How a MM Phono Cartridge Works

How a MM Phono Cartridge Works

Phono amplifier is designed for a phono signal amplification while using Turntables amplifier inside for special sound equalization circuit (RIAA) for restoring vinyl, it cannot be used for other purposes. But do you know How a MM Phono Cartridge works -- the key component that pick up the signal from the LP vinyl which is amplified.

A MM phono cartridge is a micro-manufactured electromechanical device that tells your entire audio system what is happening along the half-mile groove that is cut into a typical analog disk.

Phono cartridges contain transducers that convert one form of energy into another. Phono cartridges do it by translating variations in the groove walls into electrical signals. Great inventer Thomas Edison pioneered this technology way back in 1877 using a stylus on a tinfoil or wax cylinder.

The stylus (needle) moves horizontally and vertically as the groove of the record travels underneath it. A coil of wire and magnet at its other end generates a small audio signal.

Since then, there are two main types of phono cartridges: moving magnet (MM) and moving coil (MC). A tiny magnet rests on the end of a stylus shank that is suspended between two coils. The vibrating magnet induces a small current in the coils. 

To decide which phono cartridge will work best for you that depends on a few factors.

You will need to know how the cartridge attaches to the turntable you have or are going to buy. There are two types as below.

Standard mount that is far the most common: Two screws, half an inch apart, thread through the cartridge body to secure it to the headshell, which then plugs into the tone arm.

P-mount that is The four prongs at the back of the cartridge plug directly into the tone arm. A setscrew goes through the side of the cartridge at the back to hold it in place on the tone arm.

Elliptical (Bi-radial) or Spherical Stylus

The stylus (or needle) is really the heart and soul of the cartridge and accounts for about 90% of the cost of it.  Almost all styli have industrial diamond tips. There are two needle shapes: elliptical and spherical. Elliptical needles pick up more information from the record groove and are typically the choice of audiophiles. DJs choose spherical needles because they sit higher in the groove and result in less record wear.

Finally, a LP Turntables Tonearm Signal Cable from the output of MM phono cartridge will be connected to phono stage amplifier to amply weaker signal.There is a HIFI LP Turntables Tonearm Signal Cable that is good partner for connecting them.

More details about the cable, please find LP Turntables Tonearm Signal Cable 5 Pin Din Connector Silver Plated OFC Wire Connect for Vinyl HIFI Audio 1.5m

Tips for Adjusting Car Amplifier Gain

Tips for Adjusting Car Amplifier Gain

You will be happy after you buy a car audio amplifier, but it may be a little trouble when you set up or adjust its tone and gains after you connect it with the car speaker units according to the diagram. The article might help you set up it successfully after you read it. It is provide a general guide or tips, of course, you also shall refer to the manual.

Contrary to popular belief, car audio amplifier gain controls aren't volume controls. They are input sensitivity controls and are intended to allow the user to adjust the sensitivity of an amplifier to match the output voltage from the head unit. This is needed in car audio because there is no standard for head unit output voltage.

The purpose of properly setting the amplifier gain is three steps. 

First and most importantly, it is to allow the amplifier to reach max output when the head unit volume is at max without causing the amplifier to clip. 

Secondly, gain can be limited to prevent over-powering your speakers if the amp can put out more than the speakers can handle. 

Third, gains can be used to help balance a system, meaning adjusting the relative output levels between amplifiers so that they are operating at the correct levels for any given head unit volume setting. 

This guide is primarily aimed at addressing the first: achieving max output without clipping the amplifier. Here are a few things you'll need as below.

Power Amplifier HIFI 4 Channel 4 x 80W Brushed Aluminum alloy casing American Descent Silver 

Back View

Inside View

Hearing protection

You need ear plugs or muffs while setting gain as the system will be operating at high output levels. Hearing loss is very quick as sounds become louder, and you really need to protect your ears because building a good sounding sound system will be a waste of time if you can't hear it. Also since the output will be high while gain is being set you should perform this in a location and at a time when it won’t disturb other people.

A CD with proper test tones

You need a CD recorded at 0db reference level that contains various test tones. 50-60 Hz is good for setting subwoofer levels and 1000-1500 Hz is good for setting main stereo amp levels.

