[sdiy] DIY Mixer - please help!

[Seb Francis]

Antti Huovilainen wrote:
> On Wed, 2 Sep 2009, Paul Dhillon Weber wrote:
>
>> Often designers used output transformers to achieve greater level and 
>> headroom without having to add additional, phase inducing and noisy 
>> amp stages.
>
> Transformers actually have far worse phase problems than amplifier 
> stages. So much so that interstage transformers can't usually be used 
> inside feedback loop which is part of the reason they fell out of 
> favor in tube circuits when lower THD amount required using feedback.
>
>> Think about your favourite THICK recordings from the 70s.  That's the 
>> sound of transformers.
>
> As much or even more likely to be due to distorting transistor 
> circuitry. Vintage designs using discrete components aren't exactly 
> what you'd call low distortion these days. 0.1% THD was considered 
> good back then and in simulation many circuits produce even more 
> distortion. As for opamp designs, one word should be enough: 741.
>
> I once tried to measure distortion in a cheapo behringer DI isolation 
> transformer. We had problems getting enough signal to produce any 
> measurable distortion in FFT view.
>

I guess it's a question of whether you consider a mixing desk to be 
'part of the sound' or you simply want to mix your instruments, 
insert/send to effects, etc. and choose what colouration to add when 
desired.  I personally find it a bit limiting when my mixing desk forces 
everything to take on a certain sonic quality ... I'd rather have an 
ultra-clean signal path.

Seb