I will order parts and if I'm lucky (i.e. enough free time) maybe next weekend
In that case(balanced output), you need four AD811s, as I will use in my new DAC with two PCM1794s.
The dimensions are 70*30mm, if I used SMD electrolytes the PCB would be even smaller, but I deliberately want TH UKZ at least while there are still some to buy.
Igor
I agree, in my case the regulator and power supply are much more complicated and expensive than the IV stage itself.
I can get a 160mm X 100mm board made for
€26. 105um traces instead of 35um.
We can get 6 boards onto this area.
I need two for a differential setup.
grunf you can get two just for the cost of shipping if you like.
Shipping takes 7 days after payment.
Gerbers would be nice but pic works to.
We can up the area and put more boards on to it if interest exists.
Greets Klaus
€26. 105um traces instead of 35um.
We can get 6 boards onto this area.
I need two for a differential setup.
grunf you can get two just for the cost of shipping if you like.
Shipping takes 7 days after payment.
Gerbers would be nice but pic works to.
We can up the area and put more boards on to it if interest exists.
Greets Klaus
Thank you for your answer.
Not been clear sorry, I am using a balanced output chip (a pcm1794 per channel) into a single ended integrated amp (currently with passive iv stage). Since a single ended output is needed, what would be the best way to menage the negative ouput of the dac chip using the ad811 single ended output from the positive?
..you know two much 😉
will consider this.. I need -lowest- gain, I guess I was hoping to get away with a symplicistic reply of something like put a lowish resistor/ground the negative output thing but let’s see!
will consider this.. I need -lowest- gain, I guess I was hoping to get away with a symplicistic reply of something like put a lowish resistor/ground the negative output thing but let’s see!
Grunf, I think you have mis-interpreted the application of that 1kohm resistor..
The original Jung scheme is applying it !behind the feedback node. (below)
Your schematic means that you have eliminated the 0 ohm virtual ground that the Dac output wishes to see and now there is 1kohm I/V resistor in place, with some Volt of voltage compliance to tolerate for the Dac..
Attachments
@grunf, just found this thread, watching with intrest.
Had you thought of using some JFETS in the front end? - the same as the CEN IV https://www.diyaudio.com/community/threads/folded-cascode-cen-iv-with-fixed-rails.389776/
Had you thought of using some JFETS in the front end? - the same as the CEN IV https://www.diyaudio.com/community/threads/folded-cascode-cen-iv-with-fixed-rails.389776/
You could use the +ve input but there are better audio opamps.
I've never been convinced that the 811 is a good choice, whereas the AD844 is, for current output dacs.
I've never been convinced that the 811 is a good choice, whereas the AD844 is, for current output dacs.
Yeah... the post-DAC filter caps would (most likely) cause oscillations with AD811. Also, the Vout DACs are mostly differential-voltage-out DACs of some 2V pp... no need for an AD811, I'd say.
Today I finished the prototype PCB for IV with AD811 but this time everything with SMD components except four 100uF/50v ukz and two AD811 with heatsinks.
For the first time I used DALE PNM non-magnetic series instead of RN60, and instead of polystyrene and polypropylene TH capacitors I used non-magnetic SMD COG capacitors. AD811 is soldered direct on the PCB.
So far I can say that in this application the PNM is much better than the RN60.
For the first time I used DALE PNM non-magnetic series instead of RN60, and instead of polystyrene and polypropylene TH capacitors I used non-magnetic SMD COG capacitors. AD811 is soldered direct on the PCB.
So far I can say that in this application the PNM is much better than the RN60.
Attachments
Have you tried AD811? It's not without reason that Walt Jung made an IV for TDA1541 with AD811.