Audiophile FAQ - Best amplifier, speaker cable, best preamplifier

[@gee3883]

This is such a breath of fresh air for someone who has dreamt of owning hi end but never had the justification to spend such a huge sum. This guy is making it affordable, what a champion.

[@philipkoshy2184]

Excellent explanation . Transparent content . Many a myths , incorrect assumptions and marketing jargon are clarified . Thank you for the clean , deep and clear technical information.

[@guntarssmits2104]

Thank you, your comment is inspiring.😀

[@tweedeldee8122]

Thank you Guntars! So much straight info. You deserve an award and more subs. BTW - I love my mono-blocks.

[@roberthart9886]

Just came across this today. One year in class D is equivalent to 20++ years in SS. Time for an update. For several years now I have owned a Tweak Audio EVS1200, based on dual mono IcePower AS1200 mono modules in a single chassis, and a LSA Voyager GaN 350. I am aware there is a upgraded GaN module soon

[@Hitsujiomeguruboken]

This video is a huge eye-opener. Three !!! after every sentence you said!

[@guntarssmits2104]

Glad it was a valuable😀

[@MrTeamRobert]

You’re videos my be long but it always put me in a good mood, thank you Guntar

[@guntarssmits2104]

Your comment is inspiring. If want to explain some concept it needs some time and it is better to tell a story than make a statement.

[@Thomas..Anderson]

This channel is underrated.

[@guntarssmits2104]

Inspiring comment

[@Thomas..Anderson]

Me again. At 11:30 you mentioned that ICEpower1200AS2 benefits from bridged output stage and that you have another video where you explain it in detail. Could you please provide a link to that video?

[@gee3883]

@@guntarssmits2104 well desreved.

[@michaelrobinson9643]

Thank you for making the effort to produce this in English. I found it very educational and nicely thought out/organised presentation. I struggled a little with some terminology due to pronunciation. I hope you will be ok answering a couple of questions: 1: Does the ICEPower integrated solution have an input buffer you consider excellent? 2. I have heard criticism of the "Bass control" of ICE vs Hypex Nilai ... No technical graphs show this type of information. I think it could be reflective of the dynamic current demands of speaker being met or not. Do you think there is a quantifiable difference in the available energy store that these models have? Assuming the Nilai is built with the stock Hypex 500W SMPS that they sell. 4. My sense of Hypex and Purifi is that it would be better to source a more capable power supply than they offer. Your opinion and what you would advise? 5. What input buffer would you select for hypex Nilai or purifi and why?

[@guntarssmits2104]

In short. 1. Meaning The perfect input buffer preamplifier is to have a high input impedance of 20 kOhm and more, low output impedance below 150 Ohm, low HTD of about 0,005%, and a high dynamic range of up to 20dB (10V). Most professional preamplifiers (mixer consoles, advanced audio cards, active crossovers, etc.) meet those requirements. ICEpower 1200/2000 Series boards have a preamp built in and have 47Kohms input impedance. Boards like 200AS2 and 125ASX2 do not and have an input impedance of about 5 kOhms. But you can drive them by any professional and properly build consumer preamplifier directly. 2. There are no bass control issues with ICEpower boards. I have measured all of them and the measurements are correct. I did blind listening tests with calibrated output levels and got the same result. This argument is more related to marketing than to engineering. 3. Hypex is a good manufacturer and I am sure that the power supply delivering as promised in the specifications. I do not think there is any issue with that. 4. I think you simply need more power for your system, not just a power supply. 5. As I mentioned before any professional and consumer preamplifier with an internal +/-12v power supply will deliver everything you need. Read the specifications and find out what output impedance of your preamplifier is. Never add a passive potentiometer as a volume regulator to the amplifier stage. It will degrade your system performance. Regulations should be done between 2 OpAmps ( buffer amplifiers) to meet buffer preamplifier requirements

[@michaelrobinson9643]

Thank you sir for your considered thoughts.@@guntarssmits2104

[@cotandiet6096]

Thank you so much for your information.

[@DhenerAbade]

how about the hypex nilai? it is still behind icepower? thanks

[@michaelrobinson9643]

other information I have seen and comparisons suggest Nilai may be the best of choices and better priced too?

