You are looking at a pre-owned Buchardt i150 integrated amplifier. The amplifier is only 17 months old. The amplifier is in beautiful condition. On very close inspection you may notice an imperfection, but nothing of any significance whatsoever (please see photographs). Ships worldwide with remote control and mains cable (mains cable will only be included if the buyer lives in the U.K.) Worldwide shipping i150 DIGITAL ART, WITH AN ANALOGUE HEART We know that is a cheesy punchline of our amplifier, but we hope our explanation of it would make sense to you. With more than 5 years into the development of our active series speakers (still ongoing), we learned that a lot of what the A series brings to the table, needed to get implemented into the passive world, as it was simply too good not to do so. So the analog heart is basically a statement of the I150s core of just being a high-quality simple amplifier. We could stop right here, and you would still have a great value amplifier. But where the digital art comes into play, is when you pair it with the Buchardt app. The biggest factor in achieving great sound is by far the room you place your setup in; that is not a statement, it's a fact! The influence of the room is sadly something that most casual audiophiles do not pay enough attention to. For many, it's simply not an option to fill the whole living room with acoustic treatment, which is understandable. So if you do not have a custom-built music room, the I150 brings you the flexibility that allows your speakers to easily adapt to your room and your personal taste. We are not stating that this would fix all of your room's problems, that is just not possible, but it can help you very much! First, the I150 is a serious integrated that is actually built like a separated poweramp and preamp in the same chassis. This is a result of its unique split power supply design. The poweramp section consists of a powerful Hypex NCORE module. But where the real magic comes from is its preamp section, which we state as 70% of what you pay for in the I150. Here you have a separated linear powersupply that powers the high-end Sabre PRO DAC, analog volume control and the quad-core DSP processor which gives you access to easy and effective room correction, advanced manual EQ, easy sub integration and adjustable ISO 226:2003 compensation = Low Level Enhancement (LLE) for better performance at low listening levels. So how does it sound? Powerful and natural, with a hint of warmth thanks to the analog volume control that is a perfect match to the NCORE Class D amp section. It's capable of driving anything you throw at it with ease. Should you have anything you want to change in terms of how it sounds, then you basically have free hands to tune it as you prefer. Key Features 150 / 300 WATT 8/4 OHM OF HYPEX NCORE® TECHNOLOGY NCore® is the first Class-D amplifier not just to nudge the best linear amplifiers, but to surpass them in every aspect relevant to sound quality. If you want the ultimate in clarity, resolution and musicality, there is no longer a reason to trade efficiency or compactness. NCore® technology combines the stability of UcD with improved load-independence, lower distortion and lower output impedance. ANALOGUE VOLUME CONTROL Our volume control is done in analog domain. Purposes are several, but most importantly, it means no reduction of dynamic range out of digital domain - and on top of that, the analog volume control circuit is the ideal match with NCore® class D amplifiers, due to its ability to give the analog touch into the NCore® output stage. This leaves us with the best from both worlds. The power and control from the NCore® stage, and the wonderful sound from our ES9028PRO DAC into the analog volume circuit....to us this is the perfect match.. tuned to perfection by our engineering team. SPLIT POWER SUPPLY DESIGN The power supply design of the I150 is a history of its own. All signal circuits in the super-sensitive analog domain are supplied from a massive regulated toroid linear transformer. This means no noise or switching is introduced to any analog signals - including our DAC circuit. Result is a background blacker than black, unlike any design we ever heard. Completely separated from the analog section is the digital circuitry. It has a supply of its own, and every single bit is carried with an artistic precision through the signal path up until the very end, when it meets our state-of-the-art Sabre DAC from ESS. The ES9028PRO. THE MIGHTY ES9028PRO DAC We take signal processing quite seriously at Buchardt Audio. This means we treat signals with respect and only interfere with the original signal if we see a reason to do so. Therefore it our honor to be able to take these carefully treated digital signals and convert them into analog domain, using only the best of the best chipsets available. Our choice was the ES9028PRO DAC. This chipset simply delivers the most outstanding conversion we have yet experienced - to a degree that we can say we are actually proud to be featuring this in our product. BUCHARDT ROOM CORRECTION A thorough engineered room correction that will surprise you in a very positive way, easy and simple to use, yet fixes what you want, without the typical artifacts we sadly see from most room corrections on the market today. Mainly it’s designed to help you with room modes (bass issues caused by the room), it will adapt the bass response to your room, and the speakers placement in the room. Optimal speaker placement and huge bass traps is rarely an option for most, this might just be the biggest upgrade in terms of sound quality improvements