From KiT6550 to KaT6550 - how easy?

[Richard]

Agreed with Jerry, unlikely to be the resistor, more likely the earth arrangement, either the amp or the pot in box. Look for multiple earth paths. For instance, in the pib, isolate the phono earths from chassis and use 1 earth point which includes the casing.

[waynej4]

Thanks for the replies! At least I know more or less what to look for now.

[Chopsaw]

That resistor is only there in case the volume control ever goes open circuit.
My own AVC amps never had this resistor. When I removed the volume control and switching, as some of you have done here, I fitted a 1 meg resistor to each channel as a safeguard in case one of the phono plugs ever came out. This would obviously give the same symptoms as an open circuit volume control.

Si.

[Yellow]

Turning a KiT to a KaT is as everyone before me has posted......

However, having a volume pot on the power amp can yield great benefits in terms of balancing the pre-to-power interface.
I have tried it a couple of times, with a "mixing-desk" between my pre and power, with great results.

You can then balance your pre's Volume knob so that full volume is at "full volume" and not 8am!!

It can make things less-edgy, if you have a hard-driven system like mine.

Neil

[jdd308]

Hi folks,

At the end of 2007 I converted the KiT6550 in to a passive pre and power amp combination quite successfully as per this very old thread.

Now 9 years later and I have converted it back again!

Why, you may well ask. Well, I have also done the shunt pot mod, and put purer copper cables in, to replace the original screened cables that came with the kit in 2004.

I also wanted to see if a simpler signal path with fewer cables, components etc., would make a difference. Plus I'm running out of room on the hi-fi shelf and there are now fewer boxes!

I was delighted when I tested the voltages after finishing to get a very nice set of results.

Even better was a lovely clean, full bodied, sound. Two things really stand out: lovely wide, deep, and high soundstage, the speakers really disappear; plus a really engaging sound, it draws you in and the music is more engaging than I remember from before the mods.

One thing though - how long do capacitors last before they should be replaced, if at all? There's posts here about leaky caps, is that age related?

The black gates in the power supply, and the Dynamicaps as coupling caps are 10 to 11 years old now. They sound fine enough at the moment though.

Thanks as always.

John

[bob orbell]

Hi John, See under, WD AMPLIFIERS, row III, longevity of modern passive components, BOB

[jdd308]

Splendid thanks Bob, a really good thread!