[@riccitone]

This is outstanding, and makes me rethink quite a bit. Everything here is eye opening. Relates to your D class amp explanation: Alpha Audio has reviewed the Hypex Nilai kit to good effect, bringing it close to the sonic attributes of a Pass Labs amp - at least within their test system synergy. Would love your impressions of the new Nilai design 👍🏼

[@guntarssmits2104]

My personal experience shows that the Amplifier industry meets the point of perfection when further amplifier specifications improvement does not make sense. Current designs exceed human hearing resolution at least 10 times. The key parameter now is power. Normally you need at least 400W clean power to comply with any home usage scenario. I think the next step is active speaker architecture with an option to exchange loudspeakers. I dedicated my latest videos to this topic. I published them today.

[@lmanna]

Excellent video Guntars. Thanks for all the good work. Your videos are very straightforward and provide good information based on sound principles. How would you rate using this Ice AS1200 Amp module to drive Magnepans LRS. I see the spec is 2.7 Ohms for lowest load but Maggies can present loads lower than that, though mostly resistive. Will the AS1200 drive Maggies, that's basically the question and how does it drive them ? Have you heard them ? Thanks.

[@guntarssmits2104]

Icepower 1200 is capable drive 2 ohms speakers as well but with a bit of reduced max power. ( hit current protection) It is a perfect match for Magnepans LRS. It will be better than AB solutions due to the high damping factor which is important for low-impedance speakers. I do not have personal experience with Magnepans LRS. But anyway only real-life tests will give a final answer to you.

[@guntarssmits2104]

making things simple. Icepower 1200 can drive any speaker produced so far in the world. Do not be misled by load figures. It has a very low output impedance. A rated load means that it is capable of full power at that load. With a lower load, you can drive lower max power. For example at 1.5Ohms about 400W due to over-current protection, what is set at the rated max current. Regarding sound quality. It will be perfectly neutral with zero coloration, precise and powerful. Speakers define your real listening experience.

[@sc0or]

I always use prof Roland interconnection cables. They are cheap as €20 per 75cm, have a bulldozer style connectors, provide an excellent quality of sound good enough to use them even with a vinyl (to a phono preamp). Prof series rule.

[@guntarssmits2104]

Cool, thanks

[@StCreed]

Highly underrated video. Thanks! Edit: I do have a question about the pre-amp. How important is room correction? I found it made a huge difference in my large, weirdly shaped and echoing room where room treatment just isn't an option. I'd hate to have a preamp without Audyssey, Dirac or other room correction software. What's your take on that?

[@guntarssmits2104]

It is by far a more complicated topic than may seem. Unless you are not making a recording studio, speaker placement optimization will bring better results than simple room correction.

[@TheRealDanji]

Hey Guntars, I was wondering if it is possible to use a streamer DAC like the bluesound Node n130 directly into an 1200AS2 amp. Bluesound says it can be used as a preamp because it has adjustable volume and the specifications say it can do 2V output from RCA. It's less than half of the 5V you mentioned. Will it harm the sound quality? Or will it only limit the max volume?

[@guntarssmits2104]

Yes, It will be a perfect system without any redundancy. Node n130 has a volume regulator built in. I have checked the specifications and there is no indicated line output level. But it has a built-in power supply and seems there is no limitation to 5v USB power supply. That means the device output max level is somewhere between 2V and 4V. It is sufficient for direct operation. With 4 V you will be able to achieve full power. (What you probably do not need). For connection, you will need an RCA-XLR adapter.

[@TheRealDanji]

@@guntarssmits2104 Great, thank you!

[@hotdog9262]

@@guntarssmits2104 thougts on 1ET7040SA? looking at audiophonics HPA-S500ET

[@Mr_Wh1]

Very informative videos you provide us. Thank you. I came along a good deal on a used 1200AS2 and was about to strike, when I began to have second thoughts due to the balanced input. I do not own any balanced sources nor preamplifiers. It just feels defeating having an Audiolab 8000Q pre-amplifier which wasn't cheap, but there is no balance output to be found on this fine thing.

[@guntarssmits2104]

You can use any regular adapter cable RCA-XLR and enjoy music. Typically about 7EUR priced

[@Mr_Wh1]

@@guntarssmits2104 I am aware of this, but as far as I understand there might not be enough voltage to match the correct ratio of output?

[@guntarssmits2104]

@@Mr_Wh1 it depends on your preamplifier capability. But you can start with the audio interface as a preamp.

[@Mr_Wh1]

@@guntarssmits2104 In your opinion, is there a difference in performance on the 1200as2 between single ended operation and balanced?

