Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums > Road Test FUD Forum Archive

Camco Vortex Amplifiers

(1/19) > >>

Bennett Prescott:
I've been hearing a lot of great things about the Camco Vortex series of amplifiers, so when Jim Stahowski (my local Ashly/Camco guy) asked if I'd like to try out an amp or two, I was more than willing. Along with the Ashly PE amp he sent me that I've reviewed in another post in this forum, I received a Vortex 4 and a Vortex 3 Quadro.

They all look basically like this, which I think is pretty cool:

The Vortex line additionally includes the Vortex 2.6 (1,300 watts into 2 ohms), Vortex 6 (3,000 watts into 2 ohms), and Vortex 200V (3,200 watts into 4 ohms). All of the amplifiers are microprocessor controlled for increased linearity, advanced troubleshooting, and remote monitoring and control. The entire series weighs just over 27lbs (12.4Kg) each, features Neutrik Speakon outputs, and has a worldwide switching power supply with permanently attached mains cord.

The Vortex 4 claims to produce 2Kw into a 2-ohm load per channel and 4Kw bridged into 4-ohms. Unlike your garden variety amp, however, it will drive 4Kw into a 1-ohm load in parallel mono mode... nice to have that extra option available. It's got XLR in and through for each channel as well as switches on the back for globally lifting the input grounds, setting input sensitivity (26dB, 32dB, or 1.4v), defeating the internal limiters, and setting the amplifier mode to bridge, stereo, or parallel. Front panel lights are available to indicate per channel power, signal, and clip plus global operating mode (bridge or parallel mono) and Camco Audio Interface status (more on this later). The Speakon connectors on the back of the amplifier have both channel A and B available for easy bi-amping or what-have-you.

If you need four channels of top-quality amplifier in a lightweight package  the Camco Vortex 3 Quadro may be for you. At 750 watts per channel into 4-ohms and the ability to drive bridged loads at 8 ohms or parallel mono loads at 2 ohms with 1,500 watts of power, it certainly packs a punch. It has a few noteworthy differences from the rest of the Vortex line... while there are independent front panel attenuators for each channel (except in mono mode, in which case only the odd-numbered channel control is active) there are only two Speakon outputs on the back, with the first two channels paired to one and the second two available from the other. Channel gain and mono/stereo mode is also shared between pairs of channels, with input ground lift and limiter mode global across all four. There are XLR ins but no throughs, and they're hard-wired to the chassis unlike the rest of the line which has swappable input cards. Front panel indicators are identical to the other amplifiers in the Vortex series.

Having four channels in such a flexible and powerful package could be a real boon. You could bridge one and use the amp to tri-amp pretty much anything, one amp per speaker. You could bridge both and drive... subs! Or do two bi-amped mixes with a decent amount of power behind them, or run four channels of compression driver. I'm getting a little creative here, but you see my point.

One paragraph spec sheets over, here's what's cool. First of all, the front panel attenuation controls aren't in the signal path... they control DCAs that do the actual work. This also allows remote level control of the amplifier over CAI (Camco Audio Interface). CAI's a pretty cool thing in and of itself... string together a bunch of Camco amps using telephone cable, set their IDs using the front panel knobs (it's all spelled out in the manual) and you can adjust input level, mute individual channels, standby an entire amp, and monitor temperature, output signal, clipping, and output current.

Every amp except for the Vortex 3 Quadro also has an Extended User Interface card with the inputs on it. The stock inputs are nothing fancy, but you can swap in your own card with advanced filters, limiting, level control, or whatever strikes your fancy. Similarly to Crown's PIC concept, this would allow you to build something like your entire set of wedge processing into one card and then slap it into the amp for a simple, powerful, lightweight, bi-amped monitor mix.

The built-in microprocessor is also used to control channel limiting. With the limiters enabled, the amplifier monitors the input signal as well as the output and will use the DCAs in the front end to keep distortion below 1% at all times. This limiting function is also used to ensure that if the amplifier is loaded to too low an impedance its output will be pulled back in order to keep it operating, albeit at a significantly lower level. Perhaps this is the feature that has generated such rave reviews of the sound quality produced by these amplifiers?

