Hi all - let me start by apologising if this is covering old ground here. sorry!
I am currently starting to build enclosures for my vintage German broadcast amps, a couple of Tab v372, a couple of Siemens v272, and Neumann PV46D for now.. The latter has actually been completed and I have placed a DCDC converter (24v>48v) and the circuit based on this scheme (figure 2) https://sound-au.com/project96.htm. But I may have bodged it a bit..
It works, and on a good day is very clean, but recently I noticed sometimes, with some mics, there is a more noise on one channel (always the same channel, not the mics, not the preamp). I am using a 63v 220uf cap at C9 instead of the specified 10 uf (???) which eliminated the noise of the DC converter very well, on first multiple listens and comparisons. I ma using blocking caps of 50v 22uf, and the zener network as illustrated, but I don't really know how to improve upon it without guidance, I am very good with a soldering iron, but very noob with actually circuit logic.. I have seen other designs using 63v 100uf caps for blocking as well as DC filter..
Can anyone help me optimise this whilst being as economical as possible (i.e. not adding too many extra components)
Many thanks!!!!
I am currently starting to build enclosures for my vintage German broadcast amps, a couple of Tab v372, a couple of Siemens v272, and Neumann PV46D for now.. The latter has actually been completed and I have placed a DCDC converter (24v>48v) and the circuit based on this scheme (figure 2) https://sound-au.com/project96.htm. But I may have bodged it a bit..
It works, and on a good day is very clean, but recently I noticed sometimes, with some mics, there is a more noise on one channel (always the same channel, not the mics, not the preamp). I am using a 63v 220uf cap at C9 instead of the specified 10 uf (???) which eliminated the noise of the DC converter very well, on first multiple listens and comparisons. I ma using blocking caps of 50v 22uf, and the zener network as illustrated, but I don't really know how to improve upon it without guidance, I am very good with a soldering iron, but very noob with actually circuit logic.. I have seen other designs using 63v 100uf caps for blocking as well as DC filter..
Can anyone help me optimise this whilst being as economical as possible (i.e. not adding too many extra components)
Many thanks!!!!