Here to say, Χρόνια Πολλά, Salas.
Best festive wishes to you and all this wonderful community.
Despite being horrible 2020, this year has brought me great diy highlights. Many of them, if not all, thanks to your expertise.
Back on topic, my only regret with DCG3 is that I don't have two of them
Thanks Siberia. Merry Christmas to all.
After three years of enjoyable listening with the DCG3 I recently feared that I had caused some serious damage, which resulted in distressing headphone noises. With limited troubleshooting skills, I feared the worst. While carrying the unit (sans cover) to my table in a dimly lit room I noticed that one of the led bars remained lit (from stored capacitance I presumed) and that its related MJE sink was cold relative to the others. I soon realized that while rearranging my audio components, I had inadvertently pressed down on the DCG3’s top cover, causing it to come in contact with the MJE sinks (and possibly other parts). A new BC550 and sink insulators made for a surprisingly quick fix, and I’m back in the saddle. Bottom line…those arrays are more than pretty lights
While I had the hood up I changed out the split bobbin transformers for quieter toroidal types, and rechecked offset. It’s now back in the center of my modest but enjoyable system. Thanks for a terrific bit-o-kit Salas, and for the work you do to make ‘the good stuff’ accessible to the rest of us.
Keith
Nice quick fix Keith. Saved by the lights indeed. You are welcome.
dcg3 as opamp for dac output bAL to SE output.
attached is the «IanCanada» dac output for sabre. The one in my topping d10s 9es3038q2m has the same topology but with different opamp and slightly different resistor values (about double the values for opamp network) and i would have to desolder the capacitors to know their values. The last opamp is the one i'd like to swap for dcg3. So the gain that opamp sees is between 2 and unity....could this be a problem? i will measure the already in there feedback cap soon... but i guess i could just extrapolate the value from dcg3 guide....
cheers and merry christmas to everyone of course
attached is the «IanCanada» dac output for sabre. The one in my topping d10s 9es3038q2m has the same topology but with different opamp and slightly different resistor values (about double the values for opamp network) and i would have to desolder the capacitors to know their values. The last opamp is the one i'd like to swap for dcg3. So the gain that opamp sees is between 2 and unity....could this be a problem? i will measure the already in there feedback cap soon... but i guess i could just extrapolate the value from dcg3 guide....
cheers and merry christmas to everyone of course
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ok thanks.
Opamp choice is not really critical(from earlier posts) is that correct...? What would be the main desirable carateristics of a good dc servo opamp?
Don't want to make «princess», but ad823 is not that cheap.... would opa1656 do it? my dac uses it already as i/v . they are low noise, cmos input, but smd. I don,t mind a bit of dc offset.
https://www.ti.com/lit/ds/symlink/o...45034&ref_url=https%3A%2F%2Fwww.google.com%2F
Opamp choice is not really critical(from earlier posts) is that correct...? What would be the main desirable carateristics of a good dc servo opamp?
Don't want to make «princess», but ad823 is not that cheap.... would opa1656 do it? my dac uses it already as i/v . they are low noise, cmos input, but smd. I don,t mind a bit of dc offset.
https://www.ti.com/lit/ds/symlink/o...45034&ref_url=https%3A%2F%2Fwww.google.com%2F
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Hey Mark, great to know you got it up and running again. For assessment of a possible favorite new gen servo chip we will be happy to know about your further auditions and standard AD823 BOM chip comparisons opinion. In other words what characteristics count more for you in your system with your favorite music across more listening sessions.
I've been on vacation for two weeks and have been working frenetically on packaging my preamp. It's close, but will be a week or two before it's finished. I think you will like the result.
Here's a sneak preview. I'm building up a 20K Daven attenuator. I decided to use SMD resistors. I built this today; it was a lot of work.
-Henry
Here's a sneak preview. I'm building up a 20K Daven attenuator. I decided to use SMD resistors. I built this today; it was a lot of work.
-Henry
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Thank you, Salas, and the same to you. I've enjoyed playing with your circuit. I must have over a hundred hours in this project by now. Everything always takes so much more time (and money) than I expect at first, LOL. I have limited machine tools, so chassis work is a challenge.
Here's a few more pictures.
It's interesting (to me) that the output can swing to the positive rail. I'm used to thinking in terms of bipolar cascodes so I was surprised the first time I saw it clipping at +17V on the scope. Not that it matters for headphone use, but I'm curious if you measured the distortion when M2 saturates.
-Henry
Here's a few more pictures.
It's interesting (to me) that the output can swing to the positive rail. I'm used to thinking in terms of bipolar cascodes so I was surprised the first time I saw it clipping at +17V on the scope. Not that it matters for headphone use, but I'm curious if you measured the distortion when M2 saturates.
-Henry
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uPA68H vs LSK389
Salas... I read, somewhere in the first few posts, that you tested both devices, but prefer the uPA68H. I think that today, it would still be true. Do you agree? Boards are on the way, and I must gather the necessary components. But there are over 5K posts to the thread, it is impossible for me to read them all.
Salas... I read, somewhere in the first few posts, that you tested both devices, but prefer the uPA68H. I think that today, it would still be true. Do you agree? Boards are on the way, and I must gather the necessary components. But there are over 5K posts to the thread, it is impossible for me to read them all.