How to prototype with valves / vacuum tubes? 12AX7 or 6N2P adapter !

The Skulptor sounds O.K. recorded with a phone?

In our modern world here is evidence that size is not everything. A small blues demo with a concentrated tube amp recorded with a low quality phone camera (and microphone) through a 1×12 open back speaker cabinet, still I think it sounds great ! Thanks to Machinarium pub in Warsaw for providing the space for the No To Gitara meetings.

Room .55 Guitar Amplifier – Perfect for any home!

A guitar and the desire to rock with great tone from luxurious tubes, at home without the concert volumes?

Half a watt of pristine clean and  aggressive rock gain in one tiny box: Art is…Room .55

Loud .55 Guitar ampifier

Art is… Room .55 specifications:

Power:  0.6 Watt

Technology: Tubes

Type: Class A ( Single Ended)

Topology: Head

Controls: Gain and Volume ( also has Treble switch)

Channels: 1 Channel ( From Clean to Crunch using the Gain knob)

Input: 1 for instrument

Output: 1 to 8 ohm or 16 ohm speaker

Pre-amp Tubes: 1 x 12AX7 ( But it can be swapped by 12AT7, 12AY7, 12AU7)

Power tube: 12AU7 ( But swapped by 12AT7 or ECC99)

Special Features: SMPS High voltage control knob ,  hand-wired point to point, Feed-Back-Loop with control (FBL), FBL / Bypass / Hi-Gain switch and Country Knob

Power supply: 12V DC with 1.5 Amperes (minimum)

Size (Height x Width x Depth ): 11cm x 18cm x 11,5cm

Weight: 0.9Kg

The Skulptor 1 Watt Vacuum Tube Guitar Amplifier

For quite a while, I wanted to own a small, low power all tube guitar amplifier that would sound very Tweedy or tonally american, like the well known sounds from SRV. An amp that I could use at home with a small or BIG cabinet,  would be eco friendly because it would be made of recyclable materials and with low power consumption, easy to move around yet sturdy, and that I could play in a neighbor friendly volume, without it sounding dull.

The first step, was to look for something online, through a few web shops and publications. I researched and ended up finding mainly 5 watt,  also some lower wattage options that costed a lot more than what I wanted to spend.

I searched in few DIY guitar gear websites and forums and found a few possibilities, some easier than others, some required more money than others, some had no information concerning the the first run with flying colors.

In the end I found a lot of suggestions at a few forums. I was advised that sometimes transformers are 70% of the cost of non replaceable parts. If I would use an alternative to a power supply transformer I would save 35% of the total cost. Went to the Warsaw Polytechnic talked with a power supply specialist  and he provided me with the recipe for a SMPS Boost supply that took 12VDC to 220VDC quietly. I calculated all the tube parameters, and the end result is the amplifier you can see in the pictures ! I will try to make a low-fi video eventually.

Art is… Skulptor specifications:

Power: 1 Watt

Technology: Tubes

Type: Class AB ( Push-Pull)

Topology: Head

Controls: Gain, Tone and Volume ( also has Treble switch)

Channels: 1 Channel ( From Clean to Crunch using the Gain knob)

Input: 1

Output: 1 to 8 ohm or 16 ohm speaker

Pre-amp Tubes: 2 x 12AX7 ( But V1 or V2 can be swapped by 12AT7, 12AY7, 12AU7)

Power tube: 12AU7 ( But swapped by 12AT7 or ECC99)

Special Features: Cooling Fan, SMPS High voltage control knob , Effects loop with send level, Hardwired point to point.

Power supply: 12V DC with 2 Amperes (minimum)

Size (Height x Width x Depth ): 16cm x 22cm x 14,5cm

Weight: 1.6Kg