Hifi Tuning Fuses

Over the weekend, I replace the two internal fuses within a friend's CJ LS17 preamp with the hifi tuning fuses and the improvement was huge and beneficial - adding both depth, soundstage, and air to the music. At least as much of an improvement as connecting the Shunyata Helix Alpha powercord, and, the improvements were additive - both devices helped.

Now, I am looking to replace the fuses within my CJ CT5 preamp and in a pair of CJ Premier 11a amps. In the latter, I am hoping someone out there more knowledgeable than me can advise which of the following fuses would likely be more worthwile in replacing - there are 7 fuses in each amp, times 2 amps, time $40 fuse - I would like to add at least a little sanity to this upgrade...

Per Ed at CJ, the Premier 11A has the following:

Externally accessed:
Plate fuse: Buss BBS 3/4 A
F1 main AC fuse: 3AG 5 A fast blow

Internally accessed: on the small PCB near the back of the amp.
F2 (near front of board) 3AG 4 A slow blow ( for secondary windings for filament supply(
F3 3AG 1/4 A fast blow (bias supplly)
F4, F5 3AG 1/4 A fast blow (low voltage supply for bias LEDs)

Your advice is appreciated...

Poonbean,

I have no advice on which fuse you should change. I just replaced all three fuses in my modest integrated amplifier as a hedge against replacing the "wrong" one. Whichever fuses were the "right" ones, it made a noticeable improvement.

I was reconnecting my speaker cables in the back of my AMC 3050a integrated amp "by feel" and managed to short out one of the channels in the process. When I turned the amp back on to listen, the fuses in both the left and right channel paths blew. I had read about HiFi Tuning fuses and thought what the heck? There are three fuses in the amp that I could see: a single 4A T slow blow fuse located near the power switch (didn't blow) and one 6.3A T slow fuse for each left and right channel that were smoked. I replaced all three and prepared to be disappointed - almost $100 bucks of fuses on a sub $500 amp seemed like a questionable investment. Well, I am not disappointed.

At first power up my system sounded like a blanket had been placed over the speakers. A very expensive blanket that made my bright little integrated sound like an old tube job - any sibilance was completely gone, bass sounded warmed over and wooly, but not altogether unpleasant. After a couple of days the sound completely changed and became thiner, sibilance was still abated but the bass was attenuated, I wasn't really happy with this turn of events.

Now, after the fuses have been in my system for over 300 hours the sound has really balanced out and is noticeably better than before from top to bottom, with the bass back strong and more defined. Certain recordings that used to reveal annoying sibilance on my system now are tamed and just sound like music. Nora Jones voice that always seemed a bit harsh and made me wonder what all the fuss was about now sounds smooth and full. Leading edge attack is still fast but now rounds into the decay of piano notes or cymbal strikes in a more realistic and convincing manner. The stereo image is more coherent and "connected" within the room, and each instrument has more defined space around it.

I am surprised that I notice these differences in such a modest amplifier and overall system (Cambridge Azur 640C V2 CDP, AQ Diamondback ICs, AQ Type 4 SC, Vifa and Morell custom bookshelf speakers). My rig still runs out of steam and gets confused at high volumes, but at normal listening levels the overall sound is much improved. I would think that many pieces of better equipment would be "liberated" by the addition of these fuses and get closer to the potential inherent in their quality components.

PS - to protect my new fuse investment, I put banana plugs on the amplifier end of my speaker cables to make assembly by feel in the back of my cabinet a safer affair. Duh.

Good stuff! They helped my sytem! The detail is so much better,the amp makes me jump when I hear sounds within the recording I've never been able to hear before!What an improvement!I would do it again! I will buy more of them soon as I can.

I have done several comparisons between the IsoClean fuses which I have been using for several years and the newer Hi-Fi Tuning fuses. I discovered that the Hi-Fi Tuning fuses are directional although they are not marked as the IsoClean are. You must try the Hi-Fi Tuning both ways. I have also discovered that the IsoClean fuses sound somewhat better and, of course, are cheaper. There is no question for me that fuses are very important and directional.

I recently replaced my VAC Monobloc fuses with the Hifi Tuning fuses( 4 amp slow-blow) and the improvement was noticeable and for the positive. Not dramatic, but "icing on the cake" good. I won't be going back to the cheap glass versions. Worth it? Yes, IMHO.