Hi,
I would like to have a audio SA, and I am stuck with these three options:
- buy something like a HP3562A but they are old and very expensive, about 80dB dynamic range
(Price 1000+ EUR delivered best case)
- use my E4411A SA (9KHz-1.5GHz) with this:
NEW Spectrum Analyzer low frequency converter bg7tbl Type sa-LF os12 conv | eBay
Still about 80dB dynamic range and possibly need conditioning circuitry
(Price 70 EUR delivered) + conditioning circuitry
- Buy a good enough sound card and specific software, I have found something like these:
Creative Sound Blaster G3
Creative Sound Blaster G3 Amplificatore USB-C DAC per console di gioco PS4, Nintendo Switch, con GameVoice Mix (equlibrio audio per giochi/chat), controllo del microfono/volume e controllo : Amazon.it: Fai da te
(Price 40EUR delivered )
- CREATIVE Sound BlasterX AE-5 Plus Pure Edition
(Price about 190EUR)
32bit/384 kHz
Snr da 122 Db
I don't need exactly high end stuff, still I prefer "real" instruments, so if I will use a computer soundcard it should have way better performance than the 80dB I can have from old hp gear.
I have a HP8903B with very good software from P. Millet already.
I saw software tester that seem way more I may need, do you have recommendation for a good sw/hw audio board combination?
Max budget is 200EUR for the audio board, I would love to build a conditioning circuitry to better use the combination, so I could shell out another 100-150EUR max for it.
TIA
Giuseppe Marullo
IW2JWW - JN45RQ
I would like to have a audio SA, and I am stuck with these three options:
- buy something like a HP3562A but they are old and very expensive, about 80dB dynamic range
(Price 1000+ EUR delivered best case)
- use my E4411A SA (9KHz-1.5GHz) with this:
NEW Spectrum Analyzer low frequency converter bg7tbl Type sa-LF os12 conv | eBay
Still about 80dB dynamic range and possibly need conditioning circuitry
(Price 70 EUR delivered) + conditioning circuitry
- Buy a good enough sound card and specific software, I have found something like these:
Creative Sound Blaster G3
Creative Sound Blaster G3 Amplificatore USB-C DAC per console di gioco PS4, Nintendo Switch, con GameVoice Mix (equlibrio audio per giochi/chat), controllo del microfono/volume e controllo : Amazon.it: Fai da te
(Price 40EUR delivered )
- CREATIVE Sound BlasterX AE-5 Plus Pure Edition
(Price about 190EUR)
32bit/384 kHz
Snr da 122 Db
I don't need exactly high end stuff, still I prefer "real" instruments, so if I will use a computer soundcard it should have way better performance than the 80dB I can have from old hp gear.
I have a HP8903B with very good software from P. Millet already.
I saw software tester that seem way more I may need, do you have recommendation for a good sw/hw audio board combination?
Max budget is 200EUR for the audio board, I would love to build a conditioning circuitry to better use the combination, so I could shell out another 100-150EUR max for it.
TIA
Giuseppe Marullo
IW2JWW - JN45RQ
I undersand your preference for "real" (i.e. standalone) instruments, but I wouldn't bother with the 3562A unless you like boatanchors. It's only 14-bit, huge, and noisy. And no fun to fix if/when it breaks (been there...).
I have the PC-based 16-bit version of it (3565S) and it is good enough most of the time.
For occasional use a soundcard with software like REW makes the most sense. Even my old Audiophile 2496 gives better than -100dB THD+N throughput at 1kHz & 1VRMS.
Probably not much different from your 8903B...
I have the PC-based 16-bit version of it (3565S) and it is good enough most of the time.
For occasional use a soundcard with software like REW makes the most sense. Even my old Audiophile 2496 gives better than -100dB THD+N throughput at 1kHz & 1VRMS.
Probably not much different from your 8903B...
Thanks for your answer.
>For occasional use a soundcard with software like REW makes the most sense. >Even my old Audiophile 2496 gives better than -100dB THD+N throughput at >1kHz & 1VRMS.
