Jun 9, 2021 at 4:39 PM

#### qboogie

I am not an engineer, but I might be able to help a little.

It is a good analogy, it is called the water flow analogy. It is used all the time, to visualize electricity by replacing it with water.

If you think of a water pump as the power source (or amplifier). The pressure (psi) of the water, is the same as Volts in electricity. The flow of the water or liters per min, is the same as current in electricity. And the diameter of the pipe, is the same as resistance (Ohms) in electricity.

You can solve for the power output of electricity by multiplying Volts by Amps to get watts. And you can solve for power output from a water system by multiplying psi by lpm to get, also watts. Here the thing. I hear it asked all the time here, but in a different form. People want to know "what is the impedance at the output?". I believe really what they are asking is what are the amperes at output, lol. And that is a difficult question to answer because it always is changing. BUT there is a trick, Ohms law (who else? lol). It says that the current (amperes) is equal to the voltage divided by the resistance (Ohms). In more cases than not (for me anyway) it is easier to figure out the amperes by knowing the resistance, than figuring out the resistance by knowing the amperes. In either case you will need to know the voltage to solve. And the figure for resistance, I am pretty sure, would be just the resistance (Ohms) from the headphones ( I say this because how else are you going to quantify resistance? Add it all up, Headphone resistance plus transformer resistance? I don't think so. I think there is just one resistance figure and it is the highest one.). Anyway, Divide the output voltage by headphone ohms and that will give you the output amperes. I may be wrong but I believe that the output Ohms by nature always match the actual Ohms of headphones.

Your analogy was slightly off in the concept of a constant 500mW, (and also calling it a volume of water. The volume of water is represented by liters per min, not watts). But the idea that a hose is delivering defined and constant water from a pump is more or less correct, but how that water turns into power is changed very much by what happens after the pump. Mostly by the size of the pipe, and in your example the introduction of a finger (as it does change the size of the pipe). Which is a very good comparison to an impedance switch that can be flipped on or off independently of what the original pipe size had been. BUT, it is important to remember what that finger does, lol. It may be an impedance, but what is it doing? It is raising psi (and so does the pipe),,, or voltage... SO while it may be called impedance, because it also raises pressure it is also voltage. Your example shows how power output is never constant (if it was you would just hear one loud tone in your ear). As you put your finger over the hose, you greatly increase psi or volts, the lpm may go down a bit, but the overall power output goes way up, and can knock over the heavy object or turn a water wheel. Here is the thing, you can do it other way around too. A hose with enough liters per min going through it with very low psi or resistance, could still knock that same heavy object down. It is just generally you don't have extra lpm (amperes) to throw at stuff, but introducing psi (volts) through only resistance is usually easier. But anyway the point here is that you will always have a change going on in power output based on these factors. Which is all after output, don't forget the music itself creates variations in output. Silent is nearly no watts while loud is many. I believe what creates confusion is the power ratings manufacturers share with us. But these are maximum power ratings. They are based on the factors they know about their amps. Namely how many volts it can produce...

Look at the water pump like the tubes and transformers. They are all going to have certain ratings, and you can't get something from nothing. So in the water example By knowing you have a 1HP pump (for example), you can then figure out what flow of water you can produce, then by using a pipe, you can direct that flow, producing power. Same with an amp. The tubes will be capable of a certain output. In most headphone amps these tubes are not being used to their full potential. Which means they have some headroom, well hey what better way to use some of that headroom? Release it when changing impedance modes. I think what has happened with the MHA200 is that it's tubes don't give it this headroom. As the impedance increases on this one, the voltage is being sacrificed and goes down. Where an amp with more room to play within the tubes, will let the volts increase through all the impedance changes, building higher power ratings with each mode change, due to increased resistance.

I don't know how the manufactures actually make their impedance circuits work, so the last part may or may not be correct. I look at the impedance switch like a faucet or hose spigot/finger, and then the impedance from headphones as a straw. If I set the water to either a trickle, low, medium, fast, or gushing; I will find I can more easy direct the water into different size straws. The slow trickle into a swizzle stick, low flow into a small straw and so on. Overall the actual numbers will be determined by all these factors, and constantly changing within a range. And as far as how the amplifiers are actually working, lol, I am just making an educated guess.

So this is not in any way meaning to say the MHA200 is a bad amp, lol. In fact many may say it is the way an amplifier should be built. I wouldn't disagree, although I would like to see that power rating around 1-2 watts if it is going to be constant through impedance modes. But I also have never listened to this amp. I can say Mcintosh amplifiers are built on a rock solid reputation, that much is for sure.

