Well I bought a Monoprice tube amp/dac

[Sythrix]

How is that impressive? That means I would probably get somewhere around 3000 mW output on my Argon (53 ohm) on Balanced, or 900 mW on Single-Ended

Although I think your numbers are a little low on available power at 53 ohm, it would still translate to over 120 dB in those headphones. I strongly encourage you not to listen at 120 dB for any significant period of time. 3000 mw is the absolute limit of those drivers and quite frankly, you’d be halfway deaf by the time they exploded around your ears.

 

[solderdude]

. For example, the Argon (T50RP mod) I have, supposedly sounds very nice up to 5-6 watts of power (all Planars tend to like a lot of juice).

If you were to release 5W (Peak power using music) to your Argon, in case it were acting linear at these levels which it doesn't, it would produce 129dB SPL.
With a DR20 recording you would be listening to approx 110dB average levels... Does not sound very nice.

That 'myth' is born out of headphones like the HE-6 and Ananda for instance which are very inefficient. Those are well driven from speaker amp outputs or require powerfull headphone amps.
Modern Planars can be driven to loud levels below 0.1W ! Some even sound nice directly out of a phone.

 

[Deleted member 3566]

It's a very low distortion amplifier, especially for the price. Your NFB 11.28 might output more power, but it's unlikely to be anywhere near as clean - I don't see any useful measurements in this area in Audio-GD's official specs, so it's hard to tell... but their gear generally performs pretty poorly.
.

Ok, that's fine. But based on the measurements done by amirm on here, why are people still considering amplifiers that are less powerful and have no better performance distortion-wise, than obviously better alternatives? Like, why are some people still considering some Topping amplifiers at 10 ohm with quite "weak" power output, instead of, say, the ifi iDSD BL, which has gotten excellent feedback both for its DAC and Amp?

@generalako snip .

Thx for the explanation. So what's up with people online saying you have to have 4-5 watts output at the rated ohm of the headphones, to make said headphones (in this case planars) to sound good? Getting such powerful amplifiers with low output impedance seems near-possible. Getting such powerful amplifiers for a good price seems impossible.

You are absolutely right about listening levels, however. But that's the thing; my NFB 11 managed to get T50RP to acceptable listening levels at around half-way through with high gain. But from what I've been told on various forums, and on the Headphone discord, it's not so much as listening level as it is output power overall -- which still has me confused as I have always related output power to the need to reach desired listening levels, and nothing else.

If possible, I would love an objective explanation of this.

 

[Deleted member 3566]

My set-up is btw T50RP, EMU Teak (which can be easily driven out of even my headphones), HD800/LCD2 Classic. I recently sold my NFB 11, after having some QC issues, and getting it confirmed more problem with audio-GD even further through other people. I have been looking for a replacement set of DAC and Amp (or both), for several months now. The plan is to buy one before January, but I'm still very unsure as to what to get.
Maybe I ought to wait for THX789 to be tested by ASR sometime, first, as it seems to be the closest to what I need/think I want. Maybe it's too powerful, and you guys recommend something else?

As for DAC, there seems to be a lot of good options out there. Topping seems to get a lot of good results here.

That 'myth' is born out of headphones like the HE-6 and Ananda for instance which are very inefficient. Those are well driven from speaker amp outputs or require powerfull headphone amps.
Modern Planars can be driven to loud levels below 0.1W ! Some even sound nice directly out of a phone.

Yes, but of listening levels is what we are supposed to go by, then even that's an exaggeration. I have actually tested the HE-6 on the NFB 11, and it was able to easily drive it, in terms of listening levels.

 

[solderdude]

Why people consider other amps ?
Portability, desktop or 'home stereo', minimum or maximum requirements, looks, brand, sales pitches, recommendations, functionality, in-output connections, tube/hybrid/SS, size/weight, price, price/performance ratio to name but a few.

High power amplifiers with low output impedances are abundant and cheap. Any speaker amp does this. Not recommended for sensitive headphones !!!!
Then there is the reason that people CLAIM things about SQ based on whatever floats their boat.

The quoted output power of an amplifier is a max rating. How much power one requires depends on listening level, efficiency.
The trouble is most people confuse the words 'needs power' with volume control settings and required voltage.
A high voltage (say 10V) and low current ( say 20mA) is the same 'power' as 1V with 200mA of current.
In case 1 the volume control needs to be set higher as in case 2 yet the same 'power' is drawn by the headphone.

