Studies On Residential Power Line Noise - Part 7: HiFi Tuning and Isoclean Fuses

curbfeeler

After replacing the fuse on my Bryston BDA-1 I had found music played through it to be less coherent, and sibilances were splashed to some degree. I have been breaking in new Maggie 3.7 speakers in the course of replacing fuses, and that confused matters a bit. I had also replaced a fuse in the Herron phono stage. I found myself playing much more vinyl and less digital. I got out the Fluke multi-meter to check continuity from the line blade of the IEC inlet on both chassis to the respective end of the fuse holder. The HiFi Tuning Supreme fuse in in the Herron was oriented correctly, but the one in the Bryston was reversed. I remedied that and voila! Sibilance was controlled and it had a presentation of whole cloth.

DarqueKnight

Thanks for sharing your results.

Have you installed, or are you considering, dedicated AC lines?

curbfeeler

I installed 10-3 from the main circuit breaker panel to a plastic quad box adjacent to my Stillpoints ESS equipment rack. There are duplex PS Audio Power Port Premier and FIM receptacles on it. These are wired 180 degrees out-of-phase with respect to each other on separate breakers. I use CryoMax III power cable terminated on Furutech FI-11 connectors. The Power Port Premier is connected to a Quantum Qx4 on Stillpoints with risers. That is connected to a Quantum QB8 on Stillpoints with risers which feeds all the critical equipment. The QB8 enjoys a 6-ga dedicated ground cable connected to a copper pipe sunk into the ground outside the house. The FIM feeds a couple of older Rat Shack Archer quad receptacles to which the nettop computer, Gigabit Ethernet switch, Blu-ray player, LED backlit LCD monitor and linear 12V supply for the jkeny HiFace MkII connect.

DarqueKnight

That's a great power infrastructure. I thought you might have done some power infrastructure upgrades since you were getting such good results with the fuses. For some of my gear, I didn't get really good results with the fuses until after dedicated AC lines and power conditioners were installed.

curbfeeler

I had placed the HiFi Tuning Gold fuses on my new Maggie 3.7 speakers in the same orientation as they were on the 3.6 for no good reason. It’s likely that Magnepan doesn’t allow for tweaks when designing new products, so the polarity of the fuse holder was probably not considered. I had been lamenting the slow progress of burn-in and suffering at times excruciating discomfort, depending on the recording, caused by the out-of-balance (too strong) upper midrange and highs. Given my recent experience with the HiFi Tuning Supreme fuse having been installed in reverse on the Herron VTPH-2, I reversed the polarity of the fuses on the pair of 3.7 and was stunned by the improvement. With the Herron the sound went from thin, confused and shrill to somewhat shrill, more fleshed out and more coherent. Still it was not the sound I was looking for ultimately from the new Maggies, though. The switch on the Maggies was much more profound. The sound improved in much the same way it had with the Herron, though to a much greater extent. I could easily live with what I hear now.
You live and you learn.
Some who have tried the HiFi Tuning Gold fuses have complained that they made matters worse. I am willing to bet they never installed them in the proper orientation.

DarqueKnight

curbfeeler wrote: »

Some who have tried the HiFi Tuning Gold fuses have complained that they made matters worse. I am willing to bet they never installed them in the proper orientation.

Some people say they like them better oriented the "wrong" way.

I think, for some people, if a tweak gives them more of what they like, if it is an enhancement of what they are accustomed to, the tweak's effect(s) will be accepted. If the tweak takes them in a different sonic direction, even though the different direction may be toward more accurate and realistic sound, the tweak's effect(s) will not be accepted.

DarqueKnight

Introduction

I began experimenting with audio grade fuses in 2008 (IsoClean-Audio-Grade-Fuse-Review-2008). As far as I know, Isoclean was the first to market an audio grade fuse. When it became known that people would actually buy these things, other manufacturers entered the market (HiFi Tuning, Critical Link, Furutech, and others). HiFi Tuning fuses entered the market a year after Isoclean, but the consensus, and my personal experience, was that the HFT fuses did not sound as good as the Isocleans. HFT improved their product quality and eventually overtook Isoclean in quality and in market share.

Whereas Isoclean has offered the same product since market introduction, HFT has followed a process of continuous improvement with two generations of the original Gold fuses, followed by the upgrade SilverStar fuses, and finally the current top of the line Supreme fuses. Isoclean fuses have doubled in price since their 2005 introduction, from $25 to $50 per fuse. Adjusted for inflation, the 2005 price of $25 would equate to $30 in 2012. Isoclean has not claimed any product improvements that I know of. The only new claim I know about is the following advisement that is now included with Isoclean fuses:

"Fuses always carry high electric current thereby easily causing metal fatigue. This would then adversely alter the conductivity behavior of the fuse element and hence the performance of the equipment. Under normal conditions, Audio Grade Fuses should be replaced from every 6 to 12 months the longest."

To my knowledge, no other fuse manufacturer, audio grade or otherwise, makes such an "interesting" claim.

