Ampeg Portaflex PF-500 review

A half-stack bass amp that's full of tone

  • £1101
  • $1329.98
The high-performance solid-state head is very compact but extremely well-endowed

MusicRadar Verdict

Small head, big Ampeg sound - with plenty of tonal variation.


  • +

    Classic Ampeg sounds and power from a tiny head. The very impressive cabinet.


  • -

    No cabinet Speakon connector. No speaker leads.

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Having recently reviewed the Ampeg Micro-CL bass stack, we couldn't wait to get our hands on a bigger Ampeg gigging rig.

"In spite of its size, the Portaflex half-stack really is a serious bit of gear"

We've still not gone all the way, but this half-stack is a serious leap forward. Two new amplifier heads have just come off the production line, and we've managed to secure the more powerful of the two. In spite of its size, it really is a serious bit of gear.

Although the Portaflex name is synonymous with the original flip-top styling (where the amp is safely secured in the cabinet during transportation), here we have the regular piggyback setup with the amp sitting on top of the cabinet.

The two heads in the range offer different power ratings, and there's a choice of four cabinets that can be mixed or matched. All are covered in Ampeg's traditional tough black diamond Tolex, though it offers a chequered effect here.

PF-500 head

"The push-on/push-off switches are smooth and positive in operation and wonderfully noise-free"

In keeping with the current trend in bass amplification, this high-performance solid-state head is very compact but extremely well-endowed. A centrally positioned strip light glows pale purple when the amp is on, and the mini chickenhead knobs feel incredibly tactile and ultra-smooth in operation.

The push-on/push-off switches are also smooth and positive in operation and wonderfully noise-free. In fact, background noise is of no consequence at all here, and when the head's on standby all you hear is the gentle sound of the internal fan.

The frequency function allows for the targeting of different areas of the midrange, while an effects mix control is a welcome addition, enabling the perfect blending of foot-pedal sounds with the main instrument tone.

On a purely practical note, the substantial rubber feet reduce vibration from the cabinet, as well as preventing the amp from sliding about.

Portaflex PF-410 HLF cabinet

The cabinet employs solid construction using 15mm poplar plywood, and comes with metal corners, inset side handles and castors. It's a sealed-back design, but the front baffle allows for an across-cabinet port at the bottom, so all sounds are projected forwards.

The rear panel has two jack sockets to assist in daisy-chaining a second cabinet, but unlike the head there's no Speakon connector. There is a three-way high-frequency horn selection switch, though. There are other speaker configurations in the range, but this 4x10 is particularly impressive.


"The head offers loads of tonal variation, and with 500 watts at your disposal there's plenty of headroom, too"

As you would expect, the head offers loads of tonal variation, and with 500 watts at your disposal there's plenty of headroom, too. The Ultra Hi boost adds a little extra bite and bark, while the Ultra Lo gives a particularly pleasing lift in bottom-end, but when used together the sound gets a whole lot meaner.

Also very effective is the five-way frequency switch assigned to the midrange. Set the midrange control to maximum, hit a note on your bass, then switch from one setting to the next. As you progress through the five, you soon understand how significantly the sound is shaped.

Getting to grips with the character of these specific midrange sounds is extremely important, because it really shapes the character of your sound. The compression is extremely effective, too, and keeps the sound tight and concise, particularly when pushing the unit at high levels.

This cabinet is simply remarkable - it really can take anything you throw at it, even with the amplifier on full bass and the Ultra Lo switched in. It's both loud and body-shaking. With a 4x10-inch configuration, you'd expect tight but warm tones, but we're surprised by just how much punch and bottom end this is able to deliver.

Despite being so small, and MOSFET rather than all-valve, Ampeg has managed to retain all its characteristic sounds. It's super-powerful, but a separate compact head presents other opportunities, too: Ampeg has included an audio input and headphone socket, so the PF-500 can also be used for silent practice.

It's very well-executed, and a welcome addition to anyone's gear arsenal. All of Ampeg's cabinets have the same base dimensions, so you can mix or match cabs in any way you wish. This 4x10 is highly impressive, but we'd suggest adding a 1x15 for an awesome-sounding full stack. You deserve to be heard!