Member
Joined 2008
I think that many members might/should�� find this post helpful because with an oscilloscope we can test a used amplifier -for example- and find out if it is in good working condition or not (we all know that there are many problematic used amplifiers for sale and sometimes they sell for a lot of money) and also we might want to check our old amplifiers.
I would like to buy an Oscilloscope and use it simply for measuring audio amplifiers' output power and distortion using a square wave.
As simple as that. I would like to get an accurate measurement, quickly in order to check amp's condition/power.
I know that we need a square wave input source, an oscilloscope and a dummy load 4/8 ohms.
I am considering buying this one:
A. Hantek DSO 2C10 with 2D10 signal sourse
Hantek Digital Storage Oscilloscope 2CH 100Mhz 1GS/s DSO2C10+2D10 Signal Source | eBay
or this one:
B. Hantek DSO5102P
Hantek DSO5102P Digital Oszilloskop 2 Kanale 100MHz 1GSa/s
What do you think about the above oscilloscopes and would you buy another for that purpose?
Looking forward for your replies. Please correct me or write about anything on this subject.
We need to be able to check our amps.
Thanks for your time!
I would like to buy an Oscilloscope and use it simply for measuring audio amplifiers' output power and distortion using a square wave.
As simple as that. I would like to get an accurate measurement, quickly in order to check amp's condition/power.
I know that we need a square wave input source, an oscilloscope and a dummy load 4/8 ohms.
I am considering buying this one:
A. Hantek DSO 2C10 with 2D10 signal sourse
Hantek Digital Storage Oscilloscope 2CH 100Mhz 1GS/s DSO2C10+2D10 Signal Source | eBay
or this one:
B. Hantek DSO5102P
Hantek DSO5102P Digital Oszilloskop 2 Kanale 100MHz 1GSa/s
What do you think about the above oscilloscopes and would you buy another for that purpose?
Looking forward for your replies. Please correct me or write about anything on this subject.
We need to be able to check our amps.
Thanks for your time!
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It's a good idea and that scope will surely be useful. But you can't measure distortion with a scope, unless the distortion is many percentage points.
Even a scope with FFT usually is limited to 8bits resolution which is equivalent to about 48dB range.
That said, there are many, many things you can test to find out how well (or not) your amp works, and give you an insight in HOW it works.
Actually, if you are serious about audio electronics, you won't get very far without a scope.
Jan
Even a scope with FFT usually is limited to 8bits resolution which is equivalent to about 48dB range.
That said, there are many, many things you can test to find out how well (or not) your amp works, and give you an insight in HOW it works.
Actually, if you are serious about audio electronics, you won't get very far without a scope.
Jan
Member
Joined 2008
Thanks Jan! (at least we can check the square wave form, from their output at specific watts/ohms).
Hey everyone : PLEASE TAKE YOUR TIME AND ANSWER! Please stay on topic and write your opinions.
Hey everyone : PLEASE TAKE YOUR TIME AND ANSWER! Please stay on topic and write your opinions.
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Hi!
You probably refer to "distorsion" in a more general sense I suppose than like 0,06% something...
To check that a square wave looks OK on the output of an amp is standard procedure. Any scope will do this and it is not something challenging when it is a question for audio frequencies x10 or even 100.
Just go ahead and buy any scope as long it is not something really cheap.
Good luck!
//
You probably refer to "distorsion" in a more general sense I suppose than like 0,06% something...
To check that a square wave looks OK on the output of an amp is standard procedure. Any scope will do this and it is not something challenging when it is a question for audio frequencies x10 or even 100.
Just go ahead and buy any scope as long it is not something really cheap.
Good luck!
//
Member
Joined 2008
Thanks TNT!
please write your opinions too! 🙂
->Any suggestions for another oscilloscope?
I m off working on speakers - will answer and say thanks to everyone later on !
please write your opinions too! 🙂
->Any suggestions for another oscilloscope?
I m off working on speakers - will answer and say thanks to everyone later on !
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I´m also in the market for a (well-priced) oscilloscope.
At my distributor I see PeakTech, Rigol, GwInstek and Uni-T oscilloscope all ~ starting at 300€.
At the moment I´m leaning towards Rigol as we use a couple of their products at work for lower frequency measurements. They seem reliable and good enough so far.
I don´t have best of experiences with Uni-T multimeters but that doesn´t necessarily say anything about their oscilloscopes.
Also looking at ebay or similar now and then.
The Tektronix TDS series oscilloscope are getting older now and sometimes you see one for a fair price. They miss a lot of connectivity features (serial interface for data transfer) but are very reliable. Use them at work also.
At my distributor I see PeakTech, Rigol, GwInstek and Uni-T oscilloscope all ~ starting at 300€.
