RB 1080 Internal Fuse blowing

[Aussie Geoff]

Hi,

Given that the newer model came out in around November 2003 - If you have been sold the older one (unless it was at a big discount) I'd be asking for the newer one anyway...

That aside - I had the older model RB-1080 and the newer model RB-1080 and the newer model still had the fuses issue for me. I solved it by flicking the switch on the back of the RB-1080 so it wasn't activated by the trigger... No more issues - just great sound... And the RB-1080 mellows out beautifully being left on....

Geoff

[Azeke]

Preot,

I concur with Geoff, unless you received a discount for the older version. I would definitely get the newer version, it's your money afterall, so get what you paid for.

In reference to the 12V trigger issue and fuse blowing, I do not connect my RB-1080 to the 12V trigger any longer for fear of blowing a fuse. I have spoke with Rotel in reference to this issue and they stated they would investigate.

I would like to link my 12v trigger to my Monster HTS to see if the issue is related to my 1098, but I don't want to be without my 1080 for any length of time, since I don't have any fuses left for replacement.

I spoke with Rotel and asked them to send replacement fuses, the fuses were about a $1.00, but shipping was $50.00, go figure :E . It's not the money, it's just the principle to me.

Geoff, Andrew do you know of a place where I could purchase replacements, in the US, I would love to perform this experiment, but not without the fuses.

Regards,

Azeke

[Andrew Pratt]

I might be able to help get the parts...fire me and email with what you need and I'll see what I can do.

[Azeke]

Thanks Andrew, I have sent the e-mail.

Regards,

Azeke

[Andrew Pratt]

And I have replied

[Azeke]

Thank you sir :T .

Azeke

[steveB]

Guys

Its been 4 months now since I
blew a fuse and I have had my 1080
connected with the 12v trigger ever since and have not had
the fuse problem again...wierd isnt it.


cheers

steveB

ps Hope I dont jinx myself

[Azeke]

That's a good thing :T .

Did you hook up anything differently, i.e. different 12v trigger location on the pre-pro/receiver?

I think I will wait for the fuses before re-connecting.

Good Luck and keep up posted,

Azeke

[pbuxton]

Newer Model...

OK thanks for the suggestions.
I do have the newer model, I thought it was the older.
It has four clear capped binding posts on the back (right?)

I am not using the 12V trigger.
I haven't blown the fusses on the inside on the right and left side of the 1080 again but I have blown the 12 amp fuse on the outside and back of the 1080. Which has been a pain to replace. I had to order it form a place I discovered online called powerfuse. Their phone number is 1 800 739 9145. They are very helpful and have both the 12 amp 125 volt fast blow fuses and the 6.3 amp 250 volt slow blow fuses. You have to buy them in packs of 5 and 10 (if they have a box already open they'll sell you less.) They are kind of expensive, twice what I paid at radioshack, but radioshack is out of the 6.3 amp ones and doesn't carry the 12 amp ones).

I think my problem is that I had the 1080 plugged into a powerstrip otherwise full of my computer stuff. I know now that that's a no no.
This is my first amp drawing 550 watts. So I am waiting for the replacement fuses and will plug the 1080 into an otherwise empty powerstrip and see what happens.
Cheers,
Preot

[Stevebez]

Had my second hand "old" model 1080 for cple months now and using the 12v trigger from my 1066. The 1080 triggers the 1075 as well.

A few days back my wife tells me casually as I get home ... "the hifi is dead ... dunno what happened(!!!) :E :E

1080 was indeed dead ... PANIC!!! :E ... Immediately whipped open the chassis only to find all fuses fine and then had the horrible thought something more dire was amiss.

Anyhow slapped it all back together, checked power cord fuse and voila ... 5amp on 220/240 volts had lost its cool. Wierd blow though as some current was still flowing but at about 30-50 volts only.

Replaced with 10amp and SupraLoRad cable and Wattgate plugs and no probs since ... touch wood. So guess this problem continues to confound ....

Rgds Steve

[ROb Aspeling]

Well guys, the saga continues. After not having any problems for about 3 months (not using triggers, leaving the amp on permanently) the left channel kept blowing every time I used the 1080. I went back to the agents and they suggested I change my speakers (if you remember Jamo replaced all the drivers and crossovers on my 707's eventhough they found nothing wrong with them). I bit the bullet and was able to get a pair of Boston VR35's at a very good price.(The Rotel guys are also the importers of Boston so they helped me out - fantastic deal) Since replacing the speakers - no problems. ( I still don't use the trigger and keep the amp on permanently) My conclusion - the 1080 is sensitive to certain speakers and this might be where the problem is.

