Introducing a fully digital Class D LF amplifier with a power of 1000 W for both channels. The case was taken from previous projects that were not very satisfactory for the performance of amplifiers. The inverter is also used from previous projects, only this version has been improved. The control on the SG3525 was copied and slightly modified from the Grundig PA240 car amplifier + control transformer and transistors. The 2x75V power supply, 1100W constant output power and ETD49 core do their job perfectly. Everything runs at 60 kHz. Half-bridge topology.
ULF circuit for 1 kW class D
Class D UMZCH modules are made in accordance with the existing IRAUDAMP 9 () project, plus minimal changes have been made. Three pairs of IRFP4332 transistors per channel operate at a clock frequency of 300 kHz. DT 105 ns. The amplifier is based on IRS2092 + TC4420. PSU choke in ferrite, inductance 22uH / 30A.
The modules will output 2500 W/2 ohms at 10% and +/- 95 VDC supply voltage, with testing achieving 1800 W measured through the speakers.
Popular and effective protection measures from a series of bipolar amplifiers were used. The same circuits in class D modules have protection against short circuit and direct current; additional disabling of these protections has also been made on the relay. Behind the standard protection there is a starting current limiter, soft start.
The best part is that the entire amplifier has as many as 14 fuses to avoid the PCB fire in case of force majeure. Cooling, the inverter and modules have forced cooling, which turns on after reaching a temperature of 50C, but the PA modules do not heat up during operation, and the inverter reaches a maximum temperature of only 40C.
If you add up the total time for the project, it will probably be a whole working week. It was saved by the fact that there were no serious problems with the launch. After a thorough check and start, the amplifier started working immediately. The device turns off during surges with the mains supply voltage, that is, above 250 V or below 200 V AC. If there is a short circuit or overload in the speaker, the amplifier will also turn off and must be restarted using the switch.
Useful: Charger for calcium batteries
Car amplifier options for subwoofer
A subwoofer amplifier is the main component of high-quality car sound.
If you can optionally install the system you like in a car without any mileage, then choosing speakers and equipping equipment from the secondary market requires knowledge in the field of car audio. At a minimum, you need to understand the types of systems that you can buy, for example, the difference between coaxial speakers and component speakers, and an active subwoofer and a passive one. The built-in amplifier should not affect the sound quality; in fact, its function is to eliminate distortion during the operation of the car radio. Extraneous wheezing occurs as a result of speaker overload, which is eliminated by the car amplifier.
The market offers various devices that allow you to set the signal bar at a level that will be acceptable for each specific car owner. The simplest amplifier will provide several tens of watts per channel and is inexpensive, the most powerful models - up to several kilowatts. The price of systems varies from 2-3 thousand rubles to hundreds or more.
It is worth noting that a car device differs from a home one in that it is designed to reproduce sound in a smaller volume. The device also receives protection from shaking and other aspects associated with driving.
Technical parameters of UMZCH D class
- Continuous power consumption 1240 Watts at 228 VAC.
- Overall efficiency 84% (converter has 89%).
- Claimed output power 2×500 W / 4 ohms RMS.
- The power supplied to both channels is 1050 W.
- Minimum load 2x2 Ohm.
Everything was tested using RMS meters and an oscilloscope, 4 ohm 150 watt resistor. Voltage 2x75 in standby mode. Under load it drops to 65 VDC.
As for cooling, the air enters through the appropriate ones. The fans have never turned on and will not turn on. They are only for the case when the ULF works, for example, in hot weather in the sun. Previously, there were class AB modules, and a fan was needed here. The hottest element is the output choke; it reaches a constant temperature of about 100C, regardless of whether the amplifier is running at full power or is standing without a signal.
Amplifier sound and performance results
Of course, most audiophiles have their own opinions and tastes. Let's just say one thing from ourselves: compared to classes AB and H, class D has a more linear and detailed sound. The bass is fast and dynamic, the center is smooth, but the treble above 10 kHz seems to be attenuated. There is power, control is very good.
The project fully met expectations. The only weak link in general is the power supply; if it were more powerful, the output would be 2 x 1500 W. Work is currently underway on a new version of the 2kW power supply, which is currently somewhat oversized.
This project is probably 5 years old and still works fine. About a dozen of these homemade UMZCHs have been sold, and they also work. This switching amplifier with ADS LX 2000 termination is regularly taken for special events and concerts. The amplifier weighs just over 5 kg. For comparison, the same ADS LX 2000 weighs about 30 kg, so the advantages of D class are obvious.
