Dynaco ST-70 Original vs. VTA Bench & Listening Test Comparisons - Stereo 70 Tube Amp

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:

https://www.audiosciencereview.com/fo...

https://www.audiosciencereview.com/fo...

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