K7RHY RESONANCE LAB 5E3 TWEED-STYLE TUBE COMBO
Serial number: 5E326001
Manufactured: August 15, 2026
Amplifier output: Approximately 12 watts
Speaker: Electro-Harmonix 12-inch, 75-watt, 8-ohm
Fuse: 2A
Power cord: Attached
ABOUT THIS AMPLIFIER
This is an individually built tube combo based on the classic late-1950s Fender 5E3 “Tweed Deluxe” circuit.
The 5E3 is known for its immediate, touch-sensitive response, natural compression and gradual transition from warm clean tones into harmonically rich overdrive. Its relatively modest output makes it suitable for recording, home playing and smaller performance environments—but 12 tube watts can still become quite loud.
This is not a mass-produced reissue or an anonymous, undocumented kit build. It is supplied with an amplifier-specific inspection record and baseline operating measurements that may be useful to a future service technician.
CONTROLS AND INPUTS
The amplifier has separate Normal and Bright channels, each with high- and low-sensitivity inputs:
• Normal 1 — Higher-sensitivity Normal input
• Normal 2 — Lower-sensitivity Normal input
• Bright 1 — Higher-sensitivity input with additional high-frequency presence
• Bright 2 — Lower-sensitivity Bright input with a gentler response
Controls:
• Normal Volume
• Bright Volume
• Shared Tone control
• Standby switch
• Power switch
The two Volume controls interact even when only one channel is being used. Adjusting the unused channel’s Volume control can alter gain, tone and response. This is intentional and characteristic of the 5E3 circuit.
ELECTRO-HARMONIX SPEAKER
The installed speaker is an Electro-Harmonix 12-inch, 75-watt, 8-ohm model. The 75-watt figure is the speaker’s power-handling rating; the amplifier itself produces approximately 12 watts.
The speaker cable is soldered to the speaker and plugged into the amplifier’s speaker-output jack. It ships connected and ready to use. No separate speaker cable is required.
Before switching on, verify that the existing speaker plug remains fully seated. Never operate the amplifier with the speaker disconnected.
INDIVIDUALLY DOCUMENTED
The amplifier includes:
• Completed Build Verification Record
• Recorded as-shipped operating voltages
• Grounding and electrical-isolation test results
• Baseline measurements for future servicing
• Quick Start and Controls guide
• High-voltage Safety Guide
The completed Build Verification Record is also shown in the listing photographs.
These are builder-performed inspection and measurement records—not UL, ETL, CSA or other independent safety certification.
SHIPPING AND UNPACKING
The tubes will ship installed because they are held securely in their sockets and retainers. Removable internal packing will prevent the attached power cord from striking the tubes during shipment.
IMPORTANT: Remove every piece of packing material from the rear cabinet cavity before connecting power or operating the amplifier.
WHAT IS INCLUDED
• K7RHY Resonance Lab 5E3-style combo amplifier
• Installed Electro-Harmonix 12-inch speaker
• Installed tube complement
• Attached power cord
• Installed 2A fuse
• Completed amplifier-specific Build Verification Record
• Quick Start and Controls guide
• High-voltage Safety Guide
SAFETY
This is a high-voltage vacuum-tube amplifier. Potentially lethal voltage and stored electrical charge are present inside the chassis.
Operate it only from a properly grounded outlet. Never defeat the grounding pin, open the chassis or operate the amplifier without its speaker connected. Tubes become extremely hot during normal operation. Internal service should be performed only by a technician trained to work safely on high-voltage tube amplifiers.
RETURNS
Returns are accepted if the amplifier arrives damaged in transit or is materially not as described in this listing. Please contact me promptly and retain the amplifier, carton and all packing materials so the damage can be documented and the shipment claim handled properly.
INDEPENDENT BUILD
This is an independently built amplifier based on the Fender 5E3 circuit. It is not manufactured, licensed, sponsored or endorsed by Fender Musical Instruments Corporation.
CONDITION DESCRIPTION
Newly completed, builder-assembled 5E3-style tube amplifier manufactured August 15, 2026. Individually inspected, functionally tested and supplied with a completed build-verification record. Electro-Harmonix 12-inch, 75-watt, 8-ohm speaker installed. This is an independently built amplifier—not a vintage or factory-built Fender product. Please examine the photographs for cosmetic condition.