I think its safe to look at the RTX as a USB soundcard with selectable input and output level ranges. It might make for a really good playback or recording interface (ADDA). It should work well with Spectraplus.
How do you like Spectraplus? Can you add some user experience in the software thread?
How do you like Spectraplus? Can you add some user experience in the software thread?
Hey Demian. You may not remember me but Peter Madnick introduced us a long time ago. I designed most of the early Alchemy products. Trust your well.
I really SpectraPlus. I have the current SC version with all the add-on's. Its very stable, mature and feature packed. Like you I also still have my trusty Praxis system. I use the Praxis pre-amp / Julia with Spectra-plus. I also have one of Alex's digital signal generators which I find indispensable. Tried HpW along time ago but I found SpectraPlus more flexible and much faster.
I really SpectraPlus. I have the current SC version with all the add-on's. Its very stable, mature and feature packed. Like you I also still have my trusty Praxis system. I use the Praxis pre-amp / Julia with Spectra-plus. I also have one of Alex's digital signal generators which I find indispensable. Tried HpW along time ago but I found SpectraPlus more flexible and much faster.
Hi douggoldberg,
Small world! I was a Canadian warranty station during the time when both Audio Alchemy and Counterpoint hit the dirt. They left owing me $$. Cost of doing business. I still have some boards that I plan to do something with. Something at some point in time.
I figure that playing with them is a good way to get use to using this type of product, as in the chips, not the entire unit.
-Chris
Small world! I was a Canadian warranty station during the time when both Audio Alchemy and Counterpoint hit the dirt. They left owing me $$. Cost of doing business. I still have some boards that I plan to do something with. Something at some point in time.
I figure that playing with them is a good way to get use to using this type of product, as in the chips, not the entire unit.
-Chris
Doug
Thanks for the comparison of Spectraplus and HpW...
What do you use your software for and do you remember which version of HpW that you tried ? (newer versions may not have the issue you did not like)
There is a thread called "Analyzer Software Overview" in the software section of tools where we are discussing such things...
tia,
dennis h
I did not tried HpW, just read the description, SpectraLab/SpectraPlus - used many times.
I saw at least 2 disadvantages in Sp+ :
1) 192kHz max. , also 24 bit max.
2) ASIO not works with my XMOS interfaces.
I also use another excellent software - Wave Spectra
???????? ???????????? WaveSpectra
1) ASIO work fine
2) up to 384 kHz
3) up to 32bit, also floating point32 format
Less calculating parameters and graphs, then Sp+, but as a FREE software - this is the best!
Also free WageGene, from the same author - up to 8 independent channels with various options. Of course, up to 384kHZ, 32bit, FP32.
Unfortunately, WaveSpectra and WaveGene were not updated last 4 years.
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It is a small world indeed. I reminded of this very day.
We all took a hit when Alchemy went down.....
I use SpectraPlus for measuring audio circuits primarily. I also use it for vibration analysis. Praxis is my go to for speaker measurement and it's cool because they work together sharing an ESI Julia and the Praxix attenuators / preamp. I use an RME Babyface in my DSP room correction system and think very highly of their HW. Mixer not so much. The RME ADI2 Pro maybe the best commercial capture system I've seen at semi-affordable prices. Now if Jen's box had digital I/O it might be perfect too. As far as HpW is concerned it's very reasonably priced and may be much better than when I tinkered with it.
We all took a hit when Alchemy went down.....
I use SpectraPlus for measuring audio circuits primarily. I also use it for vibration analysis. Praxis is my go to for speaker measurement and it's cool because they work together sharing an ESI Julia and the Praxix attenuators / preamp. I use an RME Babyface in my DSP room correction system and think very highly of their HW. Mixer not so much. The RME ADI2 Pro maybe the best commercial capture system I've seen at semi-affordable prices. Now if Jen's box had digital I/O it might be perfect too. As far as HpW is concerned it's very reasonably priced and may be much better than when I tinkered with it.
Hi douggoldberg,
Well, I hope that you weren't hurt too badly when they went down.
What area were you working on? DAC, amplifers, CD transports? Your work experience might give you some more insight into this project.
-Chris
Well, I hope that you weren't hurt too badly when they went down.
What area were you working on? DAC, amplifers, CD transports? Your work experience might give you some more insight into this project.
-Chris
Chris, I'm currently working two projects in my not so skunk works. A series of very high end class D amplifiers using Gallium Nitride devices and a DAC/headphone amp. I have the previously mentioned setup, a really nice DSO and use Alex's digital signal generator a lot. I have a nice AWG for high speed / RF waveform generation. I'd like to upgrade my analog capture but would like digital in/out too. That's why the RME is very intriguing. Do you expect the analog performance of Jen's device to be significantly better than the RME? Is their any measured data available?
