(1) Onkyo TX-500
Ok, so the old AR team never produced multi-channel audio/video amplifiers, because there was no need for such technology those days - no video, no DVD, no home theater. Of course I could look at the very expensive option of running multiple AR amps to make up the 5.1 configuration, but apart from being extremely rare even in the US, the characteristically heavy weight made for a very indigestible $200 shipping invoice! Therefore, the first item to roll off the list was a normal 5.1 channel receiver, and the Onkyo TX-500 which came my way in January 2009 for a respectable $100 showed only a bit of dust in the nooks and crannies, had no scratches and was in perfect working order. It was advertised on the local version of Gumtree, 500km away in the town of George, and before I could even start working out transportation details, I learned that the seller's wife was on her way to visit her sister in Cape Town, so I could look-before-I–buy. No worries about damage during transit.
Sound wise I have great affinity for the Onkyo’s performance; I perceived its treatment of music audio as quite warm, of course vastly different from the AR amplifier which truly comes out stark and unforgiving. In reproducing a movie soundtrack the Onkyo was warm and colorful, and I guess very much what I want in a home theater setup. In your face, but rich and dynamic. Structurally it’s big and ominous, and extremely sensitive to the smallest irregularities in power and impedance. The unit often went into it’s notorious protection mode, and the only way to reset the amp was to completely cut disconnect it from the power line for anything from a few seconds to several minutes.
During December 2009 I installed a proper electrical ground connection, hooking up each piece of sound and video equipment, hoping that this would also reduce the Onkyo’s sensitivity by a good few points. But in that same period I started cranking up the volume, and this really threw the cat amongst the pigeons. What I initially thought was misplaced pistol shots in the movie, soon enough were identified as the dreaded phenomenon of clipping in the two front speakers. This situation occurs when a particular channel of the amplifier is too weak to power a speaker, and instead of a normal signal, it just streams through deadly square wave output. The speaker interprets this the same as DC input, which it of course can’t handle, and violently slams the voice coil in or out. This in turn can stretch the wiring or actually snap it off, while in other cases, being stationary with no ventilation, the voice coil heats up and simply burns itself into oblivion.
Mercifully the AR94’s proved themselves very robust units and came through unscathed, but with vintage AR’s as a rule requiring a good 50 watts to clear their throats, and the Onkyo delivering an advertised 70 watts per channel, what was going on?! A quick Google search gave part of the answer; many AV receivers simply don’t deliver what they advertise – 70 watts per channel simply is not 70 watts per channel all the time! Normally full power is not required by all 5, 6 or 7 channels at exactly the same time, so sharing takes place from the same source. Very few manufacturers publish the continuous performance figures, and very few reviewers test for that, because “normally” and under most playing conditions this will not surface. I suppose only when you are fortunate to be allowed to turn the big dial however far you please, will you know the true colors of your machine! Browsing through several reviews revealed that this was particularly evident in older and cheaper machines, but even some modern “power-houses” were not in the clear either.
So how do we know which amps speak the truth? One obvious indication is weight, because many watts require big amperes, and big volts mean big transformers. Now you know why that American tank of receivers, the Harman-Kardon is so darned heavy; its mean old mother of a transformer helps pump out continuous watts per channel often exceeding the specs. One should carefully read the information given in the product sheet or manual, looking for phrases like “equipped with 6 power amps” or “individual power channels” and so forth.
Unfortunately this wasn’t the only cement block dragging the TX-500 down. Not only is vintage AR a mean old dog to fire up, it also runs at 4 ohms, and this Onkyo asks for 8 ohms, so that impedance mismatch was largely responsible for the receiver’s protection mode kicking in whenever it felt unsafe. In the Onkyo's defense one should not forget that I was asking it to do more than what was normally required - in a less demanding environment plenty of load would have been carried by a self-powered sub woofer, but in my case two AR94's were asking double shifts from the same under-powered unit. Unfortunately the AR sub was still way off in the distance, and by now I was getting tired of pulling out power plugs to reset the Onkyo, so it was time to look for a replacement. Simply loved the Onkyo sound, but this one was heading for a home with less demanding speakers.
(2) Denon AVR-485
So, with the “demise” of the Onkyo TX-500, I started looking for the ideal replacement. The two big requirements were a continuous delivery of power and the ability to handle 4 ohms. Having grown accustomed to the Onkyo sound, it was logical that my initial searches would focus on this brand. Having read review after review, it became apparent that several current models were up to the task as far as watts were concerned, but nowhere could I find a review, owners’ manual or user recommendation confirming that any particular Onkyo could handle the low impedance without going into the dreaded protection mode. My horizon widened to take in more brands reputed to constantly run the same watts into the individual channels, and the names of Denon, Harman Kardon, Marantz, NAD and Yamaha came into the picture.
