Rat Hotrod 1 Watt Push-Pull Handwired Valve Guitar Amp Powerscaling Buffered Loop
Bias/Gain/Bright Switches Valve Rectifier Hammond 125B This was a Custom Build by Andy of Rat Electronics - and not a 'modded stock amp'. Entirely Hand Wired - he used only the metal chassis and the cabinet of an Epiphone Valve Junior. Electrically it is beautifully behaved, and it's dead quiet compared to many other valve amps which hiss, hum and crackle. Unlike Andy's usual amps this one runs the entire gamut from low gain to high gain sounds. And it takes pedals beautifully... It's in beautiful condition. Only ever used at home - and I don't play it enough, so it's for sale. Unlike other large scale production low watt amplifiers - this amplifier is ALL VALVE (no cheap diode clipping here) and incorporates Tri-Rectifier with EZ-80 Valve A Switch on the Rear Panel of the Amp Allows the Selection of 3 Different Rectifiers. 1. Silicon - Standard 'Silicon' Diodes. 2. V1 - 'Valve Rectifier' - Running at Half Power. 3. V2 - 'Valve Rectifier' - Running at Full Power. All Amplifiers use a Rectifier to convert the Raw AC Voltage from the Mains Transformer into DC Voltage. The Amp Circuits Need DC Voltage to work. If, for example, you Hit a Power Chord on your Guitar, the Amplifier Circuitry Suddenly Demands a Large Dose of Power from the Mains Transformer. Silicon Diodes are Extremely Efficient and can convert the Raw AC into DC almost instantaneously, to Feed the Amplifiers Needs. Valve Rectifiers are a Different Story. Generally Speaking, they can't Cope with Sudden High Demands of Energy and they 'Starve' the Amp of Power until they can catch up with the Demand - This is Called 'SAG' - and it Sounds GREAT! The typical sound Produced by an Amp using 'Silicon' Diodes would be - - Attack - Sustain - Release - Decay - Using the 'V1 Valve' Rectifier, the Sound would be Closer to - - Attack - Swell - Extended Sustain - Release - Decay - To your Ears - In 'Silicon Mode' the Initial Note Attack is Sharp and Crisp - Like a Modern Amp. In 'V1 -or- V2 Valve Mode' the Initial Attack is Almost Soft and Laid Back with Longer Sustain - Like a Vintage Amp.Switchable Valve rectification (Silicon, V1 and V2). so you get those lovely 'sag' sounds 3 Position Bias Switch 1 - NFB (think Fender Princeton) 2 - I'm not sure:-)) - sounds lovely for jazzy clean sounds though 3 - Modern higher gain amps (think Mesa) 3 position Gain Switch (low, medium and high gain) 3 position bright switch (for a little Fender Fullerton Sparkle) There are many Factors that influence the 'Voice' of a Valve Amplifier but the Dominant Voicing is usually achieved by setting the 'Bias' and 'Gain' on the Preamp Valve. This is preset by the Manufacturer, with No User Access. As the end user, You Can change the Volume and Tone of the Amplifier but can not generally access the Primary 'Voice' Settings. The 3 Position 'Bias' Switch and 3 Position 'Gain' Switch together give you 9 Combinations of 'Voice' settings on the Preamp Valve. From 'Pure Clean' -to- 'Major Overdrive'. A full comprehensive tone stack (Drive, Treble, Middle, Bass, Presence and Master Volume) Two 12AX7 preamp valves, switchable between 1 or 2 (use both 12AX7s for higher gain) Power Scaling (Output Power Reduction - OPR1 and OPR2) OPR-1 (Only the output valves are power-scaled) OPR-2 (Preamp & output valves are power-scaled) 'OPR' lets you get a true 'Cranked Amp Sound' at VERY Low Volume Levels - Fat Harmonics - Sustain a Mile Long - the Full works, but at a Volume level you can 'Talk' over. Simple to use, Just like a Normal Volume Control, as you 'Dial Down the Power' - The Volume Drops but the Tone is Maintained. 'OPR' Allows the Output Power of the Amplifier to be Varied from 100% down to Less than 1% of the Full Rating - Fully Maintaining the Warm Tone and Natural Harmonics of the Output Valves - Waste Heat from the Output Stage is Dramatically reduced as the Power is Dialled down, Greatly Extending Valve Life - Because of the Extra Filtering used in the Circuit, Background 'Noise' is Eliminated - Power Consumption is also Reduced, this will extend the life of all the Components in the Amplifier. The 'OPR' Circuitry is Extremely Effective and Reliable. Think in terms of a 'Light Dimmer' in the Amplifier, the basic concept is the same. Certain Voltages in a Valve Amplifier must be Maintained while others can be manipulated, directly influencing the Output Power of the Amp. Unlike a Speaker Attenuator (L-Pad or Power Brake) that 'Loads' the Output of the Amp and Stresses everything to the Edge, The 'OPR' System gives the Amps Critical Components (Valves and Output Transformer) a Holiday. When the 'OPR' Control is set to Full Power (not being Used) it has NO Effect on the Amp 'AT ALL'. The Amp will work the Same as if 'OPR' was Never Fitted. At Bedroom Volume you can TRULY obtain the Full, Sweet Valve Harmonic Overdrive Sound that you have probably always been looking for. Valve Buffered Series Effects Loop (buffered by a third 12AX7 valve) Three position power switch (off, standby, on) Hammond 125B output transformer Dummy Load - for silent recording / headphone practice Headphone out Line out (speaker emulated) Switchable output impedance ( ohms) Push-Pull 12AU7 output valves, Switchable between one (1 watt) and two (2 watts) RMS. Ad ID: Delivery Service Consumer Credit