Sunday, January 19, 2014

Telos Quantum Cap

Like the original Telos RCA Cap ?

Telos has launched their new Quantum Cap. Sold in packs of four pieces, each RCA cap is made out of copper and gold plated. The cap is subject to cryogenic treatment and treatment from Telos's proprietary QBT run-in treatment. The red pad inside the RCA cap contains undisclosed materials.

Compared to the original RCA cap (see review here), the Quantum Cap is longer and heavier.

I am still trying these caps around the house. They do clearly make a difference on equipment they are used with. During some initial experiments, I tried covering the output jacks of the Calyx Coffee DAC / headamp, and they clearly resulted in changes to the sound - a smoother presentation, albeit with some restraint and reduction in dynamics. Not really to my liking over there.

Trying them next on my Conrad Johnson preamp, I placed one pair on a spare input. The effect seems to take a while to stabilise, and I had a listen after leaving them in position for a day. The most noticeable effect on my system was a change in soundstage presentation, with the vocalist moving forward, and the midrange becoming more prominent. Pacing was much faster, to the extent that I felt the system was unnatural sounding - the musicians don't need to rush - I am not in a hurry !

Adding another pair on a output jack on the Conrad Johnson (and waiting another day) provided more balance to the overall presentation. Apart from a quieter noise floor, transients were left with a more energetic and dynamic feel. As opposed to an airy light and focussed high frequency presentation, the Quantum Cap imparts a slight increase in density and body. The effect reminded me very much like a milder version of the Telos Branda power cord.

I was also pleased that I got back a more balanced pace (no more rushing for the train), and my soundstage depth (it still moves the vocalist forward, but to a lesser extent now). Overall, it is a good effect with a more wholesome and organic feel.

Moving on to my office head-fi setup, I placed one pair on the output jacks of my Schitt Lyr. There is a lightening effect on the midrange, with an increase in length of decay. However, Piano notes had less resonance and body. Putting an additional pair of caps on my source, (placed on the coaxial digital output and remote control jack of a Marantz CD6003), resulted in a smoother midrange, and an increase in bass weight.

Intellectually, it seems odd that a pair of caps (or two in this case) could alter the sound of a system to the extent heard. Leaving any scientific explanations aside (I won't even try), you really should try them. They are low cost (the pack of four costs slightly more than 2 CDs) and quite potent. However, the effect is not entirely consistent or predictable from setup to setup. Liberal experimentation will be necessary to achieve the desired effect.

Sunday, January 5, 2014

Aftermarket Audio Fuses - a mini round-up (revised 8 Nov 2015)

(Revised - 8 November 2015)


Do you believe in aftermarket audio fuses ? This is a controversial topic - engineers and other naysayers are quick to point out the ludicrosity of the whole matter. Give it a try. If it makes no difference, you've saved yourself some money. I recently purchased the Telos and Synergistic Research Quantum Fuse and thought it would be nice to run some comparisons between these fuses and some other fuses on the market.

I took a dive into my stack of parts and found a Create Audio Luxury Nano fuse I used some years back. I texted my audiobuddy TC and he passed me a Hi-Fi Tuning Supreme and Super Cryo fuse too.

I tried the fuses on my Conrad Johnson Classic 60 SE power amp, but ended up trying the fuses on a variety of equipment.

Left to Right - Schurter SMD-SPT, Synergistic Research Red, Telos Audio Quantum X2, PADIS

New - Synergistic Research Red Fuse (US$ 89.95)

The Red Fuse has a similar tonal balance to the SR20 fuse, but has noticeably more resolution and extension, especially at the top end of the frequency spectrum. It still remains a warm and calm fuse, and should be the antidote for harsh and bright systems.

New - Telos Quantum X2 Fuse (Pricing to be determined)

The Quantum X2 fuse is a sonically more mature version of the QBT-18. There is better low end impact, with a subtle bloom, while both midrange and high frequencies have a sweeter and more refined tone. I am quite impressed with the improvements made over the QBT-18.

Synergistic Research SR20 Quantum Fuse (US$ 59.95)

Synergistic Research SR20 Quantum Fuses are German made ceramic bodied fuses that have been zapped by SR's Tesla Coil, i.e. 2 million volts of electricity. Although these fuses have no direction markings, the manufacturer is of the view that they are directional and have to be tried both ways.

The Quantum Fuse is smooth and warm. It has good bass weight and a slightly laidback midrange. The top end could be viewed as a bit too nice for some with a bit of restraint in cymbals and air. Despite its balance, it is quite detailed. For those seeking a slightly warmer balance, it would be a toss-up between the Red Fuse, Quantum Fuse and the Super-Cryo Fuse.

Telos QBT-18 (S$ 40 or about US$ 30)

The Telos fuse is a new entrant to the fuse market. The QBT-18 is a German made industrial grade fuse that has been cryogenically treated for 36 hours and then run in using Telos's in-house designed QBT burn-in machine for 18 hours.

