Atmasphere,
If the 15 dB of negative feedback was meant for discussion of the Melton MKT-88 tube amp used in the videos, I have no idea where you came up with this figure.
Melton advertises 0 dB of negative feedback, and doesn’t appear to have any components in a feedback loop when the chassis wiring is viewed.
MKT88P-80W
Integrated Amplifier
• Description
Product Description Specifications: Model: MKT88P-80W (Push Ball)
Power Output: 80 watt x 2 Output Impedance: 4.8.16 Ohm Amplifying Tube: 12AT7 x 2 pcs, 12AU7 x 2 pcs Power Tube: KT-88 x 4 pcs Rectifier Tube: 5Z4P x 2 pcs
** Tetrode Amplifier Design **
** No negative Feedback Design **
** Vacuum Tube Rectifier Design **
Superbly built integrated tube (KT88) amplifier.. .It employs specially designed simple circuitry for the well known Tetrode KT88 to make it sound at its best performance, coupled with powerful power supply and non-negative feedback design, capable of delivering lucid, melodiac, powerful sound with broad open soundstage.