Impedance matching at 500mW may be a different beast than 500mW unmatched. What's the impedance and sensitivity of the 1266? (not familiar, and have never heard, the Abyss). We generally throw more power at "hard to drive" cans because of the impedance mismatch. The load switch *should* in theory obviate the need for more power. As always, a demo is always best. Looking forward to hearing your experience...
New McIntosh MHA200 Headphone amp
- Thread starter TSAVJason
- Start date
47 ohm with 88 db sensitivity for 1266, and 42 ohm with 91 db sensitivity for Diana V2.
I'm hoping it works out, this amp ticks every other box otherwise!
I'm not confident there is enough power here to do the 1266 justice. Someone in the Abyss thread emailed McIntosh a few months ago about the pairing and their response was "audition it and you'll see."
I used this calculator to see how much power is needed.
http://www.digizoid.com/power.php
At 500 mw the MHA200 can achieve 115 db SPL through the 1266 TC. It can get plenty loud, but I'm not seeing anyone really comment on whether it is a good pairing. I am on the wait-list and will report back. I also have a Formula S coming in soon so I can compare. My main amp is the TT2
So my LCD-2's at 70 Ohms at 101db/1mV sensitivity are so adequately driven by the MHA200 its not even remotely an issue... Seems like 42 Ohms/91db should be even easier...
ThanatosVI
Headphoneus Supremus
Actually 91db sensitivity means they need 10x more power to reach the same volume level.
The impedance difference doesn't matter in the special case of the mha200, since it can output the same power into 42 ohms as into 70 ohms
When I used to own Hugo 2 and Diana V2, it also got pretty loud (louder than I could listen to), yet, the sound was lacking dynamics, until I added an external amp, or moved to TT 2 completely. Please do report on MHA200's capability to drive AB-1266 TC. What I find strange is when manufacturers aren't clear in their messaging of what their equipment can drive, was rated / tested for. Are we suppose to blind buy in the time of pandemic to hope to sell for a loss if it does not work out? Hmmm
paradoxper
Headphoneus Supremus
Pretty loud (ear deafening, in fact) lacking dynamic is the crutch.
They will espouse the nominal math to SPL for even the most inefficient headphone.
For which, you will (rightfully) continue bitching adequate isn't quite pleasing enough.
It is arbitrary in their defense.
Shrugs.
I’ll second the idea that there’s no replacement for a good listening session…everything else is supposition. With that said, there was a time not so long ago where 500mw was considered excessive…if there is one law of high end audio, it’s that you can never have too much power…I think impedance matching changes the equation. My guess, is that we’ll see much more of this in headphoneland, when it comes to tubes, I think solid state gear isn’t subjected to these limitation, but I’m no engineer (oncologist actually). The difference is that impedence matching requires some (expensive) transformer design in the tube arena. The MHA200 did it first… let’s see who follows (and exceeds) them.
carboncopy
500+ Head-Fier
Hmmm…I think the output impedance option of the Trafomatic Audio Head 2 is similar.
True - but McIntosh did impedance matching in the 60's with their tube speaker amps...
Colonel Flac
New Head-Fier
Is that really the case? As I understand it the amp has 4 distinct impedances that have the same power output: 32, 100, 250 and 600 Ohms (Similar to McIntosh's amps where you have three sets of loudspeaker terminals with 2, 4 and 8 Ohms that have the same power). Since 42 and 70 Ohms both fall into the range of the second setting, 32-100 wouldn't power scale down over impedance just like with any other amp?
Or can you just just turn up the setting regardless and get more power?
In any case I was wondering why they chose the settings the way they did. It may be my lack of experience but I think there are very few headphones in the 600-1000 Ohms range while there's a plethora of models below 32 Ohms and technically they aren't even supported.
Can someone here explain this to me? Please?
So my understanding is that the impedance matching is done by switching between different windings on the transformers - and note, there are 3 transformers, with different windings, on the MHA200. There's even a schematic of the windings displayed on the top of each transformer (2 output transformers, one power transformer):Is that really the case? As I understand it the amp has 4 distinct impedances that have the same power output: 32, 100, 250 and 600 Ohms (Similar to McIntosh's amps where you have three sets of loudspeaker terminals with 2, 4 and 8 Ohms that have the same power). Since 42 and 70 Ohms both fall into the range of the second setting, 32-100 wouldn't power scale down over impedance just like with any other amp?
Or can you just just turn up the setting regardless and get more power?
In any case I was wondering why they chose the settings the way they did. It may be my lack of experience but I think there are very few headphones in the 600-1000 Ohms range while there's a plethora of models below 32 Ohms and technically they aren't even supported.
Can someone here explain this to me? Please?