At the moment I´m leaning towards Rigol as we use a couple of their products at work for lower frequency measurements. They seem reliable and good enough so far.
I don´t have best of experiences with Uni-T multimeters but that doesn´t necessarily say anything about their oscilloscopes.
Also looking at ebay or similar now and then.
The Tektronix TDS series oscilloscope are getting older now and sometimes you see one for a fair price. They miss a lot of connectivity features (serial interface for data transfer) but are very reliable. Use them at work also.
Oh, yeah forgot about Siglent.
Pretty much unknown to me but often hear good things about it, at least from DIYers. Do you have one and are happy with it?
Here´s some more older threads:
Need oscilloscope - what to buy?
Oscilloscope woes
Pretty much unknown to me but often hear good things about it, at least from DIYers. Do you have one and are happy with it?
Here´s some more older threads:
Need oscilloscope - what to buy?
Oscilloscope woes
You'll also need a function generator, especially sine and triangle. You can use a soundcard, or a cheap aliexpress model, it doesn't need low distortion.
Feeding a square wave into the amp and looking at it on the scope doesn't give much information, but a sine gives a lot more. For example I fixed an amp yesterday, and the sine had squished tops on one polarity. It was a dead BJT in the preamp section. With a square wave, it would have still looked like a square wave, only with lower amplitude. But with a sine, it showed one driver was working well and the other was not.
Feeding a square wave into the amp and looking at it on the scope doesn't give much information, but a sine gives a lot more. For example I fixed an amp yesterday, and the sine had squished tops on one polarity. It was a dead BJT in the preamp section. With a square wave, it would have still looked like a square wave, only with lower amplitude. But with a sine, it showed one driver was working well and the other was not.
Function generator is a good point.
Especially fast rise time square wave is nice to have.
I´m using the soundcard so far (sine), tried this Espotek Labrador board but am not convinced of its quality (although the idea sure is nice to have everything on a little board).
Especially fast rise time square wave is nice to have.
I´m using the soundcard so far (sine), tried this Espotek Labrador board but am not convinced of its quality (although the idea sure is nice to have everything on a little board).
I confirm the postings above. For about 300€ you can buy a scope nowadays that will fit to all your needs. I use for years a Rigol and am happy with it. It offers upto 4 traces which sometimes is useful when monitoring power-up procedures. If I had to choose nowadays may the Siglent would be my favorite.
For repair jobs the scope is the most important tool, square wave testing is a very handy method to get an instant oversight. To trace instabilities and oscillations a scope is absolutely mandatory.
Measuring very small signals, THD noise etc - this is not the domain of a scope.
Next investment is a soundcard that you can use to measure THD, frequency response, noise etc. This eliminates the need of a distinct signal generator as well.
Next step is a speaker impedance test setup to tune vented cabinets. A simple box driven by the soundcard using a software like LIMP (ARTA).
For repair jobs the scope is the most important tool, square wave testing is a very handy method to get an instant oversight. To trace instabilities and oscillations a scope is absolutely mandatory.
Measuring very small signals, THD noise etc - this is not the domain of a scope.
Next investment is a soundcard that you can use to measure THD, frequency response, noise etc. This eliminates the need of a distinct signal generator as well.
Next step is a speaker impedance test setup to tune vented cabinets. A simple box driven by the soundcard using a software like LIMP (ARTA).
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As of Siglent vs. Rigol - A few years ago the diy star was Rigol, 1054Z (un)officially upgradable for free to 1104Z. I got one and have been OK with it since then.
Today IMO this model is a bit outdated, keeping price fixed. IIUC the top diy price/performance position was taken over by Siglent in last years
Siglent SDS1104X-E Hack to 200Mhz， and full options ? - Page 1
Unlocking Siglent SDS1104X-E, step by step - Page 13
Today IMO this model is a bit outdated, keeping price fixed. IIUC the top diy price/performance position was taken over by Siglent in last years
Siglent SDS1104X-E Hack to 200Mhz， and full options ? - Page 1
Unlocking Siglent SDS1104X-E, step by step - Page 13
An old USB1 soundcard can be useful, because you can buy USB1 isolators for a few euros on aliexpress. That way, if the amp gets cranky and nukes the soundcard, your PC is safe.
It is save to measure amp outputs via a resistor-divider attenuating the voltage by some 30dB. Never connect power outputs directly to your soundcard!
I have a Siglent 1104XE and upgraded it to 200 MHz. Its a good tool and can do a lot. However its a lot to pay if what yoy want to see is waveforms like a vintage scope would.
I also have these: https://www.amazon.com/YEAPOOK-ADS1...s=ADS1013D&qid=1621720752&s=industrial&sr=1-2 $160 from Amazon. Less direct from China Search for ADS1013D I use it for waveform and FFT. Not great but it is 2 channels 100 MHz (really, I confirmed) and battery powered. It is pretty capable.
