Hi Billy. I think the tvr1 & 2 are to trimp the DC output. I put my DC voltage multimeter. The red I put on the output (if we facing the pcb from the bottom, they're on the left side. If I'm not mistaken there are 4 points with colour cables) & black to the ground. Before I move the tvr I marked...

Halo Shipsupt. My SRM717 sound is very weak despite the vol knob on maximum. Apparently R60/61, 63/64 & other power resistors' values mostly have changed. I believe its transistors' values also have changed. How did you adjust the DC offset ?

R60/61 4.7 M (likely 1 W) & R63/64 same 4.7 M (likely 1/4 W). Recently my Stax (headphones 4070 & SRM 717) don't wanna play. Despite the vol control maximum, I only heard small music & distorted. Whn I pulled it out & test R60/61 apparently the value becomes 8 M & 6 M. R63/64, 40/41, 42/43 &...

Halo Spaceace. Are the sound cards the amps ? I think it's running on high V because there are high V caps (10 uF/ 400 V) on each card. What unit for (& where) of the ICs regulator?

Hi Duncan. I agree with you. I assembled Borberly headphone amp as dual mono. I was shocked about the air/ soundstage. At the beginning I thought why the sound became strange. Later on I realised that's the good effect of dual mono. Yes, it's hurting wallet as the price of the 2 PSU is more...