[@guntarssmits2104]

Theoretically speaking short ( up to 3m)signal cables should not be. Under the condition that the source is capable provide 4V output with some headroom. You should read your preamplifier specifications. Pro units with mains power can provide up to +12dB output ( about 10V) without distortions.

[@joeneticchan9640]

Thank you Guntars! Do you think IRS2092 still good ? It is much cheaper than IcePower modules

[@guntarssmits2104]

If you count a good power supply as well then the IRS2092 solution will be similar to Icepower 300S1 +hanger module or 200AS2. Technology is developing and the latest ICE boards are good and integrated by design with the power supply which covers most of the costs.

[@joeneticchan9640]

Thanks for your prompt reply!

[@audiogear6978]

Hi Guntars, do you have a list of those icepower board with the BTL output design? Man , keep doing this excellent work.

[@guntarssmits2104]

BTL output design 200AS2 1200AS2 and 2000AS2

[@audiogear6978]

@@guntarssmits2104 Thank you!!!

[@audiogear6978]

@@guntarssmits2104 Men , the audio industry is a lie, your channel is a hidden treasure. These kind of solutions are underrated because they can change the whole game. Imagine to have a sound of thousand of dollars for just 500!! Is crazy and I can see why they are haters for class D without event listen to them! Keep doing what you do!!! I will try to purchase a kit to support your great work

[@michaelrobinson9643]

The Power supply and input buffer are completely overlooked in many comparisons. There are many brands that are simply assembling the OEM parts in the most minimal way possible. I see no reason to buy them if I can access the parts I want in an acceptable format and price.

[@hennievangalen3789]

What is your definition of 'best' ? Class D improving on what ? Compared to what ?

[@guntarssmits2104]

The key reason why I am named the latest Icepower 1200 series board as the best in the world: Specifications 100 times exceeding human physical hearing limits (discussions about amp quality and THD specs becoming meaningless), extremely neutral sound, sufficient power for high-end systems 450W clean power +150W headroom ( where THD starts to rise up to 1%). Very low idle noise of 30mkV for 600W amp. Bridged by design which is critical to eliminate class d bus pumping artifact, power supply instant power capability of 3.8kW, Power supply power factor correction, WW EMS certifications, availability ir retail from trysted EU seller, unbeatable board price of 430EUR for the end user. 12v trig and wake up from signal integrated into the board by design. Small footprint. In my opinion, there is no other board in the market with all mentioned features. At some point, this is an end-game amplifier killing the high-end industry.

[@partyk138]

@GuntarsSmits thanks for another good movie. Maybe I'm wrong but I think that modules 700as1/2 and 300a2 has newer hardware version, when you compare 300a2 with 300a1 you can find differences, also 700as2 has lower harmonics than 1200as (I remember that THD is not most important thing). Question is what do you think about those modules, also why 1200 not 2000?

[@guntarssmits2104]

About 300a1 and 300A2 you are right 300A2 is newer and has the same architecture as 1200. Regarding 1200 and 2000 both are equally good and share the same board layout and pins. My questing is what speakers do you have when you need KW/channel for your home listening. The key here is to balance your system, which means that you have the right power for your solution not paying for extra Watts if you do not need them.

[@partyk138]

@@guntarssmits2104 I think that 300as1+300a1(150w for 8ohms) could be enough, but almost in same price you can buy 700as2 with better specs and more power.

[@guntarssmits2104]

@@partyk138 You are right about 700AS2, but if you can afford 1200AS2 is a much better solution. It has new-gen power architecture but 700 has old-generation architecture Also on paper seems that THD is better, but check 6kHz curves as well. 1200 is by far better. I have listened to this board and compared it with many alternatives. today this board is unbeatable. 1200 is one gen younger than 700 board. For active speakers or home cinemas, you can combine them with 200AS2 separating the woofer power supply from the midrange and tweeter power supply, or use 300AS2 hanger modules.

[@partyk138]

I ordered 2x700as2 and 300a2(bridged mode) for my 5 channel amp, I think it should be more than enough :D I couldn't find many differences between 1200 vs 700 vs 300a2 but they are much better than 300as1. 700 is bit cheaper and smaller, 1200 is too big for my cabinet. In free time I will check how active crossover sounds, with those components should be easy to make "external crossover" for my Proacs after soldering additional wires to bypass passive crossover for this test.

