Seymour AV Ice Block 5001 500watt Monoblock Amplifier Review

Seymour AV Ice Block 5001 Introduction

Much of what I found on the Seymour AV website was laced with a sort of sarcastic, dry humor but their 'About' page was the best (take a good look at the picture) -

Seymour AV was founded to bring unique audiophile-focused solutions with premium components to the audio/video market at factory-direct prices. We focus on delivering top quality bang for the buck by minimizing or eliminating the overhead you, the customer, aren't interested in paying us for, like chairs or water (update: we just purchased a chair but we had a coupon). We quickly answer questions and send samples. If it's not what you expected, we'll do what it takes to make it perfect. Don't worry about being less than smiling from your purchase. We’ll treat you like you’re our only customer, just not in a desperate, creepy kind of way.

Listeners of AV Rant know that I like to interact with manufacturers stealthily. I often call customer support to get help rather than our press/review contact to get the "real deal" about their customer service. If I don't tell them I'm reviewing their product (even if I do, they don't usually believe me thinking I'm just trying to get preferential treatment), I can report on how they treat Joe Consumer - not how they treat Tom the Reviewer.

I'm not going to pull punches with this review - I had problems with the Seymour AV 5001 Monoblock. I sent my review samples back. I told Chris Seymour (owner/operator/customer service rep) I didn't want to do the review. I told him (at one point) that he should just send it to someone else as my review will detail exactly every problem I had. He wouldn't relent. He wanted a review and he wanted it from me (oh, if only my wife felt the same way). If you want to skip to the good bits, hit the set-up page. But before you do, realize what this means. Seymour AV is not afraid of a little criticism. Seymour AV is not afraid of a reviewer known to be… harsh (I say honest but whatever). Most of all, Seymour AV is not afraid to have his amps put through the ringer. Well, they didn't come out without a blemish but they did shine.

History of Seymour AV

Or specifically, history of my relationship with Seymour AV. Chris Seymour is a friend of a friend. I first met him on Xbox live during marathon games of Halo 3 and Gears of War 2. At first I didn’t know much about him until finally I found out he made projection screens. Well, since I don't have a projector his product offerings seemed irrelevant for me to review. It wasn't until much later that I found out he was looking into productizing amplifiers. Specifically Class D IceBlock amps.

IceBlocks are an analog switching type amp developed and licensed out by Bang & Olufsen. I've actually been to their plant and have seen their operations. It is pretty impressive. What is most impressive is how much electronics they shove in those small, euro-design enclosures. Such tight tolerances and so little wasted space equates to two things - lots of power in a very small package and LOW HEAT. Ice Blocks are called that because they run so cool - somewhere around 83% efficient. While not as efficient as some class D designs that top 90%, that is impressive considering typical Class A amps are about 20% and A/B (the most common type these days) are lucky to hit 50%. What about the rest? Heat baby. Lots and lots of heat. That's fine if you have your amps out in the open and it's the middle of winter in Minnesota but if you have a component cabinet with less than adequate ventilation or, perish the thought, a converted armoire (you know who you are), it is a recipe for at the very least a significantly shorter lifespan on your amps. Worst case is burn-up and catastrophic failure a la red-ring-of-death (you Xbox 360 owners know what I'm talking about).

Seymour AV 5001 Build Quality

The 5001 IceBlocks came in a large brown box with separate boxes for each of the amps and separate boxes for the cables. Everything was packaged well and seemed to be well protected. Molded foam caps protect the amps from both sides, was easy to store, and worked well. After shipping them back in the same box and having them returned again, I can say without reservation that the packaging is more than adequate. Your UPS driver would have to be some sort of sadist to damage these amps.

I opted for the black version of the Seymour AV amps. They also come is stainless steel. The sides are the same (regardless of your color choice) with a semi-gloss black finish. The rounded cover is the only difference. The black top isn't exactly black - it is flecked with purple and blue creating an almost glossy night effect. I personally think it looks quite stunning - up close. From far away it looks black. Which is sort of what I wanted so again - happy customer here.

As you've noticed from the pictures, the top is rounded on the front corner. The amp is probably a bit smaller than you'd expect about 1/2 the size of a rack space (3.2" by 8.5" by 15.1"). This makes them very easy to place in your cabinet - especially in twos. They are very solid for their size with quite a bit of heft to them. Unlike some of the more esoteric offerings, they are not lead lined and nearly impossible to move, they are just as heavy as the components would indicate.

