What could be the consequences of using 42TM018 instead of 42TM022 in octavers?

[gigimarga]

Hello,

I have big problems here to find transformers, so i am forced to use only some 42TM018 that a friend gave to me some time ago.
As i know, 42TM018 have a ratio 1:1 (10k:10k), while 42TM022 have a ratio 3:1 (1.5K:600ohms).

I used 42TM018 instead of 42TM022 in Tycobrahe Octavia and Neoctavia and it sounds good.

So, which are the consequences of interchanging them?
I think that mainly the the output is changed, but i am not very sure.

Thx a lot all!

[brett]

Hi
depending on the circuit, there might be effects of input and output impedance.  Two rules of thumb are that (i)the greater the ratio of primary turns to secondary turns, the higher the input impedance, (ii) the higher the ratio, the lower the ratio of input to output voltage (ie voltage gain or loss), and (iii) the DC impedance will often be about 10% of the nominal AC impedance (ie 1.5kohms = 150 ohms of DC impedance).  This can be important for biasing class A stages (e.g. where the transformer sits on the collector of a BJT as a class A "driver" of the next stage, or a speaker or whatever.

It's not too surprising that this transformer worked well.

cheers

[gigimarga]

Thx a lot!

I am content now...