Basics setup

1. Fader, tone controls, loudness/expansion, etc. 

Fader and balance controls should be set to “normal” or zero or “in the middle.” Loudness and bass boost should be OFF and all EQ set to flat.

2. Dedicated subwoofer volume controls 

Many amps have outboard subwoofer volume controls and head units have dedicated internal subwoofer volume adjustments. These should be set to MAX.

3. Set all amp gains to their lowest point before starting. 

This is usually full counter-clockwise.

4. Input sensitivity switches
If your amp has a selector switch for different input sensitivities, start by setting it to the highest setting. These are typically expressed in voltages, for example .2-1v, 1-3v, 3-8v. Start with the higher numbers (ex. 3-8v which is the lowest sensitivity). If you can't get the amp to clip at those settings, try the next one down until you find the clipping point. You can disregard generally what the markings themselves say since there's no real standard for marking them. Never trust your system's well-being to those arbitrary numbers, they're just there for reference and are best ignored.

5. Work with one gain at a time.
For example, if you have both L&R gain for your front speakers, you'll set each side separately. If multiple amps, unplug (remove the signal from) all but the amp you're working with. If it’s a 4+ channel amp, typically you'll have only a single L & R gain, so treat it like a 2 channel. If it has multiple gains adjust each one separately.

After you set up them below, Now you can test it, the procedure as below.

1. Play the appropriate test tone

Put on your hearing protection and start your car. Select a test tone that is in the pass band of the amplifier channel you are setting. For example, if it’s a subwoofer amp select something audible below the subwoofer LP crossover setting. We like to use 60Hz. Set your CD player on its lowest volume setting and play the track in repeat mode.

2. Find the head unit clipping point

Slowly turn up the head unit volume and you should begin hearing the tone. Keep turning it up until you can hear the tone change. It will become “sharp” sounding and is an obvious change. This indicates the head unit preamp is now clipping. Note the volume level and slowly turn the head unit back down until the tone changes back to its original sound. Note this volume level. If the head unit clips at below its max level, you should NEVER turn it up past the point where the clipping begins.

If the head unit never clips, this is good and indicates you have a quality preamp. Set the volume control to about 75% or 80% of whatever its max might be.

3. Now find the amplifier clipping level

Turn off the system and disconnect all the RCA cables except for the amplifier channel you are setting. Now turn the system on and place the test tone in repeat, and turn the head unit up to the max unclipped volume discovered in the previous step. Move to the first amplifier gain control and SLOWLY turn it up until you hear the tone change quality like before. This step may get loud, so be prepared. Once you find the gain setting where clipping begins, slowly back it off until the clipping stops. This is your proper max gain setting for this amplifier channel. Leave it there. Now turn off the head unit and repeat the above step for all the other amplifier channels in your system.

After setting all the gains you can enjoy your system. 

There is also a car audio amplifier with tubes 6992 as preamplifer, if you like warm tube taste.

HIFI Car Amplifier 4 Channels Audio 6992 Tube Preamplifier Transistors Power Stage Class AB RMS Power 85 W x 4

If you like the car audio amplifier, please visit the links for details.

HIFI Car Amplifier 4 Channels Audio 6992 Tube Preamplifier Transistors Power Stage Class AB RMS Power 85 W x 4

 HIFI 4 Channel 4 x 80W Power Amplifier Car Audio Brushed Aluminum alloy casing American Descent Silver 

Know-how about glossary of Terms for Related Bluetooth technology

A

A-GPS (assisted GPS): an augmentation to Global Positioning Systems (GPS) where the mobile phone network can provide the almanac and ephemeris data. By using the mobile phone network, the GPS receiver does not need to decode data from the satellites, thus both speeding up acquisition of a fix and allowing fixes to be made in areas where GPS signals are too weak to allow decoding of data but are nonetheless strong enough to be used to measure time of arrival (see also GPS)

acquisition time: the time it takes a GPS receiver to acquire satellite signals and determine the initial position

A2DP (Advanced Audio Distribution Profile): This profile defines how high quality audio (stereo or mono) can be streamed from one device to another over a Bluetooth® connection

