The Steel Guitar Forum

Yes look what you started! Up to page 5.

Micky - its the speaker voice coil that is wound and gives the impedance. The magnet doesn't alter the speaker impedance in the least.

The fact that Roland don't give a recommended minimum speaker impedance would suggest that your 4 ohm BW should be OK. I would email Roland to see if connecting a 4 ohm speaker extension is safe.

Ken

One thing you have to look out for is don`t use a guitar lead to connect it, as I understand it has to be speaker wire not signal lead.....

Cheers Ken...glad you chimed in here ... I remember now you did tell me that when I bought the Neo Mag.

Hmmmm I see a guy with similar hairstyle to mine is on page 5 too on another thread ... don't worry I won't compete



L to R

Ken Byng and me meeting up again after 30 years

www.micky-byrne.co.uk

I contacted Roland and the cube 80 has an 8ohm speaker made by Roland, the external speaker out is wired in series so you can run a 4ohm speaker in which the amp sees 12 ohms, at least thats what they said, I would assume you would get a little volume from a 4 ohm but I'm no expert

Posted 2 Jul 2012 3:43 pm

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I contacted Roland and the cube 80 has an 8ohm speaker made by Roland, the external speaker out is wired in series so you can run a 4ohm speaker in which the amp sees 12 ohms, at least thats what they said, I would assume you would get a little volume from a 4 ohm but I'm no expert<<

That is correct, if an 8 ohm speaker were connected in parallel the total resistance would be reduced to four ohms because the amp also has an 8 ohm speaker. I would think that you would have to go up a little on the volume control to get the same loudness when you increase the resistance of the speaker circuit because the electronics is pushing through a great resistance. I would be nice if Roland made a custom external speaker for the 80XL..nothing like having things custom engineered for the product...takes the guesswork out of the equation.

Thanks Brad and Roger....Brad, I too thought that if Roland made an identical cabinet with the same speaker, it would be ideal. Whatever that speaker is in there, it's damn good. You saw Ken B's report of the Cube at an out door gig and also running his Webb. He said the Cube held it's own with the Webb. I best not connect the Cube to a 4 ohm....sooner be safe than sorry. I'll look out for a 8 ohm should I need it


Micky Byrne U.K.

If you want the external speaker to take most of the load then you *do* want a 4ohm (or lower!) speaker... as wired the impedance will never go below 8ohms, so there's no possible danger to the amp, even if the external speaker shorts to zero ohms.

One disadvantage is that the amp puts out the most power *without* an external speaker connected... any additional series load will cause the (solid-state) amp to put out less power due to the simple P=EI and E=IR equations. Tube amps behave exactly opposite since the output voltage can climb with reduced load; OTL SS amps are constant-voltage output (mostly).

So, if the XL80 amp is 4ohm-capable, then you could *double* the watts out by subbing a 4ohm speaker for the internal 8ohm. This is a cute trick for those carrying say a 4x10 8ohm bass cabinet... get a 2-ohm capable head and convert the cab from series-parallel to all parallel for *4x* power boost.

You really need to think twice about using a lower than specified impedance on a solid state amp.
Not a good idea.
The XL80 has an 8 ohm MINIMUM load.

Grab your external speaker, plug it in, if you like it, great, if not, be VERY careful on your next step.
Warranty repairs usually do not cover misuse.

Jay

Thanks guys....will stay as I am for the mean time. I see Ken B did an out door gig using the Cube and his Webb. He said the Cube performed faultlessly and stood up to the Webb, besides the line out on the Cube is great. Straight into a big P.A. system. The idea of getting the Cube apart from it's great tone and "extras" is how light it is. I'm done with heavy equiptment.


Micky Byrne U.K.

