Bugera 1960 Infinium Schematic [best] Cracked -
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The transformer steps up wall voltage to generate high-voltage DC (often referred to as B+ or HT), which frequently exceeds 450V to 500V DC to power the EL34 tube anodes.
The Bugera 1960 Infinium is a popular guitar amplifier designed to replicate the classic, high-octane British plexi tone. Built as a tribute to the legendary Marshall 1959 Super Lead, this 150-watt powerhouse blends vintage-style circuitry with modern digital management. However, gigging musicians, technicians, and DIY repair enthusiasts frequently seek out circuit schematics to diagnose faults, modify the tone, or repair physical damage like cracked circuit boards.
: Most publicly available schematics are for the non-Infinium version or are hand-drawn "reverse-engineered" diagrams found on community forums like the Bugera Amp Owners group. Common Faults and "Cracked" Issues bugera 1960 infinium schematic cracked
If the amplifier completely refuses to power on, or blows the main/HT fuse immediately upon flipping the standby switch, a shorted EL34 power tube is the primary suspect. Even with the Infinium protection circuit, a catastrophic internal short in a vacuum tube can draw excessive current before the auto-bias can compensate, taking out the fuse to protect the transformers. PCB Trace Cracks and Cold Solder Joints
Following the tone stack, a long-tail pair phase inverter (driven by another 12AX7) splits the audio signal into two opposite phases to drive the heavy artillery: a quartet of EL34 power valves running in a push-pull configuration to deliver 100 watts of raw power.
(Flashing, steady, off?) Is the amplifier making any sound at all? Does the issue occur with both channels? What is your current level of experience with
: Includes a post-phase inverter master volume, which is a common mod for vintage-style amps to achieve gain at lower decibels. Common "Cracked" & Reliability Issues
Numerous users and technicians have reported that the physical PCB inside the Bugera 1960 Infinium is prone to developing fractures (cracks) in specific areas. This is due to a mechanical design conflict where the chassis braces intersect with the circuit board, causing the circuit traces to sever over time.
The entire circuit is populated on printed circuit boards. While this keeps production costs low, it can make the unit more sensitive to heat and mechanical stress compared to point-to-point wiring. Built as a tribute to the legendary Marshall
Voices a warmer, bass-heavy tone with a larger capacitor value. The Power Section
1. Circuit Overview: Where Vintage Meets Modern Architecture
It dynamically senses the current flowing through each EL34 tube and adjusts the negative grid bias voltage on the fly.
This report is based on a preliminary analysis of the Bugera 1960 Infinium schematic and is intended for informational purposes only. Bugera, as a company, has not endorsed or verified the findings of this report. Amplifier technicians and enthusiasts should exercise caution and consult with qualified professionals before making any modifications to the amplifier.
Swapping out the standard slope resistor (typically 33k or 47k ohms) and the treble/middle capacitors in the tone stack to exact vintage values can shift the midrange sweep of the equalizer, instantly transforming the amp from a modern rock machine into an authentic classic blues-rock provider. 5. Safe Bench Practices for Repairing Tube Amps