Poll..anyone interested in an Aikido linestage PCB group buy?

[Bas Horneman]

I intend to use a higher rating diode now.

Or put two in series per leg. That way you have a rating of 2000V...Should be enough.

Peculiar that they have blown twice now. Did you connect them correctly?

 

[Geek]

I've found with 1N4007 if the transformer resistance is low enough, will throw such a surge on power on, it'll short the diodes.

A reason I've switched to the 1N5062 or MUR4100 for pretty mich everything these days.

Cheers!

 

[Brit01]

Thanks Gregg/Bas

Diodes were in correct way. Blew after some months of use, but each time when I switched on the power so was probably due to the initial surge yes.

I have some larger diodes I can put in. Or 2 together as you mentioned Bas will work well.

 

[Geek]

Are you back home now?

If it still gives you grief with a pair of diodes in series, shoot me an email (if you still have it) with your addy and I'll drop some assistance in the mail to you

Cheers!

 

[Brit01]

Hi Gregg,

Sorry back in the office again. Hardly had 5 mins to myself when I got home.
Hopefully at the weekend I'll have some time. There is a big storm brewing so good excuse to get the iron hot again without the boss complaining too much that I don't give her any attention at home!!

Many thanks for your offer of sending assistance. Were you referring to some diodes?

 

[Geek]

I sure was!

When I meant back home, I meant in the UK... or I may be confused.... didn't you do a work stint in South America at some time?

Cheers!

 

[Brit01]

You could say 'a work stint'.

Still here in Uruguay after almost 5 years! Now working as a systems analyst for an American company.
Also going to be a father of a baby boy in just 5 months time

 

[Geek]

Congratulations!!!!!!!!!!

I have no idea the reliability of post to Uruguay and courier is darned expensive

Cheers!

 

[Brit01]

No worries. The offer was appreciated.

Cheers

 

[Brit01]

All fixed now.

They were just 1A 600V diodes.

Had some 1N5408 (3A 1000V) hanging around. Soldered them in and hey presto!

 

[Geek]

Great news!!!

Cheers!

 

[erez1012]

Where they with these PCB's? Or was it a hardwired version?

What did you like about it?

Regards,
Bas

hi
want to built PS for my preamp 12ax7: ~280vdc
i have 240vac transformer with no center tap
now i have only SS.

can i build this scheme? what is the advantage?
thanks

 

[Bas Horneman]

can i build this scheme? what is the advantage?

Yes. That you can use a transformer without a center tap.
If you use a rectifier tube as well...your psu ramps up a little slower and theoretically at least you might have less switching noise.

 

[erez1012]

thanks Bas Horneman.
switching noise? that's it? maybe i don't understand:

if the PS power on 1 hour, the B+ is more quiet with the 6z4 for example?

now i have noise, 10mv
thanks

 

[Bas Horneman]

switching noise? that's it? maybe i don't understand:

A rectifier turns off and on. This creates noise which is mostly filtered out by your power supply caps. So that is probably not what you are hearing

now i have noise, 10mv

The noise is likely a grounding issue.

if the PS power on 1 hour, the B+ is more quiet with the 6z4 for example?

It does not persé make your amp quieter for your ears. It quite hard to explain.

I'll draw something tonight...it is a RRSF. You can do a google for that to do a little research yourself.

RRSF=Reverse Recovery Spike Filter.

 

[erez1012]

thanks, look for it now.

 

[erez1012]

hi
just want to confirm

the heater is 6.3 ac
the tube is 84 6z4, in the PDF is 325 or 450 v max

now i have 240vac >> 340 dc rms, the tube can handle this?

what is R1?

 

[Renron]

+1 to Bas suggestion.
Your can roll / exchange rectifier tubes too. It DOES change the sound. Their cheap and it's fun!
Ron

 

[vdi_nenna]

Hi,

Could you please tell me which schematic was used for the Aikido tube preamp PCB group buy from back in 2005?
Was gifted a set of circuit and PS boards and I would like to try this preamp after hearing it.

Thanks,

Vince

 

[Burnedfingers]

Check out posts

278, 366, 376, and 753

There may be others that I missed.