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Specific/general Rotel RA-02 questions

RobGordon

RobGordon

Well-Known Member
Took delivery of one of these yesterday, following advice here. It's an obvious step up from the midi amp I can't believe I've been using for most of the last year. There's a bit of a metallic sound from my new DAC but I think it needs to run in a few more hours. Phono stage is possibly unused - there are indications the owner mainly used the amp with a matching CD player (also for sale) listening through headphones, as it arrived with the tone set just so, Speaker A connections loose, input set to CD, ground connection screwed firmly down, and here's what is annoying me.. a scratchy headphone socket.

Would a bit of Servisol Super-10 fix the headphone socket do you guys think? Like dosing cotton buds and swabbing it internally until it is clean? I'm new to Servisol.

Also the switches and dials seem to require an unusual amount of force to move. Is this right? Do they need Servisol-ing? And if so how?

Final question: the manual says to give it at least 4 inches headroom for ventilation. It currently has this but to free up space I could put it under my turntable with about 1.5 inches headroom apart from the shaft under the centre that I think has to do with the main bearing. If I did this would I cook the bearing mechanism? The amp will almost never be cranked - it is loud (to me) at 9 o'clock on the volume dial.

Anyway, many thanks to the people who advised getting one of these. Seems like the right decision for under £200.
 
I had the RA05SE and should have kept it a real gem I had no issues with it and used the remote mostly but switches were well damped not loose feeling if that makes sense
 
Does make sense. I wondered if the looser switches I'm used to on other amps were not made to last as much as the Rotel ones.
 
I had a ra02 for a very short period of time and also noticed that the switches were stiff. I liked that cause of the good control on the bass/treble adjustments. Didn't notice the amp getting too hot or anything but to be honest I kept it on top of the black boxes stack. Sorry can't help with the other questions.
 
RobGordon said:
Took delivery of one of these yesterday, following advice here. It's an obvious step up from the midi amp I can't believe I've been using for most of the last year. There's a bit of a metallic sound from my new DAC but I think it needs to run in a few more hours. Phono stage is possibly unused - there are indications the owner mainly used the amp with a matching CD player (also for sale) listening through headphones, as it arrived with the tone set just so, Speaker A connections loose, input set to CD, ground connection screwed firmly down, and here's what is annoying me.. a scratchy headphone socket.

Would a bit of Servisol Super-10 fix the headphone socket do you guys think? Like dosing cotton buds and swabbing it internally until it is clean? I'm new to Servisol.

Also the switches and dials seem to require an unusual amount of force to move. Is this right? Do they need Servisol-ing? And if so how?

Final question: the manual says to give it at least 4 inches headroom for ventilation. It currently has this but to free up space I could put it under my turntable with about 1.5 inches headroom apart from the shaft under the centre that I think has to do with the main bearing. If I did this would I cook the bearing mechanism? The amp will almost never be cranked - it is loud (to me) at 9 o'clock on the volume dial.

Anyway, many thanks to the people who advised getting one of these. Seems like the right decision for under £200.
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You'll want to avoid having any amplifier under any turntable, as the transformer within the amp is very likely to cause excessive hum and noise from the deck. Also, the radiated heat may not feel like much to the touch, however, over time, things like plinth wood/finish can suffer.

If placing an amplifier beside a turntable on a shelf, it is generally best to arrange the two such that the transformer (heavier) side of the amp is furthest away from the tonearm/cartridge. This generally results in the amp being on the left, with turntable on the right.

Also, if the manufacturer says give their electronic component a minimum of 4 inches of headroom for ventilation then it really should have 4 inches of headroom. The engineers typically don't just make these installation recommendations up, rather they are based upon safety and reliability/longevity testing.

Funny story. An acquaintance of mine not only kept his RA-840BX2 in an enclosed cabinet, he had it hooked up to multiple room in-ceiling pairs plus a pair of patio 'speakers. All of these, in addition to his main loudspeaker pair! Each of the other room pairs were controlled via local on/off/volume control potentiometers with transformers in that were intended to keep the combined load to an amplifier safe limit. During one of his frequent parties, the sound went dead, and, knowing me to be an audio nutter, asked me to have a look; result, a whopping big blister on my hand from daring to feel the amp's temperature! Amazingly, he got away with two blown output protection fuses, however, the heat had been so great that the two plastic spacer rails that fit between amp chassis sides and cover were melted out of shape. Seems he knew well enough not to turn all pairs on at once, however, one or more of his guests thought differently. I've since lost touch with him, however, I seriously doubt that that amp is still among the living.
 
