Do you have money to burn? As if you don't understand what meaningless means. You want to commision me to do useless stuff, you pay me to waste my time for you. I accept payment through paypal, send a PM. I guarantee you can also hear a difference. I live next door to a cafe playing music all day long, you can enjoy that as a background or occasional sound of passing cars and motorcycle.
It sure didn't affect your listening test so what's the problem?
No problem, send the PM. I'll give you extra special fee if you PM soon.
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Agree so far, kinda.
Not necessarily. There are examples of preexisting bias by peer reviewers in a field, which results in multiple faulty publications. Even happens in physics, which is normally of more reliable quality than research involving humans.
For example, please see: Jeng M (2006). "A selected history of expectation bias in physics". American Journal of Physics. 74 (7): 578–583.
https://arxiv.org/pdf/physics/0508199.pdf
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Fair request, IMHO. Have tried to do just that myself, but don't know if any success. It takes some practice to get good.
However, some audio designers are acknowledged as having exceptionally good ears for sound quality. Jam is one such person at least in the opinions of a couple of well-known designers:
https://www.diyaudio.com/forums/the...wtorch-preamplifier-iii-2955.html#post5940373 ...and the post that follows.
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Regarding my own efforts to teach/coach there is a post by me on how to listen, it is #48 in this thread: https://www.diyaudio.com/forums/dig...proving-ak4490-thd-figures-5.html#post5666915
Also, the preliminary part on cymbals is in post #3020 of another thread: https://www.diyaudio.com/forums/vendor-s-bazaar/294940-fifo-buffer-rpi-sbcs-302.html#post5669890
Of course, it is much easier to coach people in a one-on-one situation where test systems exists that can be used for listening comparisons. When I listen critically and or when I coach people in person I use ultra-low distortion dacs, headphone amps, power amps, headphones, speakers, etc. In such an environment it is pretty easy to learn how to listen since the effects of most any added distortion is easily audible. In lesser systems a small bit of added distortion can be masked by the much larger distortion and noise in the existing reproduction system. Its still possible to learn under those conditions, but its harder and usually takes people longer to reach some level of proficiency.
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Now it's no problem doing ABX in your own place where you did your $15 LM1875 amp listening test so there's no need for funds to be paid. Great, lets see the ABX report.No problem, send the PM. I'll give you extra special fee if you PM soon.
What is your background in sound reproduction technology?
For my esteemed prospect customer I can always give a free and useful one. But I need payment if he wants a useless one.
What several amps are they?For my esteemed prospect customer I can always give a free and useful one. But I need payment if he wants a useless one.
Your Excellency, I did the test because it was useful for me, never advertise that it is of any use for you. Furthermore, I am currently not in a position to provide services for freeloaders and slave drivers. Judging from your fine and esoteric understanding on the matter, it is highly unlikely for me to give satisfaction to Your Excellency in a lowly public forum such as Diyaudio. Kindly notify your finance minister to send me a PM for further services that fancy Your Excellency.
I asked about what amps are tested. I know you don't want to disclose the results but at least you can disclose which amp models were tested, especially when the test is claimed to have been done already.Furthermore, I am currently not in a position to provide services for freeloaders and slave drivers. Judging from your fine and esoteric understanding on the matter, it is highly unlikely for me to give satisfaction to Your Excellency in a lowly public forum such as Diyaudio. Kindly notify your finance minister to send me a PM for further services that fancy Your Excellency.
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Your Royal Highness, it had come to my attention that you wish for an ABX result useless to both of us. The test result I provided was useful for me so it has no merit in your esteemed requirement. Therefore further information on it is worthless for you unless you are a freeloader which I do not provide service for. Kindly provide proof that Your Royal Highness has genuine interest for lowly me to provide service for and are not a freeloader
You are requesting a payment for test results which the test method details are mystery. Yeah, right. Perhaps you click on "send" upon reading an email from Nigerian Prince claiming that there is a gift waiting for you and all you need to do is give your bank account number.
You have a slight misconception about the procedure of the test Your Royal Highness. Both the recording process and ABX test will be recorded on video. Your humble servant guarantee that the result of the ABX test will be both flawless and utterly useless for any purpose for both of us at the same time to satisfy the requirement that Your Royal Highness has decreed. As usually done for International Aribitrage involving Royalty, Your Royal Highness may consider the services of 3 (three) or more witnesses to monitor the process. As per understanding of your humble servant, several large lawyer firm recognized internationally like Lloyd's do provide such services for select individual with coverage on select region in Indonesia. Your humble servant will coordinate the schedule of the test with witnesses appointed by Your Royal Highness to guarantee a smooth process, robust, scientific and objective test result.
On the financial side, Your Royal Highness also has no ground to worry. There is never a need to provide an account number. Simply send money to pay for a service (to produce one flawless and useless ABX result) to your humble servant's Paypal account. It will be fully refunded should your humble servant fail to deliver the agreed upon ABX test result.
