[Menisk]

Quote:

Originally Posted by CrackBerry9000 /img/forum/go_quote.gif Huh?

HD600s out of an iPod sounds better than iBuds out of a B22.

 

[Eagle_Driver]

Quote:

Originally Posted by CrackBerry9000 /img/forum/go_quote.gif Huh?

The first paragraph is based on my very own experience, while the second and third paragraphs put together show just how easy any headphone system at any price can produce poor sound quality (or put it this way, the sound quality is limited by its weakest link).

 

[AcousticDreams]

Quote:

Originally Posted by Eagle_Driver /img/forum/go_quote.gif The first paragraph is based on my very own experience, while the second and third paragraphs put together show just how easy any headphone system at any price can produce poor sound quality (or put it this way, the sound quality is limited by its weakest link).

I think the most people suffers under the "High-End" syndrome and the inability to build a electro-acoustically full compatible and healthy system. It is hard for them to recognise the weakest link, which is very often a insufficiently documented product. The good old method of trial and error becomes here very expensive. Simply too many factors are to be considered.

 

[Shike]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Justin, the Millett Hybrid is a fun little amp. I built one a few years ago and I like them. Like Boomana pointed out, amplification is not about power. If we want to go with a car analogy, a 500HP car might sound impressive. But if it has cable-operated brakes and not much suspension, it isn't going to be much fun to drive. An amp is also the equivalent of the brakes and suspension of a car. Personally, I'm into handling. My last car was a dead stock RX-7. Its braking and handling let me demolish cars with much more horsepower. The current car is a stock tC with TRD suspension. Again, the brakes and handling let me outrun a SUV with twice the horsepower. Part of the problem is that people really do not understand what amps do. An even bigger problem is that people make no effort to understand what an amp does. They buy on hype and word of mouth without understanding what they bought. Finesse has a much bigger role to play than simply the power output. One amp I'm building (when I am not stuck in the office as I am today) is a fairly low powered item with 417A tubes. However, it has a slick, smooth power supply and wonderful Lundahl output transformers. The power supply is tube rectified and has three chokes to ensure smooth, ripple-free DC to the circuit. In addition to the tubes and output transformers, it only has one cap and one resistor in the amp circuit. I'm putting in a stepped attenuator, as well. The parts for this amp ran just about $1,100, not including the case. It'll probably be $1,500 total when complete. If I bought large quantities of parts, I might be able to get costs down to $1,200 or so. It is not cheap to build a quality amplifier. I don't know of any other way to get a power supply this good for less - otherwise, I would have spent less. If you factor in labor, tools, overhead, taxes, and every other business cost, it would be tough to make a profit on an amp like this for less than maybe $3,000. Performance aside, you also have to look at reliability and build quality. Sure, you can find some cheaper transformers, but how much will you save if the insulation on the coils melts and you have to replace it? Not all iron is created equal and you might very well have a reliability issue if you shave dollars. I also believe in solid construction. I spend a lot of time digging out individual terminal points out of a electronics store. For those, you have to drill a hole then mount the point. They're individual points, so you need two to mount a resistor. Some might call this overkill. However, if a capacitor goes bad, I can have it out and replaced in 10 or 15 minutes. If you use a PCB, that can take considerably longer and might not even be possible if the PCB scorches and destroys some traces. Then, you'd be stuck with either replacing the PCB or performing heavy surgery that will take hours and hours. Anyhow, if you want something that performs well and is long-term reliable, you have to put time and money into it. There aren't any shortcuts. Someone might be happy with cheap parts, cheap construction and marginal performance, but that is not an excuse to disregard what is good. I just don't think many people here understand what it takes to have a good amp. If they did, we wouldn'thave these kinds of arguments.

I'm fairly curious Erik, could you post a BOM of said amp you're building?

 

[CrackBerry9000]

I enjoy my PX100II and IE6 plugged into my Blackberry. What Audio Technica cheapo's do you like?

 

[swaffleman]

Quote:

Originally Posted by CrackBerry9000 /img/forum/go_quote.gif I enjoy my PX100II and IE6 plugged into my Blackberry. What Audio Technica cheapo's do you like?

The Audio Technica ATH T22s are great. You can get em for like $35.

 

[aimlink]

Those PX100II's seem like serious bang for the buck. I may well be getting one of those for portable use!

