SE O/P Transformer A/B

[Swedish Chef]

I came across a situation earlier on where I wanted to switch between 2 o/p trannies to compare and contrast, and wondered if I could do it with a single pole changeover.
In the end I opted to just wire the secondaries to seperate jack sockets but wondered what would happen if:

You connect both primary windings to the HT
You have a SPCO to switch the o/p of the amp between the other ends of the primaries
You parallel both the secondaries.
The last point is the one I couldn't get my head around.
How will the secondary of the transformer NOT SELECTED behave and interact with the secondary that IS selected?
Obvoiusly it is a DC resistance to ground, but WTH?!!!!

chef

 

[Swedish Chef]

...but also it will act like a plain old inductor will it not?
No doubt it would screw up all kinds of things :green:

It shouldnm't have taken me so long to tumble to that.
Please forgive me!

chef

 

[CJ]

You can get away with both secondaries wired together, I believe, if the DCR of the two sec's is not that far off.
Just connect the sec hot while listening and see if any change.

Otherwise, yes, kind of a hassle to wire up a wafer switch to switch both pri and sec at the same time.

I was thinking of problems with the pri might be worse, like switching the B+ on and off while hot, thereby inducing a huge spike in the secondary like car coil, but since you are stepping down to 600, the pulse would be stepped down also, so no need for a make before brake switch.

 

[Swedish Chef]

Hey CJ

I was thinking about connecting the b+ to the plate with a high value resistance like perhaps 10M to try and maintain some voltage on the plate between the break and make of the switch...
What do you reckon?

chef

 

[CJ]

Now ya tell me!
Sounds good.