[Azeke]

Okay, I have the new fuses and I have connected my RB-1080 to the 1098 via the 12v trigger (keeping my fingers and toes crossed), so far so good.

Here are my theories:

1) The RB-1080 is very sensitive any changes (i.e. moving speaker wire, speakers, the rack). I will now power down and unplug my equipment before any changes to eliminate this issue.

2) The 12V trigger assignments, once I upgraded to the new firmware is when I experienced this issue, but of course it could all be related to theory number one.

Just my thoughts, I will keep you all posted.

Regards,

Azeke

[pbuxton]

So....

My 1080 blew its fuses even after I gave it and the 1090 their own surge supressor powerstrips plugged into grounded 3 pin outlets. This brings the total fuse blowing up to 5 times in three weeks. The cost of replacing the fusses is around 50$.

I think it is really wrong to change your speakers to get your amp working. That's facilitating bad irresponsible design. If Rotel can't build amps that work with any speakers then they need to list the ones that are qualified to work with it on the box! It is absurd to think that you could buy an amp that may not work with some speakers. I am not talking about sound quality obviously. I am speaking now to Rob Aspeling. It sounds like you got taken by your dealer. Anyways, I have a normal electrical situation in my apartment and if the amp can't handle neither my apartment nor my speakers then it has a problem. Not turning your amp off for fear that it will blow its fusses, that's a broken amp people.

I am talking to my dealer today about this problem.
I think acceptable solutions are: fixing the amp, (if it is not fixable then some kind of low cost solution to it's sensitivity like a special chord or something I don't know), or replacing the amp, (if it is a problem with the line then a refund, I don't want it.)
Anyways, I'll let you know how it goes.
Preot

[ROb Aspeling]

Hi Preot,

Yes, I agree with you that it is wrong to have to change my speakers - but it didn't end there!!!!!!!!!

Last week, the same evening that I posted, my amp had a blown left channel again - changing the speakers did not help. I got hold of the dealer the next morning and by 17h00 on the same day he had replaced my 1080, my RSP 1066, my interconnects and my speaker cables (at no cost to myself). They are just as keen to resolve this problem as I am. I now have a totally new system i.t.o. processor, amp, speakers and all connections to them. So far so good, the system is working as it was designed to. For how long - that remains to be seen. I don't know of anything else that can be done. I have a dedicated electrical circuit, surge suppression devices and I would think that I have an ideal environment for this setup. If it blows again, I will definitely insist on a different amp because that would prove once and for all that there is something wrong with the design/production of the 1080.

I'll keep you posted.

[pbuxton]

Hi Rob,

I hope replacing the entire system helps, (at no cost to you-good job!)
I do love the amps.
My dealer is talking with Rotel...So I wait.
I told him that if they wanted to try and fix the 1080 that that would be acceptable. So lets see.
I wonder how many other people are having
similiar problems.
Rob, please do keep me posted. I'll do the same.
Preot
:wink:

[Adz]

Here's my story retold in short form (for what its worth) -
Kept blowing fuses on my 1080 and 1095. Multiple channels, multiple times.
Thought it was the speakers so I had the crossovers changed
Result - fuses continued to blow.
Took one of the amps in to a local stereo doctor
He asked that I bring my speaker cables as well.
Guess what - he ran some test which I forgot what its called and he told me the speaker cable was with almost certainty the problem
I swapped out all my monster speaker cable for another very good company
Since then, and its been several months, I have never blown another fuse. Knock wood.

[Bing Fung]

OK, you guys are really starting to scare me off of that 12V trigger switch.

I don't even want to look at it much less touch it now.... :roll:

[Aussie Geoff]

Adz,

There could be something in the cable issue - especially with the high damping factor of the amp etc. Certainly I had a very thick low impedance copper cable which I changed for IXOS Gamma (6006 I think?) much thinner and interwoven against interference etc. Not only did the speaker sound clean up quite a bit but the fuses haven't blown (whether powered on and off, triggered or left on) since January.

As I've said earlier in this thread - my dealer guessed some combination of very direct amplifier link to the speaker (the crossover consists of 1 capacitor on the tweeter) and very low impedance cable and suggested the new cable as a experimental "well it might work" cure. So far they were right Also as of a couple of weeks ago the I was the still only Western Australian customer that the dealer (one of two Rotel dealers in the state) knew had the fuse problem. None of their other 1080 customers had had the issue.... Through the distributor there were 2 or 3 others in Australia - hence the 1% sense of the problem...

