I think that that'll flip the polarity. I think that that's a bad idea, although you can always turn your speakers around so that they face the wall.
Possible a couple of L-Adapter was the next buy: one for the laptop and other as spare or to to use for heaters here.
Since its a single stage unit, the common cathode gain versions will reverse phase. The cathode follower version will not. Says so in the CF link and elsewhere in the thread. Its recommended to reverse polarity at the speakers input to restore absolute phase. I compared that once again when listening to the shunt NFB gain version. Back and forth reversing the 4mm connectors at the monitor loudspeakers end. Subjectively inconclusive, maybe a bit smoother imaging on some records maybe not.
Technically important to remember do that when combining things. Like surround speakers or an active subwoofer if fed from a different phase point in the signal chain. So not to cancel sound waves energy with the mains.
Haven't had much time to revisit the PCBs this week, but I was able to get in a set of new cathode resistors for the nine-pin boards, going from a 180R to a 270R to get the cathode voltage and plate voltage up a bit. I was able to swap them in, and immediately ran out of time. Daddy duty called (I was up to start dinner- Japanese Curry with shrimp
)Also, making a note here on observations regarding the boards, and some modifications the PCBs should have implemented before being finalized.
- Nine-pin board PCB traces that were missing have already been fixed in the design file.
- Labels on the topside of the board- at the very least for all of the terminals. You can just make out a hasty post-it note I placed on the board with some penciled-in labels
- Maybe relocate the output capacitors farther from the terminals and edge of the board in order to give more room to read the terminal labels. Should be an easy "quality of life" fix that wont be much work to implement. These huge DC-link type capacitors are too good of a value to give up on so I want to make sure the board will happily work with them. If anything it'll give more room for even BIGGER caps, like these guys- Kemet R71H series 10uF, 450V (EDIT- after looking this over the capacitors will foul the mounting screws on each side of the tube sockets- maybe I'll leave this one alone? I'd have to move way too much around to accommodate it seems. Might be able to simply move the caps, mounting holes, and sockets towars the "top" an equal amount, then re-route the traces. Hmmmm.)
- Add a 2P screw terminal for the filament wiring to jump to- I find having it hardwired directly off the board via the given pads is not terribly convenient during testing. It would be nice to have it all easily disconnected. Makes swapping out PCBs later in a finished chassis easier, and allows for easy testing outside of a chassis after initial PCB stuffing with parts. It would work easily as well for DC or AC heating. I implemented this on a couple other PCB designs, and to be honest I have no idea why I didn't here I'm almost considering simply deleteng the B+ input functionality from the extra 2P terminal on that end of the board, and running the filament wiring there, since the B+ already comes in with all the other Input/Output wiring.
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Added a 2P screw terminal for filament wiring on-board, and relocated the PSU reservoir cap to center of board. Liking this much better already. Not sure I will relocate the cap outlines- It'll take too much compromise on the layout and I don't want to get the mounting holes much closer to the sockets as of now. Also added labels on the other side of the board for all the I/O terminals. Getting close to calling it done.
I should say I still copyleft my designs... I love open source
That's also why I'll probably never make any money making this stuff LOL It's all about spreading triode love
It's nice to see you feel similar working on this
I've never done a ground plane though.
That's also why I'll probably never make any money making this stuff LOL It's all about spreading triode love
It's nice to see you feel similar working on this
I've never done a ground plane though.
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Not necessarily, it is flanked by a ground terminal on either side, and can simply be left unpopulated if so desired. All the clearances are safe for the voltages we will see. On this board and others I've gotten several private suggestions that they want the option of feeding everything but the heaters from a single side.
Users can feed B+ from the other side if they so desire as well.
For the noval board with the 6P43P-E, looks like the 270R cathode resistor got me closer to the 2/3 B+ i was looking for at the plate, but not yet there. With 2.5K (2x 5K parallel) anode load I'm seeing 167 volts anode, 13 cathode. 50mA draw per channel. Maybe a 330R or a 390R next.
It'll be interesting to compare the two, 6P43P-E/6CW5 versus the 6V6/6AQ5.
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I plan to have a handful of designs with free/open access to the design files, and have a few printed boards ready to go for those who want one. Not trying to get too deep into selling but it'll be nice to have them recycle funds back into the hobby. I know my limits and by no means want or intend to go into full production. Just a small little corner of the internet with helpful stuff that works well. I build enough gear that it'll be nice to not have to point-to-point the same half dozen circuits all the time when building things too!I should say I still copyleft my designs... I love open source
That's also why I'll probably never make any money making this stuff LOL It's all about spreading triode love
It's nice to see you feel similar working on this
I've never done a ground plane though.
That's all I'll really go into here to keep from derailing the thread or bringing it too deep into selling/commercial talk.
Right? I make it easy if you want a board fro like 10$ to avoid designing your own Do it point to point if you like though, I just shared an example of the last time I did it poijnt to point in another thread...
I'll break even if I sell stuff like this but you've seen this before... 1000$ can give someone a triode amp and I break even. Besy Buy sells one that will make pancakes and shine your balls for less money though
Do it point to point if you like though, I just shared an example of the last time I did it poijnt to point in another thread...I'll break even if I sell stuff like this but you've seen this before... 1000$ can give someone a triode amp and I break even. Besy Buy sells one that will make pancakes and shine your balls for less money though
There's a chance someone will touch the B+ while fiddling with inputs and outputs. Even when power is off but the cap holds.
I am totally on board with this. May be not dangerous dangerous, but unnecessary dangerous.
How about a jumper on the trace feeding the B+ pins on the I/O terminal from the reservoir capacitor? That way for folks that don't use it it the jumper can be left off and the terminal and pads won't be live. Power users or more cautious types can populate it and have the convenience of it all on one side? I can even make it a resistor outline so that folks can run a dropper resistor there should they so choose.
I can easily toss a spot for a bleeder resistor on the board too, plenty of real estate to fit it in. One of those things that's easily overlooked at the PSU by newer users, so a good idea.
Seems like a straightforward and easy modification that would serve all users well.
With this being such a simple and beginner friendly design I want to make sure any potential users feel comfortable using the board so definitely worth having the function be optional in my opinion.
I can easily toss a spot for a bleeder resistor on the board too, plenty of real estate to fit it in. One of those things that's easily overlooked at the PSU by newer users, so a good idea.
Seems like a straightforward and easy modification that would serve all users well.
With this being such a simple and beginner friendly design I want to make sure any potential users feel comfortable using the board so definitely worth having the function be optional in my opinion.
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This set of PCBs is based on the gain version. I haven't really considered a follower version using this PCB. At the very least I think that I would need to modify the cathode circuitry to accommodate a couple larger resistors, and modify the output traces. Easy enough work, but I think better served with a separate PCB so the routing doesn't get too crazy or overwhelming at initial build out. What I think I'll do is once this design is finalized I'll rearrange a set just for the follower version.