The Cyrus Two has been on since just after my last post, and here are my
initial thoughts...

I haven't done an A/B comparison with the valve amp, just swapped them and
started listening to the Cyrus. As expected, it's way louder than the valve
amp and has easily restored the oomph that has been missing. I haven't had
it up more than about 4 (of 10) on the volume control, and that seems to be
as loud as it needs to be.

With 'noisy' music (rock, pop, etc), it becomes a little hard to listen to
at that sort of level, although I'm not sure why yet - could be the amp
starting to clip (don't know its input sensitivity for full power), the
speakers complaining, or even my ears. It isn't painful, but the clarity
seems to go a bit when it's cranked. Suffice to say that this is getting
close to 'bug the neighbours' volume levels, which doesn't happen very
often. I'll maybe mess around with the scope later, to see what sort of
pk-pk voltages are going into the speakers and try to establish how much
power it's putting out.

On the other hand, more open-sounding music, like Ricki Lee Jones' Easy
Money, is fine at 4, but the bass is a bit messy - this is down to a known
problem with the speakers (wrong cab resonance/volume for the driver). Above
the bass frequencies, this track sounds damned clean and tight. With the
bass end under better control, there's probably scope for a little more
volume on music like this.

In terms of fidelity and clarity, I would say that the Cyrus has the edge on
the valve amp, but not by much - it's not a night-and-day difference. If
anything, I'm quite impressed at how well the Maplin valve kit acquits
itself in terms of sound quality - a damn good effort for a home-brew tin
box with arguably-too-small transformers. The valve amp is in serious danger
of being retired, however - it'll have a place in the development process of
the tri-amping project, but I think it will get the boot eventually.

Sometimes, I feel the Cyrus is a little 'shouty' - more in-your-face than
the valve amp - but this could be down to me cranking the bugger up to get
the volume fix that's been missing for so long, resulting in my lug-'oles
getting hammered. If I was to try and home in on a sonic improvement, I
would say that the bass is better - a bit more solid than before, bass drums
have more thump behind them.

I'll get a better feel for the sound quality over the next few weeks as I
settle into the new sound and increased power level.


--
Wally
www.artbywally.com
www.wally.myby.co.uk