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Classé Sigma SSP and AMP5 First Impressions

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Unboxing equipment becomes a tedious rote for reviewers that it is senseless to write about.  So when something as pedestrian as unboxing equipment catches your eye, you know someone’s paid attention to detail. 

Few companies understand how important it is to create a premium experience for their customers.  The box is part of the product experience. Apple is a well-known a master of this craft.  Not only does Apple meticulously design their products, but they also focus intently upon the packaging—from outer design and feel to each step you take to lift the product out of the box.

Unboxing the Classé review units told me that Classé's industrial designers paid attention to some of those same details.  The two boxes housing the Sigma SSP and AMP5 were identical in size.  The outer boxing reflected Classé’s nod to modern style and clean lines.  It was smooth and white with minimalistic detailing.  It eschewed the typical cardboard construction and feel you get with most AV products.  It felt higher quality.  Opening the box revealed a white, similarly branded “Accessories” box.  

Sigma Box

Included in the neatly laid out accessories box was as set of brushed aluminum magnetic caps for rack mounting (more on that below) and a Classé-branded black and silver USB stick that contains the user manuals for every Classé product. 

There’s no paper manual included at all, which may not sit well with everyone.  The USB stick also doubles to provide firmware updates for the processor that are done via USB. Underneath, the Sigma SSP Processor and AMP5 were covered in a Classé branded black cloth. 

 

Accessories box details

Included accessories of the Sigma SSP and Sigma AMP5 

Think about it for a moment. It would have been far easier to use brown cardboard and labels at any point.  Instead, Classé thought through the small details to convey a sense of the product’s premium lineage or exclusivity.  Attention to such detail quickly carried over to the industrial design of the units themselves.  Classé employed the design firm Goodwin-Hartshorn in the UK to develop the industrial design for the Sigma series.  

The results paid off in spades.  The units are strikingly minimalist.  Clean lines abound.  On the AMP5, the clear, five-way binding posts are beautifully branded with the Classé logo.  To the last detail, the units screamed, “This is all Classé.” 

binding posts 

The five way binding posts on the Sigma AMP5 are branded with the Classé logo showing meticulous attention to industrial design and branding throughout

In contrast to every other Classé processor, the volume dial on the Sigma SSP lies flush to the unit’s front face.  You scroll it like an iPod scroll wheel.  You cannot handle it like a traditional volume dial.  HDMI, headphone, and USB inputs grace the front of the panel with the menu and mute buttons recessed flush against the curved black TFT screen’s glass in the middle of the unit.  

The top and sides of both units are smooth and clean without any vent holes whatsoever.  In case you are wondering, the entire chassis handles heat dissipation. The smooth surfaces accentuate the brushed black, aluminum styling and further add to the silky look of the units. 

Heat Sinks

Top view of the AMP5.  The heat sinks are covered in a pink-colored material that comes into contact with the top cover and helps dissipate any heat to the entire chassis.  In all my testing, the AMP5 never go hot.

I experienced first-hand how these units have been specifically designed to cater to high-end custom installations. Gone are the rounded, hallmark curves of Classé’s CA-series amps or SSP-800 and CP-800 processors.  Instead, you have a more traditional—yet modern-looking—box that caters to nuances for rack-mounting.  

For example, both units share exactly the same footprint and enclosure.  Only the faceplate is different.  Using the same form factor for the processor and the amplifiers in this series makes rack design and installation planning a piece of cake.  Every unit is a 2U design. In fact, if you are going to rack mount the units, there’s no need purchase an additional rack kit or use rack ears that will compromise the styling of the Sigma and AMP5.   The rack mount for the units is integrated into the side panels of every unit.  What a brilliantly simple idea; yet, silly as it sounds, it’s one of the most beautiful things to see in rack mountable gear.  

Sigma AMP5 Detail

The Classé Sigma AMP5 with integrated rack ears and magnetic caps

Simply unscrew the sides, flip them around and bingo!  You now have 19” rack compliant ears that seamlessly match the fit and finish of the units.   Remember those magnetic caps I mentioned at the unboxing?  Classé includes those magnetic caps to adhere to the mount ears.  They hide the rack mount screws and make the installation look completely clean.  Now, that is attention to detail. Whether you’re rack mounting or keeping them in a traditional cabinet, the Classé units will be functional and look great in either environment.

When I asked Dave how they came up with that idea, he told me that their industrial design firm, Goodwin-Hartshorn listened to what Classé wanted about the overall design goals for both shelf and rack-mount applications and came up with this brilliant solution. "Everyone who sees it loves it," he told me. 

 A key secret to Classé’s minimalist design lies in their longtime commitment to TFT touch-panel displays.  Everything you need to do on the processor is handled via the integrated touch-screen display.  Coming from a world where mobile devices sport retina displays, I found the TFT display to be startlingly low-resolution.  It was like going back to 480i after being accustomed to 1080p. Nevertheless, the display is infinitely flexible and functional.  You can set the display’s brightness level and time-out to turn it completely off so that it doesn’t sit as a glowing distraction.

