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stereo coffee

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About stereo coffee

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    Wellington
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    Chris

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  1. Hi Brad Hifi engine is your first place for all schematics https://www.hifiengine.com/manual_library/quad/34.shtml The suppressor is not a readily available standard part, as it contains inline resistors. in the circumstance I would contact Rob Flain at Quad UK https://www.quad-hifi.co.uk/contact-us/ The part is Quad stock no NPMR20A with a circuit board part identification as N1 If contemplating replacement less the manufacturers part with internal resistors, you will need to replace with suggested 630v rated part, the higher voltage rating will give a much better level of reliability .
  2. This might suit your requirements as, "a decent sounding dynamic speaker" ( if we have ability to swap dynamic for accurate perhaps ) and they are DIY
  3. Hi Mike Love the image ! Creating ends ( like there is no more ) worded above " the only thing that matters " to how components interconnect in this case with crossovers, is not the way I would approach As example reading Cyril Bateman's articles it is obvious there are up to 3 Zobel networks when using amplifiers cables and loudspeakers, yet just one is typically used. See post #17 https://www.diyaudio.com/forums/multi-way/190300-zobel-network-2.html Another is the preferred method of current drive vs voltage drive for amplifiers and speakers. It may be wiser to say where ever possible , that everything matters.
  4. Your best plan IMO is to locate the needed amplifier as close as you can to the subwoofer. I would look at either building a kit amplifier or getting a Class D amp module , like a Hypex and mount it on the rear, with a suitable heatsink https://www.hypex.nl/p/technology/ncore Then assess from manufacturers data, or physically draw the existing passive crossover network, and if then needed provide inductors, seen in the above image which as well as filtering, reduces what is called, back Electro magnetic force ( EMF ) from reentering the amplifier, as a un needed signal that otherwise adds to the amplifiers task.
  5. My Quad 306 amplifiers each have 0.375mv sensitivity for 50 watts output. I can compile a list of amplifiers offering sensitivity below 1v, if that might help.
  6. Today's modern sources have quite adequate output, to be more simply used with a passive volume control. In the 1960's preamps were common providing particularly selection of different cartridge loading, and offering equalisation to match tape playback. They served their purpose well back then. Today though, a stand alone DAC and phono preamp offers just as much ability as before, by tailoring to exactly what is required, and suits passive volume control that can have as many inputs as required. Some ( hanging on to the preamp era ) may argue that there is loss in passives and you always need amplification still of the source component, but this is quite unfounded as amplifying a source further always involves adding distortion or tonal colouration, and is immediately apparent, once you have compared one to the other. All one needs to do is observe the sensitivity rating on a given power amplifier to match to a passive rather than an active preamp. Typical figures are sensitivity of 1.5v or less for full output and resistance loading of 20k ohms or more. But there is no arguing, the preamps here look good.
  7. A really good audio system will present in all planes at the same time, including forward projection for some instruments typically close microphone recorded instruments, at the same time as presenting rearward projection for other instruments.. Doing so creates the space the acoustic event occupied during recording. Where the recording is not acoustic using electric instruments or mixing effects, these too can create similar ability. Assisting this proper reproduction usually requires planar speakers, however exceptionally good result is achieved with other types where the source component , attenuation, and power amplification is also up to the task.
  8. Hi Nick It may be a polarity issue then that the station is broadcasting with opposite polarity to your receiving antenna. You could check if their polarity is vertical or horizontal with either the actual station, or looking up their data at the ACMA website. some stations try their best to do both polarities with a circular polarization but it also wastes enormous power as nature and physics fights back.
  9. Here are a few tips for difficult reception areas. Point your antenna at aerials that may hopefully be at the top of the hill. If its a unused or occupied area and you have permission, climb the hill and attach another aerial or at least some metal to reflect a signal off, then point to that with the first antenna. A discone is in many ways the perfect antenna - although it is omnidirectional it has excellent impedance matching over a very wide bandwidth, as well as offering a elevated from ground, ground plane. it may prove handy in this circumstance.
  10. Thanks for your question, here is a schematic showing the general concept, of a high impedance for both anode and cathode, in this case a simple red LED seen in the image has its anode between the negative voltage rail of a LM833 op amp, and its cathode at the positive rail of a further LM833 op amp, which has its pin 4 grounded We can appreciate the anode and cathode is now vastly distant from each side the DC supply, beginning to satisfy a far better arrangement. To better visualise this, view the schematic for the LM833 here: http://www.ti.com/lit/ds/symlink/lm833-n.pdf and see the positioning of the Red Led in the image ( or LDR ) being powered ( WOW ! ) between two such circuits. This is the type of concept that makes all the difference. high impedance concept.pdf
  11. Agree totally, adding one does not have to spend anywhere near these 20kUSD figures to get close to ( if not have actual ) realism of audio at home. Regular reader will know which prior SNA review I would attach to head in that direction, which would begin with a small firm in Western Australia making electrostatic panels called the ER 505
  12. Yes the wisdom of a dedicated power amp then becomes apparent. Try to make the attenuation of level from source which has the best possible audio, to your power amp as simple as possible, and if you can also remove as many contacts where the audio signal passes. With level as low as you can get it, a neat way of testing the validity of this concept is to use the headphone out of a CD player directly to a power amp. You will typically need a stereo TRS male to RCA adapter , and repeat have level as low as possible and then adjust as needed. What this should prove in leaps and bounds, is keeping source to power amp as simple as possible, is invariably actually best for sound quality.
  13. Some info comparing each here: https://www.audiocircle.com/index.php?topic=63870.0 inferring the 12AX has higher gain Yes, but higher noise too. The AT suggests to offer best of both worlds
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