[@youtube改名也太難了吧]

Want to hear the powersoft amp someday. IPAL system looks crazy but it's too hard for diy to get/build.

[@guntarssmits2104]

You are an extreme audio lover😀. Powersoft solutions are built for the Live audio market. Seems a great device but at some point it is Live event units built with different music reproduction requirements. Closest to home users' requirements are studio solutions with power from 400W to 1200W.

[@youtube改名也太難了吧]

@@guntarssmits2104 after watching your video and reading some discussion I'm wondering how suitable for unbridged purifi/hypex amp for woofer/subwoofer usage. Is bus pumping effect a problem can be solved by amplifier stage design? There's LX521.4 user report it's not perform better than his old amp when using SMPS3K + Purifi EVAL1. But after changing to SMPS1200 everything works fine. Seems that SMPS3k is not suitable for half-bridge amplifiers. Still there's quite a lot review mentioned about superior sound quality from hypex/purifi amp though. Not sure if it's the buffer/gain stage that's more appealing.

[@guntarssmits2104]

@@youtube改名也太難了吧

[@guntarssmits2104]

@@youtube改名也太難了吧 Let us split your question into the 3 parts. First about the subwoofer. Any stage amp will be better and cheaper for a subwoofer. The key here is power. And you should not care about quality. We are talking about a frequency range from 20Hz to 350Hz max. Low-frequency woofer THD is close to 10% and that is just fine for listeners and music. If you have full-range speakers then the best class d solution is bridged with no problem of bus pumping. Good Class D amplifiers have protection against it and until your device protection does not trigger everything is Ok. SMPS 3K has an issue due to insufficient storage capacitors on the secondary side. Icepower 1200AS2 is much better designed. For me, it is a kind of reference for the engineering brilliance of class d design.

[@danaustin5869]

A quick look at ICEpower's specs shows moderately low distortion and a rising output impedance with frequency. This demonstrates that they have not been able to do what Hypex and Purifi have succeeded in doing, namely put the output inductor filter inside the feedback loop and maintain stability. This means less feedback and higher distortion caused by the output inductor being outside the feedback loop. ICEpower is thus stuck in older technology with poorer specs. Buy it if you like it, but if you want super low distortion and high damping factor at all frequencies, look elsewhere.

[@guntarssmits2104]

By drilling down into the topic you may find that human earing has relatively low resolution. THD max resolution is 0.25%, amplifiers can easily make 0.005%, and Amplitude resolution is 0.25dB at midrange around 3kHz and 3dB at 50Hz and 16kHz. Damping factor max value 50 (amplifiers can do 700 and more). The basic parameter specifications improvements do not make sense. But such things as quadro balanced (bridged), power supply instant power capability, thermal design, etc become critical parameters when we are talking about amplifier quality. And the right direction to audibly improve your system is using active crossover and active speaker systems. Most of Chipamp's active systems sound better than most advanced Icepower Hypex or Purifi most expensive amplifiers with passive crossover speaker systems. By architecture, Quado balanced design, power supply instant power capability, audio quality, output power, and telemetry built-in Icepower 1200AS2 is the best amplifier board today. The latest design boards also has inloop output filter architecture. Boards are available for the DIY community from EU-proven retailer Soundimport.

[@rogerperreault441]

You have so much good information thank you very much for your videos. Would you be able to comment on a question I have. I am building an ice power 125 ASX2 amplifier I do not have a preamp,is it a bad idea to attenuate my audio signal with a potentiometer. Others have told me I will have greatly degraded audio quality. I would value your opinion very much. Thank you.

[@guntarssmits2104]

