Inspired by Bob Dannielak (founder of the original Darling) ,Jeremy Epstein and other superb Darling builders, (and Mr.Yeo's Darling Club too) I had build a Darling amplifier with 6N1p as driver tube. 6N1p is a good sounding and affordable tube that always neglected by most of the DIYers.
6N1p have Rp of around 7K, which is nearly similar to 5965, Imax of 25mA and amplification factor of slightly lower than 5965,around 35-40.....Blah Blah.....Enough reason to use this tube, I had build and carefully adjust the bias of the first stage to get lower distortion.
Apply distortion cancellation technique between 6N1p and 1626 seems work best, I knew that some of you would say distortion cancellation technique will not sound good, but I had try several different setup, and found that 1626 is not a linear tube, (it's a transmitting or oscillator tube, after all....) If I compare the sound quality of a lowest distortion driver stage that driving a 1626, and a 1626 with distortion cancellation applied, I bet you will choose the sound that is with distortion cancellation.
Here's how it looks like
Ok! ok! I knew that the output trannies looks ugly, but that is my first hand build (few years ago) output trans that give almost flat response at 1W output, about -0.25dB 20Hz-20kHz@ 1 watt, while operate in my SPUD 6C45pi amplifier.
I'm using a small toroidal power transformer that installed underneath of the chassis, and my chassis measures 20cm X 25cm, close to an A4 size paper. I'm using Alps volume control installed on the top of the chassis, with a classic chicken head knob which is similar to old FENDER tube guitar amps..
Here's how I wired it
The center " H " shape grounding hard wire is silver plated copper, that I found it unnecessary after I finished it. The two green coupling cap is ERO MKT 1822 series that cheap but sounds quite ok, I don't want to spend expensive parts in it, and I'm sure it will sound right if carefully build. I used vintage-type-single-core-WE-alike-waxed-cloth-covered-wire, What a mouth-full of wax....wire....err.. I mean proper name of the wire, I don't eat wax or wire.
Here's the distortion characteristic of my Darling amplifier
Don't panic when you see this, if you are one of the Darling builder/owner/diyer/tweaker....etc. The distortion that I measured are mainly 2nd harmonics that can be accepted by human ears.
The full schematic can be download Here.
I'm really impressed by this cute little Darling, It can drive my Tannoy Stirling into comfortable listening level, or even more, to uncomfortable level. Natural sound with good sound stage, hard to believe its from a merely 0.7W of output power.