Living with this amp, I found that the sound signature doesn't change at all if you switch the "load" switch higher, all you get is more volume (kind of like an expensive gain switch, but sonically transparent). My LCD-2f's live comfortably at either the 32 or 100 setting. I think the higher settings will probably be used less, but are probably more relevant, as 600 Ohm cans aren't going to be happy at the lower settings, while you have more flexibility with lower impedance cans (as has always been the case - you can drive Focal Clears with an iPhone, but old school Beyers or Senns...no way).
As a non-engineer, my understanding is that instead of just throwing a ton of power at higher impedance cans (kind of a brute force approach), McIntosh has chosen to finesse the issue and match the impedances, thus allowing for less power to adequately drive the cans to high SPL. But keep in mind, you're always sending 500mW to the headphone, it's just that by matching impendence you can do more with less power.
Now this may be a poor description, but let me try: Imagine a hose that is shooting out a defined, constant, volume of water (500mW). Imagine that you want to knock over a bowling pin with that water stream. Without putting your finger over the opening of the hose, the water doesn't have the "oomph" to knock over the pin. but cover half the opening with your finger, and you can use the same amount of water to knock over the bowling pin. In this example putting your finger over the hose opening is changing the output impedance of the amp, and the weight of the bowling pin is the impedance of the headphone. A plastic bowling pin (low impedance headphone) might get knocked over with the hose wide open and no finger over the hose. While a metal bowling pin (high impedance headphone) is going to need that finger over the hose.
Hoping an EE out there can give a more technical explanation.
Last edited:
ThanatosVI
Headphoneus Supremus
My knowledge is still rather limited in here, but I try to explain nonetheless.Is that really the case? As I understand it the amp has 4 distinct impedances that have the same power output: 32, 100, 250 and 600 Ohms (Similar to McIntosh's amps where you have three sets of loudspeaker terminals with 2, 4 and 8 Ohms that have the same power). Since 42 and 70 Ohms both fall into the range of the second setting, 32-100 wouldn't power scale down over impedance just like with any other amp?
Or can you just just turn up the setting regardless and get more power?
In any case I was wondering why they chose the settings the way they did. It may be my lack of experience but I think there are very few headphones in the 600-1000 Ohms range while there's a plethora of models below 32 Ohms and technically they aren't even supported.
Can someone here explain this to me? Please?
A regular solid state amp usually "drops" power with increasing load impedance.
A fictional example of
2W into 32 Ohm would only be 1 W into 64 Ohm etc.
Now McIntosh has a very unique output transformer Design which can deliver the same power into every designed load. How exactly they achieve this is unknown to me and likely a Company secret.
When you turn up the impedance setting you don't get more power, each caps at 500mW
You will likely get a higher Max voltage and less Max current flow.
I am no engineer and all of this could be wrong, however this is how I understood it.
Colonel Flac
New Head-Fier
So my understanding is that the impedance matching is done by switching between different windings on the transformers - and note, there are 3 transformers, with different windings, on the MHA200. There's even a schematic of the windings displayed on the top of each transformer (2 output transformers, one power transformer):
Living with this amp, I found that the sound signature doesn't change at all if you switch the "load" switch higher, all you get is more volume (kind of like an expensive gain switch, but sonically transparent). My LCD-2f's live comfortably at either the 32 or 100 setting. I think the higher settings will probably be used less, but are probably more relevant, as 600 Ohm cans aren't going to be happy at the lower settings, while you have more flexibility with lower impedance cans (as has always been the case - you can drive Focal Clears with an iPhone, but old school Beyers or Senns...no way).
As a non-engineer, my understanding is that instead of just throwing a ton of power at higher impedance cans (kind of a brute force approach), McIntosh has chosen to finesse the issue and match the impedances, thus allowing for less power to adequately drive the cans to high SPL. But keep in mind, you're always sending 500mW to the headphone, it's just that by matching impendence you can do more with less power.
Now this may be a poor description, but let me try: Imagine a hose that is shooting out a defined, constant, volume of water (500mW). Imagine that you want to knock over a bowling pin with that water stream. Without putting your finger over the opening of the hose, the water doesn't have the "oomph" to knock over the pin. but cover half the opening with your finger, and you can use the same amount of water to knock over the bowling pin. In this example putting your finger over the hose opening is changing the output impedance of the amp, and the weight of the bowling pin is the impedance of the headphone. A plastic bowling pin (low impedance headphone) might get knocked over with the hose wide open and no finger over the hose. While a metal bowling pin (high impedance headphone) is going to need that finger over the hose.
Hoping an EE out there can give a more technical explanation.
Thank you! I think I got a bit of a better understanding how it works. The "expensive gain switch" analogy is compelling
Though it's interesting you're saying the sound signature doesn't change at all. I could've sworn I read somewhere that you shoud experiment with the different terminals of a McIntosh speaker amp to find the best sound...Users who are viewing this thread