you have done, no joke! The technical explanation is a huge topic you can read here : It is well known that the environment in which a speaker is used can change the listening experience significantly. Generally, about listening rooms, the dominating parts are room modes and boundary effects. Our optimization can be done in few minutes – and the data is collected continuously, using the built-in microphone of a smart phone. Please allow us to explain more about them. Room modes When music is played in a room, the boundaries of the room will cause sound pressure to be reflected at the boundaries, which is causing a phenomenon often referred to as room modes. These are resonances appearing between walls, ceiling/floor or even in several directions. They will appear at specific frequencies, depending on the room dimension. These room modes are 3 dimensional issues, meaning that they will appear differently in the room, depending on where you are located. The figure below shows room modes in one dimension of the room e.g. room width. F1 refers to the 1st order standing wave. F2 is a higher frequency mode in the same direction, and the same for f3 and f4 – this is often referred to as the mode order. In theory there are infinite room modes orders, moving upwards in frequency – we will come back to that below. Figure 1 - room modes between two walls  As can be seen from figure 1, left side, the f1 has a large area along the walls, where there is high sound pressure level (SPL) and in the middle of the room there is low SPL. For a listener, this particular frequency will appear with a lot of change, when walking from wall to wall in this room. Another thing to be noted on this basis is, that when the mode order is increased, the deviation in SPL comes close and closer together, making it difficult to distinguish each mode – and only small changes in distance will cause big change in SPL. At this point, the room is entering what is often referred to as the diffuse field of propagation – and the room is no longer dominated by well-defined room modes. It will be one big mixture of standing waves in all directions. Normally this transition happens around 250-300Hz. This transition frequency is often referred to as the Schröder frequency – and is unique for each listening room. It is shown in figure 2 below, how the transition from low modal density happens at Fs and changes into a blur of standing waves – diffusion. Figure 2 - Fs, Schröder frequency identifies where the transition from modal area to diffusion happen.  Boundary effect Another room-related problem is the boundary effect. This is what appears when you locate a speaker close to a boundary. From factory – most speakers are tuned to be linear; but this tuning is done in a free-field situation with no boundaries. When a boundary appears behind a speaker, the SPL hitting that boundary will be reflected and thrown back to the listener. This will cause two artefacts: bass-boost and interference   1. Since high frequencies are mainly thrown forward and bass low frequencies are distributed all the way around the loudspeaker, most of the energy from the speaker hitting the rear wall is low frequencies. This means a boundary will cause low frequencies to be reflected and thrown back to the listener, while high frequencies will not. This will cause an overweight of low-frequency content from the speaker as it moves closer to the boundary. More boundaries (corners) will cause this effect even more. This is often referred to as the boundary gain effect (BGE). 2. The other thing that happens, when you move the speaker to a boundary is, that the sound reflected at the boundary will come back to the listener, but now with a latency, compared to the original (non-reflected) signal. This means that at some frequencies they will cancel each other – and at some frequencies they will summarize. The boundary causes some interference which is not easily predicted. Continuous Soundfield Sampling, CSS The Buchardt room optimization method takes all the above effects into consideration when performing the calibration. When you walk around with the microphone – covering all positions in the room, we can identify each single room mode – and calculate exactly how to attack it precisely. We can identify the boundary effect caused by the loudspeaker positioning and the interference caused by the boundary. We refer to the method as Continuous Soundfield Sampling (CSS). The benefit of this method is that we have more data available than if you only perform discrete points measurements. With discrete points you have no idea if you are in a minimum or maximum of a room mode – and the risk of making wrong corrections on this basis is high. Correction only where it makes sense Since the room acoustics only impacts at frequencies below the Schröder frequency, our compensation will only correct frequencies below that. However, we do capture data all the way up to the high-frequency band. This data is used to align the low-frequency output with the high-frequency output. Since the corrections at low frequencies are quite significant, it can sometimes be difficult to see where the ‘natural’ response of the speaker is – for this we use the high-frequency part for aligning the two bands perfectly with each other. The correction implementation The mathematics and analysis tools used to analyze the CSS data is quite heavy. But the CPU of a smartphone (iPhones only as of now) will do the job for us. There is no need for cloud-service computers or home PC for this method. We have spent numerous hours optimizing our programming so that the optimizations