@Richard, how did it work out with your 334a? Did it prove good like low hanging fruit?
Or is it like planting an orchard and will take a while to grow fruit?
@ Demian, Davada or Anyman: ARTA question. Does ARTA care what or how it grabs its input data? Can it be configured for use without a sound card and take the data from
a DSP as a digital source? From USB, RS232, RS432, or from an Ethernet connection?
I've got an outboard hardware and software solution, it's just not an in-computer
soundcard...it's an out of computer digital or analog possible solution.
@ Richard, what did you do with your speakers? Did you have a sub or were you
not going to use it any longer? Did you replace it/them or were you looking for
something different?
Cheers,
Sync
Or is it like planting an orchard and will take a while to grow fruit?
@ Demian, Davada or Anyman: ARTA question. Does ARTA care what or how it grabs its input data? Can it be configured for use without a sound card and take the data from
a DSP as a digital source? From USB, RS232, RS432, or from an Ethernet connection?
I've got an outboard hardware and software solution, it's just not an in-computer
soundcard...it's an out of computer digital or analog possible solution.
@ Richard, what did you do with your speakers? Did you have a sub or were you
not going to use it any longer? Did you replace it/them or were you looking for
something different?
Cheers,
Sync
"Replace the lamps circuit with a resistor to check for loading effects."
Sorry, I don't understand this, could you explain?
I assume the lamps are never competently off (cold state) there would be to much resistance change when they would lit (I could be wrong on this). To find out the real bridge distortion ,I would have to replace the LDR's with the equivalent resistors.
Two of them is in parallel with the frequency range resistors, one is parallel with the balance pot. To measure them will not be easy. That must be even a quiescence state ,when they are not competently cold, in Manual mode. I have to check it.
Sorry, I don't understand this, could you explain?
I assume the lamps are never competently off (cold state) there would be to much resistance change when they would lit (I could be wrong on this). To find out the real bridge distortion ,I would have to replace the LDR's with the equivalent resistors.
Two of them is in parallel with the frequency range resistors, one is parallel with the balance pot. To measure them will not be easy. That must be even a quiescence state ,when they are not competently cold, in Manual mode. I have to check it.
What can be done to make it lower?? "
You probably know that better than I.
Maybe replace it with a voltage follower op amp?
"That part alone has good use with reducing fundemental for FFT processing."
Can that be useful even if the bridge distorting because of the LDR's?
Is there anything else could be used instead of the LDR's?
Naturally it is possible to remove the LDR's/Lamps and only use unit in Manual mode.
You probably know that better than I.
Maybe replace it with a voltage follower op amp?
"That part alone has good use with reducing fundemental for FFT processing."
Can that be useful even if the bridge distorting because of the LDR's?
Is there anything else could be used instead of the LDR's?
Naturally it is possible to remove the LDR's/Lamps and only use unit in Manual mode.
This is good to know Chris. It also explains why I was able see/measure the
distortion products on my Shibasoku 725D that were floating around 900kHz to about 1+MHz. (maybe just a tad higher than that @ 1.3MHz to 1.5MHz).
The 5th harmonic of a coil that had a reactance in the 330Khz neighborhood.
Cheers,
Sync
You only need to place data on win audio stream. The actual call is wavin and wavout.
Win doesn't give a **** where the data is coming from.
Okay got it, thanks Davada. Does it need to be digital and not an analog
stream? I guess I'd also need to know where the pick off point is on the digital
stream, etc.
Cheers,
Sync
How are your programming skills?
Yes it has to be digital. After all...
There are free win audio and linux audio engines available.
Mostly in C. There is also stuff available for C#. Maybe visual Basic as well
Programming skills aren't very good, I wouldn't say non existent.
The last thing I programmed was in Fortran 4+ (I think).
I did fool around with some data base thing about 25 years
ago.
There has to be some interface that I won't have to program,
that for find a student who's hot at coding.
Cheers,
Sync
This one:
XMOS U8 AK4490 Audio HIFI asynchronous USB decoder DAC with Headphone out +PSU
You can read more about here: #510 and here #512
1Audio recommended a 12V supply with it.
I bent the first 5V reg. close to the power connector ,towards the side wall.
Dremelled out a ridge in the top cover, and used heat compound on it.
Changed the 5532 to an LM4562 (not necessary).
That's it.
Attachments
I didnt pursue it much further. Moved to the 339A and others, afterwards.... a better place to begin, I thought. However, the variable notch feature still has potientail app but needs to be further investigated.... I found a passive notch filter to which I added an opamp to sharpen the notch. So, the 334A wasnt low hanging fruit enough for me. It still has potential to be looked into further.... just was not getting me what I wanted fast or easy enough. Your measurment with modification shows the potential is very good though. Just needs a meter buffer or ?? That is worth doing IMO.
The speakers went to Thailand a month ago. Replaced with a JBL M2 Master Reference system. Best upgrade I have made in many years. Still dialing it in.
THx-Richard
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what mods did you do for this level of performance??
It is low enough as the QA400 is good to not more than -100-110dB accurately.
THx-RNMarsh
BTW -- the diode half bridge circuit for the meter added 10X distortion compared to removing them. [as measured at the monitor output]
The residual of the amps in the 334A is about .0025 % THD. Mostly third. Not quit good enough in stock form for QA400 front end. But could be useful for some and they are dirt cheap and built like a tank. Just need to buffer that meter circuit.
-RNM
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Looks like a great deal and performance, too. I ordered one.
Unfortunately, it wont arrive before I leave on my annual vacation to the warm part of the winter world... Asia. But gives me something else to look forward to when I return.
THx-RNMarsh
But then if I spend all my money on test gear then I have nothing to buy parts with to build circuits. I think our governments should give us some play money if they spend what they did on cyclotrons in the 70s.
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