One of the more frequently requested projects on HeadWize has been a switchbox for selecting multiple audio inputs.
My reason for constructing this project was to develop a design for a compact integrated stereo amplifier suitable for use by a poor (but sound quality conscious!) student living in a university or college dorm.
When used with headphones - especially personal monitors, audio limiters (also called clippers) can help maintain safe listening levels. Without a limiter, large transients in audio signals could generate dangerous SPLs in headphones, although the average volume might be set at an acceptable level.
The Model HC 6 Headphone Console is a six channel headphone amplifier, consisting of six stereo amplifiers, two master stereo inputs and six individual stereo inputs. The two master stereo inputs feed a separate left and right bus to each of the six headphone amps.
This project is probably the most ambitious so far, and can be expected to be very expensive. On the positive side, it is also capable of excellent performance, and can be tailored to suit your exact specifications. There are several different input modules in the series, the first being the microphone and line input.
Transporting high-dynamic-range analog signals from one piece of equipment to another is not a trivial task. Even subtle design variations can make huge differences in the equipment's ability to reject interference from the ac power line and other sources when the equipment connects to a real-world system.
JT-11-BM High Level High Current Differential Output Stage with DC Servo.
Micropower and low-voltage op amps allow you to build high-performance analog-signal processors that require no batteries or wall transformers. Instead, you can use a capacitor as a power source.
Most PCB amps that have been produced have been poorer than tube amps, for reasons having nothing to do with the PCB. Like plastic bobbins in transformers, this does nothing to change the tone. The other poor practices that go with a cost-cutting attitude that were introduced at the same time may, but PCBs are unfairly indicted.
A stereo power amplifier is limited in its output power by two main factors - the impedance of the load and the internal power supply voltage. To obtain more power, one has very limited choices - other than the purchase of a more powerful amp.