Appreciate the honesty. So consensus is that it's not a big enough difference to make mid boost footswitchable. I'm going to think about it a bit longer but I'm leaning towards taking your guys' advice. It's always something I can add later if I think it's worth it.
PicknStrum wrote: ↑Thu Oct 08, 2020 5:00 pm
3. I'm going to wire the power LED from the relay supply - so, I'll use a 12v rated LED. Would I still need 330R and 1N4003 or are those just "decoupling" the power LED from the heaters when tapping into PT wiring?
You don't need the resistor, diode or terminal strip between that power tube and the PT. I wired my LED directly to the terminal strip by the 12V regulator (directly under the LED)
PicknStrum wrote: ↑Thu Oct 08, 2020 5:00 pm
5. I'm going to use Martin's footswitchable FET boost with a push/pull pot. I'll probably have some questions when getting into that wiring.
The layout I sent you has that covered. In the layout I separated the switch from the pot for clarity but that's exactly how you'd do it. If you're not using DIYLC, let me know and I'll make a PDF of it and will email it to you.
I agree with Marcus about the mid-boost. It's subtle. I've been noticing that with my single coil equipped guitars, if I engage the mid boost I can make the clean channel a bit crunchy more easily by digging in a little harder. I don't think I miss not having it on a FS, but it's your amp and if you want it, that's all the reason you need to do it. Shouldn't be much more effort than not having it.
Thanks Vertigo - Love to hear that about the LED going direct to the 12v. That will definitely help with decluttering. I'm curious to know why the additional resistor and diode is in the circuit when connected to the heaters. I'm going to try and dig that info up through a search but if anyone knows, I really like to get a grasp of how everything works in amp circuits so I'm interested to know.
EDIT: After a little digging, looks like the 330R is a current limiter to affect brightness of the LED - I'm guessing since I'll be using a voltage regulator, I won't need a current limiting resistor? So I get that the diode is keeping current moving one direction, but why do we need it here and why is it oriented that way?
Also, thank you for your layout Vertigo - it's fantastic! Also, helps me since my boards are setup based on Martin's ODS Eyelet patterns and I'm going to use the FET boost - you have all that setup neatly (including the foil direction!) I didn't respond at first because it took me a few days to attempt to open it and when I did, I had a little trouble (on my end; not anything to do with the file you sent).
Last edited by PicknStrum on Fri Oct 09, 2020 5:07 pm, edited 1 time in total.
norburybrook wrote: ↑Fri Oct 09, 2020 2:49 pm
wire your power LED like this. So much easier and nicer wire routing....less parts
ODS LED.png
M
So it looks like you would still recommend I go through a 1k limiting resistor to the LED, correct? I was just going to tap off the voltage regulator without a current limiting resistor - would that work also?
If you go with 12V relays, use the Hammond 166F12C (that Martin recommended to me) and the 7812 voltage regulator, you can connect a 12V LED directly to the terminal strip. You don't have to do it that way though. I have to order another one of those LED for the amp I'm working on now. If you're interested, I'll shoot you the part number after I find it later today.
PicknStrum wrote: ↑Fri Oct 09, 2020 3:00 pmSo it looks like you would still recommend I go through a 1k limiting resistor to the LED, correct? I was just going to tap off the voltage regulator without a current limiting resistor - would that work also?
You need a current limiting resistor somewhere. It may be in the panel mounted unit (check the data sheet) or somewhere else, like on the relay supply board.
Vertigo wrote: ↑Fri Oct 09, 2020 3:45 pmI have to order another one of those LED for the amp I'm working on now. If you're interested, I'll shoot you the part number after I find it later today.
It's good to just post things like this on the forum. Others may find it useful.
Understood - So I can either use a classic LED and a current limiting resistor (around 1k - I can use an online calculator) on the FWR board (or thereabouts) - this may be the route I go.
or
I can order a panel mount LED with built-in resistor rated for 12v. Something like this:
Thanks for the link vertigo! So it looks like that one you posted doesn't have a current limiting resistor built in. I'm wondering since it's tapped off the voltage regulator that it's good enough... Or does it have a limiting resistor and it just doesn't say it on the data sheet?
Not trying to beat a dead horse. Just trying to understand. After Martin's post yesterday, I did more reading up on LEDs and resistors. Sounds like if there isn't a resistor in series, it could potentially be fine but if there is any voltage increase, current could increase exponentially and burn out the LED, which really isn't the end of the world. But it's easy enough to throw a resistor in series.
ChopSauce wrote: ↑Sat Oct 10, 2020 5:26 pm
Not sure but I guess Vertigo pointed you to the most "original Dumble-alike" LED & support.
Frankly I'd prefer having to solder a resistor than having a "poor looking" LED on an ODS (especially) panel...
Makes sense. My plan has been to use a resistor. I just didn't know if that had one. I don't see it listed, so I'll just throw one in like norburybrook posted.
PicknStrum wrote: ↑Sat Oct 10, 2020 5:41 pmMakes sense. My plan has been to use a resistor. I just didn't know if that had one. I don't see it listed, so I'll just throw one in like norburybrook posted.
Those parts have an internal resistor. Order the part number that corresponds to the voltage you intend to run. I see options for 2, 6, 12, 24 DC, and 125 AC.
I don't know if it's in there or not, but it's definitely not on the data sheet. Maybe I'm naively assuming there is one in the housing because they list so many different variants for use with different voltages. It seems logical that they'd have different resistors based upon the voltage specs. Being that this is my first amp, please don't assume I'm correct.
Also, other than following the schematic and layouts provided on this site, I didn't make any purchasing decisions on what was the most original Dumble-alike. I respect how some builders do their absolute best to make as close a replica as possible, but that's not me. I was more interested in finding something that fit the AN chassis and would work off an easily accessible voltage. I followed the layout and used the limiting resistor at first, but the LED was so dim that I could barely see it. That's why I went straight off the VR.
It has to have a current limiting resistor if the specified operating voltage is greater than the diode's Vf (at which point it starts conducting significant current). Vf varies by color, typically from about 1.6 to 4+.
PicknStrum wrote: ↑Sat Oct 10, 2020 5:41 pmMakes sense. My plan has been to use a resistor. I just didn't know if that had one. I don't see it listed, so I'll just throw one in like norburybrook posted.
Those parts have an internal resistor. Order the part number that corresponds to the voltage you intend to run. I see options for 2, 6, 12, 24 DC, and 125 AC.
Cool - I'll go with the one Vertigo listed. I like the look of that one much better. Bonus that it has an internal resistor.
