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4171

Omega Electrical and Audio Help / Re: Battery problems

« on: 07 July 2015, 21:18:20 »

Clarification: the voltage checks need to be made after a full charge, yes, but then with the charger disconnected - I should have made that clearer!

Ron.

4172

Omega Electrical and Audio Help / Re: Battery problems

« on: 07 July 2015, 21:16:40 »

It's definitely the battery! Without voltage checks you can't be sure, but I suspect a dead cell. To confirm this, fully charge it off the car and measure the terminal voltage about 10 minute intervals for an hour. If it starts at approx. 12.4 volts and drops fairly rapidly over that time towards 10 volts, it IS a dead cell and will be replaced under warranty withoput quibble.
Assuming this to be the case, during driving the alternator would have been working its electrical socks off trying to bring the battery back up to full voltage and thereby taking a lot of power from the engine in doing so, causing it to get hotter.
I hope that makes sense?

Ron.

4173

Omega Electrical and Audio Help / Re: Battery problems

« on: 07 July 2015, 17:29:17 »

Firstly and most importantly from your financial point of view, as the suspect battery is quite new, you must have a warranty, so get it replaced FOC!
When you had the good battery from the 2'6 in the 2.5, did you experience the same heat/fan issues, or was that only with the suspect battery?
If all was well with the good battery in place and the alternator is outputting the correct voltage (get it checked FOC at several tyre and battery places) then you need not worry about sending a new battery to an early grave.
|Battery capacity? Simple; get the highest A-h capacity that will fit in the battery try, consistent with your finances - BUT, seek reparation via your suspect battery's warranty as a first move!

Ron.

4174

Omega General Help / Re: failed on co emissions (black smoke)

« on: 07 July 2015, 14:01:58 »

Would "Cataclean" and a motorway burst help here?

http://www.eurocarparts.com/ecp/p/car-accessories/engine-oils-and-car-fluids/car-additives/fuel-treatment/?542770410&0&cc5_169&gclid=CPuA39mJycYCFdTLtAodJV4N4g

Ron.

4175

General Car Chat / Re: dont understand

« on: 06 July 2015, 16:01:52 »

We seem to have managed perfectly well for decades without the unnecessary complication of "smart" (= over-complex) charging systems.
If you are unfortunate enough to need a jump=start with one of these systems, would disconnecting the car battery before getting a boost charge from the donor battery be sufficient to fool the smart bit when re-connected?

Ron.

4176

Omega General Help / Re: rev counter

« on: 03 July 2015, 22:13:43 »

pauls, I may have said this before (maybe not to you), but Kwik-Fit, ATS, Halfords and others will do a free crank/capacity test on your battery and a charging test on your alternator; that will at least confirm or eliminate a few things for you.

Ron.

4177

General Discussion Area / Re: Quad electro static speakers.

« on: 03 July 2015, 09:35:21 »

Kevin, stop making me feel old! In my early engineering days, those 'scopes were the first ones I had ever come across with dual timebases and they fascinated me, as a teenager, the way I could use the "A delayed by B" function to examine a small part of a complex waveform.
Nowadays such features are commonplace, of course, and with much less heat!
I have no idea how much it cost, but annual maintenance by Livingstone Laboratories (do you know them) used to take the 'scope, clean it in an ultrasonic bath, replace all of the valves, regardless, and calibrate it fully. The plug-in Y-Amplifiers were terrific, too - such high quality construction.
I do apologise to members for this piece of self-indulgent nostalgia.....

Ron.

4178

General Discussion Area / Re: Quad electro static speakers.

« on: 02 July 2015, 22:33:54 »

No old computers with spare leads, Chris? I think Poundland still do them, if not. Please report back on how you get on.
Promise me that you won't listen to the "reproduction", listen to the music - that is what Quads are all about.

Ron.

