[sdiy] Uses for Chinese Tube Preamps?

[brianw]

I have not seen that tube preamp - no idea how big it is or how much power it requires.

... but if you're building your own spring reverb driver board, and want some overdrive, I would recommend looking at the Tube Sound Fuzz circuit from Electronic Projects for Musicians by Craig Anderton. A single hex CMOS inverter chip can provide three channels of overdrive. Craig pointed out that MOSFET have similar distortion curves to tubes, so the sound is similar. The trick is to use the transistors in these logic gates as if they were analog devices, instead of digital gates.

His circuit only uses two of the six inverters in the chip, in a two-stage gain setup, so you could repeat that circuit one or two more times with just a few components. Stereo reverb! You might want to tweak the gain since outright "fuzz" might be incompatible with spring reverb.

Anyway, it's an idea that fits your project. I understand the temptation to spend 16 € on something that might be bent into shape - perhaps someone else has experience with that tube preamp.

Brian


On Oct 12, 2024, at 10:22 AM, Spiros Makris wrote:
> Hello List,
> I recently saw a short demo video of some pretty cheap tube preamps from aliexpress. I have no use for a preamp right now, but given the price (16 euros delivered!) I guess it would be fun to overdrive it or do some mods to it. I am expecting a spring rever driver PCB, and I was entertaining the idea of combining it with a tube drive, to apply on synthesizers.
> 
> Has anyone tried it? Maybe even have a schematic to share?