Passive preamp buzzing?

[Bigman80]

How big Alan?

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[Arkless Electronics]

Just but Klotz in in place of the silver copper hYbrid between Jolida and GP and it's made a huge difference. I know Jez is probably screaming at the monitor as we speak lol

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Yep you're dead right. I'll just ignore all this nonsense.... Have you tried putting a carrot on top of each speaker? It's as likely to improve the sound as anything being discussed here and would have the same scientific merit.... Carry on. I'll try and avoid looking at this thread to avoid the wincing it gives me!

[Marco]

Hahahaha "I ain't listening to no cables!!!"

Lol... "I ain't believing nothing unless my science book tells me it's true!"

Marco.

[Bigman80]

Yep you're dead right. I'll just ignore all this nonsense.... Have you tried putting a carrot on top of each speaker? It's as likely to improve the sound as anything being discussed here and would have the same scientific merit.... Carry on. I'll try and avoid looking at this thread to avoid the wincing it gives me!

Hahaha. I did Jez. Two on each but didn't help. Changed the sound when I plugged then in the horn lol

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[Yomanze]

Indeed, nor me not hear what I've heard many, many times during my experiments with passives

Marco.

...and during your experiments vs. actives, have you noticed anything of note?

[RothwellAudio]

... the Goldpoint's been designed to sound best, used with them turned down more (to achieve the same loudness level), as at that point there are less shunt resistors in the signal path.

You have both shunt and series resistors in the Goldpoint. The Z-Foils I mentioned earlier are the series resistors, and there are only two (one for each channel, left and right).

Essentially, the more you turn up the volume (increase each 'step' on the dual-mono attenuators), the more shunt resistors are 'in circuit', so the potential for sonic degradation increases with every 'click'. It's just the way it's been designed.

The so-called "series" resistor and "shunt" resistor in a potential divider are both doing the same job and one cannot be more more important than the other. Imagine as an example a poor quality resistor which has a lot of parasitic inductance: if you put it in the shunt position where, it is claimed, it doesn't matter it will still form a high pass filter. So it must matter! Of course it does or else why have it there at all? There's no rational explanation as to why one of the two resistors should be more important than the other - other than expectation bias based on a misunderstanding of electronics and a belief in "the signal path".

For the record, there is no such thing as gain structure as in something to be optimised.... other than technically. Don't bother Marco, I know you erroneously believe otherwise.....

I think you're being a bit unfair there, Jez. It's perfectly possible to have too much gain at the front end of a circuit - so it distorts - but also have some attenuation further down the line so the actual signal level doesn't appear to be overly "hot". Less gain at the front and more gain (or less attenuation) later on would cure it.
BTW, I'm not familiar with the exact circuit details of the Jolida but I have read that it does suffer from piling on the gain and then simply cutting the level with attenuation.

[Bigman80]

Ok, so from a working mans perspective. Trying to emulate the Goldpoint with cheaper alternatives. what's the most important part.

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[Yomanze]

Ok, so from a working mans perspective. Trying to emulate the Goldpoint with cheaper alternatives. what's the most important part.

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The potentiometer / stepped attenuator and the input selector i.e. switch contacts.

[Bigman80]

Thanks Neil. It's there I shall start.

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[RothwellAudio]

It's quite important to configure the attenuator in a way that never puts an undue load on the source or has an unduly high output impedance. However, that's quite simple - just wire the attenuator as a conventional volume control rather than trying to have "just a single resistor in the signal path". I set out my reasons for this in post #24 of this thread: http://theartofsound.net/forum/showt...tenuator/page3

At its simplest, you could make a passive preamp with just a pot. I'd suggest a pot between 10k and 25k. 10k will have the advantage of a lower output impedance. 25k will have the advantage of a higher input impedance.
There are plenty of pots to choose from here:
https://www.hificollective.co.uk/com...tiometers.html

Next level up is to use a stepped attenuator instead of a pot. There are plenty to choose from here:
https://www.hificollective.co.uk/com...tenuators.html

25 years ago when I started to make passive preamps there were hardly any stepped attenuators available - now there seem to be hundreds! I used to make my own with 132 steps If there's so much interest in stepped attenuators, how come I never got rich?