Take Two! After your comments from the video (now delisted), I felt it would be misleading to say that this amplifier was not flawed with the gain set on the XLR inputs, so I make this retake. You guys keep me in line!
For those of us who expecting a multi thousands dollar performance out of a cheap mass-produced Chinese amp, these minor issues are easy to fix by changing/adding few resistors/potentiometers here and there.
Some people are so picky. It's an amplifier. It amplifies. If you're looking for the best amplifier ever made this probably isn't it. But is it good enough for the market this product was designed for? I'd say yes.
3:08 Basically, the inverted signal is subtracted from the non-inverted signal; this cancels out common mode noise, which, as the name implies, will be in phase on both the signal input and the inverted signal input. However, by subtracting the inverted input from the non-inverted input the signal is doubled by superposition, which increases its level by 6dB [20log(2/1)]. Pro gear uses pads (resistors) to address this if the XLR output's too hot (the output from my Benchmark DAC3L is too hot for the XLR input to my Rupert Neve RNHP, but the Benchmark has various jumpers which bring in resistor pads as a voltage divider to allow level matching).
Close John but just an XLR attenuator pad. Everybody complaining should be classified as User error . 1. Control the volume from the DAC or Headend equipment. 2. XLR is not for everyone but I have 10 devices that use XLR I'm my setup's 3. I'm happy to see someone competent with test equipment and audio on UA-cam. 4. Just plug in XLR attenuator pads , a device that lowers XLR, It's very common to need more the other for that type connection But the post all head in the wrong direction. Why because most of HI-FI is plug and play but not all of it.
Making it more confusing is some XLR inputs are expecting the +3DB and attenuated XLR outputs will be too quiet. It's a bit of a mess so it actually makes a lot of sense to leave it naturally 'too hot' as that is just a natural consequence of including the inverted signal, and let them attenuate it themselves if necessary(or including a switch on the back for high/low gain). I personally think an output being too hot is better than not hot enough. Turning the volume down is far easier.
@@rich1051414Exactly that is also correct, Only RCA inputs when I adjust the db levels to match imaging is improved , But XLR can typically be adjusted somewhere along the line even if it is a mixing board in or out with a commercial system.
People are forgetting that amplifiers are designed with gain that should let standard level signals just reach clipping. If you feed it a higher signal, you're going to overdrive it. So if they designed for clipping from the RCA inputs, the XLR input will automatically overdrive it ... or... if they designed if for clipping from XLR input, the RCA input will underdrive the amplifier preventing it from reaching full output. This is why, even in pro-amps the _internal_ level is always volume matched. Not doing this with the H7 is a design error... and a rather serious one.
The benefit of balanced inputs isn't just with long signal runs. It's anywhere where there are multiple devices referenced to mains earth. I connect 3 computers into my studio monitors through balanced interfaces. When trying to connect unbalanced gear or the computers through the onboard sound outputs, I get a lot of switchmode noise. Unbalanced signals are OK if they are powered through floating voltage sources. I made my own mixer based around the Texas Instruments INA1650 as a differential receiver. Good differential receivers are quite pricey, so having balanced inputs is only worthwhile if you have the receivers to match. Otherwise it does become a marketing gimmick. I can't really see from your previous vid whether they are using a differential receiver, or maybe just using an NE5532 as a rudimentary diff amp, which wouldn't be very good as you'd need to precisely match input resistors.
That's quality info. My DIY equipment grounds are not earth referenced but my commercial sources are. There is a measurable noise floor difference when using balanced vs. unbalanced. I used to think XLR was a bit over the top but it is just technically a better method. The issues arise with the quality of the balanced converter circuit - should be fully buffering each signal to defeat impedance mismatches and 1% resistors are important regardless of circuit. It took me ages to figure this out. I use Rod Elliot's fully differential receiver circuit now with OPA2134's.
Yeah I guess given that this is not aimed at the pro audio market, it would have been classy to level match as a courtesy, since even IF those using this had equipment feeding this that's capable of gain staging, probably a small percentage of those people even know what that is.
i just despise detentes and those digital volume knobs the one that just keep turning lol darn name is slipped my mind as they always have to have detents as its the way they work
To be honest I am confused as to what you are moaning about XLR is supposed to be higher volume as it runs higher gain? Balanced XLR is a technologically superior form of transporting a signal I really don't understand people who don't use XLR as they say it makes no difference even though it measures better than RCA, but they do use £1000 cat7 ethernet cables into their £30 tplink router. Go figure.
The signal levels on a balanced cable are higher. That does not mean that switching inputs should result in a mad dive for the volume control. On the receiver end it's a fairly simple matter to level match the RCA and XLR inputs... it can be done with just a couple of resistors.
You are assuming a certain level of competence with that statement and I would politely suggest that people who fuss about audio equipment in this price range may not know what a resistor is. Dare I say it.....not at our le......nope I cant do it LOL !@@Douglas_Blake_579
Take Two! After your comments from the video (now delisted), I felt it would be misleading to say that this amplifier was not flawed with the gain set on the XLR inputs, so I make this retake. You guys keep me in line!