 

[CrackBerry9000]

Quote:

Originally Posted by aimlink /img/forum/go_quote.gif Those PX100II's seem like serious bang for the buck. I may well be getting one of those for portable use!

I can't recommend them enough. They are 3 times cheaper than the IE6 senns I bought and sound better to me.

 

[regal]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Personally, I'm into handling. My last car was a dead stock RX-7. Its braking and handling let me demolish cars with much more horsepower. The current car is a stock tC with TRD suspension. Again, the brakes and handling let me outrun a SUV with twice the horsepower. Part of the problem is that people really do not understand what amps do. An even bigger problem is that people make no effort to understand what an amp does. They buy on hype and word of mouth without understanding what they bought. .

Great post UE, except I bought a Yaris added the TRD suspension and it will run circles around the tC

I thought about building an amp like yours but I am also hung up on elagant design here:ecp.ccJust seems that this amp would better a ZDT or BA.

 

[erikzen]

If you want good sound, you have to be willing to invest a little. A little research, a little time listening (hopefully auditioning) and a little money.

I've been playing the headphone game here for quite a few years now. I joined Head-Fi looking for a decent pair of portable headphones and stuck around. My headpone knowledge has grown tremendously and with it my tastes and of course my gear.

My approach is to build slowly, making changes over long periods of time. I've been partially constrained by budget. I think more people should think about budget and bang for your buck. Some people in Head-Fi seem to be very casual about money. People post budget limits and then end up buying something several hundred dollars more, often times encouraged by other members.

If you have the money and that's what you want to spend it on that's fine, but it's not the only way and may not be the most practical way.

However, I think you learn more if you move up the ladder slowly. You learn what sounds good and what doesn't. What you like and don't like. This helps you make better decisions and as such you spend more efficiently. I've progressed from an Airhead, to various portable amps, transportable amps and desktop amps, headphones, sources. I'm at the point now where my rig costs me about $2000, maybe a little less. Now $2000 is not chicken feed, but it's also not an astronomical amount, especially in this neighborhood.

I've heard plenty of high end headphone rigs and I can honestly say that I am completely satisfied with what I have now. Sure I'll probably upgrade a component at some point, but I have heard what the really high end rigs sound like. My rig is not that far off and is certainly very enjoyable for me, night in and night out.

The point is, you do have to spend some money and time, to make sure all the components work well together. You can't get away cheap if you want good sound. But you don't have to go for broke either.

 

[aimlink]

Quote:

Originally Posted by erikzen /img/forum/go_quote.gif I've heard plenty of high end headphone rigs and I can honestly say that I am completely satisfied with what I have now. Sure I'll probably upgrade a component at some point, but I have heard what the really high end rigs sound like. My rig is not that far off and is certainly very enjoyable for me, night in and night out. The point is, you do have to spend some money and time, to make sure all the components work well together. You can't get away cheap if you want good sound. But you don't have to go for broke either.

Very liberating position to be in.

 

[Stooge]

Just read through the entire thread and I too would like to know if this questioned can be answered (post 167):
Quote:

Originally Posted by tvrboy /img/forum/go_quote.gif OK then, where is this information? Seriously, tell me how to find it and I will be very happy. Tell me where to find an output impedance curve for, say, the Gilmore Lite and Grace M902. I couldn't find it on their websites.

^This question was asked in response to (post 160):
Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif I disagree. There are technical specs that will tell you if an amp is a good match to headphones. You have to look at the power output, impedance match and the output impedance curve. The problem is that very few understand these things and a lot more make zero effort to understand them. There is a tendency to throw hands in the air, believe a load of nonsense about impedance and demand an amp that costs less than the headphones.

The response that I think came closest to answering the question is tomb's explanation regarding sound card amp capabilities (post 354):
Quote:

