Discussion in 'Audio Hardware' started by Soundlabs, Mar 15, 2019.
I will have to check out Icon audio 300mkll.
I have yet to hear one of these amps playing music!
I've heard pipe and slippers noises from them, and if that's what you like you'll get on famously with them.
Real music has hair on it ....
The challenge is explaining how anything like a fuse that is by definition entirely disassociated from the audio signal path could possibly be analogous to a tube that is integral to the audio signal path. The obvious admission to make is that there is no relationship between AC fuses and preamp or amplifier tubes. Equating the two things is literally impossible.
They want 6 grand for this amp. But if you look closely pretty much standard configuration of 4-300b and 4-6sn7. I couldn't figure out how they got the 30 watts per channel. My amp is pretty much the same besides 12at7 preamp tube and it can put out almost 18 watts per channel "respectively". But of course it set to push pull but majority of the guys like SE. which is all a matter of preference. I really If I can get a 300b with atleast 32 watts per channel or up, that's an upgrade for me.
ICON AUDIO - Stereo 300 MkII Tube Integrated Amplifier
Remote control: HQ ALPS motorized volume pot
Output power: 30W 8Ω
4x 300B output valve (AC heated)
4x 6SN7 (CV181) double triode
Signal to noise level: -85db
Freq resp: 20 – 20kHz -0.2 to –0.5dB (8w 6.25dB FB)
1W: < 0.05% 1khz
8W: < 0.2% 1khz
Switchable gain control: 140mV, 300mV, 790mV
Channel balance: typically within 0.2dB
Dimensions (WDH): 15" x 13" x 9.1"
Weight: 57.3 lbs.
Based on the Iconic Western Electric 300B Output Valve: Point-to-Point Hand-Wired Icon Audio Stereo 300 MkII Tube Integrated Amplifier Plays with See-Through Transparency and Beautiful Musicality
Created in the 1930s, Western Electric's 300B tube quickly became legendary for its ability to convey sound with see-through transparency, practically zero distortion, exceptional linearity, and beautiful simplicity. Seizing upon its iconic sonic prowess, Icon Audio has crafted the 30Wpc Stereo 300 MkII tube integrated amplifier around this very directly heated valve. The result: A point-to-point hand-wired component that offers listeners the kind of sumptuous midrange, pristine detail, and boundary-defying soundstaging that are often limited to the stuff of dreams.
Ideal for efficient large speakers, Stereo 300 MkII epitomizes what many dedicated listeners know as "tube magic." Replete with the advanced circuitry the four output 300Bs require and stacked with four relaxed, best-in-class 6SN7 double-triode tubes in Cascode mode to provide the critical high-definition drive circuitry, the British-designed unit provides seamlessly smooth results from any input source. Indeed, Stereo 300 MkII plays music with an unvarnished honesty that will truly reveal what's on your recordings and mask none of the potential deficiencies. In other words, it is an audiophile's treasure.
True to its take-no-shortcuts heritage, Icon Audio built Stereo 300 MkII with an uncompromising array of parts. A massive choke-regulated power supply, SCR caps, silver-plated PTFE cabling, tertiary winding output transformers, and gold-plated input and speaker terminals complement an "easy bias" meter that lets you see that the 300Bs are performing at their optimum anytime you want – and gives you a security check on whether or not you're approaching the maximum available power. You can also vary input sensibility by changing the feedback, ideal for pairing with a separate preamplifier.
I guess theyre running the preamp in cascade mode as of I remember when I built a mosfet amp back in 1982, the preamp was set in parallel if this is the same in tube.
The cascode is a means of using a pair of triodes to achieve very high levels of gain and input sensitivity from a single stage. For guitar amps it can be imagined to be a simulation of a pentode, and indeed the circuit does resemble one. It has high gain, high ra and very low input capacitance just like a pentode, but without the inherent drawbacks of noise, microphonics and expense. The two triodes are usually of the same type for the sake of simplicity and convenience, but they do not have to be. Hi gm triodes provide the most gain, and the ECC82 or 6SN7 work remarkably well as cascodes. The ECC83 will work to, though it is a little more fiddly to set up.
The operation of the circuit is simple: The lower triode amplifies in the normal way. The amplified (and inverted) signal is passed from the lower anode to the cathode of the upper valve. The signal voltage on the cathode then modulates the current flowing through upper triode, allowing the signal to be amplified yet again (non-inverting this time). The grid of the upper valve is kept at a fixed voltage (more or less) to provide the correct bias for the upper triode. Overall the output signal in out of phase with the input.
The anode load of the lower triode consists of the cathode of the upper triode. The upper cathode has a low AC impedance, so the gain of the lower triode is also low (rather like using a very low anode resistor in a normal gain stage) so it acts mainly as a voltage-to-current converter. The upper triode has a normal resistive anode load, and so has fairly normal level of gain and does most of the work. In this way, the gain of the lower triode is multiplied by the gain of the upper stage, resulting in a very high overall level of gain!
