Great point Neil, since most modern headphones are extremely efficient, the amplifier may operate the vast majority of the time in the crossover region, leading to all sorts of high-order harmonics. There seems to be the same perception in headphone amplifiers…
Hello George,
Thank you for taking the time to read and comment on this post, and I appreciate your perspective as someone with years of experience in the high-end audio industry.
You may be correct that "no one complains about the lack of a perfect log…
Other Parts Discussed in Post: INA134 Monolithic difference amplifiers are integrated circuits that incorporate an operational amplifier (op amp) and four or more precision resistors in the same package. They are incredibly useful building blocks for analog…
“Hey! Turn it down!”
You’ve probably heard these words at some point, especially if you’re like me and enjoy listening to music LOUD ! If you decide to oblige and actually “turn it down” then what must you do? Reach for the volume…
Other Parts Discussed in Post: OPA1688 , OPA1622 This post is co-authored by Bharath Vasan .
In part three of this five-part blog series , we introduced a simple control-loop model for distortion in an operational amplifier (op amp), repeated here in Figure…
Thank you for this article. I never wasted a thought on how R/R is accomplished. And on large signal, it usually is a don't care anyway. But for audio use, teh dual input stage can create even audible artifacts, depending on signal composition. On my…
I think it is important to clarify at which frequencies this effect matters. I know it is important for high frequency circuits (e.g. radio circuits and high speed data buses) and when considering electromagnetic emissions (for CE/FCC compatibility tests…
Other Parts Discussed in Post: OPA1622 This post was co-authored with John Caldwell .
In the final installment of this five-part blog series, I will discuss pop/click noise in operational amplifiers (op amps) driving headphone loads, and some techniques…
Hi Ian
That's quite an interesting circuit. I think there may be a typo in the transfer function equation given above. I worked through the calculations in 'Active Volume Control for Professional Audio' and I believe that the R1/R2 term should be multiplied…
Other Parts Discussed in Post: OPA1688 , OPA1622 This post is co-authored by Bharath Vasan .
Pop quiz! Take a look at the total harmonic distortion and noise (THD+N) curve in Figure 1. It’s for an OPA1688, a 36V, 10MHz audio operational amplifier (op amp…