diytube.com

Thanks mesherm
by not adding the A or mA due to them being the unknown factor
will the program be able to fill in the gaps?

Regards
Greg

I have only used it once over a year ago so I can't say whether or not it will work in your case.

If secondary coil has 98 ohm, it is made from thick wire, and current probably is about 150 ma and more /from my skill.../.
And it will be suitable for both channels. Is the coil 680v central tapped? Because it is very high U.
/Now I'm in Bulgaria/.

mesherm wrote:I have only used it once over a year ago so I can't say whether or not it will work in your case.

mesherm thanks again, the program does ask for the A of the transformer.

azazello wrote:If secondary coil has 98 ohm, it is made from thick wire, and current probably is about 150 ma and more /from my skill.../.
And it will be suitable for both channels. Is the coil 680v central tapped? Because it is very high U.
/Now I'm in Bulgaria/.

What are you doing there?, I hope having fun.
The transformer is 680vct
They look like a diy set.
Looks like they took there time with them

Regards
Greg

A other question on the schismatics re the opt.
I have started building the amp and I realized, this being my first SE amp that the schematic shows the the opt to have a center tap.
My transformer also has one, I did some measurements and found it to be 44%, would this be a UL tap?
Primary is Red + Blue
44% is Red/black of Red
Am I correct in saying that B+ is blue and Anode is Red.

Going by colour coding, blue is anode, red is B+ and screen *should* be orange, but I guess there was a sale on red/black wire

Geek wrote:Going by colour coding, blue is anode, red is B+ and screen *should* be orange, but I guess there was a sale on red/black wire

40% /UL-tap/ are from +B....

Thanks again guys
Colour coding is defiantly different.
Black = 0 ohm
Yellow = 4 ohm
Green = 8 ohm
White = 16 ohm
Test done with 10.15vac =
Yellow = 0.386vac 10.15/0.386=26.3 26.3x26.3=691.7 691.7x4=2766.8
Green = 0.578vac 10.15/0.578=17.56 17.56x17.56=308.35 308.35x8=2466.8
White = 0.767vac 10.15.0.767=13.23 13.23x13.23=175.03 175.03x16=2800

There are also two more cables
Green/Yellow = transformer gnd
Black/White = ?????
Resistance is found only between G/Y and BK/W of 4.8 ohm.

I forgot to say:
I have a friend that has been in the electronics retail for over 35 years and he has lots of tubes
he was mainly in the TV side of things but I think there are tubes to be found, he told me that
no matter what tube I want I can have them at 3 Euro each they are all NOS.
here is a small list that I wrote down quickly. He has another store which I will go to in a week or so
that one has a basement that no one has seen for the last 10 years.
here's the list but he also has more.
PCL805
PFC200
EF93
EF94
EF95
EF186
ECL83
EL95
6AX4GTB
12AX4GTB

And heaps more.

Finished the build last night and ran some tests, all went great. You were correct with the heat of the power resister, I ended putting a small fan to help
the cooling.
Now to get down to the sound.......
I put the EL37's and it sounds absolutely great.....
There is no distortion at all at any level.
I put on my CRO and wave gen and I can say it is the best I have seen on any amp I built.
Thanks for your help.

I know that once one of my friends hears it he will want one.
I will have to get new irons for that amp and I will look to get a power transformer at 600vct
I will have to make some changes back to original specs.
Do you have any suggestions.

Congratulations!

Thank you

Me again I was looking at using 6384 tubes in the place of the 6l6's.
Can it be done?
Another question.... I found that I could get a transformer built 12v primary with 390-0-390 200mA secondry built quite cheep,
would I be able to build this amp to be used in a car?

Ummm ... no. Transformers only work on AC. Connecting 12 volts DC from a car battery to a transformer would result in much smoke. The only way to power a tube amp from DC would be to use an inverter, although you could wire like filaments in series to power them directly from DC.

Tom I know that transformers work on AC. I was planning on using an DC to AC inverter.
The question would be, would it be worth it?
As you can see I've got time on my hands to play a round.
Tom have you any experience with the 6384 tubes?

Thanks
Greg