On the financial side, Your Royal Highness also has no ground to worry. There is never a need to provide an account number. Simply send money to pay for a service (to produce one flawless and useless ABX result) to your humble servant's Paypal account. It will be fully refunded should your humble servant fail to deliver the agreed upon ABX test result.
It was a reference to how slow the music appeared when nothing else had changed but the integrated amp.......I really don’t know if a slowing cd drive motor results in ‘slow’ sound (and your right it probably doesn’t) but in my mind that’s what it would have sounded like.....just like a slow running turntable or tape deck but seeing as the sound was coming from a cd at the moment that was my first instinctive thing to check, but when hooked back to the other integrated amp it was no longer slow.
So......something about this topology makes the sound appear slower, my research shows that truncated leading edge/trailing edge transients can have the illusion of slowness, some say slow resistors, some say the lack of high order distortion can sound slow.
In my case there is a definately lack of actual recorded information coming across as in leading/trailing edge is missing its snap then its decay.
I’m gonna try every trick there is to speed it up, if I cant then it will get traded.
Bob
I have no idea if this has been mentioned because I'm a little late to the party and I don't plan on reading 515 posts to catch up so... In my experience graininess is a problem with heat. It can be in the voice coil of a driver or in an amp/pre-amp. It starts off below the noise floor and as things heat up it raises its ugly head and pretty soon it becomes audible. I'm sure there are other reasons for grain in the playback but for me it's always been heat.
There is also a chance if you use your PC as a play back source there might be a problem with the operating system being corrupted in memory and is usually solved with a simple reboot.
There is also a chance if you use your PC as a play back source there might be a problem with the operating system being corrupted in memory and is usually solved with a simple reboot.
It's still under warranty, isn't it? If not, you can experiment with reducing base stoppers if there is any. (might need addition of small capacitance to compensate).
Yes but it went back in under warranty under the pretense something has to be wrong with this thing (every review from owners on up said the HInt is the greatest thing since sliced bread)......5 months later it comes back with clean diagnostics (according to factory spec) and still sounds the same......i’m really not concerned about the warranty at this point, in fact i’d probably just throw it through parasounds front window if I was on the west coast.
I’d really hate to screw it up so i’d need someone with experience working on these things......I’ve questioned JC a couple times to no avail (understandingly) his hands are probably tied seeing as he’s still employed by them.
Is there anyone east of the Mississippi familiar with getting better sound from these things?
I know it’s OT but it does have a little graininess on top!
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Bob, about that slight graininess on top, that is what has driven me nuts and never purchased another amp since 35+ years ago. Since I did not work in audio, my measuring equipment is rather limited so what follows is simply my simplistic observation, conjecture and supposition, could as well be wildly away from the truth. So here goes:... I know it’s OT but it does have a little graininess on top!
0. Grounding. Make sure to have a good ground every time before doing anything else, it could degrade in a sudden and unpredictable manners.
1. Noise coming in from mains and power supply switching harmonics. Most of the time the PSU has rudimentary or no RFI filter, no snubber to suppress diode switching noise and no film cap for higher switching harmonics, almost certainly no smoothing choke. I observed > 120mV 15MHz noise envelope repeating at 50Hz on a PSU V+ line with lighting and refrigerators in operation, < 20mV with all of them turned off. Companies make products to make profit for the shareholder, I make amplifiers to satisfy my most important customers, my two ears.
2. Bipolars. I avoid using bipolars as a gain element, maybe my design skill is lacking but compared to others the sonic presentation I can squeeze out is not as smooth. I'd rather use an IC such a the LM1875 when quality reproduction is not called for like driving the ceiling speakers in the kitchen.
3. Class AB. I listen to my music at low volume, the switching noise has always bothered me, comes up on sibilance and localization. But could be psychological, I have some difficulty to confirm. Have not tried a non swithching AB, next on my list to try.
4. Vertical Mosfets.
4.1 IR Mosfets. Consistently produce HF grain on my builds. Could be the non linear Crss, but could as well arise from my lack of design skill.
4.2 Fairchild Mosfets. I'd choose lowest current and voltage rating available. Adequate as followers, rather harsh as common source. NP measured better distortion figures compared to the IR. No problem for non gain stages such as cascodes.
4.3 Compared to Laterals, Vertical Mosfets has Higher and more non linear Crss. As followers, distortion started to rise early around 1kHz. Phase of fundamental could shift > 5 degrees while phase of generated H2 could shift > 60 degrees from 1kHz to 20kHz. Could be the reason for the HF grain.
4.4 I'm tweaking a cascode follower stage to try understanding effects of phase shift and grain, patiently waiting for some funds to become available since I need a new PSU for it. My income from my food business has been rather lean last couple of months.
Just my 2ct, nothing extensive nor comprehensive. For me it's just a hobby, I stopped tinkering with it for more than a couple of decades having fun raising my kid and has just been gradually back for a few years.
I know of two guys in Sicily (Check Aurion Audio) that install discrete output stages in CDP et similia. My suggestion is to go with an analogue source.I know it’s OT but it does have a little graininess on top!
At least you 'll find graininess in the low end (when hitting a grain of dust)
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