TLDR:
The water-flow analogy compares Volts to psi (pressure), Amps to lpm (flow), and Ohms (resistance) to pipe size. Volts X Amps = Watts , psi X lpm = Watts
Watts are rarely ever constant, always changing. In fact watts are probably more constant in a water system than they are in a sound system.
Thanks for the explanation and especially for the TL;DR version

Jun 9, 2021 at 10:03 PM

#### Tusirozo123

I am not an engineer, but I might be able to help a little.

It is a good analogy, it is called the water flow analogy. It is used all the time, to visualize electricity by replacing it with water.

If you think of a water pump as the power source (or amplifier). The pressure (psi) of the water, is the same as Volts in electricity. The flow of the water or liters per min, is the same as current in electricity. And the diameter of the pipe, is the same as resistance (Ohms) in electricity.

You can solve for the power output of electricity by multiplying Volts by Amps to get watts. And you can solve for power output from a water system by multiplying psi by lpm to get, also watts. Here the thing. I hear it asked all the time here, but in a different form. People want to know "what is the impedance at the output?". I believe really what they are asking is what are the amperes at output, lol. And that is a difficult question to answer because it always is changing. BUT there is a trick, Ohms law (who else? lol). It says that the current (amperes) is equal to the voltage divided by the resistance (Ohms). In more cases than not (for me anyway) it is easier to figure out the amperes by knowing the resistance, than figuring out the resistance by knowing the amperes. In either case you will need to know the voltage to solve. And the figure for resistance, I am pretty sure, would be just the resistance (Ohms) from the headphones ( I say this because how else are you going to quantify resistance? Add it all up, Headphone resistance plus transformer resistance? I don't think so. I think there is just one resistance figure and it is the highest one.). Anyway, Divide the output voltage by headphone ohms and that will give you the output amperes. I may be wrong but I believe that the output Ohms by nature always match the actual Ohms of headphones.

Your analogy was slightly off in the concept of a constant 500mW, (and also calling it a volume of water. The volume of water is represented by liters per min, not watts). But the idea that a hose is delivering defined and constant water from a pump is more or less correct, but how that water turns into power is changed very much by what happens after the pump. Mostly by the size of the pipe, and in your example the introduction of a finger (as it does change the size of the pipe). Which is a very good comparison to an impedance switch that can be flipped on or off independently of what the original pipe size had been. BUT, it is important to remember what that finger does, lol. It may be an impedance, but what is it doing? It is raising psi (and so does the pipe),,, or voltage... SO while it may be called impedance, because it also raises pressure it is also voltage. Your example shows how power output is never constant (if it was you would just hear one loud tone in your ear). As you put your finger over the hose, you greatly increase psi or volts, the lpm may go down a bit, but the overall power output goes way up, and can knock over the heavy object or turn a water wheel. Here is the thing, you can do it other way around too. A hose with enough liters per min going through it with very low psi or resistance, could still knock that same heavy object down. It is just generally you don't have extra lpm (amperes) to throw at stuff, but introducing psi (volts) through only resistance is usually easier. But anyway the point here is that you will always have a change going on in power output based on these factors. Which is all after output, don't forget the music itself creates variations in output. Silent is nearly no watts while loud is many. I believe what creates confusion is the power ratings manufacturers share with us. But these are maximum power ratings. They are based on the factors they know about their amps. Namely how many volts it can produce...

Look at the water pump like the tubes and transformers. They are all going to have certain ratings, and you can't get something from nothing. So in the water example By knowing you have a 1HP pump (for example), you can then figure out what flow of water you can produce, then by using a pipe, you can direct that flow, producing power. Same with an amp. The tubes will be capable of a certain output. In most headphone amps these tubes are not being used to their full potential. Which means they have some headroom, well hey what better way to use some of that headroom? Release it when changing impedance modes. I think what has happened with the MHA200 is that it's tubes don't give it this headroom. As the impedance increases on this one, the voltage is being sacrificed and goes down. Where an amp with more room to play within the tubes, will let the volts increase through all the impedance changes, building higher power ratings with each mode change, due to increased resistance.

