Go to  Advanced Search

Recommendation report : apparatus to amplify headphones and test sound quality

Show full item record

Files in this item

Files Size Format Description   View
Ellis_G_APSC_479_2012.pdf 4.730Mb Adobe Portable Document Format   View/Open
Title: Recommendation report : apparatus to amplify headphones and test sound quality
Author: Ellis, George
Issue Date: 2012-01-09
Publicly Available in cIRcle 2012-09-20
Series/Report no. University of British Columbia. Engineering Projects Project Lab. APSC 479, Project Conclusion Reports, 2012
Abstract: The purpose of this project was to prototype a hi-quality headphone amplifier, and to measure the amp’s performance using a dummy (pure resistive) or real headphone load. The idea was to either demonstrate how a headphone amp could quantifiably improve sound quality played out of a source, or to at least investigate typical usage scenarios and metrics for measuring sound quality. Key metrics identified for characterising the amp’s performance were: input and output impedance, signal-to-noise + distortion (SINAD), and the gain response over audio frequencies. The original discrete amplifier design chosen for the project was changed a more forgiving LM1875 op amp design during the prototyping stage due to deficiencies in parts ordered. The second amp was measured to have 21 Ω input and < 1 Ω output impedances, and a noise floor at -85 dB(VRMS) relative to the audio signal. Qualitatively, the amplifier was able to drive audio transducers from computer Line Out with impedances from 8 Ω to 100 Ω without noticeable noise or degrading audio quality. It was concluded that a medium-quality audio amplifier is not necessarily suitable for all applications. Recommendations include further testing and continued prototyping of the more ambitious (but trickier) hi-fi design.
Affiliation: Engineering Physics, Dept of
URI: http://hdl.handle.net/2429/43245
Peer Review Status: Unreviewed
Scholarly Level: Undergraduate

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893