RE; Yes, what? You asked, 'Or can they?', and
the answer is, 'Yes, easily'. Well, of course Bravo wouldn't
give figures that showed less than excellent performance. The
THD with 33 ohm load is admitted to be rather high, and we don't
know what the output voltage or power was at that THD. That is
why I gave the two pairs of amplifier figures as an example.
On 2025-02-20 18:14, Jerry Lee Marcel
via groups.io wrote:
Le 20/02/2025 ¨¤ 17:33, John Woodgate
a ¨¦crit?:
Yes, easily.
Yes what?
Consider, for example, these two
amplifiers:
a) Output power 30 W, THD 0.1%
b) Output power 35 W, THD 5.2%
Which would you buy?
I don't care, but Bravo Audio seems to care
about figures that are long accepted as performance indicators.
They are the same amplifier. Similar games
are played with signal-to-noise ratio and frequency
response.
On 2025-02-20 16:05, Jerry Lee
Marcel via groups.io wrote:
Still they are publishing specifications that pertain to
typical audio performance, such as frequency response and
THD. They can't combine both quirkiness and normality.
Or can they?
Typical "I designed it that way because I could".
IMO it justifies disdain.
Le 20/02/2025 ¨¤ 16:55, John
Woodgate a ¨¦crit?:
I suspect that the weirdness is
intentional. Weird designs have existed from? the
earliest day of DIY radio receivers, before
'electronics'? was in the dictionary. I recall a report
of a circuit that had the 2 V lead-acid cell apparently
in series with the antenna circuit. Objective
performance measurements are typically not to be applied
to such designs. DO a web search for 'Bravo Audio
reviews'.
On 2025-02-20 15:36, Jerry Lee
Marcel via groups.io wrote:
Le 20/02/2025 ¨¤ 15:27, Carlo
a ¨¦crit?:
On Thu, Feb 20, 2025 at 05:40 AM, Andy I wrote:
There is some feedback from the audio
signal into the heater voltage. Was that
intentional?? Or just an undesirable side-effect?? I
don't expect it would have very much effect on the
heater's temperature (and from there to the triode's
characteristics), but it looks undesirable to me.
Should there be filtering?
Sorry, are you asking whether the audio signal
feedback into the heater voltage comes from a design
intentional choice ? Actually I don't know since I
took it from the schematic of a commercial audio
amplifier (Bravo Ocean).
It's extremely unlikely.
Heater temperature varies extremely slowly compared to
audio signals.
It could result in distortion at very very low
frequencies, definitely out of the audio band.
Now this design is weird from the start. Choosing to power
a tube circuit from 24VDC is a major flaw, unless the goal
is to create distortion.
--
OOO - Own Opinions only If something is true: * as far as
we know - it's science *for certain - it's mathematics
*unquestionably - it's religion
--
OOO - Own Opinions only If something is true: * as far as we
know - it's science *for certain - it's mathematics
*unquestionably - it's religion
--
OOO - Own Opinions only
If something is true:
* as far as we know - it's science
*for certain - it's mathematics
*unquestionably - it's religion
John Woodgate