Sure.
http://www.diyaudio.com/forums/digi...ding-ultimate-nos-dac-using-tda1541a-516.html
post #5152.
Hopefully that doesn't upset Max too much 🙂
Output impedance will be that of the mu-node of the CCS plus the Xc of the coupling capacitor at your chosen frequency. (eg. 2k at 50Hz, 300 ohm at 1kHz)
Output at 0dBFS will be about 4.3vRMS.
Shane
Hi John,
Finally I manage to get these old 2SK170 and I have two quick questions -
- last year you said the schematics is outdated - is there any change from then ?
- is it recommendable to place two caps on the Jfet pins-plus/minus 5 V/say 10 uF/10 v ?
Thanks,
I am in deep mental masturbation after seeing that recent step up transformer schematic 🙂
I´m working something out to try with the AD1862 current output. I have transformers with around 1:30 turns ratio (salvaged headphone output transformers from a broken reel to reel deck). What about driving a ds1882 45k ohms silicon pot directly? The 45k ohms impedance will be reflected as 45 ohms or so to the primary... no I/V resistor on the primary! May need a zobel on the primary, to flatten the impedance rise with frequency?
Roughly estimating, 1mA p-p output current from the dac, into 45 ohms reflected resistance, that´s 45mV p-p. Times 30 it will be around 1.3V p-p out of the secondary.
Looking forward to pass some square waves to see what comes out. Also check freq response, harmonic distortion (I think transformers give predominantly 3rd harmonic). I wish I had all the stuff and instruments at hand, should be fun!
I´m working something out to try with the AD1862 current output. I have transformers with around 1:30 turns ratio (salvaged headphone output transformers from a broken reel to reel deck). What about driving a ds1882 45k ohms silicon pot directly? The 45k ohms impedance will be reflected as 45 ohms or so to the primary... no I/V resistor on the primary! May need a zobel on the primary, to flatten the impedance rise with frequency?
Roughly estimating, 1mA p-p output current from the dac, into 45 ohms reflected resistance, that´s 45mV p-p. Times 30 it will be around 1.3V p-p out of the secondary.
Looking forward to pass some square waves to see what comes out. Also check freq response, harmonic distortion (I think transformers give predominantly 3rd harmonic). I wish I had all the stuff and instruments at hand, should be fun!
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Hi EC, can you post a simple schematic for a treble boost filter for TDA1541A? This is my only concern running it in NOS mode that it looses this HF spectrum compared to an OS implementation so I would like to try compensate it somehow; thanks
Hi,
About tone controls, may I suggest this interesting post by Thorsten?
DIYHiFi.org • View topic - I call "********!"
I´m looking into the James-type tone control mentioned.
http://home.comcast.net/~stphkeri/James_SimpleToneControl.pdf
About tone controls, may I suggest this interesting post by Thorsten?
DIYHiFi.org • View topic - I call "********!"
I´m looking into the James-type tone control mentioned.
http://home.comcast.net/~stphkeri/James_SimpleToneControl.pdf
I realize you probably want a filter to correct the non-oversampling rolloff, not really a tone control... sorry if a bit off topic.
Are you into computer audio? I have been upsampling to 88.2KHz and dithering to 16 bits with the windows 7 audio stack. With 88.2 you are down only 1dB or so at 20KHz. And windows upsampling works as well as, or better than JRiver upsampling for me.
While we´re at it, I am also using EqualizerAPO, which is a very powerful parametric EQ and also integrates into the windows audio stack. I previously used EQ in JRiver but I´m happier now! One of the reasons might be that I changed my method for correcting baffle step: I now cut the frequencies above Fc, instead of the opposite. It´s also important to have no pre-attenuation in the EqualizerAPO config file.
Are you into computer audio? I have been upsampling to 88.2KHz and dithering to 16 bits with the windows 7 audio stack. With 88.2 you are down only 1dB or so at 20KHz. And windows upsampling works as well as, or better than JRiver upsampling for me.
