Vacuum Tube I/v Analogue Stage For Tda1543

[aht]

Howdy everyone,

I'm modify & develop valve I to V converter from Thunderstone Audio and would like to work with chip TDA1543.

My schematic still use analogue filter RLC for smooth cutting edge treble control.

I hope you'll like my Idea with complete PCB.It's use 175VAC/0.2A & 7.5 VAC/1A for rectifier.It's spec from Thunds... is

V out = 2V Rms for digital full scale
Z out < 400 Ohm (rising at LF)
Z load > 10Kohm
THD = < 0.02% (2nd Harmonic dominant)
Freq. Res. 20Hz-20KHz +/- 0.3dB (no O/S)

Component list
Resistor ¼ W 1%
R1,R9 1.69K
R2,R10 1.8K
R3,R11 100K
R4,R12 330
R5,R13 51
R6,R14 180K
R8,R16 1M
R19 2K
R20 499
R21 1M
R22 2.4M

Resistor 2 W1%
R7,R15 22K
R17 47K
R18 3.3K

Non polar capacitor
C1,C6 6.8nF/100V
C2,C7 1nF/100V
C3,C8,C5,C10 0.47uF/250V
C4,C9 33pF/250V
C18 0.1uF/250V

Electrolite capacitor
C11,C13 100uF/400V
C12 10uF/400V
C14,C15,C17 3300uF/25V
C16 100uF/25V

Diode
D1 1N4007
BRD1,BRD2 BRIDGE DIODE 400V/10
ZD1,2,3,4 1N4759A

IC
IC1 LM317T

Mosfet
Q1 IRF830

Inductor
L1,L2 6.8mH

Vacuum tube
VB1 6DJ8/6922

Socket
9 pins miniature

Transformer
IN 220VAC OUT 175VAC/0.2A, 7.5VAC/1A

Mail me if you havy any question

[aht]

With single site PCB.

Use pin 6,8 from TDA1543 for input of vacuum tube I/V analogue stage.

No adjust, No trim, No problem and resonable price for DIY.
PCB is coming soon.

Mail me if you have any question

[aht]

I can't create PROTEL file to PDF file by add printer in "ADOBE ACROBAT PRINTER" after my computer had crashed from some user.So if anybody want some PCBs please email me for them

Or somebody can help me please suggest me suddenly

regard
AHT

[maudan]

Hi

Very nice project.

What about the implementation of 1.75mA current sink you've placed in the electrical diagram? You didn't specify any component for this purpose.

Regards

Maurizio

[aht]

1.75mA come from TDA1543 I think it maybe from Rload = 1.7/2.2k = 1.75mA.

Do you think about this idea with this picture?

Regard
AHT

[Andypairo]

May I ask why you are using coupled inductors for the anti-sinc filter?

Cheers

Andrea

[Andypairo]

Originally posted by maudan
Hi

Very nice project.

What about the implementation of 1.75mA current sink you've placed in the electrical diagram? You didn't specify any component for this purpose.

Regards

Maurizio

I think it is there for simulation purposes - i.e. it represents the iout of the DAC (that for a full scale signal IIRC is slightly more than 2 mA)

Cheers

Andrea

[maudan]

Hi AHT

Are you sure about 2.2kohm load?

Your calculation is wrong.

[aht]

3.85/2.2k = 1.75mA...ha ha ha...I'm wrong.
1.7V = Vrms of TDA1543 with I/V resistor.

I borrow an inductor concept from Thunderstone Audio and you can use another way for anti-sync filter such as gyrator.

Regard
AHT

[X.G.]

hi,aht

I think lowering the impedance of your I/V circuit to 1/2 is better,cause the output level of 10K-20KHZ is higher.