|
|
|
||||||||
|
K&K Audio Phono Kits
|
|||||||||||||||||
|
The K&K Audio kits have been developed to provide building blocks for DIYaudio projects. They are designed to work together with Lundahl transformers, allowing DIYers to construct state-of-the-art audio equipment. They vary in complexity, but always include detailed instructions to make construction straightforward. The upscale components used in K&K Audio kits have been selected for the best sound/cost ratio.
|
|||||||||||||||||
|
Single-Ended Triode Parallel Feed Phono Preamplifier Kit
The SE phono preamp kit accommodates just about all of the LP playing needs that anyone could have. It comes equipped to handle moving magnet or moving iron cartridges. For moving coil cartridges, an input transformer can be added to step-up the lower output voltage. The circuit was developed to combine the best qualities of tubes and semiconductors and achieve a better result than could be had with either technology alone. The first stage for a moving magnet cartridge consists of a very high transconductance JFET / triode (6N1P) cascode amplifier. This stage is capable of very high gain (about 50dB) with very low noise. An all tube cascode could have been used, but without the simplicity and noise performance of the hybrid approach. An LL9206 or LL1678 MC input transformer can be soldered to each board to obtain more than enough gain for any MC cartridge. The hybrid cascode drives a precision passive RIAA network. This feeds a constant current source loaded triode that is transformer coupled to the outside world using the parallel feed configuration. The lack of DC in the output transformer primary allows the use of a new, very high quality amorphous core transformer made by Lundahl Transformers, the LL1676. The amorphous core material results in less audible distortion than other types of of materials while still delivering very high primary inductance to facilitate excellent bass response. A low output impedance results from the 4:1 stepdown ratio employed. Because the output is transformer coupled, both balanced (XLR) and unbalanced (RCA) connections can be used.
The kit uses top quality parts such as Kimber and Panasonic capacitors, and Mills, Holco and Caddock resistors. See the photo below and schematic here.
Gain: 45dB
Output impedance: 200 ohms
RIAA accuracy: + - 0.5dB
SE Parallel Feed Phono Preamplifier Kit (two channels) $595
LL9206 or LL1678 MC input transformer (pair) $112
Power Supply Kit (schematic) (power xfmr and choke not included) $125
|
|||||||||||||||||
 |
|||||||||||||||||
|
Moving Coil Step-Up Kit
The problem of getting enough gain to use a moving coil phono cartridge with a preamplifier designed for moving magnet cartridge use without lots of noise is easily solved using a Lundahl LL9206 transformer. This kit provides two channels of transformer-based MC Step-up. The kit includes connectors, transformers, wire, hardware, and enclosure. The enclosure is a black powder coated diecast aluminum case that provides exceptional RF shielding. The wire used in the kit is the excellent 24 gauge single crystal silver wire made by Harmonic Technology. The RCA connectors are gold over silver over brass sourced from Sound Connections. You can set this unit up for 14, 20 or 26 dB of gain. The kit can also be supplied with the LL1678 transformer for 18, 24, or 30dB of gain.
Moving Coil Step-Up Kit $235
Optional Kimber Ultraplate RCA jacks add $25
|
 |
||||||||||||||||
|
Two Terminal Constant Current Source
This circuit was developed to enable constant current operation of tube circuits without having to worry about a source of bias. It sounds better than other circuits that I have tried and is very simple. Use it to provide excellent balance in "long-tail" pair differential circuits or to obtain highly linear constant current triode operation. Add a heat sink kit for operation at higher levels of power dissipation.
CCS Kit (up to 1.5 watts) $9.99
Small Heat Sink Kit (up to 5 watts) $3.49
Large Heat Sink Kit (up to 10 watts) $3.99
DN2540N5 depletion mode MOSFET $3.00
|
|||||||||||||||||
 |
|||||||||||||||||
|
|
|||||||||||||||||
| page created with Easy Designer |