I attached non edited answer to one of my customers. Some parts would be valuable for your. Also watch one of my old videos where are details of 125ASX2 preamp part kzbin.info/www/bejne/aWjdhpSAhsiGpNE Let us split your potential solution into several parts. First ideal setup. To work always a way from clipping by the rule of thumb amplifier should have at least 3x more power than the speaker's RMS. In your case 300W capacity. Icepower 200AS2 will not be sufficient and you can not bridge it. Listening distance - If it is 1m-1.5m 100W may be sufficient, but in case of distance variations up to 2-3m you need more power. The key here is to be far away from clipping not exceeding 1/3 of amplifier power. Icepower 125ASX2 you can set in bridged configurations and get out incredible 400W- so you have a power reserve You should read the designer manual on how to properly do it). But you need 2 boards. If you have them then this is your setup. If you do not have them then in Soundimport shop Icepower125AS2 costs about 200EUR/Board and your project is going up to 400Euros. For 430 EUR you can get an end-game amplifier board Icepower 1200AS2. Do not be misled by power figures. It is just a very good 450W amplifier. Let's remember that 100W and 400W power just double the loudness. Of course, you can start with one board and a 100W amplifier. The key question is what you want to achieve. There are costs associated with any of the solutions. Regarding the Icepower amplifier boards. Those are amplifier power stages and you need an active by-the-book built preamplifier with a volume regulator. There are no shortcuts like putting a potentiometer in front of the amplifier. 125ASX2 and 200AS2 input impedance is frequency dependent from 20K at low frequency to 5k at high frequency. There is an input filter filtering noise at the board input. It will work right only if your source impedance will be about 100-150Ohms or lower which is the industry standard. If you have an old amplifier with preamp output it is one of the good options. Some budget alternatives are Professional audio interfaces, small cost-effective mixers, china DACs, and some China preamplifier boards. You can take service voltage from the Icepower boards to feed them. The key is that to regulate volume you need an active preamplifier stage. If you find some solutions with balanced outputs then you can place the amplifier close to your speakers and preamp at a listening place and connect with a standard microphone cable. There is the video where I have explained some preamp options. kzbin.info/www/bejne/bqe5maZpgJ2Zb68

[@rogerperreault441]

Thanks for your reply you have given me much to start on.

[@ladjkaoz]

so the oce is the best class D amp.?

[@ubacow7109]

Allegedly pascal from the pro audio world is pretty competitive as well

[@guntarssmits2104]

Yes, Pascal is similar, but it is not in retail and accessible for the DIY market. Practically all Icepower lineup is available at SoundImport retailer.

[@ubacow7109]

@@guntarssmits2104 VTV actually carries some of their products in their more affordable amps, not sure what kind of agreement they have because its a lot more affordable than most companies using their amps like Storm Audio. Another super competitive class D product emerging from older products are the the TPA3255 chips. Until more recently they'd been regarded as relatively cheap and not "hifi" enough but some of the latest DIY amp designers using the chip w/ PFFB have achieved higher end performance competitive w/ some of the Hypex & Icepower products at like 1/5th the cost

[@zeekbruno4869]

Hello Guntars, great discussion !! I’ve built my six channels of active system with Pascal Audio class -D modules. Have you been exposed to these wonderful designs? I would appreciate your Perspective on these modules. With the current modules Thank you Bruno

[@guntarssmits2104]

Pascal Modules has a great lineup and good quality. They are not targeting extremal specifications but those are professionally built boards and you can design almost any configuration active systems. The only thing missing is Quadro balanced designs (bridged per channel designs), which for class d is critically important for quality without compromises. Quadro-balanced design eliminates artifacts such as bus pumping and doubles sleave rate (better speaker cone acceleration when bandwidth is limited to 20kHz). You can market such solutions, but in the Pascal line up you will not find them integrated by design. As a Quadro-balanced example, you may find positive forum feedbacks about TP3255, 4 channel class d chipset set in Quadro balanced mode bridging channel pairs for stereo. And it shins for the 150W market. So far only the Icepower 1200AS series has powerful Quadro balanced design boards. This is one argument why I stick with Icepower, the second argument is that only 1200AS2 is available for consumers and the DIY market from proven retailers like SoundImport. But I like Pascal's lineup. I am impressed with the engineer’s work.

[@zeekbruno4869]

Hello Gunter, Thanks for the response! I built two 3 channel modules for my 3 way active system. They provide the 2nd channel to invert the signal So as to help the pwr supply no be drained from the positive rail. I was so impressed of your discussion of the “slew rate” of these amps most people don’t discuss. My amps sound much better thank my 600 watt MC-602, much better and I attribute to slew rate !! Your Series of videos are very very good. Have to rewatch this video to reassess my head room. My bass module is 2400 watt, mid 800 and tweeter 800 watt into 4 ohms. I believe I have the head room. Power supply that’s integrated is a huge positive. Thank you for your feedback Bruno

[@zeekbruno4869]

Gunter What about the PWM frequency used for the control are these frequencies increasing… higher is better? And I read about different class D amps output filters to solve a problem with Class D I think your video on remote turn on and idle state might be available with my Pascal modules?

