ToyX project EQ Linearizer study case4

Finish each band circuit by jump wire.

Finish EQ power circuit and do placement estimate.


Test two bands EQ function together (by cascade).


Feed SG signal in band 4 for function test.


Measure output signal form band 5 and estimate circuit where need modify for meet design.


Band 4 top view.


Today receive EQ box order from two month ago.
This is front view with ten volume knobs. Each channel with five knobs to control EQ.


Inner picture.



Rear picture.

ToyX project EQ Linearizer study case3

Tuning each inductor value for meet LC band pass filter.


Finish each band pass  structure.


Test each band the frequency of drift .


Side view picture.

Estimate EQ  Linearizer outline and prepare drawing  of  EQ case.

ToyX project EQ Linearizer study case2

Placement Band pass filter.


Solder capacitor of band pass filter.


Estimate placement.

EQ Linearizer  will be mono mono stack by two layer.

ToyX project EQ Linearizer study case1

I design a DIY EQ Linearizer call X project.
Simulate the band filter for to correct phase shift issue.
The 5 band pass CF will be 50Hz,250Hz,1KHz,4KHz,12.8KHz.

50Hz first band in band1
Band1: 5~100Hz(5 pcs 20hz band pass filter inside 5~20,20~40,,80~100hz)
橫跨頻寬20Hz 中央是相位0度,左-Pi 是-180度 & 右+Pi是 +180度相位 .

Use other program to verify L-C frequency.

250Hz first band in band2
band2:250Hz (5 pcs 60hz band pass filter inside 100~160,160~220,,340~400hz)
橫跨頻寬60Hz 中央是相位0度,左-Pi 是-180度 & 右+Pi是 +180度相位 .

1KHz first band in band3
band3:1KHz (5 pcs 240hz band pass filter inside 400~640,640~880,,1360~1600Hz..)
橫跨頻寬240Hz 中央是相位0度,左-Pi 是-180度 & 右+Pi是 +180度相位 .

4KHz first band in band4
band4:4KHz (5 pcs 1Khz band pass filter inside  1.6K~2.56K,2.56k~3.56k,,5.4K~6.4KHz)
橫跨頻寬1KHz 中央是相位0度,左-Pi 是-180度 & 右+Pi是 +180度相位 .

12.8KHz first band in  band5
band:12.8KHz(5 pcs 2.56K band pass filter inside 6.4K~ 9.86K,9.86k~11.52K,,16.64k~19.2Kband...)
橫跨頻寬2.56KHz 中央是相位0度,左-Pi 是-180度 & 右+Pi是 +180度相位 .

由此可知........
低頻橫跨頻寬20Hz 中央是相位0度,左右差10Hz 分頻器相差就達到180度相位 誤差.
低頻分頻器相差 ,造成訊號失真大,破壞音質,而不只是分頻器相差, 造成時間差而已 .
低頻分頻器相差 ,造成訊號失真, 聲音就易糊成一團 ,低頻彈跳感減弱.

.........................不知數位及DSP 等化器要如何補, 如何調?

Toy5 Take Marantz 7 and 和田茂氏 pre-amp case to build D/A

Because when I finish D/A and I connect D/A behind Marantz 7 and 和田茂氏 pre-amp then the pre-amp will decay audio signal so I know pre-amp not Hi-Fi enough.

Toy3 D/A coplue capacitor of Balance output estimate

unknow PP capacitor


Bennic PP capacitor

final use ERO PP capacitor

Toy 2 D/A Power define and verify

D/A Power plan defien and verify.   

Toy 4 D/A with 6Dj8 buffer

High voltage Tube 6Z4

through R-C-L-C to 230V

Change 6DJ8 to E88CC

D/A module CS8416+WM8740 fix volume to buffer.

Volume control 

Toy1 My first time Audio DIY ... D/A Box.

PCI D/A Card



Hand Make D/A Box
Main PCB is design for Video streaming I just take 19V adpater connect to  +/-12 V ,+5V,+3.3V switching supply power to D/A.
Sub PCB is PCI Audio Card I just take SPDIF signal connect to receiver CS8416 then transfer to PCM feed WM8740 then decode Audio L/R .