Android: Android is a software platform for mobile devices based on a Linux kernel, initially developed by Google and later the Open Handset Alliance

aptX®: CSR's proprietary low-latency, high-quality audio coding technology for high performance wireless audio transport applications such as Bluetooth stereo/A2DP

attach rate: represents the percentage adoption of additional products or technologies on to the primary or hosting product

B

baseband: describing that part of a radio telecommunication system in which information is processed before modulating on to, or after demodulating off, a radio frequency (RF) carrier wave

BiCMOS or Bipolar CMOS: is a process which combines bipolar junction transistors on complementary metal oxide semiconductor (CMOS) technology. The combination utilises the high speed, high gain and low output characteristics of the bipolar technology with the high density logic gates of the CMOS technology. It has advantages for RF performance, reduced power consumption and low noise circuits

bipolar: bipolar refers to the enhancement of the conduction of current within a transistor that enables the control of a larger electrical current thereby providing an amplified signal

BlueCore®: means the CSR family of single chip CMOS based (see below) Bluetooth® solutions which integrate onto one chip the radio frequency (RF), baseband and communications protocol stack

Bluetooth®: is an open wireless protocol for exchanging data over short distances from fixed and mobile devices

Bluetooth® low energy, Bluetooth® LE, BLE or BTLE: is designed to work side-by-side with and complement Bluetooth. It operates in 2.4 GHz ISM band. Devices using Bluetooth low energy will be smaller and more energy efficient than their classic Bluetooth counterparts

Bluetooth® v3.0 + High Speed: In April 2009, Bluetooth® v3.0 + High Speed (HS) was launched to support a higher speed, alternative media access controller and physical layer (PHY). Classic Bluetooth retained the control to ensure power consumption is minimised, but a higher speed radio is activated as and when needed to transfer large files quickly. Currently HS supports 802.11 radios, but in future may evolve to support the much higher speed UWB

Bluetooth® v4.0: see Bluetooth low energy

Bluetooth® Smart: see Bluetooth low energy

C

cellular: derives from cellphone and means a mobile phone or other device which communicates through a network of radio cells

CMOS: Complementary Metal Oxide Semiconductor technology: a semiconductor process technology that uses planar transistors to make chips that consume relatively low power and permit a high level of integration

chip: short for a microchip; semiconductor device or integrated circuit

coexist/coexistence: means the ability of two systems to operate in parallel without interfering with the other

codec: short for coder-decoder. A device or software program capable of encoding and/or decoding a digital data stream or signal. A codec encodes a data stream or signal for transmission, storage or encryption, or decodes it for playback or editing

connectivity: enabling two electronic devices to communicate with each other and transfer data (voice/audio/music/picture/word files) using radio waves

Connectivity Centre: a term first promulgated by CSR in its application to wireless connectivity solutions. The Connectivity Centre brings together many aspects of short-range wireless connectivity products with excellent coexistence capable of operating concurrently without degradation in optimum performance of each of the individual functions

CSP (chip-scale package): a semiconductor package which is as small as the semiconductor chip and is used for small form factor applications such as mobile phones, PDAs and wireless devices

CVC™(Clear Voice Capture): CSR's own digital signal processing (DSP) software technology for enhancing audio quality on wireless products. A modular suite of algorithms includes acoustic echo cancellation and noise suppression that can be applied in a granular fashion and tuned to suit the application

D

DDFA® (Direct Digital Feedback Amplifier): CSR's proprietary digital amplifer technology, a Class-D audio switching amplifier architecture that employs a fast, highly accurate digital feedback loop and which sets new standards in sound quality

design win: CSR records a design win when a product using one of its ICs becomes Bluetooth® qualified

die: another word for chip: often used to refer to the chips whilst they are still an integral part of the silicon wafer or where they have been cut from the wafer but are, as yet, unpackaged

digital: the representation of data by a series of bits or discrete values such as 0s and 1s

DSP (digital signal processor): a specialised microprocessor with an optimised architecture for the fast operational needs of digital signal processing

