Hi Frex!
Please look at this: E-MU Systems - 1212M PCIe - PCIe Digital Audio System ... what do you think this converter will have good results, similar to such as have turned out at you?
Here is use the same A/D converter: AK5394A
Hi Frex! Thanks!
IT should work with SHARC DSP but not with the PC. How to find out that this is going to work together?
Hello dirkwright,
If you talk about the AA5381v1 ADC project, no it is not dead and
some bare PCB of it are still available.
Regards.
Frex
Yeah, it's great that you did this, but I'm not sure it meets my needs. It looks like you designed this board for a specific box, whereas I'd prefer a more standard rack mount instrument with all of the inputs and outputs on the front panel. I'm sure your ADC works super and I wish you luck in what ever else you do.
Also, now it is possible to buy a quite descent sound card for not too much money.
It would make sense to build your own if it will be better than best commercially available interfaces like Lynx or RME.
So, tthe DIY ADC should have a best ADC chip and, if required, a best preamp/driver stage, may be even based on discrete parts.
What is the best ADC for today AK5394, PCM4220 or ES9102?
It would make sense to build your own if it will be better than best commercially available interfaces like Lynx or RME.
So, tthe DIY ADC should have a best ADC chip and, if required, a best preamp/driver stage, may be even based on discrete parts.
What is the best ADC for today AK5394, PCM4220 or ES9102?
First, in my tests none of the other ADC's have performance nearly as good as the AK5394A. Its a mature chip that has been used in pro hardware since about 2005 so there is stuff around with it. The Lynx card uses it but that's real money. The EMU 1212m and 1616m also use it. Getting those working well is not real easy but worth the effort. I upgraded an EMU 1212m with LME49720 opamps and got about 10 dB THD improvement of the the stock 4338? opamps.
Swapping them in the 1616m is more of a challenge since it has 3 stereo in and 3 stereo out channels. And a PITA to open and modify. I have now fried 2 by not being careful enough reassembling them. Also all 4 of the 1616's I have have failing electrolytic caps. The good aspect of the 1616M is the pretty complete isolation from a PC chassis.
There are several efforts towards making a new card with a really good ADC. I don't know the current status of them but lots of action last winter.
Swapping them in the 1616m is more of a challenge since it has 3 stereo in and 3 stereo out channels. And a PITA to open and modify. I have now fried 2 by not being careful enough reassembling them. Also all 4 of the 1616's I have have failing electrolytic caps. The good aspect of the 1616M is the pretty complete isolation from a PC chassis.
There are several efforts towards making a new card with a really good ADC. I don't know the current status of them but lots of action last winter.
Cost and supply on hand as much as anything. The THD of the LME49720 won't be a limiting factor.
Any opamp will have an input impedance in the megohms in circuit. The shunt parasitics are the bigger issue. For a high impedance source you need a Jfet opamp or to add a jfet input to the opamp. If the source impedance is high the ultra low noise bipolar opamps won't help since the source limits the noise. The LME49980 is a good dual JFET opamp that is quite affordable.
Any opamp will have an input impedance in the megohms in circuit. The shunt parasitics are the bigger issue. For a high impedance source you need a Jfet opamp or to add a jfet input to the opamp. If the source impedance is high the ultra low noise bipolar opamps won't help since the source limits the noise. The LME49980 is a good dual JFET opamp that is quite affordable.
Sorry for dumb questions, I have just some experience with tubes, not ICs.
Why getting AK5394A working well is not real easy?
Are there any DIY projects of ADC based on AK5394A?
Why it requires to put an opamp in front of AK5394A?
If I have a tube mic preamp with output tubes 6S45P, that can drive even headphones, should a buffer/opamp be placed in front of AK5394A?
Why getting AK5394A working well is not real easy?
Are there any DIY projects of ADC based on AK5394A?
Why it requires to put an opamp in front of AK5394A?
If I have a tube mic preamp with output tubes 6S45P, that can drive even headphones, should a buffer/opamp be placed in front of AK5394A?
The performance of the ADC is very good so you need attention to detail to get the most from it.
It needs a differential drive, a precise offset voltage and no overdrive or you I can damage the chip. I would use a transformer to get a low output Z and the necessary bandwidth limiting.
Sent from my Nexus 7 using Tapatalk
It needs a differential drive, a precise offset voltage and no overdrive or you I can damage the chip. I would use a transformer to get a low output Z and the necessary bandwidth limiting.
Sent from my Nexus 7 using Tapatalk
The demo board prices are not really targeted at selling. The real targets never pay for demo boards.
The AK5394 is 10-20 dB less distortion and has a flat noise floor to 100 KHz.
The TI board is a good value but a Used EMU is the same cost range with a PC interface.
As I mentioned here are several projects with good potential brewing for interfaces. For now I would get an EMU 1212M and swap opamps to get a measurement grade interface with performance on a par with an APx without the input switching and gain management.
The AK5394 is 10-20 dB less distortion and has a flat noise floor to 100 KHz.
The TI board is a good value but a Used EMU is the same cost range with a PC interface.
As I mentioned here are several projects with good potential brewing for interfaces. For now I would get an EMU 1212M and swap opamps to get a measurement grade interface with performance on a par with an APx without the input switching and gain management.
Used EMU 1212 is hard to find now. I see more old 1616 with cardbus on ebay. Why Creative stopped to produce them?
I have EMU 0404 PCI. But input channels are destroyed by overload from my mic preamp. That is why I need a new ADC. Would it make a sense to replace input opamps on EMU 0404? Or better to get 1212m or 1616 head and connect it to 0404 via SPDIF?
I have EMU 0404 PCI. But input channels are destroyed by overload from my mic preamp. That is why I need a new ADC. Would it make a sense to replace input opamps on EMU 0404? Or better to get 1212m or 1616 head and connect it to 0404 via SPDIF?
1616m only works connected to a host PC, to download firmware.
I would fix the 0404 and add protection diodes on the input. Cheapest alternative. Next would be to watch eBay for a 1212 or 1616m with a pci interface. It depends on what you want to do with it. Location recording of music is quite different from measuring amplifier distortion. For location recording a 1616m cardbus and a Dell e6500 with a cardbus slot would get a pretty clean recording setup for about $500 total. I think better results and less fussy than USB.
I would fix the 0404 and add protection diodes on the input. Cheapest alternative. Next would be to watch eBay for a 1212 or 1616m with a pci interface. It depends on what you want to do with it. Location recording of music is quite different from measuring amplifier distortion. For location recording a 1616m cardbus and a Dell e6500 with a cardbus slot would get a pretty clean recording setup for about $500 total. I think better results and less fussy than USB.
Ha! Just bought 1212m PCI on ebay! 200CAD with shipping.
Yes, I've found Vout of my preamp was ~140V after I've measured it during touching grid of input tube to make that buzz that destroyed my 0404.
After that I've put two 2.7V (could not find lower) zenners back-to back to its out, and two bright red LEDs between them so they indicate overload.
I think this will allow not more than 7Vp-p.
What diodes would you recommend?
Yes, I've found Vout of my preamp was ~140V after I've measured it during touching grid of input tube to make that buzz that destroyed my 0404.
After that I've put two 2.7V (could not find lower) zenners back-to back to its out, and two bright red LEDs between them so they indicate overload.
I think this will allow not more than 7Vp-p.
What diodes would you recommend?
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