>
>Probably not much different from your 8903B...
Long story, 8903B is "mostly" for radio use (direct SINAD readings on transceivers)...
Anyway, any recommendations for a good sound card worth up to 200EUR?
Does it make it worth stick with 32bit and higher than 192KHz sample rate, with higher than 120dB SNR?
Or anything with over 100 dB SNR with 192KHz / 24 bit will do?
Thanks.
Giuseppe Marullo
IW2JWW - JN45RQ
>For occasional use a soundcard with software like REW makes the most sense. >Even my old Audiophile 2496 gives better than -100dB THD+N throughput at >1kHz & 1VRMS.
>
>Probably not much different from your 8903B...
Long story, 8903B is "mostly" for radio use (direct SINAD readings on transceivers)...
Anyway, any recommendations for a good sound card worth up to 200EUR?
Does it make it worth stick with 32bit and higher than 192KHz sample rate, with higher than 120dB SNR?
Or anything with over 100 dB SNR with 192KHz / 24 bit will do?
Thanks.
Giuseppe Marullo
IW2JWW - JN45RQ
Many are using a Focusrite USB 2 channel model. The USB model provides input level control which is very convenient and allows a higher raw input signal, and used with a laptop it avoids any mains hum parasitic signal ingress. I don't know any 384khz sampling cards that give 192khz bandwidth, due to opamp limitations, so 96kHz bandwidth is the sweetspot. 2 channels allows features like impedance measurement from REW, which I find a great bench tool.
Trobbins,
many thanks for your answer.
Sorry to ask, do you mean this exact model?
FOCUSRITE Scarlett 2i2 (3rd Gen) (AMS-SCARLETT-2I2-3G)
Price seems okay and USB interfacing makes it way more flexible and variable gain is useful, thanks.
The one I mentioned(CREATIVE Sound BlasterX AE-5 Plus Pure Edition) has 384KHz sampling rate @ 32bit, but don't know what difference it may have, except maybe for claimed SNR (122dB). PCI only, so less flexible and more expensive.
Giuseppe Marullo
IW2JWW - JN45RQ
many thanks for your answer.
Sorry to ask, do you mean this exact model?
FOCUSRITE Scarlett 2i2 (3rd Gen) (AMS-SCARLETT-2I2-3G)
Price seems okay and USB interfacing makes it way more flexible and variable gain is useful, thanks.
The one I mentioned(CREATIVE Sound BlasterX AE-5 Plus Pure Edition) has 384KHz sampling rate @ 32bit, but don't know what difference it may have, except maybe for claimed SNR (122dB). PCI only, so less flexible and more expensive.
Giuseppe Marullo
IW2JWW - JN45RQ
That AE-5+ pure is only 96ksampling on record, so 48kHz bandwidth.
Yes the Scarlett 2i2 has had a lot of diy checking for performance if you search this and other forums, and is powered from the USB port. It isn't super expensive, and there are earlier generations around 2nd hand if you are reticent about accidentally zapping a newly purchased soundcard.
It's worth reading what soundcard input configurations can be used, such as balanced, unbalanced and for class D speaker connection. I mainly use unbalanced with a 100x scope probe on the bench, to allow direct connection of probe to reasonable voltage levels (as per valve amps and high powered amp speaker outputs), but the soundcard has to then provide an unbalanced input loading of something like 1Megohm to give a good bandwidth match, although that can need some compensation tweaking on the probe to extend out to 96kHz and then use the software to derive a flat loopback response.
Most soundcards roll-off below 10Hz, so even when compensated down to circa 2Hz for use with REW, the performance can get a bit ragged at or below 2Hz. So this is not a HP SA designed to go down to millihertz.
Some people use notch filters if trying to get harmonic measurements below 100-120dB noise floor. REW can also tweak out harmonic levels of any fundamental tone you may want to use for DUT distortion testing so that the soundcard effectively generates <-120dB harmonics and so makes a pretty nice cheap test oscillator.
Yes the Scarlett 2i2 has had a lot of diy checking for performance if you search this and other forums, and is powered from the USB port. It isn't super expensive, and there are earlier generations around 2nd hand if you are reticent about accidentally zapping a newly purchased soundcard.
