Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: Loquah on June 08, 2014, 05:10:37 PM

Title: Power specs from different output taps
Post by: Loquah on June 08, 2014, 05:10:37 PM

Sorry to ask such a mundane question here - I know it's been mentioned before, but I can't find it. Can someone please provide the power output from the S.E.X. for each output impedance setting (4 / 8 / 16 / 32 ohm)?

Title: Re: Power specs from different output taps
Post by: Paul Birkeland on June 08, 2014, 05:22:56 PM

2 Watts.

-PB

Title: Re: Power specs from different output taps
Post by: Loquah on June 08, 2014, 05:34:24 PM

Um... should I be embarrassed now?  :o  I thought the power delivered varied across the different OT wiring? Is it just a case of the output impedance changing and therefore the interaction of the OT with the headphones rather than a change in actual power?

Title: Re: Power specs from different output taps
Post by: 2wo on June 08, 2014, 05:57:50 PM

Power is power, volts X amps. By changing the transformer taps, you are changing the V/I ratio to a given load. the 4 ohm tap will deliver a lot of current at a low voltage, the same load at 32 ohms will see a higher voltage at a lower current...John   

Title: Re: Power specs from different output taps
Post by: Loquah on June 08, 2014, 06:07:53 PM

Thanks John! I understand now  :)

Title: Re: Power specs from different output taps
Post by: Loquah on June 08, 2014, 06:19:47 PM

1 further question. If using the S.E.X. with planars that are commonly reported to need more power, is it safe to say that if the volume level is ample (I use my S.E.X. at approx. 50% on the attenuator) and you still have headroom, then there is no benefit in choosing a higher impedance output tap?

In other words, am I correct in thinking that the higher voltage will result in higher volume, but not higher power available?

Title: Re: Power specs from different output taps
Post by: Paul Birkeland on June 09, 2014, 07:50:47 AM

Quote from: Loquah on June 08, 2014, 06:19:47 PM

In other words, am I correct in thinking that the higher voltage will result in higher volume, but not higher power available?

If you go up in impedance on the taps, you'll get more available voltage, more noise, and less damping.

At 50% rotation, your SEX amp could be making 0.1 Watts or it could be clipping, as the volume control is not the decisive factor in how much power your amplifier is putting out.  The experiment to do would be to try a higher impedance tap and listen for less distortion on really loud peaks, but at the same time listen to the noise floor on silent passages.

-PB

Title: Re: Power specs from different output taps
Post by: Loquah on June 09, 2014, 10:45:03 AM

Thanks PB, that's perfect.

I know the volume doesn't relate directly to power delivered. I was just confirming that I have plenty of headroom on the 8 ohm tap.