U5 Mono Instrument & DI Preamplifier

"My U5 has made me realize the potential of all of my bass equipment. More importantly, it is helping me to realize my own potential as a bass player."
- Jeff P., AZ

"The U5 is the holy grail for bass guitar. It would be a steal at twice the price." - Daniel S., NJ

"I knew I was going to like it, I just didn't know how well!
I love it!" - Randall S., OH

"Wow!! Acoustic guitar has never been better to listen to... magical!"
- Adam B., CA

"Good Day! I bought a U5 about 7 years ago to use for recording bass guitar. I just got around to recording in the last year and have been running my guitar thru a Line 6 PODHD500, but after continued manipulation I never got a decent guitar sound. I was truly ready to give up when for the heck of it, I ran my guitar (Fender Strat) thru the U5. Holy cow, what a sound! I'm back in business. Now I have a $600 guitar tuner formerly known as a PODHD500. I wanted to let you know that the money I spent 7 years ago was well worth the investment. Thanks!"
- Daniel O., Nicosia, Cyprus

The U5 high-voltage DI-preamp combines a unique passive tone selector with a variable gain preamp and filter. The high input impedance accepts a wide variety of signal levels and instruments from acoustic guitars to high-output active bass guitars and keyboards. The U5 direct box is loaded with sonic character and user features professionals demand.



  • Pure Class A, 100% discrete design

  • Smooth musical detail and sonic excellence

  • Variable gain preamp to +30dB.

  • Dual microphone and line outputs

  • Hi-Z   3,000,000 ohm input impedance

  • Very low noise -100dB

  • High headroom +30dB

  • Six tone bank selections.

  • DC coupled Class A output for superior bass

  • High cut switch eliminates noise

  • LED active signal indicator

  • Headphone monitor output jack

  • Low distortion less than 0.5% THD and IMD

  • High level 400 watt speaker input

  • Active to thru selector - ground isolation switch

  • 100% discrete power supplies for audio path

  • Internal toroidal power supply for low noise

  • Long lasting, stainless steel hardware


The Avalon U5 Pure Class A instrument DI & preamplifier is the most powerful direct box available today.  Designed to optimize absolute signal integrity and musical performance, the U5 includes many features and sonic excellence unequaled by lesser designs. The U5 is ideal for bass guitar and acoustic instruments, electric guitars, keyboards, synthesizers and low output pickups. 

Features include state-of-the-art, high input impedance input stage for zero load effect on sensitive pickups and keyboards, 100% discrete, Pure Class A signal amplifiers, practical user features and rugged hardware designed to deliver true high performance audio for many years. 

Avalon U5 DI-preamps have been in use around the world since 1995. They have found their way into the world's leading musicians rigs and recording sessions and been featured on thousands of the best selling (and sounding) albums and live performances.

The U5 includes a variable gain Class A preamplifier to boost low level pickup signals and a high level speaker input for capturing the live sound of the instruments amplifier. Six passive tone-EQ curves are also included to enhance a variety of acoustic and electric instruments. A high-cut switch eliminates unwanted acoustic pickup and high frequency noise, while a  headphone monitor amp has been included for personal listening. Twin DC coupled Class A output amplifiers drive both low level microphone preamp inputs and high level +4dB inputs for direct to tape recording or processing. The active-to-thru switch selects either the instrument input directly or sends the boosted-equalized signal to the amplifier via the front panel jack. A ground isolation switch eliminates any possible earth loop or AC buzz problems with complete safety.


Circuit Topology: 100% discrete, high-voltage Class A
Gain: Switched 3dB steps, maximum gain +30dB
Input Impedance: 3 ,000,000 ohm unbalanced (single ended)
Maximum Input Level +24dBu unbalanced, 400w speaker input
Output Connectors (2): XLR type, pin 2 hot electronic balanced
Maximum Output Level (Class A): +30dBu DC coupled, balanced 600 ohms (mic and line out)
Headphone Output: 0.5w into 600 ohms
Noise 20kHz Unweighted: -100dBu minimum gain position
Distortion THD, IMD: 0.1% at +10dB
Frequency Response, -/+0.5dB: 5Hz to 100kHz
Frequency Response, -3dB: 1Hz to 500kHz (input band limited)
High Cut Filter: -3dB at 8kHz minimum phase design
Tone Selector: Six position rotary switch, all passive filters
AC Power: Internal toroidal AC supply
Dimensions: 8.5 x 3.5 x 12 in (216 x 88 x 305mm)
Weight-Packed: 12lbs (5.4kg)
Rack mount kit (1) RM-1: Single U5 19 inch rack mount kit (holds one half rack unit)
Rack mount kit (2) RM-2: Dual U5 19 inch rack mount kit (holds two half rack units)


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Tel: +1 949 492 2000
2023 Avalon Design USA LLC