• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

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

Jump to Latest
#741
Thank you for the information. I will go with a 6.3V heater supply, with the 6SN7 heaters in series. I am not sure what the heater bias point is on the Aikido PCB. Is that the "H+"? Also not sure what are the 6.3V - CT - 6.3V windings.

Attached is a jpeg of a schematic and diagram of the 9-pin mono PCB. Although I am using the Octal mono PCB, the boards are very similar. The jpeg shows the various connection points, including the "H+". If it would not be too much trouble to veryify on the jpeg for me, I would greatly appreciate. I do not want to have any electrical accidents.

Thanks much!

Kris
 

Attachments

  • aikido_9-pin_mono_rev-b_pcbv2.jpg
    aikido_9-pin_mono_rev-b_pcbv2.jpg
    73.4 KB · Views: 805
#742
kvardas said:
Thank you for the information. I will go with a 6.3V heater supply, with the 6SN7 heaters in series. I am not sure what the heater bias point is on the Aikido PCB. Is that the "H+"? Also not sure what are the 6.3V - CT - 6.3V windings.
Click to expand...

Now you've got it mixed up. Better read my post again. If you use 6.3V heaters, you wire the tubes in parallel. CT refers to a center tap on the filament output. The center tap is connected to ground or sometimes connected to the DC reference point. If you have a transformer with no CT, you need to make an artificial one using two resistors. You can find more info on this by searching the forum.

Also, why are you asking for confirmation on the 9 pin jpeg? Why don't you just use the Octal layout that John Broskie has available? Not really sure what your thinking is behind this....
 
#744
JPS said:
For B+ of 300V. Transformer should be

Output 1 - 0-275V, 60mA
Output 2 - 6.3 - 0-6.3, 1.5 to 2A
Output 2 - 6.3V-0-6.3V, 1.5 to 2A


Solder wires from heater bias point on PCB to center tap of both 6.3V - CT - 6.3V windings



I have been searching for a transformer with the above specs, but to no avail. Anyone know of a source to which they could refer me?

Thanks

K
Click to expand...
 
#745
kvardas wrote

I will be using the Aikido PSU PCB show earlier in this thread,
Click to expand...

I meant parallel, not series....
Click to expand...


In that case you will need following transformer.

Output 1 - 0-275 V or 295V, 50mA -? I will check this again.
Output 2 - 3.15 - 0-3.15, 2A
Output 3 - 3.15V-0-3.15V, 2A
Output 4 - 0-6.3V 1A- for 6X5 rectifier tube

Two seperate filament winding for two mono boards.

regards
 
#747
another aikido

TRANSFORMER, POWER, HAMMOND 270BX, 275-0-275 V, 50 mA
Filament winding 1: 5 V, 2 A
Filament winding 2: 6.3 V, 2 A

Hi everyone, I'm putting together an aikido using Bas's PS boards along with Broskie's octal mono boards.

I've stuffed the PS boards according to Bas example, He also recommended that I go with 30 uf for c1, what voltage rating am I looking for?

The trannies Im lookin at is the hammond 270bx, 2 of them to 2 seperate PS boards for true dual mono approach. Will these work?

Can I run the 6x5 off the 5v,2A winding, and the 2 6sn7 off the 6.3v,2A?

I'm looking @B+300v , Bas has informed me that I will probably get about 280v, unless I use a choke which should be fine.

Thanks
 
#758
422 volts output

Hi guys,
using the newer board design and a Hammond 270dx, I am getting just over 312 volts from the Hammond and 422 volts output. I am using a Hammond choke 5H/50ma and a 47mfd cap. A little help please?
Also BAS suggested (2) 50 ohm resistors for the use of a non-center tapped trans. I have (2) 10 watts resistors, is this okay?
Then to confirm, I just hook them to the (2) filament wires and to the Heater Bias point?
thanks guys
P.S.
Using a 6x5 tube
 
You must log in or register to reply here.
Top Bottom