You can rename each source, input, and configuration via the display so that it’s customized to your specific installation. The display will show you the current volume in large, clear numbers that you can see across a room.  Under the volume it displays the current input, video signal (including whether it is 2D or 3D), the audio codec being used, the audio signal’s bitrate, and what audio mode you currently have selected.  

Real Time Video Preview

The TFT Display can show you a real-time video preview of your source

With a simple menu click, you can even use the TFT display to give you a real-time video preview of your selected input source.  If you are having HDMI problems you can see if the signal is arriving properly to the processor or if you have the Sigma SSP in a different room, you can monitor the input signal right on the unit for simple debugging.  Perhaps best of all, because it’s a software-driven display, Classé can update the menu offerings and features anytime with a simple firmware update.  

I’ve had quite a bit of experience dealing with multichannel processors over the years and I found the Classé to be among the most flexible.  The Sigma SSP just might be the definition of versatility. It combines the flexibility of Swiss Army knife with the precision of a surgeon’s tool in an easy-to-use package.   There’s simply not enough room here to even pretend to detail what you can do with this processor.  It’s just awesome.

What Classé chose to exclude in the design is as important to note as what is included.  Fitting electronics into such a small form factor certainly needed some compromises.  However, some that I observed are due to form and others to Classé’s philosophy. Let me explain.

There’s no video processing or scaling.  Dave told me that Classé doesn't believe that the audio processor is the proper place for video processing so the Sigma SSP offers straight pass-thru of video signals.  Classé is not alone in this belief.

Nevertheless, unlike some other competitors who omit video processing, Classé does give you an on-screen display (OSD).  When an OSD is required, it is overlaid on the video signal using an FPGA (field-programmable gate array) that writes the video from the touchscreen onto the screen, changing only those pixels that represent the OSD and passing through those that are part of the picture being displayed.

Sigma SSP On Screen Display

The Classé Sigma SSP's OSD is elegant.  It shows you the input source, incoming audio channels and sampling rate, volume, and video signal.   The OSD t takes up quite a bit of screen real estate, especially on older 480p sources. 

In this way, even when an OSD message appears, the rest of the screen remains unaffected. While Classé’s OSD messages are rendered nicely on screen, they are quite large and can also become visually obtrusive.  The great news is that you can defeat the OSD in the display setup menu.

Even though Classé extolls the virtues of balanced connections in the manual, they are limited to the front left and right channels on the processor and channels 1 and 2 on the AMP5. The remaining connections are unbalanced. The decision to omit balanced circuits was largely due to budget and the physical restrictions of the Chassis.  

I was curious about the overall circuit design of the units. When Dave and I got a bit more in-depth about the circuitry of the Sigma series he told me that the XLR connections of the units are fully balanced.  He went on to say, “In general for Classé products, we would never use XLR connectors without accompanying balanced circuitry.  For the SSP, you do accurately describe the differential output of the DACs and we maintain that in the analog path, volume control, etc. as well. For the AMP5, the amplifier circuitry is balanced for all channels through to the speaker terminals so even single-ended inputs are converted to balanced immediately on entering the chassis.”

The Sigma series embraces digital content delivery, but it does so only via Ethernet. There is no WiFi option available.  Wired connections are much more reliable with less latency. 

A potentially major compromise with the Sigma SSP is deciding how to handle your setup.  The sixth and seventh speaker outputs are called AUX 1 and AUX 2.  You can use them in only one of the following configurations: as the rear channels in a 7.1 surround system; as front height channels; as a second parallel audio zone; or as a mirror of the front L and R speakers in a bi-amp arrangement.

Sigma SSP Rear Inputs

The rear view of the Sigma SSP with balanced L and R channels and assignable AUX 1 and AUX 2 outputs.  Additional USB and HDMI input ports are located on the front.

Assign AUX

From the OSD, you can assign how the AUX output will function.  You can have the AUX speakers function differently for different configurations.

Classe provides a fully adjustable PEQ for each channel to help you dial in the best sound.

Possibly the most interesting decision for some enthusiasts will lie with the Sigma’s automated room correction or the absence thereof.  Instead of automated room correction, the Sigma SSP comes with nine bands of manual parametric equalization (PEQ) for each speaker.  You can choose to enable the PEQ on a speaker-by-speaker basis or all speakers together.    

Think of the PEQ as smoothing out bumps or valleys at a specific frequency.  Depending on how your speaker and room interact you may have smaller or larger bumps.  Classé’s PEQ is very flexible to allow you to handle pretty much any situation.  You can adjust the PEQ center band frequency from 20Hz to 20kHz.  In other words, you have no limit within the audible band of human hearing.

The center gain is the amount of center frequency cut or reduction in volume for that frequency.  You can decrease the center gain by up to 20db or increase it by as much as 3db. Remember that increasing the gain puts much more stress on the amplifier and it’s always better to address peaks than valleys.  For this reason, Classé correctly limited the increase to only 3db. 

Finally you can then set the Q value or the filter width from the center band that the filter will affect.  This value, which can be set from 1-10 will adjust the sharpness of the filter.

