tube to replace opamps in cd player

[intensate]

hello all.
I am trying to use valves to amplifiy the o/p from a tda1541 dac so to bypass the opamps.
I am using this circuit basesd around a quad 22 phono stage .
When I use a 1m as R1 and feed a normal un modded cd o/p It works like a buffer with only a small gain increase.
So I tried a 100k R1 and it over loads so I know it has gain but I am unsure how to get the gain I need so I can use the o/p from the Dac chip
This is my first time playin with tubes and I have now made a discharge lead for the caps....ouch!!so I dont get zapped.
Can anyone help me make this work

Thanks

 

[DUG]

I just looked at the tda1541 datasheet.

I have limited experience with these devices but it looks like this DAC would really be happy with a 0V current sink. Fig 1, top right.

I don't think a tube cct can work this way.

Anyone with more experience should be able to add to this.

 

[flatheadmurre]

How much of the circuit is left ?

The I/V resistor still there ?

 

[hidnplayr]

check out Lukasz Fikus Lampizator

for instance, http://lampizator.eu/LAMPIZATOR/REFERENCES/SATCH/IMG_5501.jpg

Lots of info about TDA1541 and replacing opamps with valves in CD players

 

[revintage]

Make R1 47ohm to get proper loading of the 1541. Unfortunately the EF86 has far to much gain so it won´t work anyway. If you triodestrap it it will work well, but gain will be a little on the low side.

This is good stuff that you probably missed: http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a.html

But stay away from Lampizators tube designs! Lots of good info on his side except for them.

 

[artosalo]

What you say about my circuit:

An externally hosted image should be here but it was not working when we last tested it.

It has 19 dB voltage gain, steep attenuation above 20 kHz and low distortion and output impedance.

 

[artosalo]

This is the frequency response. The gain scale seems odd, but it is due to current feed input and corresponds 19 dB voltage gain.

An externally hosted image should be here but it was not working when we last tested it.