All that aside – once I found the RB-1080 drew so little current being on – I’ve tended to run with the trigger disabled on it “just to be sure”…

Geoff

[jstaylor]

Josh

I also had a fuse blow in my 1080 and have been corresponding with Shane about the problem. I received this from him today that may also be helpful to those of you with the same problem.

From Shane: " I have just heard back from Rotel factory and they have an update on the1080 fuse issue. It seems as though they have been using 8 amp fuses in the 1080's that they have made for Europe and they recommend using them in ours as well. They feel that this will not harm the unit in any way and will solve the issue of the fuses opening up every now and then."

[GosonFletchy]

Yep, I talked with Rotel tech support today and they told me the same thing. The Rotel factory is saying that the use of 8a fuses, instead of 6.3a, will solve the problem without any chance of harming the unit. Great news.

G.

[pbuxton]

Wait a second, is Rotel admitting that there is a fuse issue with the 1080?
Who is Shane?

Preot

[Azeke]

Andrew, Geoff, can this rumor be substantiated 8) :T ?

Regards,

Azeke

[will1066]

I'm just guessing here in that it's not so much an issue as they are saying the 8A fuses will provide some cushion over the current 6.3A ones.

[Aussie Geoff]

Yes - the rumour is true...

Hi,

Bottom line is this does come from Rotel Tech Support. It is true... A manufacturing change has been introduced to change the fuses to 8 amp flow blow (or time release). If you have the problem these are 50 cents each and you need 4... Your Rotel dealer can provide and fit it you are one of the few people that need them (i.e are having blown fuses for your combination of amp, speakers and cables)

It isn't an issue with the amp - indeed in a strange way it is good news. Like all (most?) Rotel amps the RB-1080 is rated lower than it's actual power, especially into impedences lower than 8 ohm. The 6.3 amp fuse just doesn't give the amp enough headroom for its full current draw cabablities (more than enough for its rated 200w but not enough for the amps real power level). The new fuses do...

The turn on issue was (as we suspected) related to the amps very high damping factor, keeping the speakers voice coil in circuit and trying to bring in under control at turn on... Affected very few people but annoing. You could (apparently) also blow the fuse playing very loud, especially with speakers whos impdences dropped low in the bass region causing high current draws...

Geoff

[Azeke]

Sounds good Geoff, I guess we now need to test the theory 8O .

Would this fuse replacement also applicable to the RMB-1095/RB-1090 :roll: ?

Secondly, are there any fuse purchase locations?

Thanks for the update, this is indeed promising news.

Regards,

Azeke

[Aussie Geoff]

Azeke,

The new internal fuse specs for the RB-1080 are 20mm x 5mm 8 amp slow blow (or time release) fuses (up from the 6.3 amp ones used before). They are small glass cylinders with metal ends. They will usually be marked with part numbers on one end beginging with 8.0T or 8T indicating the 8 amps and time release...

Most specialist electical stores sell them - A web search for "2 x 5mm Fuse 8 amp" showed dozens of suppliers. 8 amp is one of the standard sizes. For example http://www.action-electronics.com/fus5x20.htm

Re other amps - You'ld need to ask Rotel Tech support (e.g. Shane in USA) about:
1) Whether any of them have the same issue
2) What would be the correct fuse value for that amps power rating

Geoff

[pbuxton]

Hey everyone,

So I took my 1080 to the dealer so they can try and get it to blow its fuses. They have said that there could be a problem with the power in my building, not with the amp.
Is this so?

If it is what can I do about it?

Preot

[Azeke]

Thanks Geoff for the update.

I actually have a second set of 6.3A fuses, and I am currently testing the 12V trigger once again, but the higher amperage fuse theory seems plausible. (Perhaps the 12v trigger was intially sending to much amperage to the RB-1080). I will order the 8.3A fuses, just in case. I will keep the forum posted.

Regards,

Azeke

[Aussie Geoff]

Sigh... Even the 8 Amps are not enough...

Hi,

Just an update - after operating perfectly with the new 8 amp fuses and the RSP1098 triggers for 2 weeks (with entirely new speaker cable) the Left Channel of my RB-1080 blew - first time in 5 months - I am sure it is linked to the triggers.

Back to no triggers for me.... :uhoh:

Geoff

[Bing Fung]

Bummer Geoff :nonod:

I'm still hesitant to try mine, but I will once I rebuild the Rac

[Azeke]

Sorry to hear that Geoff, I was certainly hoping that would rectify the blown fuse issue. I guess I will stick to the original theory of the 12V trigger issue, being the primary culprit.

