05-16-2026, 10:56 PM
Some of the Williamson amps made by Heathkit and Dynaco advertise very low harmonic distortion. Attached is the Heathkit WA-6M manual. Though this amp is capable of very high output, the distortion at 20 W from about 50Hz -10KHz is under 0.7%. I believe that some of the lowest distortion comes from preamps that use "Op-Amp" ICs such as the NKM2068 and the TI RC4580 have THD ratings as low as 0.0005 - 0.001%
Re guitar amps with tube rectifiers such as Fender, Ampeg, etc., Guitarists expect that the characteristics of the particular tube rectifier such as voltage drop vs current contribute to the "sound" of the amp. Many of these amps also have a "Standby / On" switch that cuts B+ to the tubes in Standby mode.
Re guitar amps with tube rectifiers such as Fender, Ampeg, etc., Guitarists expect that the characteristics of the particular tube rectifier such as voltage drop vs current contribute to the "sound" of the amp. Many of these amps also have a "Standby / On" switch that cuts B+ to the tubes in Standby mode.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
Best Regards,
MrFixr55
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
