The MAX 115 II is a later revision. Based on user reports, there may be differences in the power amplifier section and component layout. It is critical to verify which version you own before ordering replacement parts or using a schematic.
Schematic Fix: Locate the dual Zener diodes or 7815/7915 regulators on the power supply schematic. Measure the voltage across them; if you read 0V or highly asymmetrical voltages, replace the faulty regulator or dropping resistor.
If you’ve successfully repaired or modded your Max 115 using the original schematic, share your experience in the comments below. And remember: Always discharge the filter capacitors before touching any component. High voltage can be deadly. peavey max 115 schematic exclusive
: The DDT™ (Distortion Detection Technique) compression circuit prevents power amp clipping to protect the driver. Where to Find Schematics
The signal enters through either the Active or Passive input jacks. The passive input features a higher impedance to accommodate standard bass pickups, while the active input includes a resistive attenuation pad (usually around -10dB to -15dB) to prevent hot active onboard preamps from clipping the first gain stage. The MAX 115 II is a later revision
The signal enters through standard 1/4-inch jacks, often featuring a dedicated "Active" switch or pad attenuation network. This network drops the signal by roughly 10dB to 15dB to prevent high-output active bass onboard preamps from clipping the initial gain stage. The schematic utilizes low-noise operational amplifiers (op-amps)—frequently the industry-standard dual op-amp layout—to handle initial voltage amplification before passing the signal to the equalization matrix. 2. Equalization and Psychoacoustic Enhancement
To fully appreciate the MAX 115's design, it helps to see where it sits in the lineup. Peavey launched the series with several models, each using a similar design philosophy scaled for different needs. Here is a comparison of the initial generation: Schematic Fix: Locate the dual Zener diodes or
: The cabinet or chassis produces a rattling or buzzing sound at certain frequencies, particularly at high volumes.
When your MAX 115 fails, the schematic helps you isolate the problem. Problem A: Amp Powers On, No Sound Check the main power fuse.
Check the input pin of the first op-amp, follow it past the volume pot, through the EQ network, out of the preamp section, and into the power amp driver stage.
Locate the Preamp Out and Power Amp In break points. When no plug is inserted, a physical metal leaf inside the jack routes the signal across the gap. If this contact oxidizes, the signal path breaks.