Now Alex if you added a killer A/D to you sign gen and a windows driver.....
Now Alex if you added a killer A/D to you sign gen and a windows driver.....
Doug, a new version with much better A/D and other features, is under development. Last 2+ years 🙁
All free from the main job time, is dedicated to the DAC production....
All free from the main job time, is dedicated to the DAC production....
Alex your keeping stuff from us.. Can you share any data and timing when you expect to have this? I love your sig gen....
I did some small mods to my Praxis interface to get the noise and distortion lower. The cost of entry for SpectraPlus has always put me off. We should move these discussions to the software thread.
I think Alex's generator is the go-to for digital source. I would be happy with a Windows API to control it and possibly integration with some software.
What Jens has shared with me on the RTX suggests it may be the best available ADC. A premium analog implementation (AP/Shibasoku) will have better absolute numbers but that may be very academic since the DAC and ADC that is the source of most content is not as high performance. (The analog sources are all worse) so it should be more than able to show issues in any audio chain. The noise floor of available ADC's is a limit when looking at numbers compared to analog analyzers, however I think its artificial. The distortion across a 10 dB range should be pretty consistent so finer control of the input level probably is not necessary.
Jens mentioned the modular design which should enable additions/upgrades. He also mentioned that adding a digital out may be possible. The bigger challenge is a digital in with the sample rates/sync issues. Its possible but then the master clock become synced to the incoming digital and needs more hardware stuff than a simple spdif connection.
I think Alex's generator is the go-to for digital source. I would be happy with a Windows API to control it and possibly integration with some software.
What Jens has shared with me on the RTX suggests it may be the best available ADC. A premium analog implementation (AP/Shibasoku) will have better absolute numbers but that may be very academic since the DAC and ADC that is the source of most content is not as high performance. (The analog sources are all worse) so it should be more than able to show issues in any audio chain. The noise floor of available ADC's is a limit when looking at numbers compared to analog analyzers, however I think its artificial. The distortion across a 10 dB range should be pretty consistent so finer control of the input level probably is not necessary.
Jens mentioned the modular design which should enable additions/upgrades. He also mentioned that adding a digital out may be possible. The bigger challenge is a digital in with the sample rates/sync issues. Its possible but then the master clock become synced to the incoming digital and needs more hardware stuff than a simple spdif connection.
Demian, next version will have USB (Virtual COM Port), galvanic isolated from PC, of course, for Test Automation with Open API.
I have not tried the RME. Judging from the specifications and measurements in the RME manual, there does seem to be a lot of similarity.
On the DAC side this is hardly surprising, since they use the same DAC from AKM, the AK4490.
On the ADC side side there is some difference. The out of (audio) band noise of the RME is much higher than on my analyzer. This is caused by the noise shaping of the ADC. The AK5394A, which I use, has a very flat noise spectrum all the way to 90 kHz, whereas the noise spectrum of the AK4474 increases by around 30 dB at 90 kHz compared to 1 kHz. This, and the very low distortion, was a couple of the reasons for selecting the AK5394A for the analyzer.
The unbalanced input impedance seems to be 9 kohm on the RME versus 100 kohm (with very low noise FET inputs) on my analyzer.
If your main application is test and measurement, I think the RTX6001 is a good candidate. For audio playback and recording the RME does of course offer a number of features not found on the RTX6001.
For test purposes I think that the input protection of my analyzer is one of the strong points compared to a sound card.
I have shown measurements along the way in this thread, but I don't have a compiled set of measurements right now. The specifications shown in the first post in the GB section should give you some indication of the performance.
Jens
Thanks for the info Jens. You have obviously put a good deal of effort into the analog design. It's very impressive. Since you have the I2S bus running around it seems adding a SPDIF transmitter should be pretty easy. Love to see this. Maybe a DIY
- DIY hack....
- DIY hack....
Are you primarily interested in the SPDIF transmitter? As in, transmitting the audio from the generator in the PC out on the SPDIF as well as the DAC?
This will be easy to do as a DIY hack, since the signal will be available on the XMOS USB interface board. You will void the warranty though...
This will be easy to do as a DIY hack, since the signal will be available on the XMOS USB interface board. You will void the warranty though...
Jen's, yes this is what I want to do. Maybe you could include an I2S port to make this easy.......
I want to be able to generate digital test signals that correspond to the analog outputs.
I want to be able to generate digital test signals that correspond to the analog outputs.
In principle it could be done. But it won't happen on the GB model. It is simply too late to make that kind of changes at this point in time. EMC and ESD tests are almost done. Adding an I2S interface would be a big risk and could easily cause delays.