Yes likewise it is a nice sounding pre. The Nutube in my build is cushioned by some soft rubber which is the red stuff you can see under the Nutube. A sharp knuckle rap on the case causes sound through the speaker but it only lasts a second.
A Nutube based I/V stage
Hi,
Congrats to this great project and those of you who've already built it. I definitely plan to do one myself.
While on the subject of Nutubes, I have one of those niggly ideas that wont go away.
I would love to see/hear a Nutube based I/V stage for the likes of RyanJ's 1541, Ian Canada's Fifo/isolator/dac boards or as a simple single board to install in various spinners and Dac's/
I have a feeling this would sound gorgeous and could turn into a really great little project / Group buy.
I'm fairly new to diy Audio and am not quite at the stage yet where I could design a circuit or modify an existing one but I'd be most grateful for any assistance or to see someone with the skills bung out a quick circuit to breadboard. This would be a fairly simple circuit no
With thanks,
Hi,
Congrats to this great project and those of you who've already built it. I definitely plan to do one myself.
While on the subject of Nutubes, I have one of those niggly ideas that wont go away.
I would love to see/hear a Nutube based I/V stage for the likes of RyanJ's 1541, Ian Canada's Fifo/isolator/dac boards or as a simple single board to install in various spinners and Dac's/
I have a feeling this would sound gorgeous and could turn into a really great little project / Group buy.
I'm fairly new to diy Audio and am not quite at the stage yet where I could design a circuit or modify an existing one but I'd be most grateful for any assistance or to see someone with the skills bung out a quick circuit to breadboard. This would be a fairly simple circuit no
With thanks,
Very nice kit Marra 😉 Everyone that listen to this preamp loves it. Mine is dead quiet as well.
SB
SB
Hi algar
Can you share the schematic on the supply? I might be doing sigma 11 and i need to know the injection point
Can you share the schematic on the supply? I might be doing sigma 11 and i need to know the injection point
Depends on the colour and intensity you wish.
Algar used 22k for a red LED to give you a starting point.
Algar used 22k for a red LED to give you a starting point.
Rled=(U-Uled)/Iled.
For a dimmed green LED 2.5 mA is more than enough. Red, green, yellow and amber LED’s have an Uled of 1.6 to 1.8V so you can use 1.6V as difference is small. For blue and white LED’s Uled is around 4V!!!
So with let’s say you have 12V supply voltage and a green LED then it will be (12 - 1.6)/0.0025=4.16kOhm
If you choose a standard resistor you would use a 4k7. Then you can calculate how much the current will differ from the desired value. It will likely be negligable.
For a dimmed green LED 2.5 mA is more than enough. Red, green, yellow and amber LED’s have an Uled of 1.6 to 1.8V so you can use 1.6V as difference is small. For blue and white LED’s Uled is around 4V!!!
So with let’s say you have 12V supply voltage and a green LED then it will be (12 - 1.6)/0.0025=4.16kOhm
If you choose a standard resistor you would use a 4k7. Then you can calculate how much the current will differ from the desired value. It will likely be negligable.
Last edited:
Please mind this is general info so you will know how to calculate a series resistor for any low power indicator LED. I haven’t bothered to check this specific device.
Last edited:
When I built mine, I tried a standard 4k7 with a blue LED and it popped :-o (I still don't know why!).
So I would suggest to start conservatively with a higher value such as 10k or more and adjust from there.