2025年12月7日 星期日

DAC rectify tube 6z4 change to 6x4 ~2


drill slot because double trace layout




playback -1 ...before

                                                      ... after


playback -2 ...before

                                                      ... after


playback -3 My all ...before

                                    ... after  w obviously diff. fu
                                         Mariah Carey wesome


playback -4 ...before

                                   ... after  oops wrong record


playback -5 ...before

                                                      ... after












 

2025年12月4日 星期四

rectify tube 6z4 change to 6x4






6x4 raytheon

                              6Z4 北京曙光


tube amp. DAC w 6z4....coffee shop
https://kao211.blogspot.com/2012/10/da-build-in-human-vocal-4-times.html







https://kao211.blogspot.com/2023/07/jukeboxss-audio-amplifier-modify-volume.html

before tube Tung-Sol 6x4
replaced rectify tube  by 6x4 raytheon
sound more nature ~ more detail


low noise amp. w 6x4 raytheon inside
https://kao211.blogspot.com/2024/07/diy-another-rare-low-noise-tube-pre_28.html




2025年11月11日 星期二

2025年11月2日 星期日

P-P circuit implement......this case just could tie circuit to push pull amp. 


















CH-R 6JM6 PP playback sound 1
CH-R PP 6JM6 G1 shunt Imp.resistor tie to GND

CH-L PL519 PSE playback


CH-R 6JM6 PP playback sound 2

CH-L PL519 PSE playback


CH-R 6JM6 PP playback  sound 3

CH-L PL519 PSE playback







CH-R PP 6JM6 G1 shunt Imp.resistor tie to -32V playback sound 1

CH-R PP 6JM6 G1 shunt Imp.resistor tie to -32V playback sound 2

CH-R PP 6JM6 G1 shunt Imp.resistor tie to -32V playback sound 3






CH-R PP 6JM6 G1 shunt Imp.resistor tie to -32V playback

CH-L PL519 PSE playback


CH-R 6JM6 PP playback w RIAA (switch in DAC)

CH-R 6JM6 PP playback no RIAA (switch in DAC)













 

2025年10月26日 星期日

211 VT4C mono amp. L-ch SPK w noise..the check record


https://kao211.blogspot.com/2011/01/toy11-vt4c-211amp-5-verify-211-ac.html


recall ...211 VT4C plate voltage setup in 1265V w tube 211


recall ...high voltage capacitor explode

                                
                                                                

https://kao211.blogspot.com/2019/03/mono-mono-vt-4c-211-tube-amplifier.html


the record







                                      after repair ... L-ch playback check only














need re-order high voltage transformer...this case just could tie circuit to push pull amp. 

                    Ref. Cyclotron Amplifier...because Cathode output the OT Imp.

                                setup up on high voltage transformer

this case just could tie circuit to push pull amp.
                                        to estimate amp.tube g1 voltage




last time

                                            
fix 2nd stage p-p voltage


shunt Ref. voltage to estimate amp.tube g1 voltage














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