Oatley K272 DC power options.

Bibio

Member
2009-03-08 3:36 am
Few questions if you don’t mind.

I would like build the Oatley K272A Headphone Amplifier Oatley Electronics but would prefer to use mains powered supply. Having looked at the kit and done a bit of research I notice that the new kit requires the use of 3v battery + 9v battery to power the device.

Now my questions are.

Would it be possible to run regulated 12vdc straight in at the 9v battery terminals?

Using the same regulated 12vdc would I be able to use a DC-DC Buck Converter LM2596 trimmed to 3vdc in place of the 3v battery?

The source of the regulated 12vdc would be from RJM Audio in the form of the xreg RJM Audio - The X-reg Voltage Stabilizer

I would like to say that i don’t have any facility’s for making PCB’s so would not like to go down that route. However if someone has a better idea of how I can get round my problem using a ready made or kit that is available I’m open to suggestions.

thanks
 
Hey Bibo. I am working on a power supply for just that amp. I havent completed it yet, but I will post pictures of the final product, and show my power supply design. I plan on using a 12-14v wall wart and voltage/current regulators from the shack.

I have Elna silmic caps and Vishay metal film resistors for the circuit.
 
Yea bibo I will. These kits are really cool, but I have Huge plans for this amp, so it will take a bit more time. I have all the replacement Elna silmic II caps and vishay dale resistors. They are beautiful on the board. I have an aluminum box that is slightly oversized, for extra batteries and sound damping material for the highly microphonic tubes. Also a composite potentiometer I am experimenting with. This is mainly for my Fostex T50RP cans. Copper volume knob in the works as well. I will post pictures soon.

I am working on some bookshelf, full range, 5 in Fostex, in a cillindrical tube (Transmission line) enclosure with external porting used as the base for the speaker tower itself. They are so ugly that they are cool! They sound amazing with my cheap sheilded chinese full range generics that I scavenged from my Hitachi TV. I can't wait to get my Fostex 5 in.
 
Here's the updated 'C' version.
Uses +18V and 3V battery now.

Interesting design, with subminiature tubes and all. With all the high-value resistors and no xformers, I'd expect it to be on the noisy side though.

Assuming +18V supply is beefy enough to tolerate another 20 mA, 3V battery could be replaced by a preceding voltage regulator (exact voltage not critical, noise level reasonably uncritical as well - you may even get away with plain ol' dropping resistors or preferably an RCR combo).