An amplifier is a VOLTAGE source with a finite (maximum) output voltage and is CURRENT limited. Voltage X Current = Power
A headphone needs a voltage and at a certain voltage a headphone draws current depending on the impedance of the headphone.
A headphone thus draws current depending on applied voltage and impedance.
The amplifier needs to be able to supply enough voltage (to avoid clipping) and enough current.

When a current limit is reached there can't be a higher voltage so no higher SPL either.
When a voltage limit is reached there can't be a higher current so no higher SPL either.

The impedance plays a role here. Higher impedance headphones require a higher voltage (higher vol. control position) and draw less current.
Lower impedance headphones require less voltage (lower vol. control position) but draw more current.

You have different impedance headphones and some are inefficient ? You need an amp that can deliver a high voltage (higher Wattage in 300 Ohm) and one that can deliver enough current (higher wattage in 16 Ohm).

You only have high impedance headphones ? You only need enough voltage. Only have low impedance headphones you need more current.
Because of this some amplifiers are better suited for specific headphone(s)

A higher power amplifier does NOT deliver more power nor can it drive headphones 'better' or different from a lower power amplifier as long as the both amplifiers can reach the same output voltage under the same load and other conditions.
The higher power amplifier can play louder. So when one turns up the volume the low power amplifier may 'clip' short peaks where the higher power one doesn't.
A peak that is clipped doesn't need to sound like clipping/distortion (depends on circumstances) but can sound 'compressed' or 'less dynamic' when the clipping is not too severe. That's where the 'needs power' comes from.

Most planars have 'flat' bass response. Due to the way our hearing works planars will sound 'fuller' and more powerfull in the bass at higher levels compared to headphones with boosted bass. People liking 'bass' thus turn up the power with these headphones. To ensure clipping does not occur you need a lot of power. As SOME planars are notoriously inefficient this is where the 'opinion' comes from. Planars usually continue to sound 'good' at higher SPL's and so people turn them up louder than 'normal' phones (your HD800 is closer to planar than dynamic in this aspect)
Usually this talk comes from the 'more subjective' people that have no real clue how headphones and amplifiers work.

 

[Deleted member 3566]

A higher power amplifier does NOT deliver more power nor can it drive headphones 'better' or different from a lower power amplifier as long as the both amplifiers can reach the same output voltage under the same load and other conditions.
The higher power amplifier can play louder. So when one turns up the volume the low power amplifier may 'clip' short peaks where the higher power one doesn't.
A peak that is clipped doesn't need to sound like clipping/distortion (depends on circumstances) but can sound 'compressed' or 'less dynamic' when the clipping is not too severe. That's where the 'needs power' comes from.

Isn't that an argument for higher power amplifiers then -- confirming that there is some basis to the "myth" we are discussing? Like wanting something really powerful to couple with my T50RP and LC2 Classic. Or would something like the ifi iDSD BL be sufficient? After all, the latter also has fairly low output impedance, and would work better with lower impedance headphones as well.

 

[solderdude]

Isn't that an argument for higher power amplifiers then -- confirming that there is some basis to the "myth" we are discussing? Like wanting something really powerful to couple with my T50RP and LC2 Classic. Or would something like the ifi iDSD BL be sufficient? After all, the latter also has fairly low output impedance, and would work better with lower impedance headphones as well.

The output resistance isn't of any importance for the T50RP nor the LCD2C. Well... aside from the slight loss of max output power.

And no... this isn't an argument for the LCD2C (112 dB/1V) and T50RP (105dB/V).
Because of your ears ... bleeding and such.
The LCD2C = 70 Ohm let's assume 125dB SPL peak is what you want (105dB average is what you cannot listen to for long)
For this you need 4.5V = 0.3W @ 70 Ohm to give you a nasty headache after a few minutes.
The T50RP = 50 Ohm let's assume 125dB SPL peak is what you want (105dB average is what you cannot listen to for long)
For this you need 10V = 2W @ 50 Ohm to give you a nasty headache after a few minutes.

Assuming you want to keep it civilised and don't want to make your ears bleed but still play VERY loud you can get by with 1/10th of the power.
So LCD2C = 30mW and T50RP = 0.2W .... 115dB peaks is already VERY VERY loud.
No need for 5W with the LCD2C at all... 138dB SPL is not something you need.

When using an Ananda, HE5, HE6 or K1000 a high output power makes sense.

SPL is what it is all about.

