I have a Rotel RA-810A amplifier – recently serviced and in good working order – and a Yamaha CDX-730 CD player but no speakers. They were originally linked to some Tannoys but I didn’t bring them with me from South Africa.
I want to be able to play my CDs and DVDs with the speakers linked up to the TV. I’m not a purist and don’t want to pay top price. If you could point me towards a few alternatives, I can then make the decision what to pay. Maggie
The Rotel RA-810A is a classic stereo amplifier from the late 1980s. I remember it as being well made and having a decent sound. However, it does have a couple of drawbacks.
First, like all amplifiers from that era, the RCA phono inputs on the back are designed to work with turntables, CD and cassette tape players. While the RA-810A has phono sockets for AV/Aux, which you can select from the knob on the front, this input has the same spec as the others. There are no digital or HDMI sockets of the sort you would find on a new AV amplifier.
Second, the Rotel RA-810A is somewhat underpowered, delivering just 20 watts per channel. This was quickly corrected in later models such as the RA-820AX and RA-930AX. However, it does mean that you will need speakers that are reasonably efficient, or at least easy to drive.
Connecting your TV and DVD
The RCA phono socket problem, mentioned above, means that it may be hard to set up the system you want. Worse, there is no general solution, because it depends on the inputs and outputs on your specific products.
If you are lucky, your DVD player will have two phono sockets that you can connect to the AV/Aux sockets on your Rotel amplifier. Problem solved.
Alternatively, your TV set may have phono sockets, or at least some form of analogue sound output, such as a headphone jack. In this case, you can connect the DVD player to the TV set by whatever means – an HDMI or SCART cable – and then take the audio output from the TV.
This is not quite problem solved, because you may need to use the TV set’s menu system to turn on the analogue phono sockets and disable the built-in speakers. This should be explained in the manual. In fact, if it’s a good manual, it will explain how to connect your TV to a standard amplifier. (If you can’t find it, most manuals are available online in PDF format.)
In the worst case, you can usually connect a TV set to an amp by using a Y-cable with a headphone jack at one end and two phono plugs at the other end.
A geekier option is to use a SCART adaptor to break out the audio from the DVD player. The adaptor provides a video socket to connect to the TV set, and two phono sockets to connect to your Rotel amplifier.
If all else fails, a DAC or digital-to-analogue converter will convert digital signals to analogue. A DAC could solve a specific connection problem, with suppliers such as Lindy offering an impressive range of options.
Otherwise, adding a general purpose DAC is the simplest way to enable an old-style amplifier to work with digital services. I covered this in an answer in 2015: How should I upgrade my old hi-fi in a digital world?
Speaker efficiency
Most loudspeakers have a sensitivity rating, expressed in decibels (dB). For example, an 88dB loudspeaker will produce 88dB of sound at a distance of one meter when driven with one watt of power.
While 88dB is loud, a loudspeaker needs to handle transient peaks up to about 105dB. Music and movies may include dynamic sounds that are very loud for short periods, such as explosions in a blockbuster such as Independence Day. The problem is that you need twice as much power to make the sound just 3dB louder. Powering an 88dB speaker to 106dB would therefore require 64W, and you only have 20W.
Worse, it’s a bad idea to drive amps and speakers flat out: it can lead to distortion, clipping, or even equipment failure. It’s better to do 70mph in a car that can cruise at 140mph than in one that’s hitting its limits at 50mph, and an amplifier that has power in reserve will manage transient peaks better than one that’s pushing the limit.
In practical terms, you’d only need half as much power to drive a 91dB loudspeaker, while you’d need twice as much power to drive an 85dB speaker.
Lower impedance means louder sounds, so in theory you could buy 4-ohm loudspeakers instead. However, your RA-810A is designed to handle 8-16 ohm speakers, so I don’t recommend that.
Of course, life is complicated. The impedance of a loudspeaker can vary between 3 ohms and 24 ohms over different frequency ranges, so you can probably get away with a 6-8 ohm rating.
It’s a pity you can’t remember which Tannoy speakers you had, because this would tell us the dB rating, and the level of performance you found acceptable.
Possible speakers
My first thought for your system was a pair of Wharfedale Diamond 9.1 speakers. They were What Hi-Fi’s 2005 product of the year in the speaker category, when they cost £180. You can now get them for half that. Positioned close to a wall, they sound much bigger than they are.
The drawback is that they are not the best specification for your amplifier. They are 6-ohm speakers with a dB rating of only 86dB, when ideally you want 8 ohms/90dB. However, Wharfedale Diamonds are generally easy to drive – it’s one of the reasons they’re popular – and they should work fine, if you don’t push them too hard.
My other favourites for this sort of job, the Q Acoustics 2020i, have a similar problem: they are 6-ohm speakers with a sensitivity of 88dB. At £129.95, I’d pick them over the Wharfedales, but it would be worth hearing them side by side. The 3020 version is also worth considering at £148.
A better fit technically would be a pair of Monitor Audio Bronze 2 loudspeakers (8 ohms/90dB). They’re better than the Wharfedales, especially in the bass department, but much more expensive at £279. However, the Monitor Audio MR2 speakers (6 ohms/90dB) could be an acceptable substitute at £125.
Oddly enough, you could also get a beefy pair of very efficient (92dB) Q Acoustics 2050i floor-standing speakers for £269.99 or less, including free delivery.
There are lots of alternatives, and it would be worth popping into a local hi-fi shop, if you have one. Most cater to people who are spending serious amounts of cash, but I’ve happily bought tons of stuff from Richer Sounds.
At the moment, Richer Sounds has Wharfedale Diamond 2020 speakers – which What Hi-fi rates above the old Diamond 9.1 version – for £119, Wharfedale Diamond 9.0’s for £49, and Q Acoustics 3010’s for £99. All three are 86dB speakers. Mission LX2 speakers (£149) raise that very slightly to 87dB, but the Richer Sounds sales staff may have better suggestions.
Buy second hand?
Lots of great-sounding old hi-fi systems are being junked by people switching to smaller but worse-sounding systems that work wirelessly with their smartphones, Spotify and similar digital services. There are lots of old Kef, Spendor, Celestion, Monitor Audio, Tannoy and other speakers around. You might even spot some familiar front grills.
The first drawback is that old speakers tend to be big by today’s standards, or – like my beloved 82dB LS3/5a loudspeakers – hard to drive well. The second is that they may have been abused, or are failing as a natural result of old age. You might be able to find a bargain, particularly if you know a hi-fi buff who is willing to help. But if you are shopping for compact speakers at £49 to £99, it may not be worth the effort.
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