Aikido valve Preamp?

Hi all,

have anyone build Aikido Valve preamp, just want to share some experience and ideas on this Amp... :wink:

I am planning to order this kit too.
They have kits for 8 pins or 9 pins tubes.
I like 6SN7, so I might order that one.
I didn't find anything about the Power supply for this kit on their website.

hi Bongcalifornia,

at the moment i am building the mono 9pin tubes preamp, still waiting for the power supply parts, basically, you need a 200-300v B+ power supply with 12.6 or 6.3 heater supply depends which type of tubes you are using in the circuit, Mr Broskies Aikido users guide is in website, that gives you ideas for power supply...

keith.

http://www.tubecad.com/2008/06/blog0142.htm

Hi,

Can anybody help, i have put together a dual mono Aikido Line amp, and a Lite LS57 & R80-53 transformer  (from diyclub), it works fine apart from the hum in the transformer, is it the main voltage  causing it to hum its 240V in UK, the trans primary voltage is 115-0-115, secondary is  
320-0-320, but the secondary voltage gone up to 350-0-350 will it cause problem too?

if i connect a power resistor series to the main before the transformer to lower the  ac voltage to 230V, which value of the resistor i need...

Thankyou

Keith

Are you sure the main voltage casuing hum ? Normally hum arise from earth is not connected properly.

hi Accphoto,

thanks for replying my question,
the hum are not coming from the speakers, its coming directly from the transformer, most noticeable when just switch on, dont get me wrong its not a loud hum, only when there is no music on.
And for the earth connection i used the star earth method.


thanks

change Lite transformer

You can check whether the primary fo the transformer is connected not in phase. If the phase is corrected, then you need to check a transformer with 240V input.