The QBT-18 impresses with its openness the minute you hit the play button. It is highly detailed, with very precise imaging and staging. It has a leaner low end and midrange compared to the SR Quantum Fuse. The bass notes from Patricia Barber's track, "Like JT" have less weight and impact. There is also a tendency for certain sibilant tracks to come through clearly - in comparison, sibilance is flattered by both the SR Quantum Fuse and Super Cryo Fuse. This could be just the thing for darker and slower sounding systems. I personally found it a bit too bright for my main setup, although it was a perfect match for the warm and smooth sounding Job 225 power amplifier.

From top to bottom : Telos QBT-18, Super Cryo Fuse, Synergistic Research Quantum Fuse, Hi-Fi Tuning Supreme Fuse, Create Audio Luxury Nano Fuse, Stock glass bodied fuse
Hi-Fi Tuning Supreme (US$ 59.95)

Hi-Fi Tuning was one of the earlier manufacturers of hi-fi grade fuses. The Supreme is their top of the range offering. The internal wire material is made out of a silver / gold mix (99 % silver and 1% gold) and soldered using a silver / gold based solder from Mundorf of Germany.

The Supreme is cryogenically treated and subjected to a proprietary quantum treatment. There is no direction marking, but the diagram on the body makes it easy to differentiate the orientation of the fuse.

This fuse has an outstanding reputation but just didn't do it for me. It is pleasingly warm and smooth. However, I felt it obscured detail and lacked the control of the top fuses here in terms of transient control, imaging and staging. This is an expensive fuse, and my expectations were correspondingly high.

Super Cryo Fuse (S$ 40 or about US$ 30)

I don't know much about this fuse except that it is from Cryo Audio Technology Japan.

However, I do know that this fuse sounds very good in my system. It is sweet, while managing to avoid sounding syrupy or veiled. Pleasingly warm, the Super Cryo Fuse is detailed and well controlled. It lacks a bit of top end extension. Ride cymbals have a good warm strike (more so than usual), but with less obvious decay. In comparison, the SR Quantum Fuse has an overall less prominent cymbal presentation - it's all there, just softer. The Super Cryo Fuse also has less bass weight and slam but just manages to edge out the SR Quantum on the detail front. This is an excellent fuse for the money.

New - PADIS Fuse (EUR 22)

PADIS (Progressive Audio Distribution) is a German manufacturer that sells rhodium plated fuses for high end audio. It is rumoured that PADIS also produces fuses for another well-known audio company. PADIS fuses can be ordered online directly on ebay directly from the manufacturer.

These fuses punch well above their asking price. I found them to be well-balanced, and very detailed at the same time. Both ends of the frequency spectrum are very well-controlled with the high frequencies being subtly more prominent. They also have a very precise rendering of the soundstage, and placement of instruments.

Outstanding value !

Create Audio Luxury Nano Fuse (US$ 10)

This is an easily available fuse that can be ordered off e-bay from a number of China based sellers. The internal material promises nano material (whatever that means), a ceramic body and gold and rhodium plated ends. The fuse is marked for directionality.

This is an unusual fuse. Bass is warm and rounded, while the midrange is smooth and pleasant. However, the top end is quite sharp and a bit metallic and grainy. It is not a bad fuse, taking into account its very low price. Definitely worth a shot if you are skeptical about fuses, but just want to satisfy your curiosity without too much financial risk. However, this is definitely not state of the art as far as fuses go.

New - Schurter Gold Plated Ceramic Body Fuse (below US$ 2.00)

Schurter actually lists their SMD-SPT fuse line as an audio product ! Thankfully, it comes with a non-audiophile price tag. Depending on how hard you look, you should be able to find it for less than US$ 2.00

In my humble opinion, the SMD-SPT handily outperforms the Bussman Ceramic Fuse for negligible price difference.

There is good amount of detail, and nothing seems unduly emphasized. Soundstaging is a bit distant.

If your system is perfectly dialed in, this could be the icing on the cake. This fuse is an absolute no-brainer !

Stock Fuse (Negligible Cost)

This is a generic glass bodied fuse. Nothing more to say here. Vague and slightly messy. Any of the candidates here can be safely seen as an upgrade. If you refuse to upgrade the fuse, at least experiment with orientation of the fuse.

Bussman Ceramic Fuse (Negligible Cost)

Shoestring budget ? Consider the Bussman ceramic bodied fuse, which should be available from either your local hardware store, or electronic supply house. Compared to a generic glass bodied fuse, the Bussman adds a slight lift in both transparency and control. The soundstage is also moved backwards for an increased sense of depth. This fuse is easier to obtain than the Schurter, but going the extra mile to hunt down the Schurter is definitely worth the effort.


Fuse rolling provides a surprising amount of latitude in tuning a system. It is also worth noting that all of the fuses on test (including the generic stock fuse) are directional, and sound different both ways.