It's worth reading what soundcard input configurations can be used, such as balanced, unbalanced and for class D speaker connection. I mainly use unbalanced with a 100x scope probe on the bench, to allow direct connection of probe to reasonable voltage levels (as per valve amps and high powered amp speaker outputs), but the soundcard has to then provide an unbalanced input loading of something like 1Megohm to give a good bandwidth match, although that can need some compensation tweaking on the probe to extend out to 96kHz and then use the software to derive a flat loopback response.
Most soundcards roll-off below 10Hz, so even when compensated down to circa 2Hz for use with REW, the performance can get a bit ragged at or below 2Hz. So this is not a HP SA designed to go down to millihertz.
Some people use notch filters if trying to get harmonic measurements below 100-120dB noise floor. REW can also tweak out harmonic levels of any fundamental tone you may want to use for DUT distortion testing so that the soundcard effectively generates <-120dB harmonics and so makes a pretty nice cheap test oscillator.
>That AE-5+ pure is only 96ksampling on record, so 48kHz bandwidth.
Ouch, so not good.
>Most soundcards roll-off below 10Hz, so even when compensated down to >circa 2Hz for use with REW, the performance can get a bit ragged at or below >2Hz. So this is not a HP SA designed to go down to millihertz.
Not planning to go that low. I have a P4500 power amp to "test", going to build 1kw ceramic dummy load, don't think below 10Hz will be meaningful for me.
I have cheap ESS vintage 90W speakers. Main worry is not to burst the tweeters.
I also happen to have cheap 100:1 probe for my various scopes, so relatively high power (500 to 1500W) should not be a problem just in case.
Need to decide between water and mineral oil to cool down the dummy load...
Thanks a lot for your assistance, got a 2i2 seems good enough for me.
Giuseppe Marullo
IW2JWW - JN45RQ
Ouch, so not good.
>Most soundcards roll-off below 10Hz, so even when compensated down to >circa 2Hz for use with REW, the performance can get a bit ragged at or below >2Hz. So this is not a HP SA designed to go down to millihertz.
Not planning to go that low. I have a P4500 power amp to "test", going to build 1kw ceramic dummy load, don't think below 10Hz will be meaningful for me.
I have cheap ESS vintage 90W speakers. Main worry is not to burst the tweeters.
I also happen to have cheap 100:1 probe for my various scopes, so relatively high power (500 to 1500W) should not be a problem just in case.
Need to decide between water and mineral oil to cool down the dummy load...
Thanks a lot for your assistance, got a 2i2 seems good enough for me.
Giuseppe Marullo
IW2JWW - JN45RQ
Also a soundcard does not measure absolute voltage level, so you need a good meter to confirm DUT input and output voltage levels over the frequency range of interest.
Although the 100x probe may have an acceptable voltage rating, that is likely to well exceed the attenuated level presented to the input channel voltage rating of a soundcard (even the USB types). And the Scarlett 2i2 doesn't have input level indication (some soundcards do - such as the EMU0404 USB that I use), so you need to keep an eye on a voltmeter, and the software indication of input level, to appreciate if soundcard clipping is being approached, and always aim to increase any test voltage from a low level, to avoid accidental direct connection to a high enough voltage that could damage the soundcard.
Although the 100x probe may have an acceptable voltage rating, that is likely to well exceed the attenuated level presented to the input channel voltage rating of a soundcard (even the USB types). And the Scarlett 2i2 doesn't have input level indication (some soundcards do - such as the EMU0404 USB that I use), so you need to keep an eye on a voltmeter, and the software indication of input level, to appreciate if soundcard clipping is being approached, and always aim to increase any test voltage from a low level, to avoid accidental direct connection to a high enough voltage that could damage the soundcard.
Use water and a larger tank. It will limit the temperature rise to 100C You will be adding water if you are dumping 1KW for very long. If the water is reasonably pure you can just dunk the resistors. The water should not conduct significantly. Use deionized water if you can get it. Any iron/steel may rust but no other issues.