There isn't something 'magical' about 0.1W from a 5W amplifier or a 0.5W amplifier.
At 0.1W both amps supply exactly the same output voltage, exactly the same waveform and exactly the same current is drawn.
Both amps are well below their max output voltage and current.

So.. what would be different when driving headphones equally loud from 2 different watttage amps when all other aspects (frequency response well below and above the audible limits and dist < 0.01%) remain the same ?
The only difference is the 'feeling' one has knowing there is enough 'juice. But in this case, both do it's just the mind that thinks otherwise and shifts some 'enjoyment' gears in the brain.

 

[Deleted member 3566]

SPL is what it is all about.

So if something as tiny and portable as Fiio E10K/E17 or Dragonfly Red/Black can drive the HD800 at sufficient levels, which they can from my own experience, then amplifiers with any more power is by definition excessive? By those definitions even the people on this forum have DAC/Amps that are way, way more powerful than they really need or ever will need to be. You mention HE-6, for example; I have yet to see anybody with that headphone that doesn't already have an amplifier for it that isn't way, way, way over-dimensioned for it. Many times I've seen people comment how certain DAC/Amps that are actually more than sufficient to drive it at ear-bleeding volume levels, say it isn't good enough to drive it; hell, even the ifi iDSD BL kan drive the He-6 more than good enough.

 

[solderdude]

Many times I've seen people comment how certain DAC/Amps that are actually more than sufficient to drive it at ear-bleeding volume levels, say it isn't good enough to drive it; hell, even the ifi iDSD BL kan drive the He-6 more than good enough.

Everybody is free to drive their headphones anyway they want to. Over-powered, under-powered it does not matter.
Everyone can 'claim' some super synergy with amp A and say B is incapable.
Those that find the dragon fly red good enough for their HD800 should use it.

Yes, when you can power your headphones from low powered devices to high levels in a satisfactory way you simply don't need more and connecting it to a high powered amp is excessive and not really needed.

Also yes, there are lots of people (also on this forum incl. me) with heavily over-powered amps. Nothing wrong with having some headroom.
It is overpowered so I can drive all headphones I own and will ever buy with it without having to ask the question whether the amp can handle it.
I don't have the illusion though that if I had even more power it would sound 'better' in some way.
Am also perfectly happy to drive headphones from my DAP when they are suited for this.


My question to you is WHAT would make a high powered amp sound 'better' when driven well below their maximum rating compared to a lower power amp also driven below their maximum rating ? (Merely someone 'saying/claiming' it does is not the correct answer)

Is the 'quality' of the output voltage/current 'higher' in some way yet cannot be measured/shown but can be heard ?

When the electrical applied waveform is exactly the same from 2 different (power) amps will they not sound the same ?

When I use 2 of the same amps that only differ in max output voltage/current but are otherwise exactly the same and are set to the same output level (which both can reach) will the higher power version sound 'better' somehow and why would that be ?

 

[cjfrbw]

I am not really certain what drives the high power obsession in general. I think there is a meme that ultra-micro transients can be higher than 120db for brief instances, thus, an amplifier would need to be able to ascend these tiny peaks instantly and with no effort. Of course, the meme implies that these micro transients are audible.

I do not believe this, so don't shoot the messenger. It makes good ad copy and reviewer grist, however. "Listen to those perfectly rendered micro-transients and microdynamics!"

I personally just think that guys like big, hot, shiny boxes that require a team of Tongans to lug around in front of them in their audio shrines.

 

[solderdude]

People believe the strangest things.

I even believe Rod likes the Monoprice amp he bought a while ago.
He may well be right, but do think he needs something with a bit more power.

 

[Deleted member 3566]

My question to you is WHAT would make a high powered amp sound 'better' when driven well below their maximum rating compared to a lower power amp also driven below their maximum rating ? (Merely someone 'saying/claiming' it does is not the correct answer)

Oh, no, I believe you 100%. I might come off a bit argumentative, but as mentioned I'm fairly uneducated here (and basing a lot of my stupid questions on various claims and accepted truths in the audiophile segment), and I'm just interested in learning more. There's no doubt that I'm pretty frustrated in the audiophile community, because of all the subjective nonsense that is valued, even despite various objective truths. For a political scientist who strongly adheres to the truism of empirical falsification, i view the audiophile community as a whole very similiar to a religious sect, in that sense (like postmodernism turned up to 11).

