Headphone/line preamp with no GNFB

[dadod]

This is headphone/line preamplifier with very low distortion even with no GNFB used.
https://www.diyaudio.com/community/threads/gainwire-line-phone-non-gnfb-preamp.395695/#post-7265671

 

[dadod]

If someone wants to comment just go to the link in first post, there are all relevant data too.

 

[dadod]

I added some more photos in the original preamp post, follow the link.

 

[dadod]

I still have three spare boards of a preamp with the mosfet output ideal to drive headphone from 20 ohms to 600 ohms.
Price 25 EUR plus shipping.

 

[dadod]

Stll have spare bords dimension 250x120 mm. All the aditional components are transformer 30 to 50 VA 2x15 Vac and input selector.
This preamp use no global negative feedback and the volume control is between the gain block and output buffer, and that gives better signal to noise ratio.

 

[dadod]

This is real distortion measurement of this preamp.

I have one low impedance (10 ohm) headphones, hard to drive, and this preamp drives it with easy.

 

[dadod]

Merry Christmas and a Peaceful New Year

 

[dadod]

Some new here: https://www.diyaudio.com/community/...ne-non-gnfb-preamp.395695/page-2#post-7591547

 

[dadod]

Gerbers are here https://www.diyaudio.com/community/...ne-non-gnfb-preamp.395695/page-3#post-7733838

 

[Ryssen]

Is there a substitute for 2N5485?

 

[dadod]

Here is the BOM but go to the thred https://www.diyaudio.com/community/threads/gainwire-line-phone-non-gnfb-preamp.395695/ you will find all needed informations.