Jolida blowing fuses

Schwingding

Any ideas why? My SJ302A is suddenly blowing fuses after being connected to a pair of 4 ohm speakers. It was happy when driving 8 ohm speakers, but the Onix Ref 1s are 4 ohms (easier to drive, right?) and it is blowing its internal fuse after about 20 minutes.

I do know one of the power tubes has gone bad - it crackles every few minutes and the bias voltage goes crazy until it settles back down. I do have new EL34s on the way, but wonder why it would be blowing fuses with a 4 ohm load.

Any ideas?

RuSsMaN

Wait for the new tubes.

madmax

A bad tube will cause that. Plus, far as I can tell Jolida fuses their amplifiers to the absolute minimum tolerances. My guess is they would rather deal with the hassle of a lot of calls rather than repair even one amp at their cost. I've had 3 of them and periodically all would blow a fuse. None of my other tube amps have ever blown a fuse.
madmax

Schwingding

Thanks guys. The fuse is a 5a/125v - I was surprised at how lightly it was fused. It also reminded me of how futile it is for people to upgrade things like power cords, etc.. as when you see that tiny little wire all of that amp's juice runs through, you realize that power cord improvements are futile.

I'll wait for the new tubes and see/hope that fixes the problem.

F1nut

Have you actually tried any power cord/interconnect upgrades? The Jolida cdp, for example, responds quite well to both.

reeltrouble1

No, 4 ohm speakers are not easier to drive than 8 ohm, they allow more current to flow so they actually cause the amp to work harder, do you have two fuses blowing at the same time? Are the new speakers less sensitive/effecient than the prior pair?

The advice on the new tubes is good and is the first step to try, however, if the power line is not able to supply enough current when called for you can blow the fuses. This would occur as you increase the gain.

RT1

Schwingding

The unit has a single fuse. I'm going to assume it is the fault of the dying tube. It has crackled a little bit for some time, but never bothered me while driving the 8 ohm speakers. If reeltrouble's explanation is correct, and I have no reason to assume otherwise, then maybe this makes sense that its now more sensitive to load than before and the tube is causing the fuse to blow. We'll know in a few days.

reeltrouble1

Of course it is correct:D , yes, only having one fuse would certainly make the bad tube the number one suspect.

RT1

dylan

Bad tube was the problem on my 302a blowing fuses. I've had 10 backup fuses sitting next to it for about a year now. Ah well.

F1nut

RT1 is correct and you haven't answered my question.

Schwingding

Interconnects, sure. They can make a difference. Power cords? Gimme a break. Ever dig into household wiring? The crap behind the power outlet is tied together with nothing more than wire nuts. All of the noise behind that outlet, all that from the overhead transformers, all that from other sources that can interfere with those lines - they all make it right down to the outlet. How can improving a 6 foot section of power line, in light of all of those other miles and miles of power lines, possibly make a difference? There is no logic in it that I can see.

Early B.

I tried power cord and interconnect upgrades when I owned a 502, and it responded very favorably to them.

Early B.

Schwingding wrote: »

There is no logic in it that I can see.

Well, therein lies the problem. Your logic is faulty. Nothing beats personal experience.

Schwingding

I don't need to be convinced about this. It makes no sense to me, especially when you look at the tiny little fuse wire that all of the juice runs through anyway. Interconnects are a different matter as they deal with source signal, but to improve the power cord, which is simply an extension of the power lines, you can't convince me that 6' of a high quality 12 or 10 gauge wire makes up for the hundreds of miles behind it. REPEAT, I am not out to be convinced or to convince anyone else.

reeltrouble1

We have Dr. Spec, now Spock, it is totally illogical Captain.

I have had good results from power products. I would recommend giving it a try at some point.

RT1

F1nut

Thanks for your answer. There are many things about audio that defy logic, but without trying it yourself, you don't really know, you know?

By your logic, interconnects should not make a difference either as they too are hooked up to that same, "tiny little wire" inside of some gear. Yet, you obviously have found they can make a difference.

I'd be willing to let you try an aftermarket power cable for no cost other than return shipping. Not much to lose, but your logic.










Beam me up Scotty, I've had all I can take.

Ricardo

I agree it doesn't have any logic at all......but guess what....it does make a difference. Once I confirmed this, I stopped thinking on the "why" and started enjoying the benefits.
Not trying to convince you. Just posting my experience.

madmax

DANGER WILL ROBINSON, DANGER.
madmax

Schwingding

There's just no convincing some folks!

Early B.

Your Jolida isn't the only thing that has blown a fuse!:D



Just kidding...

madmax

Schwingding wrote: »

There's just no convincing some folks!

You got that right.

BTW, a ceramic fuse will make that thing sound better too.
madmax

Early B.

madmax wrote: »

BTW, a ceramic fuse will make that thing sound better too.

Yep. Tried that tweak, too, on the 502. It works, although the difference is VERY subtle.

madmax

I'm assuming the bad tube is a power tube and not a preamp tube?

Loud & Clear

Tried aftermarket power cables. Heard no difference. Not everyone has the ears for discovering the benefits of such an upgrade.

madmax

If ever I've had an amp where you can hear the differences in power cables, the jolida is it. I had 5 different kind of cables and all sounded different.
madmax