Trying to select the Aikido components

[manlystanley]

I'm trying to select the Aikido build and components. I am a real noivice at this and don't really know the advantages of the 8 /9 pin options. But with the 8/9 pin amps I've got two tube types to pick out and then synergy problems between the tubes. So, I think that I'll just go the simple path with the 5687.

What I've read about the 5687 tube, it has some really good audio properties.

Carbon film / metal resisters: I've read that metal resisters are better, correct?

For the Coupling Capacitors, I was planning on getting both: Dayton and PIO (Paper-In-Oil) Coupling Capacitors. I'd really like to hear what the differences sound like.


What do you guys think of these choices??

Best Regards,
Stan

[kacernator]

Hi,

I have built 12AX7, 12AU7 and 6SL7, 6SN7 aikido preamps. Octal sounds much better. Bigger, clearer, punchier sound. So my vote goes to octals.

I like metal films overall more, but carbon volume potentiometer sounds to me better than stepped attenuator with metal films. So I usu metal films everywhere except volume potentiometer.

As for coupling capacitor it is about personal preference. Easy to swap them, so you can try different ones.

[manlystanley]

Originally Posted by kacernator

Hi,

I have built 12AX7, 12AU7 and 6SL7, 6SN7 aikido preamps. Octal sounds much better. Bigger, clearer, punchier sound. So my vote goes to octals.

I like metal films overall more, but carbon volume potentiometer sounds to me better than stepped attenuator with metal films. So I usu metal films everywhere except volume potentiometer.

As for coupling capacitor it is about personal preference. Easy to swap them, so you can try different ones.

Interesting. Not what I expected. Thanks for the feedback!

Best Regards,
Stan

[SY]

I've built two of them- one with ECC88, one with 5692 (ruggedized 6SN7). The former used FKP caps, the weird Broskie stepped attenuator, and plain (I think Yageo) metal film resistors. The latter used Russian PTFE caps, a high end Alps pot, and bulk foil resistors.

Blind, I would challenge anyone to tell them apart. They work very well, don't distort the signal, and are reliable. I gave the first one to a friend in CO who has used it for two years with no problems. The second one I kept and pull out from time to time on the rare occasions when I need something with gain.

Basically: don't sweat the component choices too much.

[manlystanley]

Originally Posted by SY

I've built two of them- one with ECC88, one with 5692 (ruggedized 6SN7). The former used FKP caps, the weird Broskie stepped attenuator, and plain (I think Yageo) metal film resistors. The latter used Russian PTFE caps, a high end Alps pot, and bulk foil resistors.

Blind, I would challenge anyone to tell them apart. They work very well, don't distort the signal, and are reliable. I gave the first one to a friend in CO who has used it for two years with no problems. The second one I kept and pull out from time to time on the rare occasions when I need something with gain.

Basically: don't sweat the component choices too much.

Sy, then for you the 8-pin and 9-pin have sounded the same? Thanks for the advice on the component choices.

Thanks,
Stan

[SY]

Originally Posted by manlystanley

Sy, then for you the 8-pin and 9-pin have sounded the same?

Yes. Probably because I'm deaf, insensitive, have a lousy system, and hate music.

Seriously, it's a good design, and part of being a good design is that it's not terribly critical of components; likewise, it's not terribly critical of the power supply. I use a simple Maida series regulator. One thing I would do, though, is trim the hum-nulling resistors for the particular tubes you have. I did it by replacing one of the resistors with a trimpot, then using a scope to watch the output as I made the adjustment.

[syyma]

Trying to select the Aikido components

Have the amp up and running first then use it as a baseline to tweak to your taste later.

Sidney

[cjkpkg]

Yes, I would use standard values for a while but match your cathode resistors carefully based on the input and output tubes you chose whether you go 5687 or standard 9 pin or octal. The user guides have all the info you need. Dial in your B+ since theory seldom tracks to reality 100% accurately. Then cathode current, then chase down the humms and buzzes...you may get lucky but you may still need to play with twisting wires and final layout in the chassis for a completely quiet preamp.

Plan on a PSU for 250-300V. I am using JB's PS-3 solid state for my 5687 Aikido and it is very quiet - bonus is it utilizes DC for the tube heaters. I will say however that I ran the aikido on AC heaters for a while and it was still pretty quiet.

A 180-0-180 to 250-0-250 would be perfectly adequate. If you use something like the PS-3 you will not need a power xformer with 5V winding for a tube rectifier. Do make sure that you get one with at least 4A on the 6.3V winding - 6A would be better since you will want to double it to 12.6V but lose half the amperage. A small $$$ saver. Edcor has some nice iron so does Hammond and Allied Electronics.

[DualTriode]

Originally Posted by syyma

Have the amp up and running first then use it as a baseline to tweak to your taste later.

Sidney

Hello syyma,
I am with syyma, jump in. Flip a coin 9 pin vs 8. Buy the Tubecad kit, PS-1 power supply and stepped attenuator. You will be up and running. You will be set to start tweaking parts. Who knows you may love it as is.
DT
All just for fun!