4179

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 16:57:45 »

Marks, it's not the clipping characteristics that guitarists love - so I'm told, anyway, I ain't a musician, I can only play the fool - it's the massive reserve for short durations as when a string, particularly bass string, is plucked. Because of the space charge in the output valves, the peak-to-average power ratio is very high and allows for a high dynamic range and hence an impressive performance.
I hope any guitarists on here will chip in and confirm or deny the above, please?

Kevin, what a day for nostalgia! In my early days as a design engineer, those Tektronix 'scopes were like Rolls Royces; we had TWO of them, but we still fought over them!

Thanks for your forbearance and comments, Chris. I do understand your difficulty from what many of my students have said, along the lines of - "Well, we can't see what's going on insude electronic things like we can in the mechanical workshops".

Ron.

4180

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 13:27:15 »

Yes, and really nudging into another area - valve amps for guitarists....perfect?
We both know the reason, but I'm not expanding on that for fear of alienating most of the membership....apart from Essex Big Al, who is a fine player. My Tannoy Yorks would suit him down to the ground, but he ain't 'aving 'em!

Ron.

4181

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 12:26:09 »

Some say that nostalgia is best left in the past, but I cut my teeth on valve circuits so this topic has given me a warm, cuddly feeling! 
I do agree with your comments, though, especially concerning the unbalnced ratio between orders of harmonics. so we ARE on the same page, basically. Still in regard to the Quads, unless you spend that fortune that we don't have of top-notch transformers, I reluctantly admit that a decent MOSFET amplifier would win on transient response, which the ESLs would capitalise on.

Chris, I can only apologise that you feel left out; I used to teach Electronics, so I could start a fresh class for you? I dare not waste any more Forum time explaining harmonics, distortion, non-linearity and intermodulation products, all of which are factors affecting audio quality - please accept that good values in each of these parameters cost lots of beer vouchers to achieve! 

Ron.

4182

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 11:53:16 »

Thanks Kevin. Um, I'm guessing my pension won't run to those items AND keep my Omega alive! Ah well...........

Ron.

4183

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 11:17:46 »

Mark, I am fearful of hi-jacking this topic for an esoteric debate on a non-Omega topic, but the THD produced by a good vale amplifier, especially if it has an Ultra-Linear output transformer configuration, would be better than 1% across the spectrum - unless overloaded!
My greater concern regarding the effects of non-linearity in the output stage(s) would be the creation of IM products, which even to my old ears would be more noticeable.

However, I think I hate you because you have got me considering making a Mullard 5-20 valve amplifier! Now, where will I get the valves, decent transformer....where did I put my old Q-Max cutter?............

Ron.

4184

General Discussion Area / Re: Quad electro static speakers.

« on: 01 July 2015, 10:34:23 »

Mark, I always like your well-presented and reasoned input, so I'm not sure if I'm disagreeing with you here or not.....
"The old electrostatic speakers setups I always found worked best on a valve amp and vinyl source mainly due to the rich (read even harmonic distortion) of the amp"
...but my understanding is that even harmonics are cancellelled in the push-pull output transformer of a valve amplifier, leaving only the fundamental (of course!) and the nicer-sounding odd harmonics which do not spoil the enjoyment like the harsher even harmonics. Psycho-aural experts will be able to explain why: I can't!

Ron.

4185

General Discussion Area / Re: Quad electro static speakers.

« on: 30 June 2015, 23:23:18 »

UNLESS you have a Quad amplifier (303 or 405), limit the amplifier power to about 10 watts - they don't require much power to drive them anyway as they are voltage-driven. Too high a drive voltage and you can get flash-over inside the speakers, maybe killing both speakers and amplifier.
Yes, they are difficult to drive, position and even live with, but in the right location and circumstances they are wonderful!
But all the above difficulties ware why I opted for my Tannoy Yorks, large bass reflex cabinets with 15 inch dual-concentric motor units with a very solid and precise sound image - ALMOST as good as the Quads.......

Ron.