Comparing performance, I can say it's more than a Behringer MK1700. I still have a large PA power amp, which I will compare with the Q17 when I get a chance.
Hello Everybody!
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A small improvement could be made to the decoupling of the OPA1641. Rather than using C4, C5, which are connected to ground, it is better practice to put a single decoupling capacitor directly between V+ and V- as close as possible to the pins 4 and 7.
Tibi, you mentioned earlier that the matching of Q9 and Q11 is important. When using NDC7003, can we take the satisfactory matching granted, or is it still necessary to measure the two transistors within the same package? Thank you, Miklos
NDC7003 mosfets are already matched and beside this are on the same silicon substrate, this mean the mosfets are also thermally matched.
Tibi, I checked the whole thread again, ...on your boards in C7 position you used Auricap XO as well as Mundorf MCap EVO SilverGold Oil.
I wonder which of the two will give you a better sonic result.
Thank You!
I wonder which of the two will give you a better sonic result.
Thank You!
Depending on your source/preamp, you could get away without.
Just make absolutely sure you never have any DC
Just make absolutely sure you never have any DC
I only meant it ironically, I'm waiting for Tibi to comment so I can decide which capacitor to choose!
Its position is not as an input cap that blocks DC upstream, its in series with the opamp output.
What cap to choose is a subjective one, you’re probably the only one that can answer that by experimenting in your amp.
What cap to choose is a subjective one, you’re probably the only one that can answer that by experimenting in your amp.
I highly NOT recommend low ESR and low ESL capacitors on Q17 and in general on any analog design.
Sanyo Oscon are very low ESR capacitors designed specifically for digital applications. It will improve your low jitter clock, or digital reclocking circuit, but will kill sound of your preamp or amplifier.
Selecting the right capacitor for a specific application is science, but unfortunately on this forum is lot of voodoo.
Sanyo Oscon are very low ESR capacitors designed specifically for digital applications. It will improve your low jitter clock, or digital reclocking circuit, but will kill sound of your preamp or amplifier.
Selecting the right capacitor for a specific application is science, but unfortunately on this forum is lot of voodoo.
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Use the CDC recommended in BOM. It is a top one at the right price and will fit the board.
C7 is placed in negative loop of OPA1641. Will contribute to dc blocking, but you still need to take care on previous stage to be DC free. C7 can not be eliminated, due output is lifted by Q7.
PCB's are at home.
PCBs look great, no visual blemish or scratch. I am satisfied!
I'm busy with work for the next week, but next weekend I'll finally get around to mounting the pcb. I plan to turn the Q17 into a design gem. The board itself as well as the transistors will be attached with golden screws. I asked Tibi about the sound difference between the Auricap XO and the Mundorf from the MESGO series, because I'm planning to choose between the two. But I'm leaning more towards Mundorf, in conjunction with pcb this combination will look really great. CDE looks kind of plain to me.
I also have the gerber files ready for the active PSU, which will go into production at the beginning of June. Gently modified for me by prasi.
Have a nice day 🙂
PCBs look great, no visual blemish or scratch. I am satisfied!
I'm busy with work for the next week, but next weekend I'll finally get around to mounting the pcb. I plan to turn the Q17 into a design gem. The board itself as well as the transistors will be attached with golden screws. I asked Tibi about the sound difference between the Auricap XO and the Mundorf from the MESGO series, because I'm planning to choose between the two. But I'm leaning more towards Mundorf, in conjunction with pcb this combination will look really great. CDE looks kind of plain to me.
I also have the gerber files ready for the active PSU, which will go into production at the beginning of June. Gently modified for me by prasi.
Have a nice day 🙂