I wouldn't use an extension speaker cab. The amps are so cheap I would just buy a second 80XL to give the spread.

wouldn't use an extension speaker cab. The amps are so cheap I would just buy a second 80XL to give the spread<<

Ken Byng, Good advice, most external speakers and cabinets cost as much as the amp...and by buying another amp you get the best of both worlds..bigger sound and a backup amp

I think there is some merit in what Ken is saying as if they are wired in series and one speaker goes down... then they both go down... right?
But my thoughts on it are, whatever power loss you suffer through loading it down is more than made up by useing a more efficient speaker as I certainly did not notice any loss just more good vibes coming out of the JBL, in fact I am toying with the idea of taking out the speaker thats in the amp and replacing it with one of my E120`s It may not function quite as well as its tuned for the cab that its in... but I still think it may be worth trying........

As I'm an Essex lad as well, I've taken Micky's advice to heart and ordered a Cube for myself. If this works out, the Nashville 400 will be able to stay behind on future gigs.

Cheers,

Jay Fagerlie wrote: The XL80 has an 8 ohm MINIMUM load.
Jay

From the User's Manual:
EXT SPEAKER Jack
This is for connecting an external speaker.
When an external speaker is connected, sound is played both from the
external speaker and from the unit’s built-in speaker.
* When connecting to an external speaker, make sure the speaker
conforms to the following specifications.
Impedance: 8 ohms or less
Allowable power input: 80 watts or greater
* Only use speaker cable to connect the speaker. Do not use any
shielded cable designed for use with guitars.

When I called Roland about this they confirmed that it's ok to use a 4 ohm speaker, I'm taking my 1203-4 with me this sat and see if the pair can keep up in a loud band, I'm taking my Nash 112 too just in case

Hi everyone,
Just for clarification, let me add a few more things so we are all on the same page.

First, some easy theory:
As a rule of thumb, you can usually add a speaker of the same or HIGHER impedance to a TUBE amp, and here is why:
Tube amps use a transformer to transfer energy to the speaker, the impedance of the speaker is very important because the more difference there is between the actual impedance and the impedance of the circuit design, the mismatch is discarded as heat- either in the transformer or in the tubes. While not a hard and fast rule, Fender type amps have the ability to operate at up to a 50% mismatch....meaning you can run an amp designed to be connected to an 8 ohm load into a speaker load that is 4 ohms and not cause any real damage. (8 ohm internal speaker + 8 ohm extension speaker)
The typical way extension jacks on tube amps are wired are as a 'parallel' tap on the transformer. The energy is dissipated across both speakers equally, because each is the same impedance and each is fed from it's own tap from the transformer. Sometimes a company will just wire a jack in parallel with the speaker jack and allow you to load down the only tap from the transformer. With a properly designed output tube section, this will not usually cause problems.

OK

NOW- let's talk about solid state amps and the Roland 80XL specifically:

Solid state amps do not need output transformers because the output transistors are perfect for driving speakers- they produce low voltage and high current (compared to a tube circuit)which can be directly connected to a speaker/speakers.....
Here's the caveat: If you load down a solid state circuit with too low of an impedance, the output circuit will do what it was designed to do- drive it with current, to it's own self-destruction. Modern amps have designs that take this into consideration and should not ever let the amp try to deliver so much current it ends it's own life- (that's the delay that is present in current SS amps when you power them on-it's a current sensor-if the transistor are trying to provide too much current at start-up, it opens the circuit and doesn't power up)
So here's the deal with the Roland XL80- It is designed to drive a 8 ohm load -MINIMUM-....that means NO LESS than 8 ohms. So then how do we connect our external speakers? Roland did something I have never seen in a guitar amp, they made the jack connect the external speaker in 'series' with the load, NOT in 'parallel' like on a tube amp.
So plugging in that 8 ohm speaker causes the output section to 'see' 16 ohms, NOT 4 ohms like in a tube amp. Pretty slick, eh?
Now, when you add speakers, keep these things in mind:
1. Adding impedance 'lowers' the output power of the amp- If you plug in an 8 ohm speaker, the output section now 'sees' 16 ohms....using ohms law, the maximum output power is now half....what does that mean on the stage? Not much- your volume knob will definitely need to be turned up more, but in reality it should still be more than enough power. If you are really worried about maximum loudness, use a 4 ohm speaker or get another amp.