Ok, so the old AR team never produced multi-channel audio/video amplifiers, because there was no need for such technology those days - no video, no DVD, no home theater. Of course I could look at the very expensive option of running multiple AR amps to make up the 5.1 configuration, but apart from being extremely rare even in the US, the characteristically heavy weight made for a very indigestible $200 shipping invoice! Therefore, the first item to roll off the list was a normal 5.1 channel receiver, and the Onkyo TX-500 which came my way in January 2009 for a respectable $100 showed only a bit of dust in the nooks and crannies, had no scratches and was in perfect working order. It was advertised on the local version of Gumtree, 500km away in the town of George, and before I could even start working out transportation details, I learned that the seller's wife was on her way to visit her sister in Cape Town, so I could look-before-I–buy. No worries about damage during transit.
Two features of the TX-500 are of great interest here; (1) it can accommodate a phono input for a turntable, and (2) apart from the multi-channel speaker outputs, it also has a separate pair of connection posts for an additional set of speakers. That really clinched the deal; dedicated home theater speakers for movies on the one circuit, and dedicated hi-fi speakers for music on the other. You see, it was about at this time that I started formulating the plan for two separate systems; the original home theater setup with some vintage AR components, and a 100% pure vintage AR-based hi-fi setup. I had high hopes of sourcing the required number of suitable/useful/repairable AR speakers, but back then it seemed as if the hunt for the rest of the components (read amp and turntable) was going to be a long, steep and dark climb. So until the day the Sybe Bakker set arrived and filled the gaps of the AR puzzle, the Onkyo’s secondary circuit performed its duties just fine. Since then the Onkyo’s activities in driving the CD-player and turntable fell away, and it was left to only process the satellite TV and DVD signals.
Sound wise I have great affinity for the Onkyo’s performance; I perceived its treatment of music audio as quite warm, of course vastly different from the AR amplifier which truly comes out stark and unforgiving. In reproducing a movie soundtrack the Onkyo was warm and colorful, and I guess very much what I want in a home theater setup. In your face, but rich and dynamic. Structurally it’s big and ominous, and extremely sensitive to the smallest irregularities in power and impedance. The unit often went into it’s notorious protection mode, and the only way to reset the amp was to completely cut disconnect it from the power line for anything from a few seconds to several minutes.
During December 2009 I installed a proper electrical ground connection, hooking up each piece of sound and video equipment, hoping that this would also reduce the Onkyo’s sensitivity by a good few points. But in that same period I started cranking up the volume, and this really threw the cat amongst the pigeons. What I initially thought was misplaced pistol shots in the movie, soon enough were identified as the dreaded phenomenon of clipping in the two front speakers. This situation occurs when a particular channel of the amplifier is too weak to power a speaker, and instead of a normal signal, it just streams through deadly square wave output. The speaker interprets this the same as DC input, which it of course can’t handle, and violently slams the voice coil in or out. This in turn can stretch the wiring or actually snap it off, while in other cases, being stationary with no ventilation, the voice coil heats up and simply burns itself into oblivion.
Mercifully the AR94’s proved themselves very robust units and came through unscathed, but with vintage AR’s as a rule requiring a good 50 watts to clear their throats, and the Onkyo delivering an advertised 70 watts per channel, what was going on?! A quick Google search gave part of the answer; many AV receivers simply don’t deliver what they advertise – 70 watts per channel simply is not 70 watts per channel all the time! Normally full power is not required by all 5, 6 or 7 channels at exactly the same time, so sharing takes place from the same source. Very few manufacturers publish the continuous performance figures, and very few reviewers test for that, because “normally” and under most playing conditions this will not surface. I suppose only when you are fortunate to be allowed to turn the big dial however far you please, will you know the true colors of your machine! Browsing through several reviews revealed that this was particularly evident in older and cheaper machines, but even some modern “power-houses” were not in the clear either.
So how do we know which amps speak the truth? One obvious indication is weight, because many watts require big amperes, and big volts mean big transformers. Now you know why that American tank of receivers, the Harman-Kardon is so darned heavy; its mean old mother of a transformer helps pump out continuous watts per channel often exceeding the specs. One should carefully read the information given in the product sheet or manual, looking for phrases like “equipped with 6 power amps” or “individual power channels” and so forth.
Unfortunately this wasn’t the only cement block dragging the TX-500 down. Not only is vintage AR a mean old dog to fire up, it also runs at 4 ohms, and this Onkyo asks for 8 ohms, so that impedance mismatch was largely responsible for the receiver’s protection mode kicking in whenever it felt unsafe. In the Onkyo's defense one should not forget that I was asking it to do more than what was normally required - in a less demanding environment plenty of load would have been carried by a self-powered sub woofer, but in my case two AR94's were asking double shifts from the same under-powered unit. Unfortunately the AR sub was still way off in the distance, and by now I was getting tired of pulling out power plugs to reset the Onkyo, so it was time to look for a replacement. Simply loved the Onkyo sound, but this one was heading for a home with less demanding speakers.