can be calculated by a smartphone in only a few seconds!! This is thanks to a lot of creative thinking and some ground-breaking research into how an IIR filter can be calculated and ensured to be stable – and still do a perfect fit for our target room EQ response. Once calculated by the phone CPU, the data can be transferred to any DSP and executed with no addition of system latency. How to do this? We require that you have access to an Apple iPhone 6S or newer. Remember that you only need to do this once, which means, that as long as you have a friend or family member that owns an iPhone, you can do this. If you move the speakers, you need to redo the correction. Only iPhones are calibrated for the system, not iPads! Note: We are working on a dedicated microphone, so Android users can join as well. Our room correction has been calibrated to each iPhone model since the iPhone 6S. We have chosen iPhones, because they have very low tolerance regarding their quality control. This means, despite poor quality microphones in the iPhones, we can still trust them to deliver the data we need within a very acceptable tolerance for low frequencies. To bypass the noise from these microphones, we are capturing thousands of measurements doing the one minute the measurement process takes. Yeah, it’s a pretty smart team behind this, right? To get started, download the Buchardt App from the App store. When you start the room correction via the Buchardt App, you will hear the speakers do pink noise, and see a countdown from 60 seconds. Doing this countdown, walk around with the iPhone and try to capture as much of the rooms air as possible with large circular motions, but not closer than roughly 1 meter (40”) from the speakers. When the time is up, you will be shown your room’s frequency response to really get an idea of where your room modes are, within the frequency band. The phone will then use its horsepower to compile all the gathered data to calculate the perfect bass filter. It's directly tailored to your room and the speakers’ placement. You can now switch between "corrected" and "uncorrected" to instantly hear the difference. For most, this will be one of those WOW situations! We are so proud of how well this actually works. AUTOMATIC ISO 226:2003 COMPENSATION = LOW LEVEL ENHANCEMENT - LLE Low Level Enhancement: Improves the speaker performance at low listening levels to compensate for human non-linear hearing. You can activate and adjust the intensity of this effect to your liking and speakers sensitivity. To expand on this: It is well known and documented in research, that the perceived sound balance is dependent on the level at which sound is reproduced. Best example is that with traditional loudspeakers, when listening at quieter levels, there is very little experienced bass and treble reproduction, although at louder level the bass and treble is clearly present. Since we are in control of the entire sound-reproduction chain with DSP, we can predict the exposed level of sound at the listeners ears, which means we are able to compensate for this effect. However, we will only do this compensation at low levels (<70dB), where we know most listeners will not perform their critical listening. The outcome from this compensation is a smooth and constantly adapting timbre to the sound, so that it will also sound dynamic and impressive at lower levels, where you can have conversations at the same time during listening. This is a very well engineered feature primarily aimed at professorial use in studios. It allows the mastering engineers to work at lower volumes and still get a precise representation of the music. This allows for much longer work sessions without getting fatigued. For HiFi use, if you often listen at lower volumes this would be a game changer for you as well! SMART SUBWOOFER INTEGRATION Should you need to set at high-pass filter on the speakers you have connected to the I150, then you have a quick and easy way that goes as following. Press and hold the power bottom on the I150, then press simultaneously the input selector in order to toggle between inputs which give you: (LINE) = FLAT (OPT1) = 40hz (OPT2) = 60hz (COAX) = 80hz (USB) = 100hz (BT) = 120hz This is a quick setting if you want to introduce a subwoofer to your system. Another way to do this is via the Buchardt APP. Using the SUB OUT for connecting subwoofers : The I150 have ideal subwoofer integrating that would make it a breeze to properly implement a sub to your system. From the APP you have direct access to subwoofer settings such as low pass filters, polarity and even a smart distance selection where you measure the distance from the listing position to you, and set it accordingly. The DSP here gives you time alignment for your sub and speakers to give you a perfect integration. Remember to set this for the speakers as well. When all is set, run the room correction which applies on both speakers and sub(s). You are ready to rock and roll! Technical Specifications Amplifiers: Hypex NCore® 2 x 150 Watt 8 ohm / 2 x 300 Watt 4 ohm DSP: Quad Core Processor DAC chip: ES9028PRO Analogue inputs: 1 x (RCA) Digital inputs: 1 x coaxial, 2 x optical, 1 x USB Analogue variable pre-outs: 1 x (RCA) 2 x Sub out (RCA) Streaming option: Bluetooth 5.0 with aptX HD and AAC Distortion: 0.0015% <10Hz-20kHz AES17 Signal-to-Noise ratio: 121dB <10Hz-20kHz AES17 Damping factor / 8ohm: 4500 Measurements (H x W x D): 80 x 370 x 310 mm (3.2” x 14.5” x 12”) Input voltage: 100-240 Volts AC auto adjusting Weight: 10kg Warranty: 2 years (4 years with registration)
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