Craig B said:
You'll want to avoid having any amplifier under any turntable, as the transformer within the amp is very likely to cause excessive hum and noise from the deck. Also, the radiated heat may not feel like much to the touch, however, over time, things like plinth wood/finish can suffer.

If placing an amplifier beside a turntable on a shelf, it is generally best to arrange the two such that the transformer (heavier) side of the amp is furthest away from the tonearm/cartridge. This generally results in the amp being on the left, with turntable on the right.

Also, if the manufacturer says give their electronic component a minimum of 4 inches of headroom for ventilation then it really should have 4 inches of headroom. The engineers typically don't just make these installation recommendations up, rather they are based upon safety and reliability/longevity testing.

Funny story. An acquaintance of mine not only kept his RA-840BX2 in an enclosed cabinet, he had it hooked up to multiple room in-ceiling pairs plus a pair of patio 'speakers. All of these, in addition to his main loudspeaker pair! Each of the other room pairs were controlled via local on/off/volume control potentiometers with transformers in that were intended to keep the combined load to an amplifier safe limit. During one of his frequent parties, the sound went dead, and, knowing me to be an audio nutter, asked me to have a look; result, a whopping big blister on my hand from daring to feel the amp's temperature! Amazingly, he got away with two blown output protection fuses, however, the heat had been so great that the two plastic spacer rails that fit between amp chassis sides and cover were melted out of shape. Seems he knew well enough not to turn all pairs on at once, however, one or more of his guests thought differently. I've since lost touch with him, however, I seriously doubt that that amp is still among the living.
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Craig B with the incredibly useful info again. I'll keep it where it is then, on the middle shelf of a large TV stand with the turntable on the top shelf (isolated using a butcher's block and EVA pads under the block). Good thing I guess that the transformer is on the left side. Saves me moving things around yet again, nearly did my back the other day setting the amp up.

The turntable shows signs of the plinth finish being slightly melted at the front. I think the guy I bought it from had it on top of a vintage JVC amp that he was also selling.

Your acquaintance's setup sounds a recipe for disaster, only a matter of time before someone has a few then flicks some switches. It's the kind of thing I used to do when young and ignorant with cheap equipment. Used to have a £30 Bush "DJ" (not DJ) turntable from Miller Brothers hooked up via a Heath Robinson RCA extension thing to a guitar amp hanging out the window to enjoy tunes in the garden. Amazingly this was very enjoyable at the time, some of my best memories of listening to vinyl.
 
I squirt Servisol switch cleaner on pots and switches, and use cotton buds soaked in isopropyl alcohol on input and speaker connections. It can make quite an improvement in sound, particularly with older amplifiers. It transformed the 1991-ish Yamaha I’ve mentioned before from a harsh skinny bassless thing with channel dropouts into a smooth, effortless, overall great sounding performer.

I find this mild servicing worth doing every 12 months or so to maintain performance. I clean the speaker connections and cable plugs with IPA as well.

BTW I’m sorry I didn’t get to reply to your query about the JPW speakers (priorities in life got in the way) and that you didn’t enjoy the Mini Monitors. The Minims I mentioned, while similarly sized, are quite different animals with better, stiffer drivers. But try the MMs with your Rotel anyway as they do like quality power fed to them, and are fair performers in their own right.
 
Durmbo said:
I squirt Servisol switch cleaner on pots and switches, and use cotton buds soaked in isopropyl alcohol on input and speaker connections. It can make quite an improvement in sound, particularly with older amplifiers. It transformed the 1991-ish Yamaha I’ve mentioned before from a harsh skinny bassless thing with channel dropouts into a smooth, effortless, overall great sounding performer.

I find this mild servicing worth doing every 12 months or so to maintain performance. I clean the speaker connections and cable plugs with IPA as well.

BTW I’m sorry I didn’t get to reply to your query about the JPW speakers (priorities in life got in the way) and that you didn’t enjoy the Mini Monitors. The Minims I mentioned, while similarly sized, are quite different animals with better, stiffer drivers. But try the MMs with your Rotel anyway as they do like quality power fed to them, and are fair performers in their own right.
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No worries about the JPWs, they were very cheap and I can sell them on - they've been serviced and had new tweeters installed. With the Rotel they still sound inferior to the Wharfedales. Guess I need the bass, maybe why I favour Koss PortaPro headphones, been through many pairs over the years.

Had forgotten I've got a bottle of isopropyl alcohol stashed away. That is a very good idea - it is magic for cleaning cassette decks. Very easy to use with cotton buds and a bit less hazardous than Servisol.
 
I started my hifi journey with this amp, very nice. The matching CD player was good. It also has a lovely phono stage too. Enjoy, its a very good choice.

As I remember the volume pot was quite heavily damped.
 
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