11-12-2019, 07:02 PM
(11-12-2019, 07:32 AM)Diabolical Artificer Wrote: Are you building any amps yourself Tracey?
Andy.
Hi Andy, I don't do much with audio, apart from little circuits but have done a little this year.
During the summer the TV sound system failed and, because the sound was never too great plus there was no obvious fault, it was outed. I did keep the speakers though as they looked useful. I concentrated on justifying that by putting together a couple of transistor amps using some power transistors I originally bought to use as high voltage regulators (before I settled on below 100V for most of my circuits). The amps were pulled together using info from various places so are nothing out of the ordinary, just organised with components I had. I was going to post here but never got round to it (photos attached). I did need to work on preamps though but, as happens, other things came up and it never happened. Your thread is pushing me a bit though but I am not thinking in your terms though. Something fairly simple. The amps are around 10W with 15W if pushed hard (well distorted). It's really the heatsinks that limit them but I only was looking for toward 10W anyway so good for the job. With higher voltage they would need bigger heatsinks but should be well capable.
At the moment I am thinking about a valve radio with 'gram' input. I do have some valves (miniature Russian 6p30b) and around 5W out. I have an output transformer which I think was for ECL86's but need to check it's suitability for an 'ultra linear' design (it is designed for that). It's very early days as I am not sure of the design but can probably get to a test circuit easily.
Tracy
