Reproduction Ampeg Portaflex with Modern Electronics

Reproduction Ampeg Portaflex with Modern Electronics

Stephen B Harper

Project Category:
Guitar and Bass Speakers

Project Level:

Project Time:
20+ Hours

Project Cost:
Over $1,000

Project Description:
I wanted a high performance stage rig for both upright and electric bass to match the cosmetices of vintage amps I own.

Design Goals:
Match the cosmetics of vintage Ampeg Portaflex amplifiers I own and improve them sonically with modern electron ics and speaker.

Driver Selection:
Celestion K12H-TC200

Enclosure Design:
Slot loaded port

Enclosure Assembly:
3/4″ Baltic birch plywood w/ internal bracing and lined with dynamat

Crossover Design:

With the suggestion of the tech guys @ Parts Express I used the Celestion driver in my project. ALthough a bass guitar will really only go out to 4,000 HZ having the 4″ wizzer cone and the ability to be flat to 10K allows harmonics to re reproduced better than any combination of products I have owneed and used in 40+ years of playing upright and electric bass.

About the Designer:
I am a mechanical engineer by training and own an audio / video design and consulting firm.

Project Parts List:

Celestion K12H-200TC 12″ 200 Watt Full-Range Professional Woofer Driver 8 Ohm

1 comment

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  1. 1
    Dan Still

    impressive looking unit. looks first rate. I wish you would have added a few more pictures with more detail ,though I understand that can be easier said than done.

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