That's a great point Panson - I'm going to fuss at Audiomatica about that. I noticed that recently and it's really annoying - probably too brief to hurt anything, but it needs to be dealt with. Hopefully this can be addressed with a software update.
On the system I just tested, the level briefly bumps as you move between -12dBu and -11dBu as well as between +6dBu to +7dBu. Something to do with the software control of the relays that switch the resistor circuits used for gain control.
On the system I just tested, the level briefly bumps as you move between -12dBu and -11dBu as well as between +6dBu to +7dBu. Something to do with the software control of the relays that switch the resistor circuits used for gain control.
Thanks for a good info.
Has anyone had experiences with the QCBOX model 5 amplifier starting to produce power supply noises? As it's an impulse power supply what I hear and see is not a typical hum but rather a varied slowly changing noisefloor. It is there even if I disconnect all input and outputs, so not a grounding issue.
I suspected that maybe after 8 years some of the electrolytic caps have given up - so I replaced them all but that did not change the situation.
Sending it back to Audiomatica is soso option as I've added a switch for choosing 1:1 input versus variable input with volume pot. They might not necessarily like the tweaked version of their product.... But sometimes I feel more comfortable having a 2W max amplifier for example driving a test tweeter than a 50W one ... the above clicks for example can hurt lot more with 26dB of gain after them.
The mod was done years ago - so I know that is not the source of the interference issues.
Has anyone had experiences with the QCBOX model 5 amplifier starting to produce power supply noises? As it's an impulse power supply what I hear and see is not a typical hum but rather a varied slowly changing noisefloor. It is there even if I disconnect all input and outputs, so not a grounding issue.
I suspected that maybe after 8 years some of the electrolytic caps have given up - so I replaced them all but that did not change the situation.
Sending it back to Audiomatica is soso option as I've added a switch for choosing 1:1 input versus variable input with volume pot. They might not necessarily like the tweaked version of their product.... But sometimes I feel more comfortable having a 2W max amplifier for example driving a test tweeter than a 50W one ... the above clicks for example can hurt lot more with 26dB of gain after them.
The mod was done years ago - so I know that is not the source of the interference issues.
Attachments
Good job on replacing the electrolytics, I would have done that as well. One thing that lowers the noise floor with CLIO FW-0x and QCBox systems is tying their chassis together with a low impedance (large/short) wire. This will not solve your problem, but it may help, possibly significantly. The panels that Audiomatica sells that bolt the two chassis together is an ideal way to achieve this low impedance connection.
Also, with the FireWire CLIO boxes like you have, it's best to have them connected to your computer and powered on before you boot into the Windows OS. Letting it warm up about 10 minutes also reduces its noise floor. For some reason the USB version of the CLIO box does not require this - it has just as low a noise floor whether you connect it and power it on before or after you boot into Windows.
I'm not an amplifier expert, but I know someone on this forum or someone that repairs amplifiers would know what to look for in the QCBox amp given those symptoms. It can't hurt to send Audiomatica an email about it and ask them what they think.
Good luck!
Great!
Could you also ask for sweeping from low to high (increasing) in Sinusoidal? It is limited to high to low (decreasing) in current version.
Actually there's at least two very good reasons for the Sinusoidal module to sweep from high to low:
1. One of the outstanding things about CLIO is that is has (3) completely different measurement techniques to characterize audio and acoustic devices. These (3) methods allow you to stimulate a DUT in very different ways, each of which follow methods that have proven themselves over the years in dozens of measurement products and thousands of laboratories, but CLIO brings them together into one. I use all (3) when I want to fully quantify a loudspeaker.
You'll be amazed at what you'll learn by doing this - for some examples that I can think of at the moment - measure a loudspeaker you think you know everything about with these methods and prepare yourself for some surprises:
(a) Using the LogChirp/MLS Module, use 128K, 256K and 512K lengths of both stimuli types; log sweep and MLS. You will see differences and those differences are due to how that particular loudspeaker deals with RMS, peak, broadband and single frequency per time unit stimuli. Time domain views of IR, ETC and Wavelets of these stimuli will show important differences. Each are correct, but stress different aspects of the loudspeaker's moving elements, thus result in differing behaviors in some areas.
