Friday, January 14, 2011
K295 Production Version
In an earlier blog I constructed a prototype K295 for a bass player. It proved to be a great success and produced richer harmonics making the bass sound fuller and a lot warmer. This build is the production version of the K295 and the kit can be purchased from Oatley Electronics in Australia In this version only a single tube is used. The PS, including a tiny mains power transformer, is mounted as part of the whole cct. brd. but can be snapped away.
As in the earlier preamp I used a plastic case lined with bitumanised Al foil. Single pots were used to allow separate channel control and large numbered knobs used so setting can be noted for future used. The central blue "on" led marks "0" for both pots. Guitar 6.5mm jacks are on the back to allow music instruments to be plugged in. All hook-up wire is twist single strand copper.
On a short listen through my system the preamp appeared to work very well providing gain and and good control over volume levels. The left channel has a slight buzz due to it being closer to the tiny transformer than the left. A larger case would solve this problem by allowing the input and output jacks to be mounted further from the power tranni and mains (110 or 240V). Or break the PS away from the amp cct. brd. and mount it separately. All in a good build and good result.