New Headphone Amplifier Design

donovas

Member
2014-06-22 6:45 am
Have a Neurochrome HP-1 here, which IIRC uses LME49600 output buffers. Compared it to an original Pass HPA-1, a modified HPA-1, and an unnamed HPA proto. The HP-1 is kind of interesting in that it has a 3-position gain switch which appears to change negative feedback (judging by how the sound changes with switch position). Guess which HPAs are most and least preferred for listening?
So what is your preferred hpa?
 
Dreamth,

For someone who has not heard the HPA-1 you are way to quick to pass judgement. Distortion in not the final arbiter on sound quality far from it . I have replaced the output stage of the HPA-1 type amplifier with a LME49600 and no cigar.

Please do the experiment yourself. Let't say try a pair of headphones like an Audze 3 or Hi-Man HE-6 and you will see what I mean. The LME49600 has VI limiting built in, most high end desiegners of note would use this type of limiting because they generally trigger too early into certain loads. I suggest you try the experiment and unfortunately if you can't afford the headphones (or borrow) a pair I cant't help you. If the LME49600 was that great I would have used it.
This is the last I want to discuss the subject till you try the experiment.

I applaud Henry because is doing the experiment it is all too easy to be an armchair quarterback.

Regards,
Jam
 
So what is your preferred hpa?

Unnamed proto.

Neurochrome HP-1 tied for last place. (not to say its bad or anything, but the competition was very strong)

Just my personal listening preferences, others would likely disagree on whether last place was really a tie.

Also of possible interest I have a Neurochrome HP-2, which measures even better than their HP-1. Sounds worse to me...a bit time-smeared. Never use that one.

Since I had to return the Pass HPA-1 that was here on loan, the Neurochrome HP-1 is my backup HPA. Depending on the gain switch setting one can get different sounds out of it, which I sometimes like to do.
 
Please see block diagram below. The arrow over the OPA1612 shows where the gain switch operates. Regardless of where its gain is switched, there is an audible difference in SQ.
 

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dreamth

Member
2010-11-18 9:12 am
Dreamth,

For someone who has not heard the HPA-1 you are way to quick to pass judgement. Distortion in not the final arbiter on sound quality far from it . I have replaced the output stage of the HPA-1 type amplifier with a LME49600 and no cigar.

Please do the experiment yourself. Let't say try a pair of headphones like an Audze 3 or Hi-Man HE-6 and you will see what I mean. The LME49600 has VI limiting built in, most high end desiegners of note would use this type of limiting because they generally trigger too early into certain loads. I suggest you try the experiment and unfortunately if you can't afford the headphones (or borrow) a pair I cant't help you. If the LME49600 was that great I would have used it.
This is the last I want to discuss the subject till you try the experiment.

I applaud Henry because is doing the experiment it is all too easy to be an armchair quarterback.

Regards,
Jam
Why would i spend 5...10 Watts on a single channel of a 1300 bucks pair of headphones with 83 db spl when i could build some really decent horns with fairly high quality coaxial speakers and have a much better experience for the same money? I listened to almost all the best headphones in the world, but honestly and objectively there's not a single pair of headphones complete setup including the amplifier who could deserve more than 500 bucks.Yes , if i'd be the manufacturer of such products i would ask for the same shameless money just because i could and because there are always people like you, but other than that you can diy or even buy some of the best speakers in the world for the money some people pay on headphones or their amplifiers alone.And i do have a design for 5000 bucks electrostatic headphones amplifier under my belt yet i wasn't even interested in having a pair of those headphones...although i could have them for nothing at the time.I didn't like nor believed in that concept which didn't really work the way the people beleved it will and i was right.Yet i did listen for a week to Meze empyrean being completely pleased with the results as it works on any amplifier from a 5v supplied soundcard very well, but 3000 bucks a pair...sorry...i can make my own 20 watts electrostatic speakers from scratch with that kind of money.
 
dreamth,

If you do not see the value in higher priced equipment (or varients of) fine, some people here do, so I suggest you find some find some other forum to cater to your needs and do not try to impose your ideas or thoughts on the rest of us.