Speaking of esoteric - the Seymour AV 5001 Monoblocks tread the line between esoteric and budget very closely. One thing you expect in an esoteric amp is good looks. Well, the Seymour AV offerings have that in spades. Both of the finishes are stunning (I've seen the stainless at CEDIA) and the fit and finish is nearly impeccable. My only problem with the fit and finish is the Seymour AV logo sticker on the front. While it looks fine at first blush, it really doesn't look right in comparison with the rest of the unit. Better some sort of backlit cutout or an engraving or something. Anything but a sticker.

Seymour also does something that you usually only see in an esoteric amp - quality components. And not just quality - top of the line. WBT Nextgen RCA terminals, Neutrik XLR terminals, Vibrapod isolator feet, AR Pro II Ferrite Noise Trap power cord… the list goes on. Some of it has dubious value (Vibrapod feet? What, in case of earthquakes?) but it is all there. And more. If you are really into amps and all the different tweaky stuff that can go into them, Seymour AV is for you. I generally don't buy into all of that and just go Emotiva. But Seymour AV adds one additional thing:

Reasonable price. When we look at the competition, we find:

• D-Sonic MAGNUM 250M - $790 - each
• Wyred4Sound SX500 - $899 - each
• Rotel RB-1091 - $1500 each
• PS Audio GCA 500 - $3K (stereo so about $1500 a channel)
• Bel Canto Ref 500 - $5k pair ($2.5k each)
• Jeff Rowland Model 501 -$ 4,700 each

These amps all have the same B&O guts with different cases and components. At just over a grand for the 500 watt monoblock, the Seymour AV amp isn't exactly leading the pack in value but if you take into account all the components that go into them, you're going to find that they have more in common with the most expensive on the list above. Most competitors would probably like to bury the Seymour amps under a mound of "not chocolaty enough" user reviews. The price is frankly amazing for the level of workmanship and quality of components that are contained within. I asked Chris for and exhaustive list. This is what he sent:

• Stainless steel or black pearl blue 5-coat gloss finish
• Indirect power illumination (no direct LEDs firing into your eyeballs)
• Switchable balanced and unbalanced inputs
• D.H. Labs Revelation 99.99% pure solid silver signal wire
• WBT Nextgen Topline RCA terminal
• Neutrik RF-shielded XLR terminal
• Insulated, gold-plated 5-way binding posts (Uninsulated available as an option for those using massive spades. I had a customer - literally - hook up $22,000 MIT cables to the outputs, and they didn't like the insulated posts. So, uninsulated is a custom option)
• Vibrapod isolator feet
• Vibration dampened chassis (clear absorption layer in between the top and the bottom, and heavier gauge steel bottom)
• Soft clip circuitry, with red LED under the front to indicate input-shaping
• RF/EMI hardened assembly (twisted wires, ferrite filter)
• 100 hour factory burn-in (I have had customers claim a bit more change in the next 2-300 hours - I haven't heard it and I know you guys jest at such talk - just reporting what I've been told. Still, burning off the first 100 hours of component drift is unique for us.)
• 10 year warranty
• Made here in Ames, Iowa

One thing you'll need to realize is that the 500 watt rating on the 5001 is actually a 4 ohm rating at 1kHz. Unlike many amps, the Seymour AV offerings are all rated down to 2 ohms. This means that there are very few speakers (electrostats a possible exception) that would prove too much for these amps. At 8 ohms, typical for most speakers, the 5001 pushes a rated max 300 watts (technically at 4 ohms it pushes 550 watts at 1kHz). Due to the protection circuitry and limitations in the zobel network, this amplifier cannot hit its power spec at full power bandwidth.

Manufacturer's Note: B&O’s philosophy with their designs is that music is by its nature transient, and thus the power requirements are different than if you designed an amplifier to just pump pink noise or sine waves continuously on a test bench. Therefore, they’ve sized the components such as the Zobel network to handle full power, but at decreasing time limits as the frequencies increase. From Bang & Olufsen’s design manual, Figure 11 (see right) shows that if you wanted the amp to sit there 24/7 the maximum power output it can handle decreases with frequencies above 4kHz. Figure 12 shows the opposite; that if you wanted full-bandwidth amplification, how long you could sustain the signal. Being able to pump full power at 25kHz for 100ms, for example, is realistic when it comes to music or movies; you will get full power bandwidth with dynamic content. Evidence for this is that you never saw the red LED’s fire off under the front. You can jam on this amp relentlessly and the four protection circuits will keep it from being damaged. I’ve abused the modules on the test bench, but have never met constraints beyond the red soft-clip LEDs blinking with actual speakers playing content.

