input gnd and usb gnd are isolated, so if you want to remove that 60hz ripple you can connect input and usb grounds together and that should ground the circuit
The time has come to see real measurements for JAT-501. Mixed feelings because I was used to see and hear about the " 1% pilot signal distortion". I'm glad with your glad John
So awesome people like you and others who know what they are talking about with this kit are doing videos I am thinking of dusting off my piggy bank and start filling it again. Please do a proper look at the specs of a JAT501 and fiddle about with stuff ! nice one John.....cheers.
I got mine last week. I'm learning how to capture the THD harmonics as a bar graph, that is most useful for me. The frequency response curve of course too. And power vs. THD would be helpful too in my Amp building. It would be great to see one video dedicated per function of this unit, with wiring, and what buttons to push etc. It can be a bit complicated.
much better than rca The silly thing is that they use rca also for spdif cable Unbelievable Why not using a standard already tested with digital scopes i really cant understand
I got mine a few days ago. I checked the distortion levels of my function generators. The Siglent has 0.09%, The Rigol 0.013%, surprisingly the Ipad with a function generator app is at 0.007%. The QA 403 is indeed much better at 0.00009%. Impressed. This will keep me busy for months to come.
Interesting. I just got my unit today and mirroring the test that John did my THD was sitting at -118db/0.00012% which is quite a bit higher than his -128/0.00004% and slightly worse than yours. I'm a little disappointed but I guess these differences are probably coming down to component variability. My unit does meet the specs provided by Quant but just barely.
Just a thought: If you ever needed to use your “Feel Tech” sig gen, take that %THD away from the Amp's output %THD - there might even be an offset facility within QA403, great bit of kit, but way too expensive for me.
I've thought of this unit. But I need more than just THD, I need to know the level of each individual harmonic, 2nd, 3rd, 4th and 5th. Amplifiers might have low THD but they sound bad because its all 3rd harmonic distortion. And an amplifier with 1% 2nd harmonic distortion will sound better, even with the high 2nd harmonic distortion. Higher distortion at the even harmonics are musical, but even a small amount of odd harmonic distortion is dissonant. Can this unit graph out the individual harmonics? Or is it still limited to only doing THD?
He showed how you can label arbitrary frequencies. Also the software provides an API through http (a bit wierd tbh) so you can grab all the data you want for processing in your favourite language.
The QA40x Software has a feature built in which is called THD Bargraph Visualiser. It shows you all the harmonic in a bar graph, with the dB volumes of each harmonic
A BIG Thank You to my Patreon supporters. You made the purchase of this gear possible! It is priced fair for what it is, but $600 is a stretch for me.
This is something I will probably never have, but it's so good to learn something new. Thanks a lot for your videos!
Didn’t know I needed one of these, but I probably want one for my upcoming 60th birthday. Thanks for the review!
You can find out if all those hifi myths are true regarding expensive cables, resistors, capacitors and all the other stuff people buy.
input gnd and usb gnd are isolated, so if you want to remove that 60hz ripple you can connect input and usb grounds together and that should ground the circuit
The time has come to see real measurements for JAT-501. Mixed feelings because I was used to see and hear about the " 1% pilot signal distortion". I'm glad with your glad John
What an awesome piece of kit. I feel a whole bunch of previous built and tested amp kit retests coming. Again awesome!
I will be excited to see what is coming with this new kit! Awesome Sauce!
Hey John! Glad you got it! Let me know if you need that USB power insert board and data pass through board I made. Helps a lot with mine.
Looking forward to seeing it hooked up to your amplifiers !
So awesome people like you and others who know what they are talking about with this kit are doing videos I am thinking of dusting off my piggy bank and start filling it again. Please do a proper look at the specs of a JAT501 and fiddle about with stuff ! nice one John.....cheers.
I got mine last week. I'm learning how to capture the THD harmonics as a bar graph, that is most useful for me. The frequency response curve of course too. And power vs. THD would be helpful too in my Amp building. It would be great to see one video dedicated per function of this unit, with wiring, and what buttons to push etc. It can be a bit complicated.
Using BNC connectors for audio is unique
much better than rca The silly thing is that they use rca also for spdif cable Unbelievable Why not using a standard already tested with digital scopes i really cant understand
The QA403 is terrific!
I got mine a few days ago. I checked the distortion levels of my function generators. The Siglent has 0.09%, The Rigol 0.013%, surprisingly the Ipad with a function generator app is at 0.007%.
The QA 403 is indeed much better at 0.00009%. Impressed. This will keep me busy for months to come.
Interesting. I just got my unit today and mirroring the test that John did my THD was sitting at -118db/0.00012% which is quite a bit higher than his -128/0.00004% and slightly worse than yours. I'm a little disappointed but I guess these differences are probably coming down to component variability. My unit does meet the specs provided by Quant but just barely.
Just a thought: If you ever needed to use your “Feel Tech” sig gen, take that %THD away from the Amp's output %THD - there might even be an offset facility within QA403, great bit of kit, but way too expensive for me.
very good point i understand that cheap generators have high distortion ? i cant find the value in the specs
This is weird a very important point
I've thought of this unit. But I need more than just THD, I need to know the level of each individual harmonic, 2nd, 3rd, 4th and 5th. Amplifiers might have low THD but they sound bad because its all 3rd harmonic distortion. And an amplifier with 1% 2nd harmonic distortion will sound better, even with the high 2nd harmonic distortion. Higher distortion at the even harmonics are musical, but even a small amount of odd harmonic distortion is dissonant. Can this unit graph out the individual harmonics? Or is it still limited to only doing THD?
He showed how you can label arbitrary frequencies. Also the software provides an API through http (a bit wierd tbh) so you can grab all the data you want for processing in your favourite language.
The QA40x Software has a feature built in which is called THD Bargraph Visualiser. It shows you all the harmonic in a bar graph, with the dB volumes of each harmonic
Amp builders both hifi and for guitar would surely be interested in that demo! Thanks.@@dedondigital
Thank you
Test the JAT501 & JAT801 THD soon
Hi great video. Can you please test JAT501 amp with this instrument. This will be helpful.
Very good thanks
You need a small tripod. I'm sure you already know this. 😂
Great! For $600 it is quite a bargain. I don't know if you are aware how much Audio Precision is asking for their products.
Nice toy!!!