@Thermionman1970 I liked the transformer and tube rectifier as well. I feel safer with isolated circuits, and silicon diodes just aren't as much fun and aren't anything to look at! I think adding coils would be interesting, but I don't know where I should put them. If I build enough of these circuits and had ways of changing the waveforms, I could make a tube synth.
@Thermionman1970 In theory, yes, but if I actually do it...now that's a different story! I should try that sometime when I get around to it. The problem is there so many things that I want to try, and I'm usually so preoccupied with the current project that I forget (right now it's video on reel-to-reel tape). I really should start making a list of things to test, measure, and explore. I'll start that list right now.
@LeviMan2001 Also, would it be possible to use a 12ax7 and get a lower note? I'm thinking of building a tube synth just for fun, maybe hook it up to a keyboard type thing.
@LeviMan2001 I had it go through the entire range, and the lowest note isn't very low at all (disappointing). A 12AX7 should work too, but you'll need to experiment with the capacitors and resistors to make a longer time constant for lower notes. The only problem is that this may cause the oscillator to not oscillate at all! I found this circuit to be kind of tricky when I built it.
@CameramanLink Hmmm I see. I notice in the schematic the HT isn't too much, only like 125 volts? So could I just use rectified wall power for this and run the filaments off a 12 volt wall wart?
@LeviMan2001 NO! That is WAY too dangerous! I did this once for another project and boom!!! I blew up everything connected to it. Never do this unless your project is completely isolated and you cannot touch any electrical part of it, even ground! I cannot stress this enough. You need an isolating transformer. I know it's pretty expensive but it's critical to your safety and to the protection of connected equipment. I learned this the hard way!
@CameramanLink Sounds like it. I guess I figured if AAFive radios could do it. But yeah. An isolation transformer couldn't be that much, could it? just like a 1:1 ratio?
@LeviMan2001 Yes, they have some cheap ones, but you're better off using the transformer shown in the schematic. I think that kind is even cheaper than the small 1:1 transformers. The one in the schematic provides filament and plate voltages rather than just the 120V.
@AllAmericanFiveRadio I have an audio generator (transistorized) that I bought online. It can go well into the RF spectrum, allowing me to test radios in new ways. I also have a Heathkit one but the controls are seized--I can't even turn them with a huge wrench! Unfortunately I can't find a replacement switch.
@naagayaa123 I really have no idea! I just got the circuit online and built it.
CameramanLink 4 months ago
what would I need to get higher and lower frequencies??? much much higher and lower.
ianlutz 9 months ago
@ianlutz Probably different capacitors.
CameramanLink 9 months ago
I like that you are using a transformer and a tube rectifier.It would be cool to add coils(inductors) etc. to make other complex waveforms.
Thermionman1970 1 year ago
@Thermionman1970 I liked the transformer and tube rectifier as well. I feel safer with isolated circuits, and silicon diodes just aren't as much fun and aren't anything to look at! I think adding coils would be interesting, but I don't know where I should put them. If I build enough of these circuits and had ways of changing the waveforms, I could make a tube synth.
CameramanLink 1 year ago
@CameramanLink Just wondering, if you increased the capacitors a huge amount would that significantly increase the bass frequencies?
Thermionman1970 1 year ago
@Thermionman1970 In theory, yes, but if I actually do it...now that's a different story! I should try that sometime when I get around to it. The problem is there so many things that I want to try, and I'm usually so preoccupied with the current project that I forget (right now it's video on reel-to-reel tape). I really should start making a list of things to test, measure, and explore. I'll start that list right now.
CameramanLink 1 year ago
you useing that light bulb as a ballst resistor or something?
DRNEGOLICIS 1 year ago
@DRNEGOLICIS Yes, the light bulb changes resistance depending on the current going through it.
CameramanLink 1 year ago
That is so cool! Did we ever hear the lowest note?
LeviMan2001 1 year ago
@LeviMan2001 Also, would it be possible to use a 12ax7 and get a lower note? I'm thinking of building a tube synth just for fun, maybe hook it up to a keyboard type thing.
LeviMan2001 1 year ago
@LeviMan2001 I had it go through the entire range, and the lowest note isn't very low at all (disappointing). A 12AX7 should work too, but you'll need to experiment with the capacitors and resistors to make a longer time constant for lower notes. The only problem is that this may cause the oscillator to not oscillate at all! I found this circuit to be kind of tricky when I built it.
CameramanLink 1 year ago
@CameramanLink Hmmm I see. I notice in the schematic the HT isn't too much, only like 125 volts? So could I just use rectified wall power for this and run the filaments off a 12 volt wall wart?
LeviMan2001 1 year ago
@LeviMan2001 NO! That is WAY too dangerous! I did this once for another project and boom!!! I blew up everything connected to it. Never do this unless your project is completely isolated and you cannot touch any electrical part of it, even ground! I cannot stress this enough. You need an isolating transformer. I know it's pretty expensive but it's critical to your safety and to the protection of connected equipment. I learned this the hard way!
CameramanLink 1 year ago
@CameramanLink Sounds like it. I guess I figured if AAFive radios could do it. But yeah. An isolation transformer couldn't be that much, could it? just like a 1:1 ratio?
LeviMan2001 1 year ago
@LeviMan2001 Yes, they have some cheap ones, but you're better off using the transformer shown in the schematic. I think that kind is even cheaper than the small 1:1 transformers. The one in the schematic provides filament and plate voltages rather than just the 120V.
CameramanLink 1 year ago
@CameramanLink What transformer is that?
LeviMan2001 1 year ago
@LeviMan2001 It's a Hammond "plate and filament" transformer for preamps and low voltage power supplies. You can find it at tubesandmore[dot]com
CameramanLink 1 year ago
Neat, audio generator are very handy too.
AllAmericanFiveRadio 1 year ago
@AllAmericanFiveRadio I have an audio generator (transistorized) that I bought online. It can go well into the RF spectrum, allowing me to test radios in new ways. I also have a Heathkit one but the controls are seized--I can't even turn them with a huge wrench! Unfortunately I can't find a replacement switch.
CameramanLink 1 year ago