Taking apart the amp, we find the Bang & Olufsen's patented analog ICEPower amplification module mounted to a fairly substantial piece of aluminum. Around the top of the unit is a blue LED strip providing the internal lighting. I suppose if you really don't like the lighting, you could ask Seymour AV to eliminate that strip (it is plugged into the board for power and glued in several places). Between some of the components there is what looks like caulk seemingly for vibration control. I couldn't get a picture of it but there is also a sort of shock system under the aluminum plate most likely for the same reason.

I was unable to measure this amplifier since I don’t have the proper test gear to do so and it’s a bit trickier than traditional amplifiers because of the high clock frequencies associated with the amplifier topology that can manifest as poor performance results on test gear if not properly preconditioned.

Seymour AV Ice Block 5001 Setup

The back of the Seymour AV 5001 is as Spartan as you'd expect a monoblock - maybe moreso. There is an RCA and XLR balanced input, a pair of 5-way binding posts, a three prong power port, and an input switch. The power switch is fairly standard but lacking one feature you might expect - any sort of power saving function. Now, one of the first things you'll learn about class D amps is that they are very power efficient. At idle, the 5001 amp only consumes 9 watts. Still, I don't always want my amp powered up regardless of how efficient it is. A 12 volt trigger would have been appreciated. I personally don't like (and refuse to use) auto-on functions that sense an incoming signal and switch on so I don't mind that it is absent on the 5001.

One thing to consider with the 5001s (or any monoblock for that matter) is space. Monoblocks typically take up much more space than their multichannel brethren. It would be nice if Seymour AV came out with a few multichannel amps but so far, no dice. If you consider the size of a even the behemoth Denon 10 channel POA-A1HDCI, 6 or 8 Seymour AVs probably take up more room. But that's sort of the price of a monoblock, and something to be considered for your long term purchasing plans.

The first hurdle you're probably going to face is plugging the amp in. I say that because Seymour AV provides an Acoustic Research Pro II Ferrite Noise Trap (FNT) IEC power cord sometimes used to eliminate radiated noise. This is not a desirable solution. Seymour AV has placed a ferrite filter on the power line inside the case which seems to have pretty much eliminated the noise coming in or out of the amp. They say that the power cord can be switched out with a standard one without appreciable noise increase. Apparently, the upgraded power cord was just a precaution.

The AR power cord, in practical terms, may look cool but it is the single least flexible power cord I've had the misfortune of using. While it is probably fine (and maybe even preferable) for open configurations (i.e., on a piece of marble in the middle of a room with cable elevators everywhere), forget about using them in a component cabinet like my Sanus CFA56. They just don't work. I had to use some extras I had lying around. While the cords look nice and feel very esoteric, they just aren't very practical.

Next, you'll want to decide how you are going to connect the source to the amp. I am sporting a Denon AVR-2307CI, an Emotiva RSP-1, and a Denon DVD-3910. The Denon is a fairly middle of the road receiver and has no balanced preamp outputs. Instead, I needed to use the RCA outs. I used the same connection with the Emotiva. With either preamp, I ran them in source direct through the analogue inputs with the DVD-3910. Regardless of how you connect the amp, make sure you set the switch to the correct input. This will affect grounding, cut your signal strength if not properly set, and may eliminate/reduce hums.

The Seymour AV 5001 amp (and all the amps in the line) has a very unique lighting scheme. If you follow the line of the amp between the top and the sides, there is a small piece of plexiglass which is backlit by blue LEDs. This makes for a very smooth and, dare I say it, designer look. One of the things that the esoteric crowd has over the budget offerings is looks and the Seymour AV amps are nose-and-nose with the best, leaving many others in the dust. The only thing that is missing is some sort of front lighting. The Seymour AV logo sticker (the only blemish on the amp's perfect aesthetics) is placed on the front but in a darkened room, all you're going to see is the side lighting. This makes for a very nice effect if the amps are out in the open (something I think even the most devoted HGTV watcher wouldn't have a problem doing with these gorgeous amps). Installed into a cabinet, you can barely see them. This is especially true if the amps are placed fairly close together (a typical arrangement in a cabinet). What you end up with is a bit of light from the sides but really mostly nothing to look at. I'm sure there are plenty of spouses that will love to read this (go ahead and bookmark this guys) but I'd like to see a little something on the front. Maybe a backlit logo or something. There is also a complete lack of ability to dim or shut off the light. When the amp is on, the light is on. While it is far from bright (it is actually a very nice brightness - bright enough to notice in a well lit room but not so bright it is distracting in a darkened on), I'm sure there are some that would like a little more control. This is a good example of where a 12 volt switch would be useful even if you aren't worried about power consumption. If nothing else, it turns off the lights.