Good on you John. High praise for integrity.
For those of us who expecting a multi thousands dollar performance out of a cheap mass-produced Chinese amp, these minor issues are easy to fix by changing/adding few resistors/potentiometers here and there.
Nobody should have to do repairs on a brand new product. If they can't make it correctly... don't buy it.
This channel may not be "flashy" but this guy knows his stuff. I like these breakdowns of "cheap" audio equipment
Some people are so picky. It's an amplifier. It amplifies. If you're looking for the best amplifier ever made this probably isn't it. But is it good enough for the market this product was designed for? I'd say yes.
3:08 Basically, the inverted signal is subtracted from the non-inverted signal; this cancels out common mode noise, which, as the name implies, will be in phase on both the signal input and the inverted signal input. However, by subtracting the inverted input from the non-inverted input the signal is doubled by superposition, which increases its level by 6dB [20log(2/1)]. Pro gear uses pads (resistors) to address this if the XLR output's too hot (the output from my Benchmark DAC3L is too hot for the XLR input to my Rupert Neve RNHP, but the Benchmark has various jumpers which bring in resistor pads as a voltage divider to allow level matching).
Close John but just an XLR attenuator pad.
Everybody complaining should be classified as User error .
1. Control the volume from the DAC or Headend equipment.
2. XLR is not for everyone but I have 10 devices that use XLR I'm my setup's
3. I'm happy to see someone competent with test equipment and audio on UA-cam.
4. Just plug in XLR attenuator pads , a device that lowers XLR, It's very common to need more the other for that type connection
But the post all head in the wrong direction. Why because most of HI-FI is plug and play but not all of it.
Making it more confusing is some XLR inputs are expecting the +3DB and attenuated XLR outputs will be too quiet. It's a bit of a mess so it actually makes a lot of sense to leave it naturally 'too hot' as that is just a natural consequence of including the inverted signal, and let them attenuate it themselves if necessary(or including a switch on the back for high/low gain).
I personally think an output being too hot is better than not hot enough. Turning the volume down is far easier.
@@rich1051414Exactly that is also correct, Only RCA inputs when I adjust the db levels to match imaging is improved , But XLR can typically be adjusted somewhere along the line even if it is a mixing board in or out with a commercial system.
People are forgetting that amplifiers are designed with gain that should let standard level signals just reach clipping. If you feed it a higher signal, you're going to overdrive it. So if they designed for clipping from the RCA inputs, the XLR input will automatically overdrive it ... or... if they designed if for clipping from XLR input, the RCA input will underdrive the amplifier preventing it from reaching full output. This is why, even in pro-amps the _internal_ level is always volume matched. Not doing this with the H7 is a design error... and a rather serious one.
The benefit of balanced inputs isn't just with long signal runs. It's anywhere where there are multiple devices referenced to mains earth. I connect 3 computers into my studio monitors through balanced interfaces. When trying to connect unbalanced gear or the computers through the onboard sound outputs, I get a lot of switchmode noise. Unbalanced signals are OK if they are powered through floating voltage sources. I made my own mixer based around the Texas Instruments INA1650 as a differential receiver. Good differential receivers are quite pricey, so having balanced inputs is only worthwhile if you have the receivers to match. Otherwise it does become a marketing gimmick. I can't really see from your previous vid whether they are using a differential receiver, or maybe just using an NE5532 as a rudimentary diff amp, which wouldn't be very good as you'd need to precisely match input resistors.
That's quality info. My DIY equipment grounds are not earth referenced but my commercial sources are. There is a measurable noise floor difference when using balanced vs. unbalanced. I used to think XLR was a bit over the top but it is just technically a better method. The issues arise with the quality of the balanced converter circuit - should be fully buffering each signal to defeat impedance mismatches and 1% resistors are important regardless of circuit. It took me ages to figure this out. I use Rod Elliot's fully differential receiver circuit now with OPA2134's.
Yeah I guess given that this is not aimed at the pro audio market, it would have been classy to level match as a courtesy, since even IF those using this had equipment feeding this that's capable of gain staging, probably a small percentage of those people even know what that is.
i just despise detentes and those digital volume knobs the one that just keep turning lol darn name is slipped my mind as they always have to have detents as its the way they work
To be honest I am confused as to what you are moaning about XLR is supposed to be higher volume as it runs higher gain? Balanced XLR is a technologically superior form of transporting a signal I really don't understand people who don't use XLR as they say it makes no difference even though it measures better than RCA, but they do use £1000 cat7 ethernet cables into their £30 tplink router. Go figure.
The signal levels on a balanced cable are higher. That does not mean that switching inputs should result in a mad dive for the volume control. On the receiver end it's a fairly simple matter to level match the RCA and XLR inputs... it can be done with just a couple of resistors.
You are assuming a certain level of competence with that statement and I would politely suggest that people who fuss about audio equipment in this price range may not know what a resistor is. Dare I say it.....not at our le......nope I cant do it LOL !@@Douglas_Blake_579
You sound SO much like the hoax hotel anti scammer guy!!