A selection of power amplifiers for a home DIY subwoofer
Today's post is about power amplifiers for a homemade home subwoofer. In a high-quality subwoofer, the amplifier plays an important role; it allows you to fully unleash the potential of the low-frequency speaker, provide a high damping coefficient and make the necessary adjustments to the volume and cutoff frequency.
In a DIY subwoofer project, you can use an amplifier in the form of a separate unit (case), which will contain a single-channel amplifier board and a power supply. Such a block will be connected to the subwoofer housing with wires. Or embed a panel with an amplifier and adjustments into the subwoofer body and get a more aesthetic design, like a factory product.
Let's look at several popular options for single-channel subwoofer amplifiers in different designs on the AliExpress site.
Board based on TPA3116D2
Find out the price
The selection opens with a simple and budget option for an amplifier board for a subwoofer based on TPA3116 D2. A pair of op-amps TL072C is responsible for signal processing. It requires a power supply from 12 to 24 V 5 A. The maximum power is about 100 W.
This option is suitable for a compact, desktop 2.1 system. The size of the woofer for the project is in the region of 4-5″, the resistance is 4-8 ohms.
The board dimensions are 83x55 mm, there is volume and cutoff frequency adjustment (20-180 Hz). Input on 3.5mm or JST jack.
Board based on TPA3255
Find out the price
Next, a board version based on TPA3255 from GHXAMP. The TPA3255 version of the class D amplifier is more modern and powerful than the 3116. The board is equipped with passive cooling of the chip with an aluminum radiator.
Maximum power into a 4 ohm load in BTL mode 260 W (THD <1%). This, coupled with a powerful power supply, is capable of “boosting” a 6-8″ speaker. Power required 30-48 V DC.
Board size 150x74 mm. The cutoff frequency is fixed - 95 Hz (can also work across the entire frequency band).
AIYIMA discrete amplifier
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A variant of a discrete mono amplifier with a heatsink from AIYIMA. The kit consists of two boards: an amplifier itself with an aluminum radiator and a control board with regulation and an RCA pair input. The level and cutoff frequency are adjustable.
Amplifier dimensions: 157x107x42 mm, control board - 112x55 mm.
The amplifier uses two pairs of Sanken output transistors. Maximum power 250 W. For power supply, you need a network transformer with a secondary winding with a midpoint voltage of 24-32 V. Such transformers were used, for example, in powerful music centers.
Board for IRS2092+IRFB4227
Find out the price Pre-amplifier
We cannot ignore the very powerful mono amplifier boards based on the IRS2092 + IRFB4227 mosfet combination. For projects with large 10″+ woofers and low sensitivity and design, a closed box.
The board measures 175x96x55 mm and produces a maximum of 600 W at 8 Ohms (900 W at 4 Ohms). But you need a powerful power supply, namely a transformer with secondary windings of 65-80 V with a midpoint and an additional 12-15 V.
There are no adjustments; you need to use a special preamplifier.
Triphonic panel HIFIDIY
Find out the price Option with DAC
Let's move on to panel options built into the body. An inexpensive option from HIFIDIY for a 2.1 system with a power of up to 50x2+100 W. An external power supply is required (hence the low price), the unit parameters are 12-24 V DC.
The amplifier with inputs and controls is mounted on an aluminum plate 2.5 mm thick. Panel dimensions 115.7x125.7 mm.
The lot has a choice of several options: TPA3118 (2x30+60 W), TPA3116 (2x50+100 W) and both options with or without Bluetooth. The second link is the same panel but with a DAC on board, you can connect optics and coaxial. Based on this option, you can build a 2.1 computer speaker desktop system.
ZHANZHI
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Next, another panel version, but with an integrated switching power supply and an external radiator. In the lot you can choose the required power: 150 or 200 W.
The heart of the panel is the TDA8950 or TDA8954 amplifier chip (200 W version).
Panel dimensions 200x145 mm. All required sizes are in the lot description. There is a full set of inputs: linear and high-level. The settings include phase reversal by 180 degrees and cutoff frequency adjustment (50-150 Hz).
ZHANZHI with balanced input
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The selection is completed by an advanced version of a panel amplifier for a homemade subwoofer from ZHANZHI. The declared power is 350 W at 4 Ohms, powerful transistors are used. There is a cutoff adjustment and smooth phase adjustment (this is useful for setting up a subwoofer indoors). In addition to the linear signal input, there is a balanced one on XLR connectors.
The switching power supply is integrated into the panel; you can select the required power plug in the lot.
The panel dimensions are 255x205 mm, the cutout in the body is 225x175 mm.
I hope the selection of amplifiers for a homemade subwoofer in a 2.1 audio system was useful, and you will choose an option to suit your taste and budget.
Happy shopping! Don't forget to apply AliExpress coupons and discounts.
