At Amazon.com you will be able to find a great variety of converter boxes for old TV sets that are not equipped to receive digital signals, and the prices are affordable
it is an DAC (Digital to analogue converter
ADC analog digital converter
A digital converter converts the analog signals that are received by your TV to digital signals. Most TV providers only offer digital TV these days, so you only need it if you're still using analog.
a modem
Analog instrument are interface with digital instrument with the help of analog to digital converter(ADC).ADC converts analog signals to digital signals.
Information about a digital to analog converter can be found on the site Hardware Secrets which divulges that real world signals such as light and sound can be converted into digital signals by a circuit called ADC (Analog-to-digital converter) so that the information, once converted, can be processed and stored digitally.
DAC - Digital to Analog ConverterADC - Analog to Digital Converter
No, you should not need a digital converter box anymore (unless you are still using an old analog television). Most digital televisions sold are capable of receiving both digital signals and the few remaining analog signals (permitted for very low power stations only at this time).
The set top box that your provider gives you is what converts the Digital signal to the analog signal. The digital signal is compressed at the provider and sent to the end user. The "tuner" (which can be built into a tv, a set top box or a cable card) Then decompresses the digital signal and converts it into an analog signal. There is much more to this did not know how technical you wanted your answer.
From what I have been able to gather, the digital converter set top box will be needed only if you receive television signals via an aerial antenna and you don't have a digital television set. If you are hooked up to cable or satellite, the digital converter will not be needed. I, for one, use a "rabbit ears" antenna and don't have a digital television and will need to purchase the DTV converter box.
TV converter boxes are used to convert signals which cannot be understood by your TV into a signal which can be understood. A common use is to translate analog signals into digital ones.
A digital converter converts the analog signals that are received by your TV to digital signals. Most TV providers only offer digital TV these days, so you only need it if you're still using analog.