(2) Denon AVR-485
So, with the “demise” of the Onkyo TX-500, I started looking for the ideal replacement. The two big requirements were a continuous delivery of power and the ability to handle 4 ohms. Having grown accustomed to the Onkyo sound, it was logical that my initial searches would focus on this brand. Having read review after review, it became apparent that several current models were up to the task as far as watts were concerned, but nowhere could I find a review, owners’ manual or user recommendation confirming that any particular Onkyo could handle the low impedance without going into the dreaded protection mode. My horizon widened to take in more brands reputed to constantly run the same watts into the individual channels, and the names of Denon, Harman Kardon, Marantz, NAD and Yamaha came into the picture.
In the end, with the reviews and opinions available to me, the search narrowed down to Denon. Although not clearly stating that its machines would easily handle 4 ohms, the recommendations (and warnings) in the Denon owner manuals were none the less very promising. To literally quote a Denon manual;
“The protector circuit may be activated if the set is played for long periods of time at high volumes when speakers with an impedance lower than the specified impedance (for example speakers with an impedance lower than 4 ohms) are connected. If the protector circuit is activated, the speaker output is cut off. Turn off the set’s power, wait for the set to cool down, improve ventilation around the set, then turn the power back on.”
The way I understand this, the Denon will handle the load until the set gets too hot, unlike the Onkyo which simply switched off the moment it detected a mismatch. Further to this, add lots of cooling and the point of switch-off is pushed out even further. This “theory” was supported by the testimonies of Denon owners using low impedance speakers and having no signs of compromised performance. After a few failed eBay auctions I secured a Denon AVR-485 for $132 from Hayward in California early January 2010. I had by now overcome my fear for shipping heavy items from the USA, because even after adding the excruciatingly painful shipping cost of $139, the final total of $271 was still half of what these were selling for on the South African used market.
The possible stumbling block of having to drop the South African voltage down from 220 to the Denon’s US-based 110 volts, was easily dealt with by introducing a 1000 watt step-down converter supplied by Protec in Durban, South Africa; for the mega bargain price of $30. Yes, half that power would have been sufficient for driving the Denon, but Protec only had the one converter in stock and the price couldn’t be matched anywhere in South Africa. Don’t be mistaken; this is no little converter you drop into the bag for powering your iPod attachments in India. It’s the size of a biscuit tin and features two handles to support its heavy weight.
After about a month of running the Denon, I still had to fine-tune all the different settings, but my initial impression was one of satisfactory performance. It was handling the 4ohm load of all the AR speakers with great ease, and the old Onkyo scenario of going into protection mode thankfully seemed to be something of the past. As for handling the power requirements of the five AR speakers I couldn’t detect the unit running abnormally hot – in fact it was definitely running cooler than the Onkyo, and I was yet to run into the dreaded clipping stage. A month or two later I replaced the sole surviving AR1ms (acting as center speaker) with a much “heavier” AR4, and still the Denon did not falter. After having played it for six months and showing it no mercy, I was truly convinced that the amp could handle 5 very demanding speakers all at once.
As for quality of sound, the Denon of course was way different from what the Onkyo produced - in general it appeared to be clearer, but it was definitely engaging the bass drivers of the two front speakers in a different fashion. Keep in mind that I was still doing without a sub woofer, so the two big AR94’s had to supply the low frequencies. With the dB’s set equal or close to equal on all channels, there wasn’t much oomph being produced; only when turning the levels up to at least 80% of max did the drivers come alive. As for home theater performance, the Denon did an outstanding job in reproducing Dolby Digital, and it did a better job in creating surround sound from a 2-channel stereo source.
To conclude, I have never for one moment regretted my decision to go with Denon, and it's definitely one AV brand that delivers on all of its promises and do the job it's supposed to do.
After about a month of running the Denon, I still had to fine-tune all the different settings, but my initial impression was one of satisfactory performance. It was handling the 4ohm load of all the AR speakers with great ease, and the old Onkyo scenario of going into protection mode thankfully seemed to be something of the past. As for handling the power requirements of the five AR speakers I couldn’t detect the unit running abnormally hot – in fact it was definitely running cooler than the Onkyo, and I was yet to run into the dreaded clipping stage. A month or two later I replaced the sole surviving AR1ms (acting as center speaker) with a much “heavier” AR4, and still the Denon did not falter. After having played it for six months and showing it no mercy, I was truly convinced that the amp could handle 5 very demanding speakers all at once.
As for quality of sound, the Denon of course was way different from what the Onkyo produced - in general it appeared to be clearer, but it was definitely engaging the bass drivers of the two front speakers in a different fashion. Keep in mind that I was still doing without a sub woofer, so the two big AR94’s had to supply the low frequencies. With the dB’s set equal or close to equal on all channels, there wasn’t much oomph being produced; only when turning the levels up to at least 80% of max did the drivers come alive. As for home theater performance, the Denon did an outstanding job in reproducing Dolby Digital, and it did a better job in creating surround sound from a 2-channel stereo source.
To conclude, I have never for one moment regretted my decision to go with Denon, and it's definitely one AV brand that delivers on all of its promises and do the job it's supposed to do.