Originally Posted by tomb /img/forum/go_quote.gif Now, if we look at the HD580/HD600, it has an efficiency of 97dB at 1mW, along with a maximum sound pressure capability of 116dB (HeadWize - Technical Paper: Understanding Headphone Power Requirements by Dennis Bohn). If we're talking about peaks - not just steady-state listening levels, and the difference between listening levels and peaks are part of what define "high-fidelity", then we'd want an amplifier with the capability to utilize that peak in the Sennheiser headphone of 116dB. The reference above seems to indicate that falls just between an orchestral climax and a live rock concert, so it's not really a stretch to want to have that 116dB available - for peaks. Just figuring for those values, using Ohm's Law and the Power relationship, we have P = (V^2)/R. Or, to find the voltage needed, V = SQRT(P x R). We start with 97dB and 1mW. Every 3dB increase is going to double the needed power. So, 100dB needs 2mW, 103dB needs 4mW, 106dB needs 8mW and 109dB needs 16mW. Let's just stop there - barely perceived above the volume level of an orchestral climax. (Note that it may still not be as great a level as a single cymbal crash transient.) The voltage needed at 109dB is SQRT(0.016 x 300), or 2.19V. Since music is reproduced in alternating voltages (sine wave), the complete voltage swing needed is +or- 2.19, or 4.38V. Note that the typical power supply for a PC is only 5V, assuming no losses. Every opamp needs a base-loaded voltage, so the sound card will probably need at least 1 or 2 volts more than the 4.38V, so the sound card's ability is already impacted. However, if we want to utilize near full capability of the headphone, we need 64mW at 115dB! Using the equations again, that results in +or- 4.38V, or a total swing of 8.76V! This is physically impossible for a sound card to provide! (A CMoy can easily manage it if using 2 x 9V batteries, though.) An amplifier must be able to supply this voltage, even for split-second, transient peaks or clipping/distortion and accompanying degradation in sound quality will occur.

Can the formula described in tomb's post be used to determine if an amp will be suitable for a given headphone? Using Sennheiser's HD 650s as an example, boomana mentioned (post 27):
Quote:

Originally Posted by boomana /img/forum/go_quote.gif Some folks think that portable amps can drive the 650s well. That is 100% false, though they can sure make them loud, and some folks will enjoy the sound.

What are you looking for in an amp that determines whether is can drive HD 650s properly? I understand that higher impedance headphones require greater voltage swing, but what amp measurements do you use to determine an amps voltage swing (or any other requirement that an HD 650 would need to be driven properly)? Can someone provide an example of an amp with measurements that are obviously not suitable (portable amp?), as well as an amp with measurements that are? Can you break down the reasoning the way tomb did?

Post 150 asks the same questions (with a Beyer DT880 600Ohm as an example), so if the way I phrased things is unclear please refer to it as well.

 

[Shike]

Quote:

Originally Posted by Stooge /img/forum/go_quote.gif What are you looking for in an amp that determines if it can drive HD 650s? I understand that higher impedance headphones require greater voltage swing, but what amp measurements do you use to determine an amps voltage swing (or any other requirement that an HD 650 would need to be driven properly)? Can someone provide an example of an amp with measurements that are obviously not suitable (portable amp?), as well as an amp with measurements that are? Can you break down the reasoning the way tomb did?

An example of a portable amp that wouldn't work well for HD650s would be the AMB Mini^3. The highest impedance it can do before the measurements go to heck is 300ohms.

On the other hand, most decent quality desktop amps are able to swing enough voltage. For example, my x-head can output 5W into 600ohms and 2.5W into 32. Needless to say that's enough power to reproduce without clipping.

There's other considerations though such as SNR, Frequency Response, THD+N, and IMD. Then you have the constant debate of whether output impedance impacts headphones like it does speakers (I'd say to a limited extent).

 

[Stooge]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif An example of a portable amp that wouldn't work well for HD650s would be the AMB Mini^3. The highest impedance it can do before the measurements go to heck is 300ohms. On the other hand, most decent quality desktop amps are able to swing enough voltage. For example, my x-head can output 5W into 600ohms and 2.5W into 32. Needless to say that's enough power to reproduce without clipping. There's other considerations though such as SNR, Frequency Response, THD+N, and IMD. Then you have the constant debate of whether output impedance impacts headphones like it does speakers (I'd say to a limited extent).

Can you clarify why the AMB Mini^3 is unsuitable for HD 650s? How can you calculate what impedance an amp can handle? In your x-head example can you provide a breakdown like tomb's example that would show the amps ability to provide adequate voltage swing (assuming the specs for this are available for this amp) for headphones such as the HD 650s?

All I'm looking for is a foundation so that I can determine when an amp is obviously inappropriate for a given headphone. Thanks for your response.

 

[MomijiTMO]

You're gonna run into HUGE problems if you follow that route. There are many amps people say work well with a dt880 250ohm [for an example] that I don't think have a chance in hell of driving them. Let's just say that the more you spend, the weirder things get.