I don't know how the manufactures actually make their impedance circuits work, so the last part may or may not be correct. I look at the impedance switch like a faucet or hose spigot/finger, and then the impedance from headphones as a straw. If I set the water to either a trickle, low, medium, fast, or gushing; I will find I can more easy direct the water into different size straws. The slow trickle into a swizzle stick, low flow into a small straw and so on. Overall the actual numbers will be determined by all these factors, and constantly changing within a range. And as far as how the amplifiers are actually working, lol, I am just making an educated guess.

So this is not in any way meaning to say the MHA200 is a bad amp, lol. In fact many may say it is the way an amplifier should be built. I wouldn't disagree, although I would like to see that power rating around 1-2 watts if it is going to be constant through impedance modes. But I also have never listened to this amp. I can say Mcintosh amplifiers are built on a rock solid reputation, that much is for sure.

TLDR:
The water-flow analogy compares Volts to psi (pressure), Amps to lpm (flow), and Ohms (resistance) to pipe size. Volts X Amps = Watts , psi X lpm = Watts
Watts are rarely ever constant, always changing. In fact watts are probably more constant in a water system than they are in a sound system.

Jun 10, 2021 at 2:17 AM

#### Colonel Flac

I am not an engineer, but I might be able to help a little.

It is a good analogy, it is called the water flow analogy. It is used all the time, to visualize electricity by replacing it with water.

If you think of a water pump as the power source (or amplifier). The pressure (psi) of the water, is the same as Volts in electricity. The flow of the water or liters per min, is the same as current in electricity. And the diameter of the pipe, is the same as resistance (Ohms) in electricity.

You can solve for the power output of electricity by multiplying Volts by Amps to get watts. And you can solve for power output from a water system by multiplying psi by lpm to get, also watts. Here the thing. I hear it asked all the time here, but in a different form. People want to know "what is the impedance at the output?". I believe really what they are asking is what are the amperes at output, lol. And that is a difficult question to answer because it always is changing. BUT there is a trick, Ohms law (who else? lol). It says that the current (amperes) is equal to the voltage divided by the resistance (Ohms). In more cases than not (for me anyway) it is easier to figure out the amperes by knowing the resistance, than figuring out the resistance by knowing the amperes. In either case you will need to know the voltage to solve. And the figure for resistance, I am pretty sure, would be just the resistance (Ohms) from the headphones ( I say this because how else are you going to quantify resistance? Add it all up, Headphone resistance plus transformer resistance? I don't think so. I think there is just one resistance figure and it is the highest one.). Anyway, Divide the output voltage by headphone ohms and that will give you the output amperes. I may be wrong but I believe that the output Ohms by nature always match the actual Ohms of headphones.

Your analogy was slightly off in the concept of a constant 500mW, (and also calling it a volume of water. The volume of water is represented by liters per min, not watts). But the idea that a hose is delivering defined and constant water from a pump is more or less correct, but how that water turns into power is changed very much by what happens after the pump. Mostly by the size of the pipe, and in your example the introduction of a finger (as it does change the size of the pipe). Which is a very good comparison to an impedance switch that can be flipped on or off independently of what the original pipe size had been. BUT, it is important to remember what that finger does, lol. It may be an impedance, but what is it doing? It is raising psi (and so does the pipe),,, or voltage... SO while it may be called impedance, because it also raises pressure it is also voltage. Your example shows how power output is never constant (if it was you would just hear one loud tone in your ear). As you put your finger over the hose, you greatly increase psi or volts, the lpm may go down a bit, but the overall power output goes way up, and can knock over the heavy object or turn a water wheel. Here is the thing, you can do it other way around too. A hose with enough liters per min going through it with very low psi or resistance, could still knock that same heavy object down. It is just generally you don't have extra lpm (amperes) to throw at stuff, but introducing psi (volts) through only resistance is usually easier. But anyway the point here is that you will always have a change going on in power output based on these factors. Which is all after output, don't forget the music itself creates variations in output. Silent is nearly no watts while loud is many. I believe what creates confusion is the power ratings manufacturers share with us. But these are maximum power ratings. They are based on the factors they know about their amps. Namely how many volts it can produce...

Look at the water pump like the tubes and transformers. They are all going to have certain ratings, and you can't get something from nothing. So in the water example By knowing you have a 1HP pump (for example), you can then figure out what flow of water you can produce, then by using a pipe, you can direct that flow, producing power. Same with an amp. The tubes will be capable of a certain output. In most headphone amps these tubes are not being used to their full potential. Which means they have some headroom, well hey what better way to use some of that headroom? Release it when changing impedance modes. I think what has happened with the MHA200 is that it's tubes don't give it this headroom. As the impedance increases on this one, the voltage is being sacrificed and goes down. Where an amp with more room to play within the tubes, will let the volts increase through all the impedance changes, building higher power ratings with each mode change, due to increased resistance.