(b) Using the FFT module in Live (real time FFT) mode, what happens when you drive that same loudspeaker with a swept sine vs. periodic pink noise stimulus - both at the same levels? What happens when you approach that loudspeaker's maximum output capability? At what frequencies do you see the changes? Why do you see changes (compression) there and not other places in the passband? Now try the multitone stimulus and observe behavior in the same frequency regions as you raise levels. Fascinating stuff that can lead to superior loudspeaker design.
(c) Use the Sinusoidal module with continuous log sweeps that start at HF and end at LF. Use the same levels you did with the log sweeps in the LogChirp module that swept from low to high. You will see differences at low frequencies, why? Is it better or worse? Make sure you have the delay correct in the Sinusoidal module because it does something entirely different than the other modules and most other measurement systems on the market - it follows the sweep with a tracking filter for incredibly high noise rejection and incredibly accurate distortion analysis up to the 10th harmonic. Now change from continuous sweep to stepped sine bursts. You can also narrow the measurement's range down to the width of a single octave you you'd like. What differences do you see with the stepped stimulus? Now do the really cool thing and add gating to the stepped sine bursts. Try 1/24th octave, Slow (that means you end up with about 12ms long bursts). Now you can do maximum output testing of amps and loudspeakers without damaging them. Watch the distortion plots to find when you are getting near the end of the road for that DUT. Amazing stuff you won't find in a single product anywhere else. CLIO is indispensable in any serious designer's tool set IMO.
2. I'm stealing the following from the wonderful people (and products) at Listen Inc.:
"It is best to sweep your test signal from high to low frequency as the transducer stabilizes (resulting in accurate measurement) faster. Low frequencies have a longer wavelength/period than high frequencies, therefore contain more energy. When starting a sweep at low frequency, the initial burst of energy causes the transducer to ring, so it takes longer to get a stable measurement. Starting at a high frequency ensures a gradual fade in of energy, resulting in a stable measurement sooner, therefore a shorter test time."
Since the Sinusoidal module is all about the highest possible accuracy in distortion measurements, high to low is the only way to go.
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Actually I do have an example dealing with distortion measurement of the same DUT using all (3) modules:
http://audiomatica.us/resources/Education/AN-002_SS.pdf
CLIO 12 can be used for 800W speaker just as well but you'd need to use another amp as the QCBOX v5 amplifier that CLIO sells has 50W/8ohm capability.
800W itself does not tell much more than what is required from the amplifier. You'd need to share more info on the type of speakers you'd be testing and what is their sensitivity. 800W low sensitivity subwoofer could probably be measured with CLIO-s microphones, but higher sensitivity speakers would need high SPL capable lab microphones from G.R.A.S or B&K or others.
800W itself does not tell much more than what is required from the amplifier. You'd need to share more info on the type of speakers you'd be testing and what is their sensitivity. 800W low sensitivity subwoofer could probably be measured with CLIO-s microphones, but higher sensitivity speakers would need high SPL capable lab microphones from G.R.A.S or B&K or others.
Hello all:
Just wanted to mention that both CLIO 11 and CLIO 12 have free software updates available:
CLIO Software Updates
Bug swatting, increased stability and speed and in the case of CLIO 12 some important low-level USB management improvements.
Just wanted to mention that both CLIO 11 and CLIO 12 have free software updates available:
CLIO Software Updates
Bug swatting, increased stability and speed and in the case of CLIO 12 some important low-level USB management improvements.
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Hello:
I actually had the upgrade done to one of my CLIO 11 systems, but I don't think that counts because I'm the guy that sells them. Everyone I helped through the process is quite happy with the result. Hopefully someone will chime in on their experience.
In my opinion, the best aspects of the upgrade are:
1. USB. Any decent laptop and you're up and running.
2. Audio hardware is updated to brand new specs.
3. Cycle wavelet plotting. That is a fascinating and helpful addition to the standard wavelet plot.
In the mean time, here's the post that explains the process.
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Thanks guys for the replies. Based on positive experiences, I'll package mine up and send it in.
Langston, in your experience, is it okay to send the FW-01 with USPS Priority International? Sending it with Fedex or UPS is much more expensive. I got a few things from you last year, but not the CLIO 11, which I had for a while.
Langston, in your experience, is it okay to send the FW-01 with USPS Priority International? Sending it with Fedex or UPS is much more expensive. I got a few things from you last year, but not the CLIO 11, which I had for a while.