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Amp upgrade for Wharfedale Diamond 220 speakers

I've got the service manual! Hopefully will be invaluable down the line. Just had not twigged that the original cart was actually an AT, or thought to look to make the connection with the original interconnects.

Only had this table 6 or 7 weeks. It's an absolute revelation and hopefully will not need maintenance for the forseeable, touch wood (=own head).
 
Just jumped on a Rotel RA-02 that appeared on ebay overnight. Serviced by an audio dealer with nothing but positive feedback. £180. The power of forums.. I think if I still prefer the Kenwood then my hearing must be abnormal judging by comments above.

If the Kenwood sounds better, then it is better. Trust your ears.
 
Just don't like the hassle of the inevitable return, and possible non-communication/dispute by the seller. Some are lovely about it, some not so much. Might still take a gamble.

Maybe being thick but can't see how or where to post a WTD ad. Maybe need to post 50 times, should start advising people as opposed to just being advised. I know a lot more about music than equipment mind.
I have managed to use the Bay and PayPal with little problem. The only issue I had was an uncomfortable4 change with a guy from the Canaries. Despite me stating no overseas shipping he kept bidding on the item and tried to negotiate a reduction in price. eBay were great and put pressure on him.Though he outbid the competition I gave the win to the guy he outbid. I’d rather deal with the Honest.
 
Safe bet and easy to find, get a Rotel.

Whafdale speakers, typically, have a thick, slow sound and need a bit of power to wake them up. If they can be woken up. Rotel is bright and dynamic so will be a good match. Also easy to find, cheap and reliable.

Avoid Arcam, Yamaha, Marantz as they all have a laid back sound which isn't what you want.

There are other good options but Rotel is a simple and safe choice.
Actually, my Yamaha amp works very well with Diamond 9.1s. Laid back, it is not. It brings the 9.1s to life as well as the Rotel does (if not better!) and clears up the bass thickness in a way the Rotel doesn't.

However, the Rotel has a superior phono stage. Yamaha phono stages are known for their crapness - and mine for its absence!
 
Actually, my Yamaha amp works very well with Diamond 9.1s. Laid back, it is not. It brings the 9.1s to life as well as the Rotel does (if not better!) and clears up the bass thickness in a way the Rotel doesn't.

However, the Rotel has a superior phono stage. Yamaha phono stages are known for their crapness - and mine for its absence!

I tried a Yamaha last year and didn't like it much. Good news on the Rotel phono stage - have been reading that they are supposed to be good. I have a good feeling about this.
 
I tried a Yamaha last year and didn't like it much.

Yamaha amps vary. The cheaper ones tend to sound dull and un-dynamic, although not all of them, and the expensive ones can be very good. That's why I wouldn't blanket recommend them. Rotel on the other hand pretty much always sound good. Some are better than others but I've never heard a bad one.
 
Just jumped on a Rotel RA-02 that appeared on ebay overnight. Serviced by an audio dealer with nothing but positive feedback. £180. The power of forums.. I think if I still prefer the Kenwood then my hearing must be abnormal judging by comments above.
Good find. Can’t imagine you’ll be disappointed.
 
I've got the service manual! Hopefully will be invaluable down the line. Just had not twigged that the original cart was actually an AT, or thought to look to make the connection with the original interconnects.

Only had this table 6 or 7 weeks. It's an absolute revelation and hopefully will not need maintenance for the forseeable, touch wood (=own head).
The nice thing about these models is that the electronics are all discrete components but for a fairly common IC op amp. The only thing that would concern me after all these decades is that Hitachi did not foresee a need to re-lube the main bearing. A quick test here is to remove the outer platter and spin the spindle by hand; also lift and drop it (there should be some vertical play here). It should feel well damped and smooth, and be very quiet.

Just jumped on a Rotel RA-02 that appeared on ebay overnight. Serviced by an audio dealer with nothing but positive feedback. £180. The power of forums.. I think if I still prefer the Kenwood then my hearing must be abnormal judging by comments above.
Excellent choice, sir.

Although not mentioned within the published specs, RA-02 features 150pF loading caps between the phono inputs and the popular NE5532AN IC op amp. This will be fine with any A-T MM you'd care to run on your Hitachi DD.
 
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The nice thing about these models is that the electronics are all discrete components but for a fairly common IC op amp. The only thing that would concern me after all these decades is that Hitachi did not foresee a need to re-lube the main bearing. A quick test here is to remove the outer platter and spin the spindle by hand; also lift and drop it (there should be some vertical play here). It should feel well damped and smooth, and be very quiet.


Excellent choice, sir.

Although not mentioned within the published specs, RA-02 features 150pF loading caps between the phono inputs and the popular NE5532AN IC op amp. This will be fine with any A-T MM you'd care to run on your Hitachi DD.

Hmm that sounds like good advice about the TT. The service manual says to be very careful with the bearing, but I think I will have a try at the above. I wonder if it is not lubricated, would Technics spindle oil do (ISO 68 I think).

Aha I had looked at the schematic for the Rotel and guessed at 150pF. Nice to be correct.
 
Yamaha amps vary. The cheaper ones tend to sound dull and un-dynamic, although not all of them, and the expensive ones can be very good. That's why I wouldn't blanket recommend them. Rotel on the other hand pretty much always sound good. Some are better than others but I've never heard a bad one.

It was a cheaper one, and dull and un-dynamic was indeed how it sounded. The ebay seller had bought new and was selling at half price "because it's not loud enough", I think because it sounded dull more like. I sold it on to a very keen guy, wonder if he still has it.
 
