🚀 go-pugleaf

In article <paul.734825375@suite.sw.oz.au> paul@suite.sw.oz.au (Paul Antoine) writes:
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>In <1qfiedINN1qc@ariel.ucs.unimelb.EDU.AU> salman@ariel.ucs.unimelb.edu.au (Salman Shami) writes:
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>The biggest difference actually appears to be in the
>capability/robustness of the power supply.  My partner has a simple
>Yamaha 80W/channel amp.  I knew that compared to a Rotel I had once
>owned, this thing sucked when it came to transient response.
>
>I pulled it apart, and upgraded the cheap and tacky wiring to the
>speaker outlets with some good quality cable.  The sound improved
>quite a bit.  And before we get onto a cable war again I'll point out
>that the existing wire and mounting connectors were clearly
>inadequate.
>
>I then decided to upgrade the power transformer with a 300VA torroidal
>one, the bridge rectifier with a chasis-mounted 400V PIV 25 amp one,
>and new power wiring (of course) to the PCB.  The difference was
>stunning!  The transients were now fantastic, with a complete lack of
>the muddiness of the original.
>

Hope you don't mind me throwing in my two bits worth (I'm new to the group)
but I would like to mention that if you are in the mood for diving in with
a soldering iron, and know how to read a circuit diagram, you can do wonders
with even a relatively inexpensive amp by replacing all the interstage coupling 
electrolytics with new ones *at least twice* the value in uF, (watch the 
polarity and working voltage) with a greencap in parallel.

Do the same with the bypass electros in each stage, and the same with the 
power supply filters.  The greencap in parallel *does* make a small but 
significant difference.  You will be amazed by the difference in the 
transparency of the sound.  The method of parallel caps has been used by
JBL for years in speaker crossovers.  I have tried using tantalum caps for 
these mods, but for reasons I don't yet understand, the resulting sound is 
not as pleasant (?) Perhaps this is subjective, but the sound seems cold and 
somewhat clinical. Strangely, if tantalums are used in the tuner section of a 
receiver, they are ok. Someone may care to enlighten me on this ... Incidentally, 
extra filtering around the tuner display electronics doesn't do any harm, as some 
display circuits can generate hash which, while not actually audible, can 
degrade a receiver's sound by reaching the audio circuits thru the power supply.

Of course, replacing any internal speaker cabling with something heavier 
will also make a difference, but in my experience, the external speaker 
cabling should be separated (ie. just pull the cable apart where it is 
joined.  The small capacitance effect of the conductors being in close
proximity over a long run will be obvious as soon as it is removed.