I've narrowed it down...


So my first venture into tube equipment will be an integrated amp based on the recommendations of this fine group of enthusiasts. I have narrowed the field to the Rogue Audio Tempest III, Rogue Audio Cronus Magnum, the Cayin H-80 and Cary SLI-80.

All of this is based on what I have read and what fits in my budget. The Cary is a little over but for something I think I'll have for a lifetime I'm willing to go a little over...

I will be driving B&W 602S3's until more $$$ are available for something else.

My intent is to listen to vinyl then maybe venture into CD's or digital music. Any feedback or suggestions are appreciated.

Going somewhere to listen to any of these is not an option for me, and room size is undetermined as I am in the process of moving.

Thanks.
botit

Showing 3 responses by magfan

B&W is not generally a tube-friendly load.
Crossover? Well, electrically, most B&W are a very reactive load...meaning it looks like a capacitor or inductor to the amp. Large impedance swings aren't fun for tubes, either.

SS is best.
I suggest auditioning speakers WITH proposed amps.

Buying speakers for amps OR amps for speakers is the short way to madness.
Buying / auditioning together, especially for people just learning, is best done in a shop with some experienced guidance.
Online? Well, that's much more of a risk, IMO. Unless, of course, some background exists to ease the choice / reduce risk. Others have the 'buy it used and test it' philosophy, thinking they can sell whatever for pretty much what they paid for it.
The online approach is, to me, anyway, for the more experienced or those with deeper pockets.

Un, with much more experience can target into a class or perhaps even a brand of amp which has very high probability of satisfaction.

Overall, I'd say to buy the source first. That'll make run of mill stuff sound better and perhaps even survive a few upgrade cycles.
Botit,
Phase angle? Well, a resistor is sort of a pure load. Any energy stored is generally as heat. Voltage and current rise and fall together.

With capacitive or inductive loads, voltage and current do NOT rise and fall together. Tubes typically do not like driving a load which looks too much like a capacitor. Both inductance and capacitance are 'stored' energy = reactance.

There is some math involved, but basically, the angle between voltage and current determines how much power is actually available from the amp TO the load to do actual work. At 90degrees, NO power is available. So, in a high reactivity load you may not get 'advertised' power.
B&W is demanding of an amp because it is reactive at some frequencies.

Look up Power Factor. The Wiki article is simple and has illustrations.

As for impedance, lower also makes more demands on an amp. Speakers are rated at a 'nominal' value, but can vary a LOT from that value. At the more power demanding end of the spectrum, say below 300hz, a large dip in impedance at the same place as a large phase angle will result in large demands on an amp.

Here is link to the power cube way of measuring amplifier performance. Note how some 'poor' amps fall down when asked to drive hi phase angle at low impedance. Even some good amps don't necessarily shine in this test.

http://www.audiograph.se/Downloads/PowerCube_12p_brochure_complete.pdf