And one of these New Digital 2.4" LCD Handheld Oscilloscope DSO1511E+ 120MHz 500MS/s ARM FPGA ADC | eBay which for $80 w/ probe has worked out great. Also battery powered so you can make isolated measurements and very portable, like a DVM. It also has measurement readouts that work as a 3 digit DVM for amplitude and frequency.
I also have these: https://www.amazon.com/YEAPOOK-ADS1...s=ADS1013D&qid=1621720752&s=industrial&sr=1-2 $160 from Amazon. Less direct from China Search for ADS1013D I use it for waveform and FFT. Not great but it is 2 channels 100 MHz (really, I confirmed) and battery powered. It is pretty capable.
And one of these New Digital 2.4" LCD Handheld Oscilloscope DSO1511E+ 120MHz 500MS/s ARM FPGA ADC | eBay which for $80 w/ probe has worked out great. Also battery powered so you can make isolated measurements and very portable, like a DVM. It also has measurement readouts that work as a 3 digit DVM for amplitude and frequency.
Attachments
Don't dismiss keeping an old analogue oscilloscope handy, can be very handy for spotting oscillations and making certain types of adjustments on audio gear.
Member
Joined 2008
Thanks for your replies!
I think that many members will find this thread useful. There are MANY expensive amplifiers for sale with serious problems. We must find a way, we need an oscilloscope - and there is no plug n play kit for testing audio amplifiers.
I think that many members will find this thread useful. There are MANY expensive amplifiers for sale with serious problems. We must find a way, we need an oscilloscope - and there is no plug n play kit for testing audio amplifiers.
Member
Joined 2008
1audio thank you so much ....
i will check them out and maybe ask about them.
Thanks for your great advice
My journey has been a little different, but it looks like we would like to do similar tests.
I rushed out and bought an oscilloscope before it really needed it. I went for 4 channel MicSig. Has the safety of also being run by battery also. I could of waited to decide on the spec needed.
I was thinking of buying a standalone signal generator, and a dedicated distortion analyser, but then started thinking of a different approach with QA401 Audio Analyzer. It has just been updated to QA402, but I will wait longer to decide.
At the moment, I want to spend money on better components, and trying not to to blow anything up, or get burnt.
Before I attempt to learn how to do any tests, I will be setting up a dim bulb current limiter, and an isolation transformer.
I rushed out and bought an oscilloscope before it really needed it. I went for 4 channel MicSig. Has the safety of also being run by battery also. I could of waited to decide on the spec needed.
I was thinking of buying a standalone signal generator, and a dedicated distortion analyser, but then started thinking of a different approach with QA401 Audio Analyzer. It has just been updated to QA402, but I will wait longer to decide.
At the moment, I want to spend money on better components, and trying not to to blow anything up, or get burnt.
Before I attempt to learn how to do any tests, I will be setting up a dim bulb current limiter, and an isolation transformer.
Member
Joined 2008
Thanks for your reply as well rootscript!
For audio amplifier output evaluation: sine and/or square wave, comparing left and right channels, max power output measurement...
...What do you guys think for the following 2 devices:
1. Signal generator
DDS Signal Generator Counter,Dual-Channel Arbitrary Frequency Counter 60MHz a11 | eBay
2. Oscilloscope
1013D 2 Channels 100MHz*2 Band Width 1GSa/S Sampling Rate Oscilloscope+LCD Y3F5 | eBay
Please remember that our aim (on this thread) is to check the output of an Audio Amplifier, to evaluate/measure its power output, the distortion, to get a sine/square wave.
What do you think about the signal generator listed above as well as the 1013d oscilloscope?
Please add anything useful for this thread. Write you opinion and don't forget that our aim is to evaluate and measure the output of an audio amplifier using an oscilloscope - nothing else 🙂
Many many thanks to each one of you for your time. Looking forward for your comments.
For audio amplifier output evaluation: sine and/or square wave, comparing left and right channels, max power output measurement...
...What do you guys think for the following 2 devices:
1. Signal generator
DDS Signal Generator Counter,Dual-Channel Arbitrary Frequency Counter 60MHz a11 | eBay
2. Oscilloscope
1013D 2 Channels 100MHz*2 Band Width 1GSa/S Sampling Rate Oscilloscope+LCD Y3F5 | eBay
Please remember that our aim (on this thread) is to check the output of an Audio Amplifier, to evaluate/measure its power output, the distortion, to get a sine/square wave.
What do you think about the signal generator listed above as well as the 1013d oscilloscope?
Please add anything useful for this thread. Write you opinion and don't forget that our aim is to evaluate and measure the output of an audio amplifier using an oscilloscope - nothing else 🙂
Many many thanks to each one of you for your time. Looking forward for your comments.
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