I asked you to try an experiment but you seem to want to change the subjuct to a personal rant that has nothing to do with the engineering question at hand........the use of a LME49600 with difficult loads. I don't really don't care on what you can build unless it is a contrubition to the spirit of this thread.

If your $200.00 headphones are all you need , I am happy for you but I don't want to listen to your infantile diatribe about your personal feelings about audio in general that is not what this thread is about.

Regards,
Jam
 
I can make my own 20 watts electrostatic speakers from scratch with that kind of money.

The two questions are, 1) Is the HPA-1 a superior amplifier, and, 2) Is it worth the price?

The first question can't be answered because it depends on unknowable, personal, subjective experiences by individual listeners. I take subjective reports at face value because I believe most people are sincere. That doesn't mean I accept the claims as facts, but I don't dismiss them out of hand, either. I'm building this amp to find out for myself what it's all about.

On the second question, nobody "needs" a $3500 headphone amplifier. You could even argue (elsewhere, please) that products like this are symptomatic of a broken capitalist system. I don't want to go there. It costs a lot of money to make and sell a low-volume consumer electronics product, and this is clearly targeted and priced for the luxury goods market (https://en.wikipedia.org/wiki/Veblen_good). Make of it what you will; I didn't start this thread to have that argument.

Congratulations on designing and building a simple, low-cost, efficient amplifier that meets your needs superbly. If you can find a way to build and sell thousands of them cheaply, and stay in business, you can start your own successful audio company. Or maybe just get a build thread going and spawn the next viral forum project.

This is going to sound obnoxious -- it is obnoxious, and I apologize -- but in a true sense, I am selling a service here: cheap entertainment for forum readers. I'm grateful that the thread has gotten some traction; evidently one or two people value what I have to say enough to invest the time to follow it. You have a thread for your unique amplifier design, and some firmly-held beliefs you want to share. This thread is probably not the best venue for promoting your ideas. My advice for you, and I don't mean this in a mean-spirited way, is figure out who the audience is you want to reach, then go in your thread, start writing, and see who shows up.
 

dreamth

Member
2010-11-18 9:12 am
I didn't realize we are in the commercial section of this forum...
It looks like the absolute opposite project to yours is not mine, but JRC's.
It's called NJM2100 and it costs around 0.5 euros.
0.005% thd up to 20khz at 1.5v output on 4kohm loads(enough to drive any buffer) with +-3v supply, 4v/us slew rate and it works even with +-1v supply rails with +-1.5v max input...
If you don't like the slew rate, lm6172 can do 750v/us at 2.5v into 100 ohms with +-5v supply...
I wish you success with Audeze and Hifiman usual Rolex watches clients, but i don't see many of them daily and those who eventually do buy it aren't into diy products simply because they didn't make their own fortunes...there were others making the money for them ;).
I have the slight feeling that your buddy didn't even touch a hifiman he6 or any audeze headphones , but i won't dive here into this.
Being expert in the rarest things you never saw, heard and touch other than with google search instruments is the cheapest experience you can have.
 

dreamth

Member
2010-11-18 9:12 am
I don't want this to turn ugly. I am grateful to be relatively well-off financially and mindful that many people are not. That said, I'm done with the topic dreamth has brought up.
Nobody wanted anything to turn ugly.
If you are a good designer you know what low voltage operation means and you can easily adjust your design to any specification.My only personal remark was about the power supply .A good op amp can operate very well from very low to its highest supply voltages .Your design is basically a discrete op-amp that is why i dared making suggestions...
If you are not interested in making your design more versatile that's fine for me...
 
Well Meze Empyrean is made in your country, but only one guy from the entire country bought it ...and I KNOW that's not you ;)
My country is also your country.
And I don't think only one man in Romania bought those headphones. You are completely unreal and it is irrelevant if I or someone else, apart from that one person, can afford to buy.
Nobody asked you to make fun of yourself, but I see you're an expert on that. Keep it like this.
Disappear in the fog, please.
:ROFLMAO: :ROFLMAO: :ROFLMAO: :ROFLMAO: