Dynaco ST-70 Original vs. VTA Bench & Listening Test Comparisons - Stereo 70 Tube Amp
Published at : 23 Dec 2025
In this video I compare the differences between a stock restored Dynaco ST-70 and VTA modded ST-70. Bench tests include frequency response, max clipping power, and THD+N at various power levels and frequencies. I also conducted a casual listening comparison with friends.
My bench test results seem to reflect the results found by ASR. You can find the VTA and Original ST-70 write ups here:
00:00 Introduction 00:58 Physical Comparison 04:13 Original ST-70 Bias Adjustment 05:09 Original ST-70 THD+N & Max Clipping Power 09:53 Original ST-70 Frequency Response 13:07 VTA ST-70 Bias Adjustment 14:11 VTA ST-70 THD+N & Max Clipping Power 18:02 VTA ST-70 Frequency Response 20:52 Bench Result Comparison 20:55 Listening Testing 29:08 Outro