Austrovox Bass 150 Head

The amp was made in the early 70ies, by a small austrian manufacturer, that doesn't exist anymore.
The features are very basic, yet weird. It has two different channels "bass" and "organ", the second one sounding a bit brighter. each channels has two inputs that can be used at the same time. In theory, one could send 4 different signals into the amp.
each channel has seperate bass, treble and volume controls. The treble control is set at a very high frequency. for bass guitar, and even for electric guitar, it is rather a "edge/brilliance" control. But it can be very helpful. turned up, you get a surprisingly clear, sparkly sound. turned down, it gets real mellow.
there is a seperate main "booster" (affecting both channels). basically, it adds the extra bit of "booom" to your bass sound.
It's all tube.
I'm not sure about the wattage. Someone who supposably knows a lot about this amp (who restored an amp of the same model) told me it is 50 watts, out of two EL34 tubes. I don't know if it's true, i didn't yet open it. But in combination with a 1x18" box, also by Austrovox, it is loud as hell. I have it standing in my appartment, because i have not had the possibility to get it into my rehearsal room. and this thing is just way too loud for an apartement. For practice, i have it on 1, for indoors-jamming that won't call the police, i put it on 2. on 3, it is too loud already. and the scale goes up to ten, of course.
It has 5 outputs, for different combinations of ohmic resistance.

No effects loop, no tuner out, no headphones.

I'm using it with a '04 fender american precision deluxe, with a p/double j pickup combination and an active onboard eq.
In general, i want my amp to reproduce the fine sound that my bass gives out. It does that perfectly, better than i expected it to do. the amp will give me cristall-clear sound when i want it, and every adjustion that i make on my bass' controls will be perfectly found in the sound.
Plus, when i turn the treble all the way down and switch to my p-pickup, i can find the muddy, down-low blues rock tone i always wanted.
I find it noticeably silent, considering it's age. I will not even notice that it's on as soon as no signal goes into it.
I don't know if it distorts at high volumes, because i have not had the possibility (or the guts) to turn it up all the way.

I also used it with a friends epiphone les paul, and it sounds just as good. it has a very even sound, with a distinct bass, the highs could use a little extra sweetness, but this is, after all, a bass amp.

have not had it long enough. i heard the preamp tubes are rather hard to get and expensive, but very reliable.

the company simply does not exist anymore (supposably, it turned into a guitar shop, but i don't know that for sure. there is a company of the same name now, but they produce pa systems and speakers)

I have been playing for a year now. Other amps i was buying for longer time were several guitar amps and a hughes&kettner combo.
Of course, nothing comes even close to this thing. When i bought my bass, i tried it through a GK in the shop, and i loved the sound. now, i can have that sound if i want it. sounds crazy, but the amp perfectly reproduces the bass' sound, and can sound suprisingly brilliant, almost hi-fi. however, it can go down and dirty just as easy.
if it were stolen (good luck running with that thing, it's really heavy), i'd hang my head and cry, because getting another one seems very unlikely.
Basically, the amp is amazing, considered that i paid 350 euro for the amp AND a 1x18 cabinet. plus i think that it's value will rise again (not that i'm planning on salling it)