Goldpoint SA4M-47 passive 'preamp' winging its way to Marco Towers...

[Desmo]

... I have a slight hum with my current set up but wether I would go the extra mile to add a circuit like this (although relatively simple) is a different kettle of fish...

I too have a very slight hum from my super cheap valve pre amp, and this has inspired me to plan a visit to Maplins later this afternoon, so I'll cetainly be trying out the circuit. Funnily enough I know the ESP website quite well having built a couple of Rod Elliott's amps, but had not stumbled accross that particular article before - it looks pretty good.

[awkwardbydesign]

You might be amused to know that I first saw this circuit when Paul (Reffc) was a member of HiFiWigwam and posted it there! It's no longer on his site, and it took a bit of searching to find it again. So thanks to him for bringing it to my notice.

[anubisgrau]

who's gonna borrow marco a decent AVC or TVC?




















just jokin'

[struth]

who's gonna borrow marco a decent AVC or TVC?




















just jokin'

Not me...mine is indecent

[Audio Advent]

Yes, but the Z-Foils might make it there in yet!

Marco.

I'm a bit late to this thread - things have moved on from this post..

Those leads on the z-foils were rather long so they might improve if they were trimmed down and installed. I'd guess it was possible for them to act a little like radio aerials as tested.

[Stratmangler]

I'm a bit late to this thread - things have moved on from this post..

Those leads on the z-foils were rather long so they might improve if they were trimmed down and installed. I'd guess it was possible for them to act a little like radio aerials as tested.

Go back a bit and you'll find out the reason why the legs were left long.

[Audio Advent]

Gah... too many pages.

[Stratmangler]

Ah well, it's your choice

[Light Dependant Resistor]

The well established method of star grounding, that is treating each
of the many paths returning current to have its own return to a central location,
which is in almost every case to chassis, and for chassis to have mandatory
grounding to the household ground, will solve the majority of unbalanced audio
system grounding issues.

Unbalanced vs Balanced audio is explained here: https://www.youtube.com/watch?v=jo5HhfIUSP0

Sadly we keep on using unbalanced audio devices, or unbalanced audio equipment lacking
method of ground loop breaking, which can be greatly assisted to include
at low level stages transformer, or optical transfer. To use these methods in unbalanced systems
will invariably improve signal to noise ratio, the result is more music enjoyment. and explains
why transformer or audio optocouplers should be used widely.

More or very problematic grounding, needs further methods of isolation, and
to the rescue are loop breaker circuits. http://sound.westhost.com/earthing.htm

Cheers / Chris

[Marco]

Gah... too many pages.

Hi Sam,

They were left long simply for testing, in case I wanted to sell any of the 'losing' resistors on

A bit of an update actually... I had mentioned that I needed to try the Z-Foils in my system, before settling on either those or the AN Tants, well good job I tried them because they are SUBERB!

I had been enjoying the ANs for the last few days, but had detected a slight bloom in the lower-midrange area, causing female vocals to sound a touch too warm and cuddly, for my liking (this is after the ANs having burned in a bit since I first listened to them).

Therefore, I popped along to Duncan's place to have the Z-foils fitted again, as well as to listen to the Shinkohs I'd ordered (in 18K). Anyway, we fitted the latter first, as they're supposed to be similar to the AN Tants.... Dunc liked them, but I wasn't really keen, finding them a bit of a soulless listen, compared with the ANs. Yes, they sounded tighter and were pretty detailed with nothing overtly wrong, but the 'magic' was gone, and their addictive musicality, as described in my earlier review when the An Tants first went in.

So we popped the Z-Foils in (after cutting the legs down as short as possible) and both of us were blown away by the improvement these brought about, over the Shinkohs, in terms of top-end extension, air and space and a beautifully liquid sounding midrange. Low-end frequencies were also taught, defined and well extended: in short, the Z-Foils just seemed to let music flow rather effortlessly. They also appeared to have no overt sonic signature, and exhibited a rather addictive 'hear-though' quality with all recordings. Mesmerising stuff!

Therefore, I headed home to try them in my system, and proceeded to play some of the music I had been listening to recently with the AN Tants.

Bear in mind too, that the Z-Foils are 20K, compared with the 22K of the ANs, which appears to be the magic value for my system, ensuring that the sound has enough 'balls' lower down on the volume controls, where I want my normal listening levels to be, in order to keep the shunt resistor count down (more on that later).

Well, to cut a long story short, they did the same trick in my system, as they had in Duncan's, sounding 'fresher' and more musically 'alive', than the ANs, and highlighted that as good as the ANs were, they exhibited a slight tonal richness that wasn't entirely neutral, and which had been bothering me a little over the last few days.

That's totally gone now, leaving me with a truly superb wide-open sound - the best I've heard the Goldpoint sounding yet... So, in the final analysis, the Z-Foils won!

I always had a sneaking suspicion that they might triumph in the end, when I got to hear them in my system, and so it proved. Job done and dusted, and time now to allow the Z-Foils to burn in and just enjoy the music, until the LDR Stereo Coffee unit arrives. That will certainly be an interesting one, and it will have to go some in order to oust the Goldpoint, as right now the latter is the finest sounding passive preamp I've heard to date

More when the LDR arrives (sometime later this week)!

Marco.