Hmm that sounds like good advice about the TT. The service manual says to be very careful with the bearing, but I think I will have a try at the above. I wonder if it is not lubricated, would Technics spindle oil do (ISO 68 I think).
The Hitachi bearing is a captive ball against thrust pad design and should be oiled the whole way down. As should the Technics, but the bottom of the SL-1200/etc. bearing housing is essentially a sieve. IOWs, the main bearings of a lot of DD decks are almost an afterthought.

The lack of any form of oil reservoir is why Technics specify such regular oiling, although their 'techniques' ignore the fact that there exists a spindle end down the bottom there. IOW, it is an oiled sleeve bearing that just happens to sit upon a thrust pad.

Keep in mind that putting a tiny drop of oil round the upper lip of the bearing well, Technics service style (post cleaning any ring of dirt away), isn't necessarily going to lube the whole works. I suggest you repeat working in a drop at a time, lifting/lowering and rotating the spindle each time to help each drop be drawn in, until such time as none will be accepted.

WARNING: Under no circumstances should you follow the instructions posted within the vinylengine thread entitled Hitachi Direct Drive Unitorque Motor Oiling.
 
The Hitachi bearing is a captive ball against thrust pad design and should be oiled the whole way down. As should the Technics, but the bottom of the SL-1200/etc. bearing housing is essentially a sieve. IOWs, the main bearings of a lot of DD decks are almost an afterthought.

The lack of any form of oil reservoir is why Technics specify such regular oiling, although their 'techniques' ignore the fact that there exists a spindle end down the bottom there. IOW, it is an oiled sleeve bearing that just happens to sit upon a thrust pad.

Keep in mind that putting a tiny drop of oil round the upper lip of the bearing well, Technics service style (post cleaning any ring of dirt away), isn't necessarily going to lube the whole works. I suggest you repeat working in a drop at a time, lifting/lowering and rotating the spindle each time to help each drop be drawn in, until such time as none will be accepted.

WARNING: Under no circumstances should you follow the instructions posted within the vinylengine thread entitled Hitachi Direct Drive Unitorque Motor Oiling.
You know, I asked to be banned from VinylEngine at the end of last year, because a burgeoning audio obsession was making my head spin with all the technical talk and I kept making bad decisions. Now, with a bit of hindsight and more knowledge, I can see how much many posters there get wrong. They either issue plain wrong advice, or are seemingly unable to interpret simple English, leaping onto a newbie's problem with a perspective coming from totally the wrong angle, ignoring the obvious. Plus many seem permanently angry. It's still a good resource, but from a distance.

Many thanks for the bearing insight. I have the oil left over from owning three low-end Technics T4P decks. All complete turkeys. Well, my dad has one now and likes it, but he's playing battered records through computer speakers.

Edit: If I may ask a question, it is safe to flip the table over and balance the whole 9kg on the dust cover in order to carry out maintanance, say to change the interconnects? Seems a bit sketchy.
 
If I may ask a question, it is safe to flip the table over and balance the whole 9kg on the dust cover in order to carry out maintanance, say to change the interconnects? Seems a bit sketchy.
Depends upon the dust cover, the hinges, and whether or not rubber pips are present at the front corners, IME. I keep a few wide strips of neoprene foam on hand for just this sort of thing.

If you do try this (at your own risk, mind), I suggest placing all on a soft non-grippy surface. A baby receiving blanket upon a solid table or bench is perfect. You don't want a grippy surface, as any rotational torque you apply (with a wrench, for example) will be efficiently transferred through the hinges and into the cover, any of which can break. Also, a soft none grippy surface makes it easy to rotate the plinth round for better access without interruption of work.

I've done a lot of these sorts of jobs over the decades, so have a universal turntable jig that clamps a wide range of rectangular plinth sizes and can be flipped and locked to any position through 360º.
 
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Edit: If I may ask a question, it is safe to flip the table over and balance the whole 9kg on the dust cover in order to carry out maintanance, say to change the interconnects? Seems a bit sketchy.
You know would it not just be simpler to remove the lid, platter, counterweight and headshell then flip it over and support on 3-4 toilet rolls. I’ve done this many times without incident.
 
I think Fergus has the answer here. The neoprene pads are present but I don't like the idea of supporting it on the dust cover, risky as Craig says. OK with a much lighter Technics table, have done that a few times. Thanks guys!
 
It was a cheaper one, and dull and un-dynamic was indeed how it sounded. The ebay seller had bought new and was selling at half price "because it's not loud enough", I think because it sounded dull more like. I sold it on to a very keen guy, wonder if he still has it.
I'd be grateful if you could name the model. My Yamaha amplifier, a budget AV receiver, came with two pairs of said Diamond 9.1s. I was expecting rubbish but it quite exceeded my expectations and turned out to be a very good match for the speakers. It's as detailed as the Rotel and dynamic enough. Its small soundstage is the only real issue I have with it, so I've become interested in proper 2-channel Yamaha amplifiers: I've heard some very good ones.
 
I think Fergus has the answer here. The neoprene pads are present but I don't like the idea of supporting it on the dust cover, risky as Craig says. OK with a much lighter Technics table, have done that a few times. Thanks guys!
I meant at your own risk.

I've flipped 100s of decks on their lids and have yet to damage a single one. This including SL-1200 Mk2 @ 12.5kg (although the arm clearance bubble makes a thick slab of foam rubber a better bench cover with these).

YMMV.

P.S. The merest thought of using toilet rolls makes my arse clench! o_O
 


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