Fuse for MKII

Only read a two posts on internet about folks ruining power transformers stepping up fuse. One from member of this forum So it is not likely. A correctly functioning unit should not pull much more current than fuse rating slow blow will allow unit to exceed current limit for a bit. It takes heat for a fuse to blow or a breaker to set. I’d say for a transformer to go there we’re already more problems in those units for awhile. The risk to unit is possibly more damaged if early Life failure component goes and other components do not fail open. I have read of people losing SR fuses. Generally s bigger fuse or wire sounds betterup to a point unless lots of small diameter wire’s are allowing equivalent flow and have wire weaving or separating techniques that lower LRC like Iconoclast designs explore or some power cable companies.

The PS audio Regenerators have High Current circuit limits. So as long as that works it is redundant safety measure. A DAC I would not be to sporty with as something with other protections. Some of my LPS have current limit circuits too since the fuse allows more current for peaks yes bigger sounds more open as do bigger power transformers. Know your equipment before upsizing fuses. If there is redundancy your safer to upsize but I would not recommend to exceed it. There’s always a chance a redundancy circuit will fail too. Ted did some interesting power circuits in MK2 to make sure their is balanced power draw it probably is not as sensitive to a fuse size.

A company that charges $200 for a fuse must make it meet its rating! If it fails it should be their responsibility. You should not have to buy over rated fuses.


In a perfect world perhaps in the USA not so How do you prove the fuse you bought was correctly rated? Then hold them accountable. It is a non policed or regulated area unless the reseller required. Audiophile is small niche business.

Well non of these audiophile fuses send the fuses or power cords send products out to UL listed to get safety rated or you would read about in their literature or on the product. If it was something that had obvious health and safety repercussions yes just to protect themselves from a law suit. UL listing is voluntary. They rely on the UL isted circuit breaker upstream for redundant shut off if their product fails. The 200 fuse would likely cost 300.

Even the circuit breakers that are known to cause safety issues they still sell replacements though some municipalities will require you to rewire the home to eliminate them. But only if they are called into to inspect them because they are requiring permits to generate income. Most contractors skirt that process since municipalities cannot inforce money generating permits in their city codes for minor.

If fuse makers that sell glass fuses have to comply to UL safety charging 50 cents to a 100 for a fuse can comply so can the exotic fuse makers. a 1 amp fuse MUST be a 1 amp fuse!


… and here I was, thinking it would be the shortest thread ever. :roll_eyes:

1 Like

Sorry nice thought but not correct assumption.

I sent a message to Synergistic Research about the issue. I will report when I get their answer.


Iam sure their products are only designed and tested in house. Not to UL sample levels and stringent requirements in an outside lab. These audiophile fuses are drilled and soldered an caps ground flat. The wire filaments depending on where sourced and how processed and specified coatings are likely full of process variations.

I get stacks of supplier disclosures where we find out connectors used in aerospace products did not get tested to requirements and those are regulated by government specifications with required data submission. Guess what the agency required to monitor dies not hold them accountable. This is from big name manufacturers not even mom and pop shops like these small time audiophile companies.

I don’t care how they manufacture the fuses or if the bless them with holy water. If they mark the fuse as one amp it sure as hell should pass 1 amp without blowing. That is my point. I am anxious to hear their response to my inquiry!


Well maybe a Lot Acceptance Test (LAT) on one item assuming they are batch produced and continuity confirmation on the others. One likely would not test to maximum current on a sacrificial product. If it worked to spec and failed open it will not work again.

The cable company says they are built individually to order on many of the audiophile fuses. That would rule out LAT.

The beeswax fuses are built to order the Synergistic Research are mass produced. They need to gaurantee their performance.


Then perhaps they are better tested. I am interested how they spin how they guarantee values. I am not giving you a hard time, I just have read about failures with blowing SRs and damaging beeswax with handling.

A niche products both have improved my sound and not ready to go to UL listed auto fuses.

I am bit blunt and realistic in supply chain problems with decades of having to get manufacturers to fix problems with product and processes. That makes me more skeptical and know where to look for the skeletons hidden in the closet and where companies typically cut corners. Testing and Quality control is like the wild west frontier. They tend to run open loop especially when not monitored. I found never assume even when you think they have learned a lesson. Those rarely stick.


I promised to post the Reply from Synergistic Research regarding the accuracy of their fuse values. Here it is!
Good question! Our fuses are very tight tolerances and as such are very accurate to the rating. Most fuses are up to 20% +/- rated value, which some manufacturers take into account when they spec a fuse. When inrush current at startup exceeds the value of a fuse and it has latitude above the rate stated they will take the abuse for quite a while. Our fuses are designed for best audio not for exceeding spec or for ultra high impact installations (I would suggest using it in an off-road race truck or speed boats). if you buy a fuse and upon initial installation it pops we would make it right for you. As always check with manufacturer.

David Weintraub

Director of Marketing & Sales

Synergistic Research

M) +1-847-912-0555


The guarantee is for early life failure initial installation only which is expected . At least they are touting manufacturing to tight tolerances. Still not stepping out saying much about testing either Lot Acceptance or during manufacture or they promise durability.

Thanks for sharing!

1 Like

Has anyone determined the proper direction for an SR fuse in the DS MK2?

Yah, I know I can flip and listen A/B, and probably should, but I thought I’d ask.


Most say the R in SR should go into the fuse holder end. Worth trying both ways…

Same fuse rating as for MKI?

“… R should go in the fuse holder end.”

Just to be clear, what is the fuse holder end? Is it the cap that comes out, or the inside of the MK2?

Earlier, I flipped the fuse so that the R was stuck in the cap, with the S leading the way into the MK2. I think it sounds better that way, but haven’t had a chance to really listen.

At least we no longer have to pop the top on the DAC to get at the fuse.

Hi RobH, The Fuse holder is always hot at the opposite end of the cap for safety reasons, so when you pull the fuse out from the holder and power is connected, you will not get shocked when the back end of the fuse should touch the front end of the fuse holder. I have tested the fuse holder with an electrical tester and found this to be true. I also tried putting the SR Master fuse in both ways and the R facing the cap does indeed has more clarity to the sound.