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Equipment Review

September 2003

H2L Gold and Silver Contact Enhancers

by Bill Cowen


Review Summary
Sound "Improvement was noticeable, easily heard, and repeatable with either of the enhancers applied"; "the most identifiable improvements heard initially were in the midrange," where there was "added clarity…with more inflection and inner detail"; will not cure the sonic ills however -- they "simply are not magic bullets."
Features "Two pens that contain gold and silver particles suspended in a squalene solution and applied via a chisel-shaped felt tip"; "each pen reportedly contains 'innumerable' 8-nanometer pure-silver or -gold particles."
Use Bill "was unable to discern a difference between the gold and silver particle treatments, [although] it was quite easy to hear an improvement when one or the other was applied."
Value "The H2L pens are very worthwhile additions to your audio toolbox."

Show-of-hands time: How many of you remember a product called Tweek that was popular back in the mid-1980s? Everyone? Well, in the event you’re young enough not to have your hand in the air, Tweek was a liquid contact enhancer that was supposed to improve sound by filling in the microscopic pits and irregularities in the metal surfaces of connectors -- RCA plugs on interconnects, phono-cartridge pins, speaker-cable spade lugs and the like. By filling in these "voids," a better signal transfer was claimed to result, along with improvement in the overall sound of the audio system.

While contact cleaners and conditioners have likely been around as long as electrical connections have existed, Tweek was one of the first products (if not the first) that was targeted directly at the audio-enthusiast market. But while Tweek had a serious liability (more on that to follow), the products from Hamada-Hayashi Laboratories (H2L) reviewed here do not.


H2L manufactures, among other things, two pens that contain gold and silver particles suspended in a squalene solution and applied via a chisel-shaped felt tip. This format aids in easy application, and the particle/squalene concoction is delivered through the tip via capillary action (think felt-tip marker). Two pens are available -- one with silver particles at $15 USD and one with gold particles for $22. Both prices include airmail shipping within the US and are available only via direct order from RTL Audio. The pens are roughly the diameter of a standard #2 pencil and about half as long.

Each pen reportedly contains "innumerable" 8-nanometer pure-silver or -gold particles. I had to look up "nanometer," and found it to be equal to one-billionth of a meter. I verified that this was, well, impossible to verify visually. Even with the aid of a jeweler’s loupe, I spotted no gold or silver particles when the tip of the pen was swiped across a white sheet of paper. But all I was really interested in was what contribution this product would make (or not make) sonically. And if you were thinking that $20 would buy you a pen full of pure gold, you’re probably in the wrong hobby anyway.

Due to the microscopic size of the metallic particles in the solution, and due to the very thin layer of film that the felt-tip applicator applies, there’s not much to be concerned with as far as bridging hot and neutral (or positive and negative) contact areas. The literature does suggest that high-voltage connections be checked with a meter to insure that no shorts exist, but unless your application involves tiny high-voltage traces on a circuit board, I cannot fathom how a short could be created. However, always follow the manufacturer's instructions. Erring on the side of caution is much better than barbecued components (or audiophiles).

Test procedure

This review took quite some time to complete due to the complexity involved with doing a thorough test. First, there were two different products to evaluate. Second, I have more than 45 connections in my system if both analog and digital sources are included (and the power cords feeding them all). Third, a baseline had to be established (more on this below). And finally, I wanted to keep things in place long enough to see if the pen’s chemicals would cause any kind of reaction with the connectors’ metal on a long-term basis.

To narrow things down just a bit, I omitted the connections between the cartridge and tonearm wiring, as well as the DIN-to-tonearm cable at the base of my Graham tonearm. I wasn’t merely being lazy -- undoing the cartridge connections affects azimuth and vertical tracking force, and messing with the DIN connection requires removing the tonearm from the turntable. Both would have compromised a clear evaluation, as it would have been impossible to insure that things were reset exactly as they had been before.

To begin, and prior to any evaluation of the benefits (or lack thereof) of either the silver- or gold-particle enhancers, it was necessary to establish the aforementioned baseline. Simply removing and re-plugging a connection anywhere in the system can result in a sonic difference, as even an invisible layer of oxidation will be scraped away in the process and a fresh metal-to-metal connection will occur when the connection is re-made. Add to that the fact that some of the connections in my system had already been treated with Caig Laboratories Pro Gold, so it was necessary to remove all traces of that. And as it had been several months since I had last done any contact cleaning in the system, there was undoubtedly some oxidation, if even a minor amount.