My experience is that anything better in the electrical path makes a difference in our gear.
Thanks for the comic relief.
"I spent my weekend fuse rolling"
You going for NOS fuses? Or wait, better yet, cryo'd?
Fuse rolling.... my side hurts from laughing....
Yes its a term used by ps audio Paul. I figured you guys need a good laugh.
Even if the electrical path you’re talking about never makes it past the conversion from AC to DC in a component’s power supply? Even if the frankly extremely difficult to measure differences (when they actually exist in the first place) are literally many, many decades below the threshold of detectability by the finest instruments and even farther than that below human audibility? Even if your definition of better - a fuse in this case - isn’t supported by actual electrical testing that has showed clearly in too many cases that the so-called audiophile fuses did not break when they were supposed in fast-break applications? We must not risk the potential for that sort of damage to our equipment!
Perhaps most important, since when did “difference” necessarily equate to “better”? The two words do not mean the same thing at all.
Sounds like a weekend listening to music! WooHoo!!
Ive been rolling power cords for weeks. I cant wait to start on fuses! So many to choose from.
Handful someone gave me.
Love this cord.
Fish you are a guy that is actually going to try rolling fuses. Let me know how things go for you. For me anything I upgraded in the electrical path has helped out for the better.
Ha! Good point.
Hey, different strokes, you guys must have all the other aspects of your system absolutely tuned and nailed down tight if your now down to comparing the differences between power cords and fuses.
Curious - how much difference do you perceive when rolling a cord or a fuse? Is it subtle? Vast?
Ive found that Amps ive had or played with dont care very much so its very subtle.
Preamps are a mix of subtle and more so.
DAC/CDP's mostly respond allot, somewhat dramatic.
Computers have recently shown me they show dramatic changes to power cords and outlets.
Personally, i think once you have good revealing Interconnects and Speaker Cables in your system the Power Cords and Fuses make the Most difference in comparison. Once you get past that foundation you can go back and improve on the Interconnects if you want but for me the Outlets and PC's will ultimately make the most differences.
But yes, you are correct. This is tuning and tweaking. The room/system has to reach a point were it starts to show enough to warrant the time and expense. And you will find out which component(s) is the weakest link, the one that stops responding to changes before the others. Its Very hobbyist.
I think many components and power-foundations are not revealing enough and reduce the effectiveness to tweaking. Again, Very hobbyist.
Aren't the Human Ears Amazing feats of evolution!?!? All our senses are! I believe we can perceive things we aren't even aware of yet, no less can measure. Measuring things is limited to our technology and understanding. I mean, just the other day (historically speaking) we thought the earth was flat. The universe revolved around the earth. People were killed for thinking otherwise. We just didn't know any better then and we're still learning.
I insist on cryo, silver and single malt wiring from the pole to my panel and then to the outlets used for my gear. Audiophile breakers are a must also. Who needs an expensive fuse? Fix it at the source! After much research I have found a definitive and complete explanation for how fuses, wires and the rest cause amazing and stupendous improvements in our systems. Enjoy!
I can say if I were to start over building a system, I would start at the power side. A good outlet, good power cords and a good power conditioner. Then add the best gear I could buy. And the same for cables and the the fuses last.
I don't remember where I saw it, some pictures of Japanese audiophiles setups. One showed a dedicated tap that started at the pole by his house. Quite amazing.
RiCat I seen that same picture. The electric pole was right outside his window.
I actually have some audiophile fuses in my CT-5 preamp but only because the previous owner stuck them in there. They're supposedly orange or purple or something like that. Nothing has blown up or caught on fire so they have exceeded my expectations and then some.
Why would they catch fire. The purple fuse came out middle of October. Orange is SR last generation of fuses. So to help you out here, the Orange is white in color. The purple fuse is a dark purple color.
I have an old EQ and one of them looks like it has a regular fuse and the other high end looks like this. I don't know if this is one of your magic fuse. Besides the discrepancy, this is a 1/3 octave 1980's eq that sounds light years away from it lower model which is the 15 band. Its got a spring and like a resistor inside..... Pretty much I know the in and out of this unit besides a few areas and one of them is that fuse.
Ah - the technical jargon clip was but a poor copy of the original
As I said earlier, fuses (at least ones that are UL tested, or bear an British Standard kite symbol) have a safe rupture current. It is not what happens when a fuse blows when the current is just above the rating - it is what happens when there is a catastrophic fault - a hard short circuit. Maybe the mains transformer or switched mode supply has developed a fault which puts essentially a short circuit across the mains power. Under those circumstances you need to have a fuse that has been tested at UL and has a safe rupture current.
For a qualified fuse, bearing the UL or BS logos, you know that they will safely blow without physically exploding during a catastrophic fault. That is typically 1,500A.
Those fuses look like the older slow blow type fuse.
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