Bugera 1960 Infinium Schematic Jun 2026

Disclaimer: Working on tube amplifiers involves lethal voltages (up to 500V DC). Even when unplugged, filter capacitors can hold a deadly charge. If you do not know how to safely discharge capacitors, take your amp to a professional. This article is for informational purposes only.

Before we look at circuit paths, we must understand the beast. The 1960 Infinium is not a direct clone of a vintage Marshall. While the preamp topology borrows the classic cathode-biased, three-stage design, the Infinium system adds a layer of complexity.

The power amp section of the schematic shows a resistor (R88) connecting the 16-ohm output tap back to the phase inverter. Typical value: 47k. If you want a looser, more modern feel, the schematic tells you where to solder a 100k resistor in parallel. If you want tighter, metal-style response, you replace it with 27k. Bugera 1960 Infinium Schematic

This is why the schematic is hard to find. If Bugera released the full PDF, competitors would see exactly how cheaply they achieved the circuit (using JFETs instead of relays for switching, using SMD resistors instead of carbon comps). For the repair tech, this is a relief—it means you can substitute parts from a Marshall DSL schematic if you cannot find the Bugera original. For the purist, it is a letdown.

Official Bugera schematics are not publicly hosted on their site, but they are available through: This article is for informational purposes only

Here’s a technical write-up for the , aimed at amp techs, DIY builders, and advanced guitarists.

Because the circuit balances tube drive dynamically, you can mix and match compatible tube types (e.g., EL34, 6L6, 5881) without needing a professional technician for biasing. Monitoring: aimed at amp techs

Without the schematic, you cannot properly troubleshoot a failed Infinium system – for example, one tube constantly redplating despite “good” bias readings may indicate a failed sense resistor or dead IC channel.