[@zeekbruno4869]

Guntar ( spell check) sorry

[@guntarssmits2104]

@@zeekbruno4869 Yes, inverting channels make sense and it is solving bus pumping artefacts issue.

[@ladjkaoz]

ice amps are rated at 80% efficiency vs hypex are rated at 90 91%... may not be big difference but 10% it is.

[@guntarssmits2104]

In practice Hypex amps and kits working temperature is high and there are complaints in the forums about it. I did not find overheating complaints regarding ICE amps. We need to drill deeper into designs and pay more attention to idle power. Practically all solutions that I have seen have idle power consumption from 10 -40W. Efficiency is a kind of tricky parameter because it is measured to max output power which you normally never use. You are working at 1/3 of the power where idle heat is dominating.

[@robertgreene1946]

You are just wrong, Icepower amp is ok but not as good as a Purifi Eigentakt-based amp. I own both the Purifi is a more transparent better sounding amp.

[@guntarssmits2104]

It is a never-ending story about which manufacturer amplifier Hypex, ICEpower of Purify is better.😀 I do not have experience with Eigntact, just with Hypex and Icepower top models. All those companies designed today exceed human hearing limits and you are not able to distinguish differences in blind tests. I did it with Icepower and Hypex top models. When your test is set properly and output power is equal set with measurement equipment, people cannot tell which amplifier is working when listening on high-resolution studio monitors. Me neither even having good ears. Regarding Eigentact supremacy. None of the three leading companies are developing semiconductors and chipsets. ICEPower stated that they have 2 chips developed by themselves but most probably there are third parties involved who did this job. That means designers have limited options to develop something better than other companies as long as the architecture is correct and semiconductors are selected from the right manufacturers. But if you carefully inspect Eigentact designs you will see that 400W rated amplifier power suppression (the moment when THDs start to grow) starts at 250W for 4 Ohms and 150W for 8Ohms. There are some probabilities that midrange accents and feeling of details are due to limited power capability and low power supply rail voltage impacting sonic balance. The amplifier a bit suppresses low frequencies peaks and the midrange becomes accented. In ICEpower 1200 it is engineered in a way that the board is working in bridged mode and power is limited by the provided power supply current, not by rail voltage. ICEpower 1200 can provide spotless power up to 450W keeping perfect sonic balance for 4Ohms and 8Ohms load with an extra 200W power buffer reserve to clipping. The key advantage there is the delivery capability of the same power for 4 Ohms and 8 Ohms speakers which other competitors' designs can’t. But maybe Eigentact has some miracles. Need the blind test to verify your statement. I hear real improvement in sound moving from passive speaker to active speaker architecture. I think it is the right direction for future sound reproduction improvement.

[@MSiAventador]

You mentioned the 70% who couldn't hear the difference... If the pilot loses consciousness in the plane, 70% of the passengers will not be able to control the plane, this proves that planes cannot fly?!?! 🤣🤣

[@guntarssmits2104]

It is reality, most of music mastering specialists and musicians above age of 40 do not hear high frequencies, but can play, record and master music. 90% of music content is within 12KHz, and 98% music within 16 kHz. They still can do the job. They can still "drive a plain" and doing that.

[@breathofawareness7903]

Hypex Nilai.

[@RomanTecDev]

oh boy! so many false statements here... amplifiers have surpassed the human ear.. wow... bla bla bla and .. the icepower is becoming the best amplifier. again according to Guntars. Are you affiliated with Icepower sales anyhow? For example he's comparing Purifi's and Icepower's THD+noise vs power graphs - and the icepower shows like10 times higher distortion and in high frequencies the distortion gets even worse but Guntars with a straight face tells you that icepower is better digressing on cars horse power keeping mum on the obvious drawbacks. Any icepower boards measure worse that purifi and hypex NC. Eg - icepoer's thd+noise reach 0.01% (purifi below 0.0002% on listening levels) Those best specs like noise etc are only measure best at over 70% of power. At listening levels the distortion is worse. How often do you listen to music at home at 700 watts?? may be at 1200 watts? Icepower is worse on multitone signal measurements as well. Sonic-wise, i've owned a number of icepower's, hypex's, purifi's boards and hi-end assemblies, icepower is only interesting in the mid-bass, overall loses to purifi and hypex (NC). icepower is on par with UcD. And if you do a clean proper power on the buffer stage replacing the obsolete opams then UcD sounds better. You can't do much about those stupid icepower's chips. They use only basic power cleaning on the buffers. Proprietary chips approach is con, not pro. Generally, Icepower are decent energy efficient amps, especially for stage use and multi way diy speakers tending to lose microdetails compared to real hi-end amps being tube, solid or class-D and it's not home audio high-end domain yet as proven by listening and measurements. Seems, Gutars's a good engineer, I'd suggest he gets to build a proper speaker system around topline Scan-speak, Seas Excel or even Purifi or Accuton drivers then we debate on "Current designs exceed human hearing resolution at least 10 times". Still interesting video, liked.

