Amp tinkerers and people who aren't afraid of 700 volts or so in here....

Moderators: Slowy, Capt. Black

User avatar
BY Single coil
#769760
Nah man, flood the page. This is great.

Reckon it’s possible to do in black and white (for the colour averse among us)?
BY Marshmallow
#769797
Single coil wrote:Nah man, flood the page. This is great.

Reckon it’s possible to do in black and white (for the colour averse among us)?


Haha yea happy to do so!

Re: Amp Build + Mods,

I've actually just realized something. I noted that I need a 5e3 Transformer for my build with a 330---0---330 spec. Wrong.. Because I am not using a rectifier, I would need something below:

Input = 100 volts/ 220V secondary or vise versa
HV = around 275---0---275 @ 100--120 ma
6.3 volts @ 2--2.5 amps.

If anyone is able to help with this! Just checking if I anyone have this spec locally.
BY Marshmallow
#770022
I may have found a power transformer.

Just a quick question though. There's an output transformer with:

And it is Series connection 220v,or In parallel connection 110V.
Core size:76x40
270---0---270
6.3V 3.15Vx2

Just wondering what would happen if I ran 110V on a 100v socket? It was noted to me by the company that they sell amps to Japan market with 110V voltage. Just not quite sure how it would work. Cheers
User avatar
BY SimpleSi
#770050
Marshmallow wrote:I may have found a power transformer.

Just a quick question though. There's an output transformer with:

And it is Series connection 220v,or In parallel connection 110V.
Core size:76x40
270---0---270
6.3V 3.15Vx2

Just wondering what would happen if I ran 110V on a 100v socket? It was noted to me by the company that they sell amps to Japan market with 110V voltage. Just not quite sure how it would work. Cheers

"Ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change."

so generally if one drops the other will too. - Assuming your loading is the constant.
if you under-voltage your current will too..

not sure how well tubes cope with being under-currented - or over currented


if it helps though..
Here in New Zealand we're a "230v" country.. but most things that come in are rated 220-240v

and most of the time, you'll find the power at the outlet at your house usually sits between 235-245 depending on how close you live to the Transformer on the line. :clap:
BY Marshmallow
#770264
SimpleSi wrote:
Marshmallow wrote:I may have found a power transformer.

Just a quick question though. There's an output transformer with:

And it is Series connection 220v,or In parallel connection 110V.
Core size:76x40
270---0---270
6.3V 3.15Vx2

Just wondering what would happen if I ran 110V on a 100v socket? It was noted to me by the company that they sell amps to Japan market with 110V voltage. Just not quite sure how it would work. Cheers

"Ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change."

so generally if one drops the other will too. - Assuming your loading is the constant.
if you under-voltage your current will too..

not sure how well tubes cope with being under-currented - or over currented


if it helps though..
Here in New Zealand we're a "230v" country.. but most things that come in are rated 220-240v

and most of the time, you'll find the power at the outlet at your house usually sits between 235-245 depending on how close you live to the Transformer on the line. :clap:


110 should be fine then. Thanks man! btw I've ordered the transformer! should arrive in 2 weeks!
BY tubeswell
#782337
Marshmallow wrote:I may have found a power transformer.

And it is Series connection 220v,or In parallel connection 110V.
Core size:76x40
270---0---270
6.3V 3.15Vx2

Just wondering what would happen if I ran 110V on a 100v socket? It was noted to me by the company that they sell amps to Japan market with 110V voltage. Just not quite sure how it would work. Cheers



Multiply the PT's rated secondary voltages by 100/110

270 x 100/110 = 245 (so 245-0-245, which will produce a B+ of 345ish with a SS 2-phase rectifier). So we'd expect the high tension winding will be good for 5E3 voltages (Assuming you're running 6V6s)

However, 6.3 x 100/110 = 5.72, which may or may not be a problem. Heaters usually function okay within a band of +/- 10% of the design voltage (but the closer you get to the edges of the 10% limit, the less reliable they are). 6.3 - 0.63 = 5.67 So you'll have to see when you get to Japan. Might be fine. If there's a problem when you get to Japan, go to the local electronics store and buy a little japanese mains/filament transformer rated for 2 to 3A (assuming you're running 6V6s) and wire your heaters to that.