Perceived loudness and power are a logarithmic function- An increase/decrease of 3 dB corresponds to a doubling/halving of power...that's 3 db folks, not much at all.

OK, that's all of Jay's amp talk for today....

BTW, I plugged my ShoBud into this thing and turned it up just to see how loud it would go before it started distorting enough to make it audible- I never made it- it was WAY too loud! If anybody here is having that problem you really need to make sure you are wearing earplugs- that volume will do SERIOUS damage to your ears!

Jay

Jay, that's great info. Thank you for posting that. I've been using the 80XL for almost two years now and I am finding better ways to utilize it nearly every time I go out now. My latest phase has been the Brit Combo phase. Great for chunking a rock/blues line.

Great post Jay - really informative. What I found immediately when I got my 80XL last year was that it had headroom galore, and has a very efficient speaker that stays clean even when the amp is delivering a lot of volume. One doesn't get ear fatigue from the speaker when it is pushed.

I forgot to add in my previous posts that one surprising bonus after buying my amp was to receive a letter from Roland UK informing me that the amp was covered by their 3 year warranty. How cool is that!

John Davis states>>The speaker in the cube is very very good but IMHO. nothing beats an E120 but they seem to work very well together.<<

John D. Remember, every speaker needs some breakin time..so if the Cube 80XL speaker is as you say, very, very good..it will get better when it has more playing or breakin time.
Brad

on the Blackface it was clean and true way past anything I would need to use..... <<

Hey John D. I'm really liking the black panel setting..it reminds me of the Fender Twin Amp..a real good setting for the steel..plus you have the volume and gain controls on this setting.
This is a great amp..glad Micky and Ken told me about it.

I bought this footswitch for my amp. Good value from Behringer. It can be set as latching or non latching.

http://www.behringer.com/assets/AB200_P0344_M_EN.pdf

Hey Ken,
You do realize that switch is for multiple guitar>amp or multiple amp> guitar, right?
It does not function as a channel/FX switcher.... unless you plug in shorting plugs and 'switch' them into the FS jacks on the Cube 80.

Jay

Edited to add:
If you plan to use this to switch between your steel and a guitar into the Cube 80- it's perfect.
I may need to get one of these for that.
I picked up a pair of FS-6 from Amazon for channel /FX switching...

Jay
I play Telecaster and steel, so it will be ideal for switching between both.

The switch will work on the 80XL to switch channels. I have an acquaintance who has one of these switches and he has made it work OK on his 60XL.

Sure it will work-
You'll just need some dummy plugs

J

Well Micky you sure have created a monster thread here-re the cube 80!
Sooo it's about time I chipped in from Devon Uk.

As Micky knows I have been playing dual Cube 60's for the last 7/8yrs and I believe he saw me play them at our good friend Roger Deans tribute gig a couple of years back. Roger was a truly brilliant guitarist and a very funny man-sadly taken by the big C.

These little cubes are just bloody amazing, the sound is as close as I've ever got
to a good old Vibrosonic with a JBL! They will cope easily with most 'normal' gigs and when you play large theatres etc, when they are DI'd into the desk- PA wise,well the sound is as near as dammit to recorded stuff!

The Vibrosonic was the only amp up to getting the Cubes that would also handle a Telecaster or an El/Acoustic WITHOUT having to alter anything!! Bloody superb.

The big thing as with most of us that dictated the purchase of a smaller/lighter
amp was -yes you guessed it-The BACK-thanks to amps like the Vibrosonic
the Roland JC 120- and yes in the earlier rock days a Marshall stack-not
forgetting the D10 itself, my back is non existant!! Sooo the two Cube 60's
were just the ticket. I know I'm not achieving a true stereo sound with the amps
but strategically placed they give me what I want on stage AND in the studio,
unless I go direct.

Finally I was going to go for a pair of the 80's but but, then why, when the
60's do such a great job- like someone else mentioned there will be a plethora
of great sounding leviathans on the market now, including my FET 500 !!

Anyone interested ?- Oh and an MCI D10 RangExpander as well ?

GUS YORK DEVON UK.