Aikido octal floating output

jeekee · 2nd February 2013, 08:52 PM

Hi guys,

I've got an aikido octal all-in-one running and noticed that my output is drifting even though measured after the DC coupling output caps (russian PIO's). Any idea's what might be the problem here?

Cheers

Rundmaus · 2nd February 2013, 09:40 PM

How did you measure it to be 'drifting'? Was the output left open or connected to another device?

If left open, does the output of the Aikido have any resistor after the output cap referencing the output to ground? The results of leaving this resistor out have been discussed here before...

Greetings,
Andreas

jeekee · 2nd February 2013, 09:43 PM

Output was directly coupled to the oscilloscope (so not connected to a poweramp). I've got the output resistors in place as suggested by Broskie.

jgf · 6th February 2013, 07:42 PM

I had the same problem with mine (cathode follower only version.) Turned out the RC filter at the output is letting low enough frequencies through that perturbations of the line voltage were affecting the output. I went to a regulated supply, which cured the problem.

jeekee · 7th February 2013, 05:57 AM

Thanks JGF,

Unfortunately I've already got a regulated power supply for both the HV and LV part. Also the output just randomly shoots up from time to time almost like one of the caps was dicharging every few seconds...

DF96 · 7th February 2013, 09:57 AM

Look for instability in the regulators. Or serious flicker noise in one of the valves?

2nd February 2013, 08:52 PM	#1
jeekee diyAudio Member Join Date: Jun 2012	Aikido octal floating output Hi guys, I've got an aikido octal all-in-one running and noticed that my output is drifting even though measured after the DC coupling output caps (russian PIO's). Any idea's what might be the problem here? Cheers

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2nd February 2013, 09:40 PM	#2
Rundmaus diyAudio Member Join Date: Aug 2005	How did you measure it to be 'drifting'? Was the output left open or connected to another device? If left open, does the output of the Aikido have any resistor after the output cap referencing the output to ground? The results of leaving this resistor out have been discussed here before... Greetings, Andreas

2nd February 2013, 09:43 PM	#3
jeekee diyAudio Member Join Date: Jun 2012	Output was directly coupled to the oscilloscope (so not connected to a poweramp). I've got the output resistors in place as suggested by Broskie.

6th February 2013, 07:42 PM	#4
jgf diyAudio Member Join Date: Jan 2010 Location: PA	I had the same problem with mine (cathode follower only version.) Turned out the RC filter at the output is letting low enough frequencies through that perturbations of the line voltage were affecting the output. I went to a regulated supply, which cured the problem.

7th February 2013, 05:57 AM	#5
jeekee diyAudio Member Join Date: Jun 2012	Thanks JGF, Unfortunately I've already got a regulated power supply for both the HV and LV part. Also the output just randomly shoots up from time to time almost like one of the caps was dicharging every few seconds...

7th February 2013, 09:57 AM	#6
DF96 diyAudio Member Join Date: May 2007	Look for instability in the regulators. Or serious flicker noise in one of the valves?