[@guntarssmits2104]

There is no magic in amplifier design. Non of Hypex, Purify, or Ice power has its developed semiconductors. Today, the amplifier game is over. There are lines of amplifier boards exceeding human hearing limits. In most cases, the statement that this amplifier has better mids, in reality, means a power supply problem and suppressed low frequencies. In simple amplifier has coloration. According to TI research 100W amplifier power supply should be capable of delivering 800W short-term power. Most 400W amplifier designs power supply is a limit to perfection, not THD. Genelec - a World higher resolution studio monitor manufacturer states that amplifier THD for their speakers should be 0.01%. I know that consumer marketing is crazy strong and some messages are seeded in the audiophile community, but it is nothing about precise audio performance. 20 other specs are having more impact on sound reproduction than THD. My focus on Icepower is due to their professional board’s availability to the consumer market and reasonable pricing. Today you can make high-end amplifier within a 1000 EUR budget and it is very close to perfection. Want to get better sound reproduction you should go for multi-amplifier architecture with active crossover where the number of loudspeakers in a box is driven by dedicated amplifiers. The worst thing you have in your audio system is passive crossover. Once you get rid of that you are at a different reproduction tolerance.

[@RomanTecDev]

@@guntarssmits2104 SPL dB/w/m min/max guitar: 40/55, rock band: 80/110, orchestra: 35/110, jet plane: 130. To reproduce an orchestra you need spl of 110 db W/m. Regular speaker drivers' sensitivity is 86-89 dB W/m, better ones reach 98-103 literally meaning you need to connect 1 watt to a driver and you get spl of 86 to 103 dB at 1kH depending on the driver. Hence to reach orchestra spl you'll need only several watts, in case of ineffective drivers - tens. Hi-end single ended tube amps often have like 8w output. So, the statement that you need 400W or even 1200W to reach realistic SPL level even considering low frequencies and picks is limply incorrect. Yes, i'm aware on the studies that power units should be able to deliver higher level of power instantaneously and this is not for SPL reaching but for the amplitude to rise fast enough. And it's true there. Like many I tend to disagree with you that the amplifiers game is over otherwise all amplifiers would have sounded the same had you connected them to your speakers. But this is not happening. The bottleneck will always be transducing electric signals to sound waves (speakers). The best of these have THD around 0.5% in the mids but not three - four zeros after the dot. Multi-amplifier is a good approach; but you gotta make sure that your drivers are properly time delayed from the lowest woofer in the system and equalized. Interesting fact that Troels found that multi-amplification speakers sounded worse then passively x-overed. And from my experience I tend to agree. I saw you had built some of Troel's speakers. On the other hand a proper active crossover is much easier to build than a passive one.

[@guntarssmits2104]

@@RomanTecDev To limit the long discussion, I recommend watching the Harbeth lab ( ex BBC acoustics research lab) experiment where a lifetime top speaker designer demonstrates real speaker peak power consumption. kzbin.info/www/bejne/j2S6oYWPYqqnjpo Before calculation, we should drill down a bit into the physics topic. Speaker sensitivities are given to 1kHz where huma has high sensitivity hearing. For 100Hz our hearing is 100 times lower and for 40Hz 1000 times lower. Sound is all about speaker acceleration (not movement); we are dealing with high mass and high-power motor physical models for low frequencies. There are similarities with a car accelerating from a red light where an odometer shows fuel consumption of 50L/ 100km. When we finish acceleration, it is just 6l/100km. Amplifier peak power capability is the same as 50L/100km. In the moment you are not able to provide it your drum kick is suppressed. Music mastering in the studio is done on high power-driven speakers capable of significant SPL at low frequencies and you at home should be able to replicate it.