NEW PROTOTYPE FUSES COMING >>>

That is a mistaken characterization, my RM-9 serial # 536 came from his bench w Wondercaps…. arguably the first “ boutique “ cap.

of course some skin in the game warranty claims might had something to do with his disdain…perhaps you can clarify RM’s question about the suitability ( compliance to a specification )  of that particular fuse for use in a high voltage tube circuit…. ?

What is the warranty on gear you modify ?

Agree on the warranty claims and how that would cause one they have a certain view on boutique fuses. I am actually making the same point.

I have no idea what you are referring to in terms of the actual fuse value in the amplifier in question. Don’t know if it was a lower rated fuse, fuse rated in spec, fuse rated over spec?

In the end,  it really doesn’t matter because the fuse did not act as the designer wanted and caused some major issues. I would stay away from those particular fuses from that manufacturer in that amp 😁

JW Blue, Jim? Now yer talkin’! I bypassed the fuse (in fact the entire fuse block, as well as the horrid speaker connectors, installing Cardas binding posts in their place) in my Magneplanar Tympani T-IVa.

Roger’s views on audiophile parts is often over-simplified. He DID consider electrolytic caps unsuitable for some applications, fine for others. It’s all in his AudioCircle writings. And he was making speaker cables at the end, and not just to make money.

It was the use use of fuses that were not of "high breaking capacity" design that he warned against in his amps, and in fact as part of any amp to which such a fuse was connected to output tubes. He received back at his shop an RM-9 that was destroyed by a full compliment of Hi-Fi Tuning fuses which did not preform their primary task: protecting the circuitry they were connected to. 12 non-performing fuses which cost as much as the amp itself? Ridiculous!

Latest update >>>

Well, Mister Golden Ears and I had an interesting two-hour listening session this morning. We started out with the full complement of the prototype fuses. I thought the sound was spectacular. Then we changed out the prototypes for two QSA Yellow fuses, one in the line stage and one in the amp. We did an a/b/a/b/a comparison. The sound was also spectacular, however different. We both heard the same things.

We played both CDs and LPs.

The prototypes, in my opinion, are overall a better musical experience, in that the tonal balance is more accurate, and instruments actually sound more real. There is a more realistic sound space as well.

Mister Golden Ears thought the prototypes sounded a bit "dryer" than the QSA Yellow fuse. I didn’t hear that at all. I heard more separation of instruments, more individual voices fleshed out in choir music and a little more tube-like lushness throughout. I like that.

This is not meant to take anything away from the QSA Yellow fuses at all. They have their strong points.

My final analysis from today is this ... If you like the sound of neutral tube electronics like modern ARC gear, I believe you are going to like the prototype fuses better than the QSA Yellow fuses. If you are a Krell kind of a guy who likes modern solid-state gear, then maybe the QSA fuses would be more your cup of tea. That’s not my preference, so I will be sticking with the prototype fuses.

Either way, the SR Orange fuses that were in the system before all of this started, will be relegated to the spare fuse box. The prototype fuses walk all over the SR Orange fuses.

I have another friend coming up next Sunday, I believe. He’s using a QSA Yellow fuse in his system. He tells me that he is experiencing the same midrange anomaly that I am. I will be doing a/b/a/b/a experiments with him as I did with Mister Golden Ears this morning.

Also, as a side note, I received a PM from another A’gon member who is using the QSA Yellow fuse, and he is having the same midrange experience as the two of us.

Yer money, yer choice.

Frank