So, to get to the root connector "sound" and insure that I was hearing only the effects of the gold- or silver-particle solutions, I first removed and cleaned all connections in the system with 94% isopropyl alcohol. I listened to the system for several days, and then applied the silver-pen solution. Following that, I cleaned each connection, listened, then applied the gold-pen solution and listened again.


So what exactly do the H2L solutions sound like? Well, obviously a contact enhancer can’t sound like anything -- it’s what the resulting reproduction sounds like after the solution is applied. At this point, I wish I could tell you that there were dramatic sonic differences between the gold and silver versions of the H2L pens, but I can’t. I can tell you that an improvement was noticeable, easily heard, and repeatable with either of the enhancers applied, but I’ll be darned if I could tell you which was in use without knowing it beforehand. Toss all your preconceived notions about the general sonic traits of silver-plated, pure-copper, or gold-plated wiring and connectors, as they simply don’t apply here. These H2L pens bring about a noticeable improvement, but to my ears there was little difference to be heard between the two versions.

While the listening notes below were derived from a completely treated system (excepting only the turntable connections as noted above), there was definitely a hierarchy to effectiveness. The most noticeable improvement came at the source end -- the RCA connection between the tonearm and phono preamp, and between the CD player and line preamp. Second up was, surprisingly, the power cords, and, again, those powering the source components offered the most noticeable improvement. The line-preamp-to-power-amp link followed that, and at the speaker-cable level there was little if any noticeable improvement. This is likely explainable by the larger mating surfaces that spade lugs and binding posts offer over RCA connections, and possibly the higher voltages present at that point as well.

To the music

The most identifiable improvements heard initially were in the midrange. This surprised me a little, perhaps only because a standard cleaning ritual normally has a more pronounced effect in the higher frequencies. For example, with "Dreaming Man" from Neil Young’s Harvest Moon LP [Reprise 9362 45057-1], there was an added clarity to Young’s voice, with more inflection and inner detail. The resonance of the guitar strings was more pronounced, yet not in an artificial manner. The magnitude of improvement here was similar to that of a freshly brushed, sparkly clean cartridge stylus versus the same stylus that needed cleaning five albums prior. Monumental? No. Noticeable (and enjoyable)? Way.

Associated Equipment

Loudspeakers – Coincident Speaker Technology Total Eclipse.

Amplifiers – Cary Audio Design 280SE "V-12i" monoblocks.

Preamplifier – Cary Audio Design SLP-2002.

Phono stages – Art Audio Vinyl One.

Digital – Cary Audio Design 306/200, Audio Electronic Supply CD-1, and Opera Audio Consonance Reference 2.2 CD players.

Analog – Eurolab Premiere turntable with 80mm platter, Graham 2.0 tonearm with 2.2 bearing upgrade, Zyx Fuji and Benz-Micro Wood LO-2 cartridges.

Interconnects and speaker cables – Shunyata Research Aries interconnects and Andromeda speaker cables.

Power conditioners and power cords – Shunyata Research Hydra power-distribution center, Shunyata Research PowerSnakes Anaconda Vx, King Cobra, and Diamondback power cords.

Accessories – Black Diamond Racing cones and Round Things, Solidsteel and Target racks, ASC Half Rounds and Tower traps, Michael Green Designs Pressure Zone Controllers, Marigo Audio Labs VTS tuning dots, Walker Audio Ultimate and Standard Valid Points, both racks fitted with Greater Ranges Neuance shelving for all components.

"And She Was" from Talking Heads Little Creatures LP [Sire 7599-25305-1] showed some improvement in the treble with a bit more splash to the cymbals, but again the vocals were where the improvements really stood out. There was more separation between the microphones, and a better sense of air and decay in the soundstage as well. Micro detail was upped just a hair, which, for me, always results in more involvement with the music.