This manual approach provides more control to the dealer or installer.  I asked Dave about this point specifically.  “We have a global network of distributors who are familiar with the Sigma series and provide dealer training.  For dealers already familiar with Classé, the setup and operation of the SSP is quite familiar. As always, the most important part of the setup is positioning the loudspeakers and dealing with room problems, which is true of all audio system installations so not unique to Classé system installations.”

On the one hand, Dave is completely right.  Speaker placement is paramount and you want to limit the amount of EQ you are applying.  And when you need to apply EQ, you want to have the proper flexibility, limit EQ to the lower frequencies and let your ears decide. 

On the other hand, this choice underscores a presupposition that these units will be expertly installed by your local dealer.  If you chose to forego dealer installation, beware!  If you don’t know how to take proper measurements and understand what the PEQ settings are doing then you should leave the PEQ disabled and focus your energies on placing all the speakers properly in your room. The bottom line here is that Classé’s approach is a completely valid one but may not please everyone. 

The eight HDMI ports (7 rear and 1 front) are HDMI 1.4.  With UHD displays and content hitting the market I was pleasantly surprised to hear that Classé is planning an HDMI 2.0 and HDCP 2.2 hardware upgrade path for Sigma SSP clients.  The HDMI 2.0 upgrade will upgrade all inputs and outputs. Classé specifically designed the board to be modular to accommodate upgrades.  Dave told me that by the time actual UHD content became available they would have access to the full 600 MHz bandwidth parts. Because the parts have been coming slower than expected Classé plans to offer an interim step later this year for people who want or need it to accommodate UHD Blu-Ray players, which will be appearing at about that time. 

What about immersive audio? 
The SSP does not natively support any immersive audio formats. I asked Dave if there would be a firmware or hardware upgrade to support Dolby Atmos, Auro3D or the newly announced DTS:X.  He told me, “Most surround processors and AVRs have limited DSP capabilities and require shuffling of processing resources to accomplish multiple tasks at once. Would you want your TrueHD signal down-sampled whenever the EQ was engaged? That’s a pretty common technique. The DSP required for doing 3D audio properly (everything at full resolution) in a Sigma SSP is a bit more powerful than what is currently on board, so a hardware upgrade to a new dual DSP will be offered, probably later this year. Anyone who owns a Sigma SSP will have the option to upgrade it if they want to do so.”

Considering that the Sigma is only a 7.1 channel system, I asked what configuration users could select if they upgraded.  Dave said, “As you point out, since we have eight channels, the only 3D application for this model is going to be 5.1.2. At the moment, Dolby Atmos is the only 3D format we are planning to support on the new Texas Instruments platform. Whether others can be accommodated is yet to be determined.”

 

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Recent Forum Posts:

Alexandre posts on June 27, 2015 11:41
Alexandre, post: 1087631, member: 73792
Because the 2 components are in different rooms (the power amp is in a closet a little further away), I still want to go the trigger route. I'm going to play around with an Arduino but this also looks like a great option: http://www.nilesaudio.com/product.php?prodID=CS12V

I just installed the Niles Audio plug and it works perfectly! It even learns the standby draw of the device you're plugging to it which is really handy.
Alexandre posts on June 26, 2015 01:46
slipperybidness, post: 1087509, member: 56559
Get a power-sensing auto-on power strip for the amp. Problem solved.

Because the 2 components are in different rooms (the power amp is in a closet a little further away), I still want to go the trigger route. I'm going to play around with an Arduino but this also looks like a great option: http://www.nilesaudio.com/product.php?prodID=CS12V

Alexandre posts on June 25, 2015 13:58
slipperybidness, post: 1087553, member: 56559
You have a mistake in your logic. You avoid ground loops by insuring that you have only 1 return path to ground. One way to accomplish that would be to have all of your electronics plugged into the SAME outlet.

Right, thanks for the correction. And yes, I'm probably going to go the arduino route.
slipperybidness posts on June 25, 2015 13:09
Alexandre, post: 1087549, member: 73792
Thanks for the advice, in my setup, the amp is in a closet nearby while the SSP is under the TV, the 2 are plugged to different wall outlets so I'm not entirely sure the auto-on outlet would work for me but maybe (I was hoping to keep the amp plugged to a separate wall outlet to avoid ground loops and to avoid overloading that one outlet).

The other approach I'm thinking about might be a DIY arduino/CAN BUS/relay system… that could be a fun project… if I had time on my hands that is.

Alex.
You have a mistake in your logic. You avoid ground loops by insuring that you have only 1 return path to ground. One way to accomplish that would be to have all of your electronics plugged into the SAME outlet.

Yeah, an arduino or similar system would also do the trick, it really wouldn't be too tough to build at all.
Alexandre posts on June 25, 2015 12:36
slipperybidness, post: 1087509, member: 56559
Get a power-sensing auto-on power strip for the amp. Problem solved.

Thanks for the advice, in my setup, the amp is in a closet nearby while the SSP is under the TV, the 2 are plugged to different wall outlets so I'm not entirely sure the auto-on outlet would work for me but maybe (I was hoping to keep the amp plugged to a separate wall outlet to avoid ground loops and to avoid overloading that one outlet).

The other approach I'm thinking about might be a DIY arduino/CAN BUS/relay system… that could be a fun project… if I had time on my hands that is.

Alex.
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