E

EDR (Enhanced Data Rate): allows for faster data transfer over Bluetooth

eGPS™(enhanced GPS): as the name suggests an enhancement to GPS whereby measurements are made by the GPS receiver on the signals received from the mobile phone network which allow both fine time and frequency assistance to the GPS receiver. This further accelerates acquisition of a fix, as well as allowing, when GPS signals are unavailable, fall-back to a fix made solely from the measurements made on the cellular network (see also GPS)

ERP System (Enterprise Resource Planning System): is a company wide computer software system used to manage and co-ordinate internal and external resources. The system facilitates the flow and management of information to improve data sharing and decision making using a computer network

F

FM or FM Radio: is a radio wave broadcast technology that conveys sound – voice and music – using a carrier wave which varies its frequency during transmission, producing high quality audio clarity and tone

fabless: short for fabricationless, a business model used in the semiconductor industry, where the manufacture (or fabrication) of ICs is subcontracted to a foundry

fabless semiconductor company: company that uses a third party semiconductor fabrication service to manufacture silicon chips as opposed to fabrication facilities owned directly

feature phone: a mobile phone which has added functionality over and above a base model designed specifically to meet the requirements of a particular market segment. Typically these features can include a digital camera, Bluetooth® connectivity, FM radio or MP3 player. These phones are intended to occupy the mid-market segment

firmware: software which interfaces with and typically configures and manages the hardware in a system

flash memory: electronic memory where the contents (usually an applications programme) may be programmed prior to use and which retains its contents irrespective of applied power

foundry: a wafer manufacturing site that makes integrated circuits

G

Galileo: a global navigation satellite system (GNSS) being built by the European Union (EU) and European Space Agency (ESA)

GNSS (Global Navigation Satellite Systems): the standard generic term for satellite navigation systems ("sat nav") that provide autonomous geo-spatial positioning with global coverage

GLONASS (Global Navigation Satellite System): is a radio-based satellite navigation system, developed by the former Soviet Union and now operated for the Russian government by the Russian Space Forces.

GPS (Global Positioning Systems): a satellite based radio navigation system that allows receiving devices to take an accurate location fix of the device on the surface of the earth. Positions are derived by measuring the time of arrival of signals broadcast from the constellation of satellites, and knowledge of the instantaneous positions of the satellites. (The information required to calculate this being broadcast at a very low data rate by the satellites themselves, and is known as almanac and ephemeris data.)

H

HID (human interface device): any device to interact directly with humans (mostly input) 
such keyboard, mouse, joystick, or control devices such as a remote controls

host software: software running on the system in which the device is embedded

I

IC (integrated circuit): a semiconductor device consisting of many thousands or millions of interconnected transistors and other components

ISM Bands: ISM Bands or Industrial, Scientific and Medical are radio frequencies reserved around the world for unlicensed use originally intended for industrial, scientific and medical products rather than general communication. Their international unlicensed status makes them suitable for lower power communication systems like Bluetooth®, WirelessLAN etc. and means they are being widely adopted in these areas

L

Location-As-A-Service (Laas): see LBS

LBS (location-based services): are information and entertainment services, accessible with mobile devices through the mobile network and utilising the ability to make use of the geographical position of the mobile device. LBS include services to identify a location of a person or object, such as discovering the nearest banking cash machine or the whereabouts of a friend or employee.

LE: Bluetooth® low energy.

M

MAP-X™: audio processor SoC family

memory: any device that can store data in machine-readable format which may include RAM, ROM and Flash

MEMS (microelectromechanical systems - also written as micro-electro-mechanical, MicroElectroMechanical or microelectronic and microelectromechanical systems): the technology of very small mechanical devices driven by electricity; it merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology. MEMS are also referred to as micromachines (in Japan), or Micro Systems Technology - MST (in Europe).

microcontroller (MCU): often defined as being a microprocessor together with its memory and a means of allowing input and output

Module or Multi-chip Module: is a self contained component that comprises a number of integrated circuits (ICs) and discrete components on a substrate to allow the module to be used as if it were a single component.