For those that are thinking they would like to place their new amp purchase in a cabinet and are worried about heat, the Seymour AV amps live up to the low-heat promise. When you plug the amps in, they will actually cool down slightly..This is because Class D amps run cooler at full power then they do at no or low power levels. This is what class D is for, this why Ice Blocks were designed, and the Seymour AV offerings deliver. At first I thought they ran a little hot - and they sort of do at idle. A class A/B biased at a low quiescent current will feel cooler to the touch at idle (in my experience) but wait until you start pushing them. The Seymour AV will feel about the same (or even a little cooler) while the Class A/B will start cooking.. Cooking the rest of your gear I mean.

There is a reason, in fact, to set your new Seymour AV amps on a cabinet. Basically, there is soft-clip circuitry. According to Seymour AV:

Ice Block amplifiers are equipped with a soft clipping circuit that applies light compression at maximum output, limiting the maximum signal level. This eliminates the clipping that traditional amplifiers experience when their signal exceeds the capabilities of the output devices. This feature ensure that you have optimum sound in high-level situations and protect both the amplifier and your speakers from dangerous tweeter-frying distortion.

The negative impact of this protection circuit is that this amplifier cannot do full power bandwidth continuously into a 4 ohm load as per the B&O Application note and Audioholics prior measurements of these amplifier modules. This is a limitation of the B&O module design and not representative of a flaw in the Seymour design. In most cases this won’t present a problem for real world applications but it's important to note the tradeoffs and limitations of this amplifier design.

Unlike most other ICEPower applications, the Seymour AV Ice Blocks feature a separate indicator light to let you know when the amp is shaping the input signal. You not only benefit from knowing the soft clip circuit is protecting your system, but will also learn under which conditions the amp is compressing your signal and whether or not you've properly sized your amplification power to your system and listening habits. This translates into a little red light that fires down out of the front of the amp (hence the shelf placement). This light bounces off the shelf and reflects up to you. Now, you'll have to take Seymour AV's word that this is the case - in my evaluation period I never had a clipping situation. According to Seymour AV, "We drive every module to soft-clipping to test the protection circuitry and LED on the test bench, but the 500ASP and 1000ASP are too difficult to bury for us using speaker." Remember, however, that it may be the case that clipping is occurring before you see the light so you might want to back it off to where the light isn't illuminating and then maybe a few more notches down. One thing to note is that the Vibrapod feet can leave marks on stained wood. Consult with Seymour AV if you are worried about it. They also stick like suction cups to glass (personal experience) but I don't think you need to contact them about that.

The biggest problem I had with the Seymour AV 5001 amp was a hum. It was a ground loop - the one that comes from your cable TV. I knew it, Seymour AV knew it, but nothing seemed to fix it. I did everything I could but the hum remained. I was able to reduce it from an "oh my God! What is that thing?" level to an "I can still hear it, barely, but it is still there" by employing a few tricks but that wasn't really good enough. I wasn't willing to have an amp that hummed in my system and Seymour AV wasn't willing to give up on the problem. Out of all the amps they have sold, they have only had a similar problem with one other customer and they were able to resolve that one. With me, it was a little more difficult.

I ended up sending the amps back for additional testing and modifications. The amps returned (undamaged thanks to their good packaging) still humming. I think both Seymour AV and I threw our collective hands up in disgust at this point. I even sent him this email:

I hooked up the modified amps again today and again got the hum. This is with everything plugged into the same outlet through the same APC H15. I was able to reduce the hum considerably by adding an isolator and passing the signal through the APC but I was not able to eliminate it. It was still audible during quiet passages from my listening position. I'm not sure the problem but it looks like your amps and my system are just not compatible. I'm sorry that this couldn't have worked out better.

