The December 2010 issue of audioXpress magazine includes a review of the $30AU Oatley Electronics K272A tube based Headphone Amplifier Kit. Mark Houston completed a review of the Oatley Electronics K272 Headphone Amplifier Kit in August 2009 and since then many hobbyists have enjoyed this inexpensive audio kit. The hybrid headphone amplifier kit uses 6418 sub-miniature vacuum tubes and a headphone driver integrated circuit (PT2308). Adding appeal to the tube based kit is battery operation.
Highlights from the audioXpress Reliable Review of the Oatley Electronics K272A Headphone Amp by Aren van Waarde.
"Oatley Electronics (www.oatleyelectronics.com), which sells electronic parts and used equipment in New South Wales (Australia), has launched a small range of audio kits based on tube technology. My interest was raised by glowing reviews written by Mark Houston, ..."
"My initial impression of the sound of the K272A: warm, pleasant, and detailed. Organ music sounded great."
"... the K272A/Grado combination produced excellent sound: a fne bass (powerful and deep but not overblown), detailed mid-range, sweet top-end. Tonal colors of string instruments and vocals of male and female soloists were naturally represented. Many small, previously unnoticed details of recordings were revealed."
"In direct A/B comparisons, the K272A sounded better than the G4OEP (3/08 aX, p. 36) and even slightly better than the Stor class A amplifier (6/03 aX, p. 30)."
"For the asking price of 30 Australian dollars, the K272A is an absolute bargain. And it does not involve any dangerous voltages."
The full review of the Oatley Electronics K272A Headphone Amp is available as a direct download from audioXpress [PDF- 737kB].
Additional Oatley Electronics Audio Kit Information:
- Mark's review of the Oatley Electronics K272 Headphone Amplifier Kit.
- Tube Matching circuit in the Oatley Electronics K282 RIAA Phono Preamplifier Kit review.
- Forum thread: 6418 Tube / Opamp Headphone Amp (Oatley Electronics K272A Audio Kit).
- Forum thread: Oatley Electronics K281 6418 Tube / LM1875 IC Amplifier Kit
What's Playing: Clannad - Macalla
For $30 this really is a great kit. Stuffing the board is very easy but some skill will be required to incorporate the circuit into a shielded and damped enclosure. You need a solid enclosure to get the best performance of of this kit. I've been enjoying mine for more than half a year and have also built two more as gifts for family.
ReplyDeleteKeep up the great work.
Steve (USA)
What size is the PCB?
ReplyDelete138 x 66 mm (5-7/16 x 2-7/16+ in.)
DeleteThe K272A PCB measures about 66 mm by 138 mm. You will need about 40 mm of clearance to mount it in an enclosure.
ReplyDelete