I don't know how the manufactures actually make their impedance circuits work, so the last part may or may not be correct. I look at the impedance switch like a faucet or hose spigot/finger, and then the impedance from headphones as a straw. If I set the water to either a trickle, low, medium, fast, or gushing; I will find I can more easy direct the water into different size straws. The slow trickle into a swizzle stick, low flow into a small straw and so on. Overall the actual numbers will be determined by all these factors, and constantly changing within a range. And as far as how the amplifiers are actually working, lol, I am just making an educated guess.

So this is not in any way meaning to say the MHA200 is a bad amp, lol. In fact many may say it is the way an amplifier should be built. I wouldn't disagree, although I would like to see that power rating around 1-2 watts if it is going to be constant through impedance modes. But I also have never listened to this amp. I can say Mcintosh amplifiers are built on a rock solid reputation, that much is for sure.

TLDR:
The water-flow analogy compares Volts to psi (pressure), Amps to lpm (flow), and Ohms (resistance) to pipe size. Volts X Amps = Watts , psi X lpm = Watts
Watts are rarely ever constant, always changing. In fact watts are probably more constant in a water system than they are in a sound system.
That's a taking the analogy to its limit - thanks for the explanation!

One question though: If the amp was "sacrificing" increasingly more headroom for higher impedance modes, why is there a plain "1.5dB" of dynamic headroom in the specifications? Or would that still be correct for all modes because of the decibel unit (I always trip over that)?

Jun 10, 2021 at 7:33 PM

#### jwbrent

I’m still interested in the MHA200 and will be checking it out when I attend CanJam SoCal. The one issue I’ve read about is the loose volume control knob which would be a bother to me, hopefully McIntosh is tightening that up.

Jun 10, 2021 at 9:17 PM

#### Maelob

I’m still interested in the MHA200 and will be checking it out when I attend CanJam SoCal. The one issue I’ve read about is the loose volume control knob which would be a bother to me, hopefully McIntosh is tightening that up.
Did you see the discussion about the volume knob in this thread. I dont think it is an issue as i remember.
From Source Av
"It is not a defect or deficit to the amp. It is the type of pre VC they are using. It is a non-issue. If you want to understand this attribute and you have a McIntosh dealer nearby with any of the preamps that have an EQ in front, it’s the same type of knob as the EQ knobs with the same exact feel"

Jun 10, 2021 at 9:29 PM

#### jwbrent

Did you see the discussion about the volume knob in this thread. I dont think it is an issue as i remember.
From Source Av
"It is not a defect or deficit to the amp. It is the type of pre VC they are using. It is a non-issue. If you want to understand this attribute and you have a McIntosh dealer nearby with any of the preamps that have an EQ in front, it’s the same type of knob as the EQ knobs with the same exact feel"

Thank you for your reply, but a wiggly volume knob on a \$2,500 component does not seem appropriate, to me anyway.

Jun 10, 2021 at 10:00 PM

#### TeNeT

That's a taking the analogy to its limit - thanks for the explanation!

One question though: If the amp was "sacrificing" increasingly more headroom for higher impedance modes, why is there a plain "1.5dB" of dynamic headroom in the specifications? Or would that still be correct for all modes because of the decibel unit (I always trip over that)?
"dynamic headroom refers to the ability of a stereo, home theater receiver, or amplifier to blast the power to higher levels for short periods of time. This is meant to accommodate musical peaks or extreme sound effects in films."

lol, that is straight from google. I didn't know that hehe. So it sounds like dynamic headroom is that extra power you get with dynamics in the music.

Excuse me if I use incorrect verbiage when calling what I am describing "headroom". Here is what I meant by that:

I looked up the wattage of the 12bh7a power tube the MHA200 uses. It is rated at 3.5 or 7 watts depending on plate config. So each channel has a tube rated at say 3.5 watts. Headphone amps use no where near all that the tube has to offer. So that is what I meant by headroom. And whether or not it is better to use those extra watts (volts) or not comes down to how the manufacturer feels through testing. I have no doubt McIntosh does a ton of testing.

