Gyuri's Pass SONY VFET2 build.

[Gyuri]

It seems that this is now inevitable.
Plan for front panel:

https://1drv.ms/i/s!Fr9ftlB9y5TojQo5IXJrciFyMFRadyQM

 

[Gyuri]

Some parts what I would like to use:


https://1drv.ms/i/s!Fr9ftlB9y5TojQ05IXJrciFyMFRadyQM

The main point seems to be the best, I think.
This is a half-liter bottle, only because of the dimensions.

 

[MASantos]

What value are those capacitors and transformers?

 

[Gyuri]

Capacitors are from F&T GM series, 47000uF 40V.
I've bought these some years ago.
http://www.ftcap.de/fileadmin/user_upload/produktboxen/elektrolyt_kondensatoren/webboxen/Gewindeanschluss/GM.pdf
Trannies are from BULL-GAMMA 115 computers.
I have four of them.
Useful secondaries are center tapped, 2x28VAC.
A little bit high, though.
Center taps are connected.

 

[MASantos]

That will give you 38VDC, you'll have to reduce at least 8 volts to be within design parameters for the amp.

 

[buzzforb]

I think you will like this amp very much. Must share your opinion of it in comparison to the F6. Front Panel is perfect.

 

[Soundhappy]

It seems that this is now inevitable.
Plan for front panel:

https://1drv.ms/i/s!Fr9ftlB9y5TojQo5IXJrciFyMFRadyQM

Hi Gyuri

Looks you are french Peugeot cars logo aficionado ?
Yours is from 1950 😀
Wish you enjoyable amp build

 

[Gyuri]

How much can be an acceptable off-load current consumption of a cc. 600-700VA/230V toroidal transformer?

 

[Gyuri]

Actually that was my first car's logo, that was a Peugeot 504 GL from 1972.
I liked it very much, unfortunately the rust liked it as well.
Since then I have been use my third Peugeot.

 

[Gyuri]

So I must have to ask again, how much the estimated current of such a tranny, (about 600-700VA/230V) without load, say 5mA, 50mA or 500mA?

 

[buzzforb]

With no load, I would expect no current flow. With attached to PSU, very little current flow once caps are charged. The load determines the current flow when all is said and done.

 

[Gyuri]

Thanks Buzz!
You know, I'm asking because it is buzzing, without any load.
I have measured, and it is draw about 240 mA at 230VAC and about 114mA at 220VAC.
It is an old toroid, it was designed for 220VAC/50Hz mains.

 

[Gyuri]

If I raise primer voltage above 242VAC, it suddenly sucks more than 5A!
I don't think there is a sort circuit between windings, because secondary voltages are O.K..

 

[Gyuri]

At the moment of measure, practically there are no DC level at the mains power line.

 

[Gyuri]

For the record, I have measured an other 1000VA toroid,
with it, I can raise primary voltage till 274VAC, and it sucks only 33mA!
Any thoughts?

 

[buzzforb]

Nope. Beyond my knowledge level.

 

[Gyuri]

Thanks again. This is why I also asks.
Well, lets see how it is with that big Bull Gamma 115 trannies.

 

[Gyuri]

Those big black trannies sucks 112mA at 230VAC:
https://1drv.ms/i/s!Fr9ftlB9y5TojQ05IXJrciFyMFRadyQM

I didn't go higher, because I don't want to kill them, and not myself as well.

 

[Gyuri]

To summarize:
I know that there are core loss, winding resistance, hysteresis, eddy current losses.
I know that old tranny was designed for 220VAC.
Perhaps outdated (it is about 35-40 years old), but the question is:
Can be accept it as is, or forget it and send it back to seller?

 

[Gyuri]

The transformer in the middle is what I ask:

An externally hosted image should be here but it was not working when we last tested it.