Perfect! So You can easily verify level of vibration with and without DC blocker.

No I done it with Mjolnir 2. Schiit equipment use very similar construction transformers quite sensitive to DC offset in AC main. Should help in Mjolnir 3 case too.

Vibration can be removed by proper DC blocker.

In some point it's possible. More tests are needed done by others than me :). For now I'm only able to make few prototypes and it's takes too much time. But for sure it could be perfect kit for someone who has Takstar already and basic DIY skills to solder driver to the new shell.

With this rig link

This version sounds more open. There is no material damping so there is no shell effect. When I wear them I don't feel that there is anything between my ears and external world. At the same time, the diaphragm is under control so the sound is not flashy or harsh.

Version 2 modifications of Takstar headphones. Much lighter shells. New pads.

Dac2541 was on my radar for its calibration feature until I notice that I couldn't replace original filters with DIY. Build-in filters appear be similar or identical to filters from other Soekris products family and are quite similar in sounding. When I wrote that difference could be significant...

As you can see below DIY filters are not for DAC2541. For others DACs no problem at all, and yes there could be significant difference in sound according to chosen filter. Link

DAC2541 does not support DIY filters.

Those are components of tubes heating. Two caps close to regulators seems to be "dirty" symmetric power supply mentioned somewhere in this thread (not part of heating circuit)

There is no problem to run amp without heating connected. Regulators for tubes heating are marked in circles. If you remove them you have perfect spot to connect GND(big pad) and+ from external regulator by for example banana socket mounted on back of the chassis . It could be even simple...

You have full picture, you decide. According to some research lowering tube heater voltage from specified 6.3 V to 6V as we have extends tubes life about 50% so I have no problem to short a little bit that period :)

If you want to improve tube filament heating circuit before final closure the chassis there is way to do that by increasing capacity of two 1000uF/25V capacitors near power switch. Voltage for heaters are controlled by two voltage regulators LF60A with fixed voltage of 6V and according to data...

Look at the picture in second post. Eardrum is angled vs ear canal. From my perspective simplified model of human ear need to have cone ear canal and angled mic. Outer ear creates harmonics making things complicated :)

The measurement will be different so flip of microphone is needed. That's why my rig has two eyes and ears to made it easy :) In real world after initial measurement of both drivers I just use one side.

All caps are film caps. You can use anything what suits you and fit small space (maybe WIMA would be better). Multicolor cap is 0.270uF 600V for HV, all others are 0.220uF.

On this picture you can see heat sinks for all bridge rectifiers. I also use passive radiators on enclosure. Unfortunately I don't have now picture of the bottom of board where across bridge rectifiers input I put caps. I ended with 0.220-0.270uF film caps only without resistor, but it is my...

Thanks. I was thinking about ODAMs only in signal path as replacement of 0.47uF Wimas because they are extremely expensive. 1000uF I already replaced wit Elna Silmic II. I also discovered that lowering temperature of heater bridge rectifier and using snubber eliminate problem of amp long run...

@ShortBtwnHdset Did you installed ODAM capacitors? Can you compare them to original Wima or Mundorf?

I just wanted to find out from the source why Nyquist's theorem is violated, what are the pros?

Unfortunately in this two tubes comparison there is no night and day difference, so nobody should run to near shop to buy new one or in panic sell old one. Tesla is allrounder easy to listen, S4A has litte more high extension whit all benefits and consequences. That's all.

No idea who makes them but they sounds better than Tesla and they have regular legs not gold one.

I just switched to S4A E88CC for check. Noise level on high gain is quite similar but 2nd and 3rd harmonics are more or less equal. Raised 3rd H maybe caused by my rig. More or less from my perspective you have to have amazing tubes and perfect power source to get closer to low gain performance...

Tesla ECC88 with gold pins.