While we´re at it, I am also using EqualizerAPO, which is a very powerful parametric EQ and also integrates into the windows audio stack. I previously used EQ in JRiver but I´m happier now! One of the reasons might be that I changed my method for correcting baffle step: I now cut the frequencies above Fc, instead of the opposite. It´s also important to have no pre-attenuation in the EqualizerAPO config file.
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Dear John, guys,
I've been unable to find suitable source for the recommended Rohpoint resistors. I need 2.5K for the transimpedance amp and that means I can't make it as a DIY honeycomb...unless I put 5 in series(10 overall).
I hope someone can point me to some source for them.
Thanks in advance.
M.
I've been unable to find suitable source for the recommended Rohpoint resistors. I need 2.5K for the transimpedance amp and that means I can't make it as a DIY honeycomb...unless I put 5 in series(10 overall).
I hope someone can point me to some source for them.
Thanks in advance.
M.
Hi, I got them here:
https://www.rhopointcomponents.com/
https://www.rhopointcomponents.com/components/resistors/precision-through-hole.html
Rather high shipping costs though.
I found something in Farnel /5 K-0.33W/ so you can check it somewhere closer to you. Do non know whether 0.66 W is OK with you.
Cheers,
http://uk.farnell.com/rhopoint/8g16d-10k-0-1/resistor-0-33w-0-1-10k/dp/9622055
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Sorry, mistyped - that is the right one -
8G16D 5K 0.1 - RHOPOINT - RESISTOR, 0.33W 0.1% 5K | Farnell element14
8G16D 5K 0.1 - RHOPOINT - RESISTOR, 0.33W 0.1% 5K | Farnell element14
Dual Mono DAC
😎
At last I had the time and energy to build -EC's- Dual Mono 1543 DAC.
After a couple of big mistakes (pin inversion on logic chips and lost of ground connection on on DAC chip) I finally succeded!
First impression is very good.
Unfortunatelly, I'm going on vacation so no more listening for a couple of weeks, but I couldn't go without finishing it. Probably will be the best (together the DIM4) and I will next make it DC coupled with John's idea.
More pictures on my Picasa album:
https://picasaweb.google.com/lh/photo/2dQJPRY1AcjmRChO38NlV9MTjNZETYmyPJy0liipFm0?feat=directlink
Thank you John!!!
M.
😎
At last I had the time and energy to build -EC's- Dual Mono 1543 DAC.
After a couple of big mistakes (pin inversion on logic chips and lost of ground connection on on DAC chip) I finally succeded!
First impression is very good.
Unfortunatelly, I'm going on vacation so no more listening for a couple of weeks, but I couldn't go without finishing it. Probably will be the best (together the DIM4) and I will next make it DC coupled with John's idea.
More pictures on my Picasa album:
https://picasaweb.google.com/lh/photo/2dQJPRY1AcjmRChO38NlV9MTjNZETYmyPJy0liipFm0?feat=directlink
Thank you John!!!
M.
Attachments
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Max, photo number 2 is awsome ! Art piece about how it is looking : you found a new art movement : you should write a manifest and exposition with x 100 size instead the little pcb !
Like very much this hand made job ! looking diy and not out of the factory !
Like very much this hand made job ! looking diy and not out of the factory !
Thanks guys and sorry: I'm on the mountains without internet access and I don't have here the schematics, but I'm sure a quick search on the thread will succeed.
Yes dear Eldam, I am better than CNC machine tool, hehe. I used a "Dremel". Not ellegant but eficacious.
😀
As usual, the important is the surroundings: excellent voltage regs, excellent voltage reference, excellent honeycomb I/V R.
Yes dear Eldam, I am better than CNC machine tool, hehe. I used a "Dremel". Not ellegant but eficacious.
😀
As usual, the important is the surroundings: excellent voltage regs, excellent voltage reference, excellent honeycomb I/V R.