You'd think at this point he'd just give up. Nope, he kept at it. So if you're wondering how this guy got married - pure persistence is my guess. With his tenacity, he's probably married to a supermodel. Finally, someone over at Bang & Olufsen suggested that while the "…star ground is correct, with some systems, power ground and signal ground can have too great a difference." Seymour AV suggested that I cut a single wire. Voila! Fixed. Apparently this one little wire was the culprit and will forever be banished from all future Seymour AV amp offerings. Score one for me I suppose. Also, note the level of customer service here. This is not just above and beyond because I'm a reviewer, but it was a matter of pride with him. I gave him a free pass out of the review. He could have just cut and run. But instead, he stuck with it even though he knew (or should have known) that all of this would be in the review. That's what Audioholics is all about - telling you how it is. That's why he wanted us to review his amps. That's what he got and that's what we're providing you the reader. Should you read this and say, "Whoa, that amp hummed?" No! You should be thinking that anyone that is willing to risk a bad review because he wants to make the perfect amp is probably going to make sure that you're just as happy with your purchase. Something to consider.

My last, and most petty, gripe with the Seymour AV Ice Block 5001 500watt Monoblock amplifier is the name. It doesn't exactly trip off the tongue if you know what I mean. I'm thinking SeymourAV IB5-1 or even IB-501. Something a bit shorter and easier to talk about on the podcast.

Seymour AV Ice Block 5001 Listening and Conclusion

Ah, listening evaluation - my least favorite portion of an amp review. I've already stated that I never clipped the amp and it is well reported on Audioholics that performance between non-clipped amps is very, very hard to identify. Subtle is a word. Non-existent according to some. Many of those performance differences should be most noticeable in the bass response and in my testing, I didn't notice any. While I'll let the tech-heads on the forums argue the finer points of amp sound quality, let me say a few words about my experiences.

Never once did I feel like the 5001 was hitting its limits. I never noticed it clipping or attenuating the signal in any way. I've had a myriad of different speakers through here - everything from Infinity to Dali to Salk to MCM… all from a wide range of price points. The 5001 played nice with all comers and provided ample power and headroom. Deep and resonant lows, airy and accurate highs… pick your adjective. Lots of chocolate, vanilla, grit… the Seymour AV amp had it all. In fact, I've come up with a little formula for you:

People often talk about the importance of _________. When I plugged in the Seymour AV 5001 amps, I couldn’t help but be blown away by its ability to provide impressive ____________. Even my wife, who normally isn't interested what I do in my "man cave," remarked from the kitchen that the system sounded different. When I explained to her about ________, she sat down and took a listen. She even had me switch to my other amps for a quick comparison. Her eyes were wide as, for the first time, she started to understand why it is I'm so into this hobby. Thank you Seymour AV.

Just fill the blanks in with your esoteric descriptor of choice - transients, dynamic range, microdynamics, crystal clear highs… whatever. It all works. All you writers over at those esoteric review mags need to start giving me a percentage from now on. I'm just saying.

Conclusion

It's not hard to see that I'm impressed with the Seymour AV Ice Block 5001 500watt Monoblock Amplifier. It has plenty of power, great aesthetics, and near perfect functionality. Seymour AV seems ultimately dedicated to taking care of their customers which is a good thing. Most of all, they provide esoteric components, looks, and construction at near enthusiast prices. That alone should be a huge selling point for those with smaller wallets but refined tastes. The fact is that other lower priced amps tend to come in big, industrial boxes. That's fine if those are the aesthetics you're into. On the other hand, if you want a great amp at a decent price with fantastic looks, the 5001 is for you. Plus, you'll have an amp that is not only a show piece for the uninitiated but also sports all the "extras" that will impress your esoteric friends. What more could you ask for?

Seymour AV Ice Block 5001 500watt Monoblock Amplifier

$1099 (each)

Seymour AV

515.450.5694

www.seymourav.com

About Seymour AV
Seymour AV was founded to bring unique audiophile-focused solutions with premium components to the audio/video market at factory-direct prices. We focus on delivering top quality bang for the buck by minimizing or eliminating the overhead you, the customer, aren't interested in paying us for, like chairs or water (update: we just purchased a chair but we had a coupon). We quickly answer questions and send samples. If it's not what you expected, we'll do what it takes to make it perfect. Don't worry about being less than smiling from your purchase. We’ll treat you like you’re our only customer, just not in a desperate, creepy kind of way. All of our product is manufactured to order in Ames, Iowa.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Fit and Finish
Ergonomics & Usability
Features
Appearance
Performance
Value