As would be expected from a high end amp, these also have a truly all-encompassing list of protection features. Three-point DC monitoring, servo-coupled capacitorless inputs, over current, under current, thermal protection, inrush current limiting, variable-speed fans, and input current protection (the amp monitors itself to ensure it does not exceed 30 amps of current draw at 120v) all combine to make this amp virtually Bennett (er... fool) proof. In case of a non-recoverable fault, the amplifier will indicate its fault status by blinking the "On" LED of the channel affected in one of 9 different ways.

So far I've used these amps twice, both times driving monitors. Unfortunately, it wasn't exactly a critical listening test, and I certainly wasn't driving them up against their rails so I didn't get to experience how they performed under duress. I also recently used a Vortex 6 while working with another company, and it was good to me as well, but since it was running front fills I barely tickled the signal lights. Since I'm doing a bunch of suitcase gigs this time of year, I palmed both amps off on others... John Chiara and Mike Butler should be showing up with their opinions soon. I'm sure they'll put them to good use, and after they're done we can move them on to others who may be able to subject them to some real world abuse.

The product page for these amplifiers is available here:

John Roberts {JR}:
I'm not sure I follow the benefit of "world-wide" (universal voltage?) switching PS with a permanently attached line cord (over voltage?). At least with an IEC line cord you could also plug it in "world-wide" too.

I'd also need to check the schematic for those "servo-coupled capacitorless inputs". All the typical DC servo circuits I've seen use capacitors. I guess they could use D/As to add a DC correction but I'd need to see that since it's expensive overkill.

I'm not picking on you Bennet, this must be the part of the review thread where you paraphrase and/or paste the company's marketing FAB. AFAIK these amps are not turds so they shouldn't need polishing.


Jim Stachowski - Ashly:
Darn, I saw my name and have to come out of lurking mode. Many thanks for the Camco Vortex overview and kind comments.

Though I am not the technical person for Ashly or Camco, I must point out the worldwide switching power supply for the Vortex amps is not universal. There are separate 120V and 230V versions.

Also, a big thanks to the Wedge-Fest crew and PSW for taking the time to play with these little amps.

Jim Stachowski
(the marketing guy)
Ashly Audio, Inc.

Bennett Prescott:
Jim Stachowski - Ashly wrote on Mon, 25 September 2006 10:23
Though I am not the technical person for Ashly or Camco, I must point out the worldwide switching power supply for the Vortex amps is not universal. There are separate 120V and 230V versions.

Oops! Sorry, folks, the manual made it appear as though the PSU was universal. Jim, if I buy a 120V version and want to use it with 230V mains, is there a switch or do I need an entirely different amp?

Also, could you please have one of your technical people elaborate on the line from the manual describing the input stage's DC blocking techniques? Here it is quoted.

John Roberts  {JR} wrote on Mon, 25 September 2006 09:41
I'm not picking on you Bennett, this must be the part of the review thread where you paraphrase and/or paste the company's marketing FAB.

You bet!

John Roberts {JR}:
The PS issue is worth clarification as portability across different voltage mains could be useful to some customers, but the "no capacitors in the signal path" is more a matter of personal amusement than of any real significance one way or the other.

First because the implied benefit is based on the questionable premise that DC blocking capacitors degrade signal integrity. Secondly the classic 'DC servo" circuit does indeed still use capacitors. Instead of large electrolytics in the forward path, smaller high quality film capacitors are used in combination with an opamp (as an impedance multiplier or scaler) in an overall feedback loop. While perhaps not obvious to those unskilled in circuit design, the capacitors in the feedback loop are indeed very much in the audio path. Any who don't believe me are invited to replace those capacitors with diodes and see how clean their audio path sounds.  

This little bit of marketing puffery is so old I wrote about it in my "audio mythology" column back in the '80s. Of course my comments here are an abbreviated version.

I appreciate the difficulty of creating the impression of a merchantable difference between modern amplifiers when most deliver quite good bandwidth and linearity, but keeping with the spirit of the LAB being a hype-free zone I will point out claims that appear worthy of investigation.  



[0] Message Index

[#] Next page

Go to full version