The M700 AC-power fuse is a 5X20-size...

…‘LF T6.3AH250VP’ ceramic-bodied fuse, mounted on the output-stage board and not accessible at the amp’s rear. I presume ‘LF’ means ‘Littlefuse’.

I looked because I might have installed an aftermarket ‘audiophile’ fuse, but find one to buy I did not. (I didn’t shop extensively; mostly at Parts Connexion’s discounted* HiFi Tuning sections. I did find some larger ones for the BHK300.

  • Even after buying $7500-times-2 poweramps, $7500-RR preamps, $20,000-RR speaker systems, $2000 ICs, etc., I still can’t pay $50 - $100 for AC-power fuses. 114_gif


Look at the AMR’s at Tweek Geek. $15 plus shipping. That’s what is in all of my BHK gear. OBTW did you get the isolation devices from Chris and if so what do you think?

Thx dawk; I just ordered a couple.

Yes I received the spring-based isolation devices but decided not to use them–they left my amps less physically stable than I felt comfortable with. I decided to use Herbies Tenderfoot isolation feet with Hi-End Booster Bases, 6 pairs per amp (BHK 300s, which should be here next week).

dawkinsj said Look at the AMR's at Tweek Geek.
How do you like them?

I like the Tweek Geek’s description of their product, the rational price, and their honesty in acknowledging after market fuses may not handle in-rush current as well as standard fuses.

I like them well enough to buy them, and their explanations do indeed sound reasonable.


I have been using the AMR fuses for about 3 years now and have tried them in tube preamps, Class AB amps, DACs and two different Class D amps and they have all been trouble free. I found them to be a slight upgrade but nothing night and day in most gear especially the PSA gear as they are using a better grade fuse than most to start with. While I certainly believe in tweaks and have Rubbermaid containers of cables, tubes and different types of isolation devices to prove it I have found the fuse thing a little hard to grasp therefore the AMR is about as high up the food chain as I am willing to go.

I thought the M700 has no fuses, as stated in the user manual “There are no user serviceable fuses inside this product.”

Yeah that’s what I thought…

I’m not worried though cause I got better speakers and the stock fuse is way better in the SGCD.

You may not always get a benefit. It may change the Voicing.