Switching over to digital put a little more focus on the treble. Things were not necessarily smoother, but there was more clarity and a bit of enhancement to the presence. The 1999 Sony remaster of Stevie Ray Vaughan’s Texas Flood [7464-65870-2] is rather variable -- some of the tracks are very impressive, and some are only marginally better than those on the original Epic recording (which was marginal on every track). I got lucky. "Tin Pan Alley" is one of my favorite Vaughan tunes -- it also happens to be one of the best recordings on this CD -- and with the H2L enhancers at work, it was even better. I heard more harmonic content in the guitar notes, and more resonance from the sharply plucked string notes. Again, the vocal portion stood out with more detail, better depth, and simply sounded more like a live voice in the room.

Finally, and just for kicks, I threw in an old, old Telarc recording of Frederick Fennell conducting the Cleveland Symphonic Wind orchestra  (Holst: Suite No. 1 in E-flat, Handel: Music for The Royal Fireworks, Bach: Fantasia in G [Telarc CD 80038]). This CD was a digititis tour de force when I first bought it, and as my system has evolved and become more resolving, it has graduated from ear-bleeder to ear-shredder status. Sorry to say, but the H2L pens didn’t cure it. But don’t take that as a criticism of the pens -- they simply are not magic bullets, and if that’s what you’re expecting, you’ll be disappointed.


As I mentioned in the introduction to this review, the discontinued Tweek contact enhancer had one serious liability: When it was used between dissimilar metals, a thick layer of black gook built up on the metal surfaces, and this could happen within a very short time frame. This gook was very difficult and sometimes even impossible to remove completely -- I managed to destroy the RCA plugs on a fairly pricey pair of interconnects trying to get it off. Since then, I’ve stayed away from contact enhancers, although I have made use of the Caig Pro Gold. But Pro Gold is billed as a preservative rather than an enhancer, and I’ve never had a problem with it causing any kind of chemical reaction on metal surfaces. For straight cleaning, I use either isopropyl alcohol, or when confronted with badly oxidized connections, Caig’s DeOxit. In both instances, the cleaner is applied and then completely removed, rather than left in place like Pro Gold or the H2L solutions.

From the enhancement aspect, I’ve never been able to hear much of a difference with Pro Gold applied. It works exceedingly well at keeping oxidation at bay, but never offered any sonic improvement to speak of. The H2L pens are the clear winners here, as their sonic contribution is readily apparent.

In terms of cleaning, H2L states that the pens are in fact suitable for the task, so I put them to the test with a pair of cheap patch cords that had been sitting unused in a drawer for several years. The tin plating of the RCAs was pretty dark and grainy-looking, and provided at least a visual clue as to cleaning effectiveness. I applied the H2L silver pen to one end, and Caig DeOxit to the other. After letting both sit for five minutes, I removed the loosened oxidation with a pipe cleaner. Both ends came out cleaner, but the DeOxit-treated RCA was shinier and brighter. Also, the crud that came off the RCA plug during application left some residue on the felt tip of the H2L pen. While it was easy enough to wipe this off, it can only hamper the effectiveness of the (porous) tip for subsequent applications. Although the H2L pen was true to its word in cleaning ability, I’ll personally stay with DeOxit for that purpose and save the H2L pens strictly for enhancing.

On a final note, the H2L contact enhancers have been in use in my system for more than five months, and there are no signs of any reaction taking place on any of the connections. For Tweek-o-phobes like me, that’s a really, really good thing.


The H2L contact-enhancing pens, like almost any system-enhancing item, will not make a silk purse out of a sow’s ear. They provide subtle and incremental improvement to be sure, but even a small increment is worthwhile to many audiophiles. Had the price of these pens been in the multiple-hundred-dollar range, it would have been difficult to make a recommendation. As inexpensive as they are, however, the recommendation is easy and, to my ears, justified. While I was unable to discern a difference between the gold- and silver-particle treatments, it was quite easy to hear an improvement when one or the other was applied.

Whether you’re fanatical about the connections in your system or not, the H2L pens are very worthwhile additions to your audio toolbox.

...Bill Cowen

H2L Gold and Silver Contact Enhancers
Prices: Gold enhancer, $22 USD; silver enhancer, $15.

International distributor:
RTL Audio & Music Pte. Ltd.
1 Fifth Avenue #02-12 Guthrie House
Singapore 268802
Phone: 6463-8812
Fax: 6463-8616

Email: hideo@rtlaudio.com
Websites: www.rtlaudio.com , www.rtlestore.com

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