NAD: IIB "300 Series" Coliseum... As a bass amp?

[s-fresh]

Hey All!

I just ordered a IIB Coliseum and am looking for some feedback. I remember reading on the Boogie Files that these could be used as guitar OR bass amps? Was this an officially supported use from Boogie or just someone's idea of fun? I also have a 15" combo cab and was thinking about combining the two into a Coliseum/15" bass amp. One challenge there is it would be a single 15" EVM-15L taking the full power of the Coliseum. I'm pretty sure the one I have coming is a half/full power option, although it is a very late model. No Simul-class sticker. Either way it's going to be run with 6x 6L6s. Is this going to melt a 200 watt speaker? I don't understand the power rating VS peak output. I see huge numbers referenced for the Coliseum amps but the factory rating is 180 watts tops, right?

Also, is there any obvious way to tell if the 15L I have is the 200 or 400 watt version?
Here's a photo of the back: http://i.imgur.com/021WzMa.jpg

Boogie Files link here: https://web.archive.org/web/20120519071709/http://homepage.mac.com:80/mesaboogie/IIBHead.html

Thanks for any feedback!

 

[MK IIB]

I couldn't tell you MESA's take on it but if the speaker can handle it I can't see it doing any harm to the amp.Especially the colliseum.
A guy in a band I knew used a 60 watt mark II with only the original 12" speaker with a really powerfull early Schecter bass and blew the speaker but the amp was fine.
That EV speaker just looks like the regular 200 watt version.

 

[Wyzard]

I don't understand the power rating VS peak output. I see huge numbers referenced for the Coliseum amps but the factory rating is 180 watts tops, right?

Thanks for any feedback!

The power section in mine shows just a hair over 190W at 5% distortion on the scope. I reckon I can drive that a bit higher too....

 

[morgan138]

One challenge there is it would be a single 15" EVM-15L taking the full power of the Coliseum.

I doubt it, even if it's the higher-wattage version. I had a D-180 (also 180 watts with 6x 6L6 power tubes) and when I ran that through a 1x15 I could see the speaker working pretty hard even before I got it super loud. This was with an EVM-15L, and then later an Eminence Kappalite 3015 in the same box.

I bet a Coliseum will sound great on bass though! For awhile I was hoping to get one for exactly that reason, but I eventually realized that it'd be easier and cheaper to just combine a Studio Pre with a 2:90 power amp. Great bass rig right there, probably the same ballpark as a Coli...

 

[s-fresh]

One challenge there is it would be a single 15" EVM-15L taking the full power of the Coliseum.

I doubt it, even if it's the higher-wattage version. I had a D-180 (also 180 watts with 6x 6L6 power tubes) and when I ran that through a 1x15 I could see the speaker working pretty hard even before I got it super loud. This was with an EVM-15L, and then later an Eminence Kappalite 3015 in the same box.

So I am reading this as "I doubt the EVM-15L would last", or "I doubt it would be a problem" ???

The power section in mine shows just a hair over 190W at 5% distortion on the scope. I reckon I can drive that a bit higher too....

So does that mean it is safe for a 200W speaker or is that 'bit more' going to be a problem?


Thanks for all the feedback so far!

 

[gratefuljed]

I think Mesa put the 15 in a combo with the coli. Mine sounds great and can get loud. My 15 says 400 watts on it. My other 15 does not say 400 but I play it just as loud. In the 2b instructions it says to run the amp at half power and use the 4ohm jack with an 8ohm speaker. Full power puts the speaker in the 8ohm jack. Can't answer to bass, but do find a diesel or roadready mesa thiele and dig on that.

 

[morgan138]

So I am reading this as "I doubt the EVM-15L would last", or "I doubt it would be a problem" ???

Haha, I'm sorry! I meant to say "I doubt a single EVM-15L will last if you're playing bass through it, unless you're consistently keeping it below medium-loud volumes." The couple times I used just a single 15 at shows (with a comparable Mesa head), I felt like I was pretty close to the edge.

 

[morgan138]

So does that mean it is safe for a 200W speaker or is that 'bit more' going to be a problem?

You have to be more careful with bass rigs, because at low frequencies you can blow speakers without even exceeding their power handling.

When I put a 5 string bass through my D-180 into two EVM-15Ls, I could hear them starting to fart out on low notes even though they were nominally 400 watts' worth of cab handling only 180 watts' worth of power.

I have no doubt that a Coliseum with the bass turned up could pop an EVM-15L like a balloon, even if it's the sturdier version.

 

[s-fresh]

I think Mesa put the 15 in a combo with the coli. Mine sounds great and can get loud. My 15 says 400 watts on it. My other 15 does not say 400 but I play it just as loud. In the 2b instructions it says to run the amp at half power and use the 4ohm jack with an 8ohm speaker. Full power puts the speaker in the 8ohm jack. Can't answer to bass, but do find a diesel or roadready mesa thiele and dig on that.

They did put at least a few of these monsters in 15" combos originally, but I haven't been able to find any 300 Series manuals. It might be like the normal IIB they suggest half power like you were saying.

I guess if I want to do this right I will have to think a little bigger. Maybe build a TL-606 for this 15" and a separate 2x10" to help share the load. I already have a Mesa Thiele but it is only 12" and I am using that with my Mark III.

Thanks again for the responses, all!

 

[s-fresh]

I got the Coliseum today and started getting it ready to swap in the combo cab. I took some gut shots. Pretty clean although the controls do show some wear. You can click these to look at a larger version.




It came with some 415s too! No idea if they are still good though.

I'm looking forward to messing around with this when I have some free time. Too bad I am busy the next two weekends!

 

[Wyzard]

So does that mean it is safe for a 200W speaker or is that 'bit more' going to be a problem?

I just got back from my tech with the Coli: 204.7W @ 10% (pure power stage) distortion. On a big bass note, this could quite possibly take out an EVM cone before you knew what had happened, whether 200 or 300W.

I'm proposing to use mine with my two EV Road ready cabs for some light bass work.

 

[s-fresh]

Sounds like I've got some reading/learning to do about all of this. Without asking here I would have seen 200W = 200W and just plugged it in. Honestly I don't play very loud so I probably wouldn't have run into problems in my garage, but it sounds like it just takes one time of cranking it a little more to destroy a speaker. I have enough wood to build some nice hardwood cabs so I guess it is time to start cutting!

 

[Wyzard]

As a side-note, we tried ANOS ECC81 and ECC83 in the phase-inverter, and ended up preferring a Siemens ECC83. Plus, all the power tubes are now STR415s, and my box of spares is looking a lot emptier....

Anyone else got any observations about the glass in these?

 

[gts]

It came with some 415s too! No idea if they are still good though.

STR-415's are rugged and a 10,000 hour tube.
I be they're still good.

 

[s-fresh]

It came with some 415s too! No idea if they are still good though.

STR-415's are rugged and a 10,000 hour tube.
I be they're still good.

They ended up reading fine on my little tube tester.

 

[GJgo]

I just picked up a minty IIB Coliseum combo with the 15" EV. As a sealed cab guy I have to say it's the first combo that I've actually liked the tone in, mostly because this speaker can really pull the bottom end. It sounds HUGE on cleans.

I did have the idea of picking up a TL606 cab to put it in though, anyone done this with guitar?