Drunk Beaver's #28 Pedal Drop sees the third of its mini-tube loaded preamps, this time the Hostomel Tube Driver

This is not another BK Butler Tube Driver take - like say the recent CTC Venus, this model is rather more derived from the Tubeworks Real Tube RT-901 if anything. Of course significantly evolved by Vitalii - and using one of those really cool mini tubes that he seems to have a knack for finding!

The Tube here is the 6Н16Б-В (6N16B-V) (where V denotes military version) - subminiature dual triode (mu of 25). As mentioned - the circuit is closer to a Tubeworks Real Tube RT-90, but far from an exact replication (the EQ as such is the closest to that version!),

So like a Tube Driver - it has an OpAmp buffer, then OpAmp gain stage (Vitalii used NOS German TFK TL082 as it delivered the highest output swing at 24V power supply - of 22.4V before clipping.

The main post controls the gain level of the OpAmp stage - after 1 o’c the OpAmp starts clipping the signal. Then it goes through a high pass filter into 2 triode gain stages with shared cathode bias. The first triode does asymmetrical clipping and inverts the signal, then the second triode clips another side of the signal.

As in the Tube Driver - tube anodes are running at 24V - AKA a starving tube arrangement. Vitalii did not accommodate a bias pot (a popular mod on the Tube Driver), because the bias range for the 6N16B-V is relative narrow!

The 3-Band EQ is very amp-like overall - with those controls being highly interactive. Vitalii then added additional low pass filtering after the EQ - in order to smooth out the signal further - as the original could sound a little harsh at times. And of course a BF245 FET output buffer was added to the end of the circuit for better signal fidelity / integrity!

The pedal does everything from a little breakup to wild tube fuzz. It runs 9V standard PSU but requires at least 500mA of power (tube heaters alone need 400mA). There will be 40 units available on the Drunk Beaver Rocks Webstore - going for $175 + tax.

Vitalii has proven to be quite the expert for these kinds of tube circuits (this is his third one I believe) - and I’m really looking forward to getting my hands on this device - where incredibly I will then be running 4 different tube overdrives in my rig - which would have been unheard of just a couple of years ago - I’ve really ramped up quickly for Tube Overdrives - I guess there are more suitable and practical varieties available nowadays - indeed like this very unit.

As always - this is a rapid prototyping project which goes up for sale as soon as those pedals are built and ready to ship. There’s no time to send out the pedal for demos - so you will just have to take it on faith - which I’ve been doing all theses years - and not once been disappointed!

I will reference a Tubeworks Real Tube RT-901 for sound sample purposes therefore!