I am trying a different experiment, I am leaving the 12V assignments for each source set to all, if it blows this time, I will just turn on the 1080 manually.

I did talk to Rotel tech support and while back and they stated they would investigate the 12V trigger assignment issue, as a possible problem. (My reasoning, before upgrading to version 2.12, I experienced no issues with the RB-1080, 12V trigger and the 1098 ).

Andrew, anyway to follow-up with the tech guys on this theory?

Any thoughts or comments on this theory are welcome.

I will keep you all posted on my current experiment.

Regards,

Azeke

[Aussie Geoff]

Azeke,

With 2.1.2 I changed my trigger assignments to ALL on the RSP-1098 so that doesn't seem to be the issue. I can even leave the trigger in the RB-1080 - just not use it to turn on. Sigh!

I just leave it on now - no problems - great sound...

Geoff

[Azeke]

Geoff,

I am certainly understand your feelings, thusfar everything seems in working order, with the 12V trigger on the RB-1080 (and I have extra fuses). Whenever, I move any of my equipment, I completely turn off the RB-1080, manually (to eliminate any sensitivity issues).

I know Rotel still needs to address this issue, and I still believe it is related to the 12V trigger, but as the blind man said, we shall see.

Stay tuned,

Azeke

[Stevebez]

Have only found ceramic 8amp slow blow fuses here - does it have to be of the glass type??

Rgds Steve.

[Stevebez]

I have a theory on this - quite different to others I think and that is that the capacitors are not able to discharge properly on shut down ... when it trigger starts the current rush into the system causes an "overload" with the charge held by the capacitors and we get a pop of a fuse. What is very curious about this is that it is not a consistent fault but happens occasionally over time.

This is purely speculation and not based on anything other than a hunch.

How does one discharge the capacitors when replacing fuses etc anyway?

I am replacing with 8amps tonight .... interstingly it was also my left channel that went... the one closest to the mains cord input ...???!!?!??

Older coloured binding post version.

Rgds Steve.

[aarsoe]

Stevebez


Discharging is easy.
The professional way is to take a screwdriver and short the connectors on the cap's. Will create a spark - but pretty harmless.
I prefer a gentler way (hate big sparks) take a lightbulb, makes no difference if it is 110V or 230V, and solder some wires to it and then use that. A lightbulb is a perfect resistor that will handle a lot of power (ie. amps) without any problems - oh and the higher the watts on the lightbulb - the faster the discharge..

Which way you choose is up to you..

PS. If you dont know what you are doing, then DONT try this! Will assume no responsibility..

[Andrew Pratt]

Interesting enlightening idea on the bulb :W

[Bing Fung]

I have been running my system triggered now and all seems well so far. I hope I have not jinxed my self. :roll:

Because of this threads caution, I have run the trigger to the 1095 and then from the 1095 to the 1080. All Triggers selected on the 1098.

Here's hoping.

Bizzare how all Rotel's Power LED's all stay on, even when the power is off. :scratchhead:

Kinda negates the idea of a power LED, no?

[GosonFletchy]

HEHE, I don't think it is a power LED in that sense. I always thought it was there just to let you know that there was power to the unit, not that the unit was on. Maybe I am wrong though, lol.

G.

[DelRay]

One more way to get around the 12 volt trigger. I use my 12 volt trigger to turn on my monster 3500 surge protectors amp outlets. I can also have a delay for the amps, incase of any popping. Anyone else using this method?

[Elmac]

I do and it works Perfect with my signiture HTS 5100 and I do use delay for an RMB 1075

[Leef DaLucky]

Hmm.

I'm leaning more and more to A.G.'s mildly incompatible speaker cable theory.
How many people are bi-wiring?
Has anyone blown a fuse that ISN'T bi-wiring?
Would that (in combination with the 12v trigger) make a difference?
I know that a couple of you are.
GenesisFreak bi-wired. I know that much. (before he u\g'd to the 1090).
just a thought.

L.

[Aussie Geoff]

Leef,

I blew my first fuses on mono-wire very thick cable (10 Gauge copper). Blew several times and changed to no tricgger and different Cable (IXOX 606). No fuse problems for months

Went to bi-wire IXOS 808 , 8 amp fuses and trigger - blew fuses again.

Back to no trigger and still bi-wired - fuses (touch wood) are fine again!

Who knows.....

Geoff

[RisingPhoenix]

I have maintained my 1080 and 1095 as Always on, i guess i may be keeping our electricity provider happy.. But until noone else has fuse problems, im afraid to trigger my amps on (and my 1068 hasnt even arrived yet).

Steve