The Kuartlotron - keantoken's simple error-correction superbuffer

[Theodosis O.]

Thanks Kean,
So we are looking for Fairchild.

Must be matched all together (npn and pnp) ?

[Project16]

Hello all

I put another manufacturer transistor (CDIL) in several Kuartlotron and the result is impeccable and so far no behavior problem after several months of operation.
For information the amplifier controlled by the Kuartlotron is a USSA (class A amplifier very transparent).

Regard's

[Destroyer OS]

I could be wrong but I don't think there's much need to match them?

[keantoken]

I won't predict what people will hear but there is no technical reason for the transistors to be matched except for DC offset. The Kuartlotron doesn't work against the transistors' nonlinear nature so the effect of a mismatch is minimal. I don't know if it makes an audible difference (probably insignificant if so) but it won't break the circuit.

[RCruz]

A breath of fresh air came into my lab....

Two days ago I received two Kuartlotron boards (new version) from Kean. I started populating those asap and it was a breeze to do so... all parts are perfectly identified and the pads have good sizes. The transistors holes are far apart so soldering is quite easy to do.

I did not match the transistors better than 10% and got output offset lower than 10mv.

Second day (today) I prepared a case, connected a pot and two 10v V12r (modified) regs from Salas.

The scope showed wonderfull squares up to 500MHz and absolutely no phase shift whatever voltage or freq I dialed in.

Then I connected the rig to my lab system and guess what.... a true breath of fresh air... The Kuartlotron is an exquisite piece of elegant engineering and it delivers.

Effortless dynamics, punchy tuneful bass blending to the wonderful flowing mids and topped by some of the best highs I ever experienced.

After I built my p2p DCB1 with modified V12R I believed there could not be anything better but now I have a serious contender.

Must thank Kean for sharing this special buffer and for letting me beta test it's new board.

[RCruz]

Some pics

[RCruz]

The lab system

[RCruz]

No detectable phase shift at 20khz

[keantoken]

Thanks, it looks good.

Now that the new boards have been tested, they are available for the same price and I will contact those on the waiting list.

[RCruz]

What type of glue can I use to glue the transistors together so heat transfer is improved ?