MP3: a file format which compresses or shrinks voice and music files for transfer between one electronic device to another whilst retaining CD quality audio

non-cellular: as used by CSR means an electronic device which uses Bluetooth but is not a cellular device

N

NFC (Near Field Communication): is a short-range high frequency wireless communication technology which enables the exchange of data between devices over a distance of about four centimetres. Its application includes secure payment transactions using the customers mobile phone or transfer of files for example photo images from a digital camera to a PC

nm (nanometre): is a unit of length in the metric system, equal to one billionth of a metre

O

ODM (Original Design Manufacturer): a manufacturer that designs and manufactures equipment for another company who will, in turn sell this to the end-user

OEM (Original Equipment Manufacturer): a manufacturer that sells equipment to retail and wholesale outlets

P

PDA (personal digital assistant): a pocket-sized personal computer

package: the package of a semiconductor is the physical and electrical interface between the chip and the system in which it operates

playback: the characteristic of a device to be able to play selected music or video tracks which are stored on that device

PND (Personal Navigation Device): is a portable electronic product which combines a positioning capability (such as GPS) and navigation functions and enables the user to find out where they are located and get directions to move from one place to another

protocol: a method by which two dissimilar systems can communicate

R

RF (radio frequency): frequencies of electromagnetic waves between approximately 3 kHz and 300 GHz

ROM (read only memory)

S

semiconductor: a material, typically crystalline, that can be altered to allow electrical current to flow or not flow in a pattern; common semiconductors are silicon, germanium and gallium arsenide and the term is also used to apply to ICs made from these materials

silicon: a semiconducting material used to make wafers, widely used in the semiconductor industry as the basic material for integrated circuits

short range: Bluetooth® is principally used for communicating over ranges of up to ten metres

smartphone: a generic name for a voice centric mobile phone that also offers advanced capabilities often using a computer-like operating system (OS) to enable PC functionality

sound bar: a special (sometimes wireless) loudspeaker which creates a stereo- or surround-sound effect from a single cabinet, usually much wider than it is high, and mounted above or below a display device, e.g. atop a computer monitor or beneath a television screen.

stereo headset: a mobile headset which connects to a mobile phone, PDA, MP3 player or other device using Bluetooth® and sits on both ears of the user

SoC (System-on-Chip): is a technology that takes all the necessary electronic circuits and parts for a complete system and integrates them into a single circuit (silicon chip)

software stack: is a layered set of software subsystems or components that are combined and integrated to provide a fully functional product or service with structured communication through the stack

software solution: a solution where instructions and data are read from memory (or memories) and then the instructions interpreted and executed by a microprocessor to modify the data in the intended way

Sub-band coding (SBC): is any form of transform coding that breaks a signal into a number of different frequency bands and encodes each one independently

T

Tier One: a description of a leading, normally global manufacturer that supplies products in high volume to end user markets

TTFF (Time to First Fix): the time it takes a GPS receiver to find satellites after the user first turns it on (when the GPS receiver has lost memory or has been moved over 300 miles from its last location)

U

UWB (Ultra WideBand)

urban canyon: is a built up urban environment similar to a natural canyon which interrupts radio signals. It is caused by streets cutting through dense blocks of structures, especially skyscrapers or other tall buildings

V

VAM (value added manufacturers or value added manufacturing): where the value of gross output is greater than the value of intermediate inputs used in production

V&M: voice and music

W

wafer: a disc made of a semiconducting material such as silicon, usually between 150mm (6’) and 300mm (12’) in diameter, in which integrated circuits are manufactured; a wafer may contain several thousand individual integrated circuits

Weightless: a proposed, proprietary, highly secure, open wireless technology standard for exchanging data between a basestation and thousands of machines over white space radio channels

white space: radio frequency bands - moreso in the UHF radio spectrum - allocated to (television) broadcasting services but not used locally

Wi-Fi® (Wireless Fidelity - also known as IEEE 802.11): a data-centric wireless communication standard typically associated with wireless computer networks at home and in the office and public spaces, operating at raw radio rates from 1Mbps to 600Mbps

Wi-Fi® Direct: a standard that allows Wi-Fi devices to connect to each other with no need for a wireless access point

WLCSP (Wafer Level Chip Scale Packaging): the technology of packaging a chip at the wafer level instead of the traditional process of assembling the package after the wafer has been diced into individual chips (see CSP)

Y

yield: when used in connection with manufacturing, the ratio of the number of usable products to the total number of products on a wafer