> one side of the OT was 29 ohms and the other was 37.5!
This is typical.
We want DCR to be Zero, but that can't happen. We would accept DCR less than 10%, preferably less than 5%, of Audio Impedance, because that's a small loss.
Big 6L6 stages work with 4K load per pair. If this is a four-bottle amp, that would be 2K load per quad. Assume this is 1K per side. Applying the 10%-5% guide, we want less than 100 Ohms, preferably less than 50 Ohms, DCR per side.
There are ways to get both sides same-DCR if required. (Ask CJ.) But they are extra work, thus extra cost.
The designer did a test-wind and figured the total was going to be under 50 Ohms per side. And since 2K is a fairly low impedance, and "it is only a guitar amp", fancy interleaf winding is not needed to get the treble.
It is probably wound:
half Primary
half Primary
Secondary
It might be wound:
half Primary
Secondary
half Primary
Either way, with the same number of turns in each half, the outer half has longer length of wire per turn, so a higher DCR. But the DCR is much lower than the audio impedance, so we do not care exactly what it is or if it is equal.
> May this can help: ... the Stdby-Switch only switches the Screen Voltage
Argh!! (see attached) That is so unusual! And makes a mess of many simple techniques.
This is typical.
We want DCR to be Zero, but that can't happen. We would accept DCR less than 10%, preferably less than 5%, of Audio Impedance, because that's a small loss.
Big 6L6 stages work with 4K load per pair. If this is a four-bottle amp, that would be 2K load per quad. Assume this is 1K per side. Applying the 10%-5% guide, we want less than 100 Ohms, preferably less than 50 Ohms, DCR per side.
There are ways to get both sides same-DCR if required. (Ask CJ.) But they are extra work, thus extra cost.
The designer did a test-wind and figured the total was going to be under 50 Ohms per side. And since 2K is a fairly low impedance, and "it is only a guitar amp", fancy interleaf winding is not needed to get the treble.
It is probably wound:
half Primary
half Primary
Secondary
It might be wound:
half Primary
Secondary
half Primary
Either way, with the same number of turns in each half, the outer half has longer length of wire per turn, so a higher DCR. But the DCR is much lower than the audio impedance, so we do not care exactly what it is or if it is equal.
> May this can help: ... the Stdby-Switch only switches the Screen Voltage
Argh!! (see attached) That is so unusual! And makes a mess of many simple techniques.
