Fuses do affect sound, the question is how much

[Sal1950]

Is it suitable for anything other than Hendrix and Prince?

WHO ???

 

[mhardy6647]

WHO ???

Yes.

oh, wait a minute...

 

[jsrtheta]

I have an Acurus A250, a somewhat utilitarian stereo amp. Rating 250/350 8/4ohm.

My speakers (Martin Logan reQuest) are rated 4 Ohm and measure 4 Ohm (DC), with the usual electrostatic dip up top. 48x15 panel, 12" sealed woofer, 180Hz cross.

View attachment 11733

Big transformer, big caps, fused input (which remains) and 6A fast blow on each driver board, I assume near the input.

Since it had a fused input, at some point about 1999 I tried bypassing the board fuses, and the result 'sounded' good. The subjective impression was a little more forceful presentation. A little more stable. I liked it, so they stayed.

No measurements other than VOM volts and simple 'scope waveforms across the fuse holders were possible. I don't remember the numbers but they were substantial enough to encourage me to bypass them.

It was retired from front-line duty 4 years ago for a pair of Krell FPB 350mcx, which, subjectively, are much more better. My ear says the harmonics (which give tones texture) are much closer to where they should be. the Acurus is in a side room and plays Tibetan chants to my dead relatives from time to time.

The other mod I applied to it was to bypass the big caps with some small non-electrolytics liberated from Telecom Duty at work. And ferrite clamps, reducing RF hash on cable ends, whether actually beneficial or not. Lots of them, still have a big bag.

The Krells... Horribly complicated ( regulated power, stepped bias, sort of Class A) and not green at all (100W idle each) but real nice sounding. They have breakers as power switches and unknown protections beyond that. Power rating 350/700/1400 8/4/2 Ohms. No mods anticipated here.

What year are these amps?

 

[Sal1950]

What year are these amps?

1947

 

[jsrtheta]

1947

I ask because William Snyder, once the design manager for Krell, left to work for Mondial, who made Acurus (and Aragon). I was curious about the difference between the amps you showed.

 

[Sal1950]

I ask because William Snyder, once the design manager for Krell, left to work for Mondial, who made Acurus (and Aragon). I was curious about the difference between the amps you showed.

That's not me, it's @RayDunzl . I was just making a joke to tease him. Sorry for the confusion, I'm sure he'll answer you soon.

 

[jsrtheta]

That's not me, it's @RayDunzl . I was just making a joke to tease him. Sorry for the confusion, I'm sure he'll answer you soon.

Sorry!

 

[RayDunzl]

What year are these amps?

The Acurus - about 1995 (bought new)

The Krells - 2005 per serial number (bought used in 2011 or 2012)

 

[jsrtheta]

The Acurus - about 1995 (bought new)

The Krells - 2005 per serial number (bought used in 2011 or 2012)

Snyder was with Mondial by then, I believe. But he'd been with Krell into the early '90s. It just struck me that these amplifiers looked very different to me in design, which struck me as odd.

 

[RayDunzl]

Snyder was with Mondial by then, I believe. But he'd been with Krell into the early '90s. It just struck me that these amplifiers looked very different to me in design, which struck me as odd.

https://www.manualslib.com/manual/647029/Mondial-Designs-Limited-Acurus-A250.html

http://krellonline.com/assets/support/0162_020_MAN.pdf

 

[jsrtheta]

https://www.manualslib.com/manual/647029/Mondial-Designs-Limited-Acurus-A250.html

http://krellonline.com/assets/support/0162_020_MAN.pdf

Thanks, Ray!

 

[Sal1950]

https://www.manualslib.com/manual/647029/Mondial-Designs-Limited-Acurus-A250.html

I love the power spec, 250 wpc continuous, both channels driven, 20 to 20K, into 8 ohms, at no more than 0.06 THD !!!

 

[digicidal]

I love the power spec, 250 wpc continuous, both channels driven, 20 to 20K, into 8 ohms, at no more than 0.06 THD !!!

How nice and easy is that? I mean for the consumer... not necessarily for the engineer or manufacturer. I wish all specifications were that way... easier than needing a graph to see how far past the elbow they're looking.

 

[sejarzo]

I had an A150 and sold it years ago, before I knew better. Solid piece of gear. The only common issue I heard of was the LED in the power switch going bad.

 

[MRC01]

Reminds me of an example of how the comma can fundamentally change the meaning of a sentence:
Let's eat, Grandma.
Let's eat Grandma.

 

[tomelex]

bit of thread drift here

 

[solderdude]

don't blow your fuse over it ...

 

[Alice of Old Vincennes]

OUCH, that sucks Don.
I've never heard anything like the God Amighty noise made when my Phase Linear 700B blew up into my Klipsch La Scala taking out a woofer voice coil, the mid driver and tweeter all at once.

Maggie's don't need a fire to smoke. I gave up and am not a headbanger.

 

[Alice of Old Vincennes]

I have circuit breakers in the panel coming off the line from Duke Energy to my house. Really affects the sound. Maybe I should by-pass and burn the house down

 

[mhardy6647]

I have circuit breakers in the panel coming off the line from Duke Energy to my house. Really affects the sound. Maybe I should by-pass and burn the house down

Although, to the best of my knowledge, this was never covered by

Duke,

The Duke, (*)

or the Thin White Duke.

_________________
* Note the sly deployment of the Oxford comma, just to stay on topic.