The whole Schiit-SBAF-Head-Fi-ASR debace, is a great example of this. Reading through some of the justifications on various threads on SBAF, for example, is so embarrassing, it's hard to go through. The absolute disgust and loathing people have showed to objective science is really worrisome -- I've rarely seen anything quite like it.

We'll see what I end up buying, in the end. Preferably, I can buy a DAC/Amp combo -- this time one that I can buy forever, down the road. For portable use, the 3.5mm adapter of my Pixel 2 XL runs my Campfire Andromedas just fine (although I would be really interested in seeing amirm test it), so I've got that covered. Right now, the DX3Pro looks interesting.

 

[solderdude]

i view the audiophile community as a whole very similiar to a religious sect, in that sense (like postmodernism turned up to 11).

The whole Schiit-SBAF-Head-Fi-ASR debacle, is a great example of this. Reading through some of the justifications on various threads on SBAF, for example, is so embarrassing, it's hard to go through. The absolute disgust and loathing people have showed to objective science is really worrisome -- I've rarely seen anything quite like it.

I fully agree here. As with everything in life there are some rotten apples in every basket as well as some really fine ones.
One of the finer apples pointed me to the fact that there seems to be more interest in drama on most forums than in the exact workings of audio.

We'll see what I end up buying...Right now, the DX3Pro looks interesting.

That one seems future proof and good enough spec. wise.
As with everything there will be people loving it and others hating it (for whatever reason) and telling people it does not cut the mustard and brand X or Z is 'better'.
What about the Monoprice ? well... maybe the esthetics are an acquired taste.

 

[Rod]

I am running into one issue with this amp. I acquired a pair of Massdrop 6xx headphones at 300 ohm which is the only high impedence headphones I have so this issue didn't exhibit during my first few weeks of ownership of the Monolith. With low impedance headphones(for example 80 ohm dt-770's)with the impedance switch set at 65-150 ohm, I hear no hum. Might be there but I cant hear it. But when I connect the 300 ohm 6xx with the impedence switch set to 300 ohm I do hear hum. If I move the impedance switch back to the 33-64 ohm setting the volume decreases but so does the hum until I can't hear it anymore. Not a big deal, I just turn it up some with the switch set to 33-64 ohm or better yet, just listen to low impedance headphones with it. Every tube amp I have had in this house hums but this is the best I have had for not having it, even if it means changing the impedance switch. I dont know if its the house wiring or just tube amps, but I can at least get rid of the hum with this amp, which I couldn't do with the others I have had.
Wish these tube amps didn't hum at all of course, and someone else may not have the same issue at all. I wont know unless I take it to another location and plug it in.

 

[raindance]

Running a tube amp 24 hours a day is just silly. You'll wear out the tubes fast and you're causing a potential fire hazard. Have you confirmed that it's designed for USA 120 volt mains voltage and not 110 volts which is half the Chinese market 220 volts? Does it have the necessary certifications to not nullify your home insurance?

It's quite unusual to see those power tubes used with an output transformer; they're one of the better OTL amp tubes.

The older Cayin headphone amp used EL84 tubes with a transformer coupled output. It hummed because they didn't create a mid point ground to balance heater currents; I used to modify them to correct that issue. They were lazy and just grounded one side of the heater supply.

 

[Boris Badinov]

View attachment 15360

After a while if anyone is shows interest and if Amir wants to measure it I will send it to him. But give me a few weeks/month to enjoy it(or not).

Love this pic!

 

[lashto]

Planners(He-440i) sound lifeless. Not for them. The dt-770 80 ohm gets a little louder each click(2 of them) from 16-32 ohm to the 65-150 ohm settings. 32 Ohm Nad HP-50 I cant tell any difference in any of the settings.

He-440i and most planars won't sound good on (almost) any tube amp. Those are all low impedance cans (32ohm for 440i IIRC) and tube amps usually have high output impedance. The worst combo. On my Darkvoice 336 the he-440i sound exactly as you described: lifeless.

An excellent HP for tubes would be Sennheiser 650/6xx. They sound so good and clear on tube amps, I checked the cables twice when I first tried the Darkvoice. The Senns sound better and more enjoyable on that "distortion monster" amp than on any other amp I tried.

You can try a cheap impedance adapter. Even so, the he-400i won't sound as good as the Senns on tubes but at least it won't be so "lifeless"

Edit: Oh, I see you have the 6xx. What about the measurements through Amir?

 

[CADCAM]

Anything ever come on measuring this amp? Just too heavy to ship?