By comparison for example; an EL34 tube (also used in a lot of headphone amps) is rated at 55 watts. I could be wrong, but I think 55 watts in your headphone might just kill you lol. That is what I mean, although headroom may be the wrong term for it, that is to what I was referring.

And what I meant by saying sacrificing volts, was just math. Most amplifiers will see an increase in watts with impedance increase. This is the finger over the hose effect. Math tells us to do this the volts must go up. But if the watts remain the same with the impedance going up; it can only be because the voltage is decreasing...
EDIT: I mean it could also be the current is decreasing. In fact that is the natural outcome of simply introducing impedance. If the volts are constant, when you add impedance (headphones) the current will drop. But I believe the whole intent of the impedance switch (I could be wrong); is to more or less have the current remain constant. SO they do it with voltage changes. So with raised impedance, and current and unchanged final watts; volts would have to drop.
DOUBLE EDIT: I apologize for thinking out loud LOL. I just realized the above described scenario is impossible. Because, current equals voltage divided by impedance (Ohm's law). So if Impedance has increased, current cannot go up without voltage also increasing. If you look at just volts X amps = watts the above would have made sense. But since we are also dealing with increased impedance, it also has to work within Ohm's law. SO, really what we have hear is a misunderstanding from the specs given, and described below.

Remember though, the 500mW rating we get on this amp, is just that, a rating for maximum output. Just because they give it the same rating on all impedance modes does not mean the actual wattage is really staying exactly the same with each mode change. I would say it probably most likely is not. Although it also is not seeing as much change as an amp that has higher output rated tubes.

Last edited:
Jun 10, 2021 at 10:14 PM

#### Crowbar44

Thank you for your reply, but a wiggly volume knob on a \$2,500 component does not seem appropriate, to me anyway.
So as an MHA200 owner...the volume knob on my unit does have some VERY slight play. It's not enough for me to send it back and/or ask for another unit, it doesn't really bother me. I'm quite pleased with the sound of the amp and it's ability to drive all my headphones very well.

Jun 11, 2021 at 1:20 AM

#### jwbrent

So as an MHA200 owner...the volume knob on my unit does have some VERY slight play. It's not enough for me to send it back and/or ask for another unit, it doesn't really bother me. I'm quite pleased with the sound of the amp and it's ability to drive all my headphones very well.

Thank you for your reply. I figured there must be some variance with the volume knob between units. I’ll check it out at CanJam SoCal as well as give it a listen.

Jun 11, 2021 at 6:26 PM

#### TSAVJason

We are happy to announce our July 17th Zoom meeting with Ken Zellin from McIntosh. Ken will be online to explain all the technology used also how and why McIntosh used this platform for the MHA200. We will be having a Q&A session so that can ask all the questions you might have.

Date: 7/17/2021
Time: 2:00pm Pacific time
On Zoom

I’ll announce more about this Zoom meeting very soon. We are still working out a few details but Ken is great and very fun source of information from The McIntosh Group.
We hope you join us for what should be very informative and knowing Ken, very fun meeting!

start collecting your questions and curiosities now

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Jun 11, 2021 at 7:20 PM

#### TSAVJason

Thank you for your reply. I figured there must be some variance with the volume knob between units. I’ll check it out at CanJam SoCal as well as give it a listen.

we’ll definitely have a few for sale and demo at SoCal CanJam

Jun 11, 2021 at 7:24 PM

#### jwbrent

we’ll definitely have a few for sale and demo at SoCal CanJam

Looking forward to seeing you, Jason, I’ll be there Sunday helping out for the first half of the day, the second half to see how much money I can spend!

Jun 11, 2021 at 7:27 PM

#### TSAVJason

Looking forward to seeing you, Jason, I’ll be there Sunday helping out for the first half of the day, the second half to see how much money I can spend!
yeah, I have the same challenge ….. it’ll be cool to C ya!

Jun 11, 2021 at 11:48 PM

#### Crowbar44

We are happy to announce our July 17th Zoom meeting with Ken Zellin from McIntosh. Ken will be online to explain all the technology used also how and why McIntosh used this platform for the MHA200. We will be having a Q&A session so that can ask all the questions you might have.

Date: 7/17/2021
Time: 2:00pm Pacific time
On Zoom

I’ll announce more about this Zoom meeting very soon. We are still working out a few details but Ken is great and very fun source of information from The McIntosh Group.
We hope you join us for what should be very informative and knowing Ken, very fun meeting!

start collecting your questions and curiosities now
Outstanding....looking forward to it!