JC 1 Power Amp Fuses

I initially replaced only the 12 amp main power line fuse and the two 1 amp power supply fuses in my initial investigation. Whereas I went from stock to Isoclean, to HiFi Tuning Gold, to HiFi Tuning Supreme fuses with my phono preamp, line level preamp and SACD player, I did not upgrade the complete fuse complement in the JC 1 monoblocks due to the number of fuses required (sixteen total). The preamps required one power line fuse and the SACD player required two power line fuses. When Parts Connexion had a closeout sale on the HFT Gold fuses at 45% off retail, I decided to go all in to see if replacing the other JC 1 fuses would provide any audible benefit. If they didn't work, I could return them. Parts Connexion was sold out of HFT Gold fuses in the 1 amp small size (5mm x 20mm) fuses required for the protection circuit. HFT SilverStar fuses, which are upgrades over the Gold fuses, were used in the protection circuit. They were found at 12% off at Music Direct.

Parts Connexion's 45% off sale provides some insight into the astronomical retail markup of some audio accessories. Even at that substantial discount, you know they still made a handsome profit.

The HFT, as well as the Isoclean, fuses are directional and should be oriented with the case arrows pointing in the direction of current flow. I had already determined the current direction for the power line and the two power supply fuses purchased earlier. Rather than poking around inside an amp with a meter to determine current direction of the additional fuses, I sent a Saturday evening email to Parasound's service department requesting the information. I received this reply a couple of hours later from Parasound's president Richard Schram:

"Hi Ray,

I think you and I corresponded once before.

You will make HiFi Tuning very happy. If you have good enough speakers and you listen very critically I'm told you might hear a sonic improvement with the silver fuses.

Please call our tech dept at 415-397-7100 x120 before 2pm PST M-F. A tech can give you this info.

Please note the 5 digit serial number of each JC 1 and have that available so the tech knows which production series they are in.

Please be very careful when you poke around inside the JC 1. The big filter caps stay charged for a long time and you don't want to play the game called "Guess the B+."

Kind regards,

Richard Schram
President
Parasound Products, Inc.

Tony in Parasound's service department provided the following information:

All fuses are slow blow type.

1. 12 amp large size (6.3mm x 32mm) main power line fuse, arrow points to rear of unit.

2. 1 amp large size (6.3mm x 32mm) power supply fuses, F1 and F2, arrow points to rear of unit.

3. 12 amp large size (6.3mm x 32mm) power supply fuses F7 and F8, arrow points to front of unit.

4. 1 amp protection small size (5mm x 20mm) circuit fuses F1 and F2, arrow points to rear of unit.

5. 1 amp protection small size (5mm x 20mm) circuit fuse F3, arrow points to top of unit.

Tony advised that he didn't think there would be any audible improvement with replacing the protection circuit fuses (but there was). He also said I could use 12.5 amp fuses in place of the 12 amp fuses, which were not in stock at that time.

Fuse Replacement Procedure


Figure 1. Each Parasound Halo JC 1 power amp contains eight fuses. I made HiFi Tuning very happy.

Fuse replacement was first done in the right amp, then compared with the left, then fuses were replaced in both amps. Listening was done in mono and stereo.

Step 1. Reinstall all the stock fuses, then compare Isoclean 12 amp power line fuse to HiFi Tuning Gold 12.5 amp fuse. The stock fuse sounded veiled compared to the Isoclean fuse. There was a lateral expansion of the sound stage. The Isoclean fuse sounded veiled compared to the HFT. Music was apparently louder with the HFT fuse compared to the Isoclean.

Step 2. Replaced three stock 1 amp fuses in protection circuit with HFT SilverStar fuses. The sound was apparently louder with the HFT fuses. I heard more fine details overall, but bass impact was softened. Bass softness went away after six hours.

Step 3. Replaced stock 1 amp fuses in power supply with 1 amp HFT Gold Fuses. There was a small increase in apparent sound level. Low level detail was improved. Fine details such as breath noise in wind instruments and the decay of string instruments was more pronounced.

Step 4. Replaced stock 12 amp fuses in power supply with 12.5 amp HFT Gold fuses. The sound volume was apparently louder. Image weight was heavier. There was a little more tactile sensation. There was more detail in ambient sounds. Bass was softer for the first two hours, then more detailed and articulate.

After nine days with the HFT fuses, I put all of the stock fuses back in. Overall, the JC 1's still sounded great, I was just missing details I had grown accustomed to. The sound stage was reduced 2 feet at the sides and 1 foot front and rear. There was a glaring reduction in apparent sound level due to the increased noise floor. Some ambient details were muted or missing altogether. I listened with the stock fuses for two days, then the HFT fuses were reinstalled.

Discussion of Results

I do not think I would have been as impressed with the results of this total fuse replacement had I not done other prior power infrastructure upgrades, speaker upgrades, and room treatments:

1. A dedicated 20 amp AC circuit for each JC 1, terminated with a PS Audio Soloist SE in-wall power conditioner.
2. Upgraded power cord (PS Audio AC-12) for each power amp.
3. Upgraded AC regenerator (PS Audio P10) for preamplifiers and source components.
4. Upgraded power line fuses for preamplifiers and source components.
5. Speaker crossover inductor upgrades.
6. Installed additional crossover circuit board vibration abatement.
7. Custom heavy duty non-common ground AI-1 interface.
8. Installation of active room resonance cancellation.

Further Study

I am considering comparing the effects of replacing each amp's HFT Gold 12.5 amp main power line fuse with an HFT SilverStar fuse and then an HFT Supreme fuse.


Figure 2. Such Good Sound...made better!