AUDIO DUMMY LOAD
Ok for the water, oil is messy. Got one of these:
1000 WATT 8 ohm carico fittizio di prova non induttivo per amplificatore audio | eBay
I am looking at plastic food containers to put it into.
Wondering how long deionized water would last without getting contaminated.
Anyway I don't plan to use the ampli at max power for too long, it is a 480W CH/8ohm or 1440W bridge, really just a quick glance to see if it works properly.
SOUND CARD INTERFACE
Waiting for the 2i2 sound interface to come, now starting to look at options for a board to condition the signal at the input.
Pete Millet's one is tempting, but getting the box is not easy in Italy. I started to check to bom, and for example the display is not available either from Digikey and Mouser, so I have a bad feeling about availability.
I saw somewhere a simpler one, forgot where I saw it. I don't need RMS reading, I have a 34401A that would work hopefully on the whole audio spectrum with good accuracy.
Will keep you updated...thanks for now.
Ok for the water, oil is messy. Got one of these:
1000 WATT 8 ohm carico fittizio di prova non induttivo per amplificatore audio | eBay
I am looking at plastic food containers to put it into.
Wondering how long deionized water would last without getting contaminated.
Anyway I don't plan to use the ampli at max power for too long, it is a 480W CH/8ohm or 1440W bridge, really just a quick glance to see if it works properly.
SOUND CARD INTERFACE
Waiting for the 2i2 sound interface to come, now starting to look at options for a board to condition the signal at the input.
Pete Millet's one is tempting, but getting the box is not easy in Italy. I started to check to bom, and for example the display is not available either from Digikey and Mouser, so I have a bad feeling about availability.
I saw somewhere a simpler one, forgot where I saw it. I don't need RMS reading, I have a 34401A that would work hopefully on the whole audio spectrum with good accuracy.
Will keep you updated...thanks for now.
A simple resistor divider should be fine - identify the max input level to the 2i2 before clipping and work through the divider ratio needed (with some margin) for your expected amp output level - do a loopback with the divider included and prepare a calibration file.
Search the forum for how to manage bridge-mode measurements.
Search the forum for how to manage bridge-mode measurements.
Once you electrolyze water, whether it starts out de-ionized or not, it will end up messier than oil, since you'll have corroded metal and dissolved metal salts (usually toxic). Forced air flow is probably much less messy than either.
Using nichrome wire on a ceramic former (like a ceramic tile) can handle high powers (Its OK upto dull orange heat in free-air as any toaster can attest)
There is a local web hosting company which sunk its complete servers into mineral oil, running perfectly OK while heating the local city swimming pool, parking lots, surrounding buildings with the waste heat.
WEDOS – The official website of WEDOS Internet, a.s. - section WEDOS DC2 – OIL, with pictures.
WEDOS – The official website of WEDOS Internet, a.s. - section WEDOS DC2 – OIL, with pictures.
Thanks for the link.
An interesting project in its own league if carried out properly (Fluorinert?...joking of course).
Seller stated that up to 1kw air cooling is fine, I could add a fan and be done with it, maybe a simple noctua fan leftover from my computer junk box.
2i2 is arrived, just installed yesterday. Looking at T and pi attenuators, maybe a simple double zener as limiter and I could start playing.
What kind of output impedance should i set? It seems that the best input is the MIC one (XLR?), it should be 3k ohm.
The input one could be 600ohm, right?
Max input is +9dBu, I could assume 0dBu is a safe limit.
An interesting project in its own league if carried out properly (Fluorinert?...joking of course).
Seller stated that up to 1kw air cooling is fine, I could add a fan and be done with it, maybe a simple noctua fan leftover from my computer junk box.
2i2 is arrived, just installed yesterday. Looking at T and pi attenuators, maybe a simple double zener as limiter and I could start playing.
What kind of output impedance should i set? It seems that the best input is the MIC one (XLR?), it should be 3k ohm.
The input one could be 600ohm, right?
Max input is +9dBu, I could assume 0dBu is a safe limit.