Boss WAZA Tube Amp Expander- a heads up

TINMAN82

For anyone considering one of these, you should be clear on the following issue as I’ve recently sold mine as a result.

I’ve had official correspondence from Boss/Roland stating unequivocally they shouldn’t be used to attenuate (although technically they reamp) any combo amp or cab with speaker(s) rated under 100watts. The TAE has a built in 100watt power amp which can fry the speakers. So despite having recommended load settings for the likes of a deluxe reverb combo, the unit is deemed unsafe by the manufacturer for use with the speaker in that combo.

This might be obvious to some but given the limitation doesn’t apply to the Ox, Captor, hotplate etc. I purchased the TAE without considering it.

Its fine if the lower rated speaker isn't connected and the TAE is purely used as a load for silent play etc. But if you want to play using a combo’s speaker while simultaneously running through the TAE (even just for its onboard effects), you’re risking the speakers, unless they are rated 100watts plus.

It’s a shame there’s no option for hardwire bypass of the poweramp in the TAE. It would probably be the perfect all rounder unit of its type if that were the case. Sounds great (through a cab or direct to DAW). Smooth unstepped attenuation. Superb build quality with sturdier feel and more solid knobs than a Captor. The effects (delay, reverb, compressor) are excellent and can potentially displace some pedals from you’re board. But the power issue isn’t as well advertised as it might be, or at least could catch out the less tech savvy like me.

mattdavis

Sorry if this is showing my stupidity, but doesn’t it depend on how loud you set the TAE? Surely if you are attenuating the amp, the speaker is having to deal with less power than would be produced by the amp normally? 
I can see it being a problem if you use the combo speaker when you are making a small amp louder using the TAE (thus asking the speaker to deal with a higher power load than normal). 
Is that not right?

mrkb

Um that’s obvious, it has a 100w power amp, so if it’s running into a lower rated speaker you need to not run it at full power.

monquixote

mrkb said:

Um that’s obvious, it has a 100w power amp, so if it’s running into a lower rated speaker you need to not run it at full power.

^ This

It's equally applicable to any 100W amp running into a low powered speaker.

Just don't turn it up full and you are golden.

digitalkettle

I didn’t know the TAE was a reamper...I hadn’t looked that closely...I use a Fryette Power Station (50w). With the TAE, it doesn’t matter what’s going on up front, your speaker is on the receiving end of a 100w amp...but, if you’re careful, you’ll be fine (as the chaps said).

I was using my PS on a tweed combo...so that was 50w potential hitting a Celestion blue...always attenuating which was never a problem. These days, I’m driving a couple of 20w greenbacks so I’m even less concerned.

WiresDreamDisasters

Yeah, what these guys said. It may have a 100-watt poweramp built in, but at reasonable volumes you're not using 100-watts. More like 30-50, max.

As I understand it, If I plugged my Diezel head into a single V30 and cranked the hell out of it, I'd probably blow it. If I did it with 4 V30's in series, less likely to blow them because 4x60watts is my available wattage headroom.

Basically - turn the amp up as loud as the speakers will allow it and no more. Even if it's the Boss WAZA unit, or anything else.

TINMAN82

I addressed the keep it low thing with Boss. The official line is that I shouldn’t be connecting it to a lower rated speaker, period. Warranty gone.

In theory, keeping the volume very low “should” be safe. That’s how I was using the unit at home (with a 20watt Marshall combo / 25watt rated G12M). Problem is that might be ok at bedroom volumes but there’s no way of monitoring the power being delivered to the speaker as volume rises, it’s basically guesswork. To my understanding there will also be transient spikes in power even at moderate volume.

Its not an issue if the user understands all of this and proceeds with caution. Used as designed it’s an excellent unit with some advantages over its rivals. 

I’m pretty sure I won’t be the only person who would have appreciated a fuller understanding prior to purchase, hence the post. Those who find all of this obvious probably aren't the intended audience!

goldtop

In this high-tech era, and at that price, Boss could have designed some smarts into the TAE such that it learned the actual output power of the attached amplifier and set the output power of the TAE's in-built amp to match it.

If that was too hard, then a physical L-pad attenuator on the speaker output, set by the user to match their speaker would have done the same job and cost SFA in money and design effort.

mrkb

goldtop said:

In this high-tech era, and at that price, Boss could have designed some smarts into the TAE such that it learned the actual output power of the attached amplifier and set the output power of the TAE's in-built amp to match it.

If that was too hard, then a physical L-pad attenuator on the speaker output, set by the user to match their speaker would have done the same job and cost SFA in money and design effort.

But one of the use cases is to allow a small valve amp to be amplified by the TAE to a higher wattage and run into a separate cab with a higher wattage speaker. So a 5w amp could be used at a gig. I think the issue is people don’t read manuals any more.

monquixote

It's a solid state amp and most speakers are conservatively rated so I don't think most people are going to have a problem.

TINMAN82

monquixote said:

It's a solid state amp and most speakers are conservatively rated so I don't think most people are going to have a problem.

Probably, most of the time. I don’t want to gamble though so it’s sold on.

its a shame because they really have thought of and covered almost everything with the TAE.

Perhaps version 2 will have scaleable power output and Bluetooth functionality. That would be nigh on perfect.

goldtop

mrkb said:

goldtop said:

In this high-tech era, and at that price, Boss could have designed some smarts into the TAE such that it learned the actual output power of the attached amplifier and set the output power of the TAE's in-built amp to match it.

If that was too hard, then a physical L-pad attenuator on the speaker output, set by the user to match their speaker would have done the same job and cost SFA in money and design effort.

But one of the use cases is to allow a small valve amp to be amplified by the TAE to a higher wattage and run into a separate cab with a higher wattage speaker. So a 5w amp could be used at a gig. I think the issue is people don’t read manuals any more.

Well, exactly: the second option I suggested would achieve that.

I also forgot - if the TAE designer had taken a look at the Katana front panel with its power-level switch, he might have got a clue on how to avoid this issue, and keep everybody safe and happy. It's really a trivial problem to solve.

I'm with the OP. If your amp has a Celestion Blue (etc), the TAE would be an entertaining way to turn it inside out. Same was true of the Ultimate Attenuator and that was about 15 years ago.

TINMAN82

mrkb said:

goldtop said:

In this high-tech era, and at that price, Boss could have designed some smarts into the TAE such that it learned the actual output power of the attached amplifier and set the output power of the TAE's in-built amp to match it.

If that was too hard, then a physical L-pad attenuator on the speaker output, set by the user to match their speaker would have done the same job and cost SFA in money and design effort.

But one of the use cases is to allow a small valve amp to be amplified by the TAE to a higher wattage and run into a separate cab with a higher wattage speaker. So a 5w amp could be used at a gig. I think the issue is people don’t read manuals any more.

Re the manual comment.

This is what it says:

“Speaker input capacity

1) The power amp built into this unit has a 100 W output. Connect a speaker that has a rated input capacity of 100 W or greater.

2) If you use the speaker of a 100 W or lower tube amp, you must use it at or below the volume at which you play that tube amp by itself with the speaker connected directly.”

Point 1 seems pretty clear that the speaker (or cab with >1 speaker) must be rated for at least 100watts. 

Point 2 is a bit more ambiguous for two reasons. First, they advertise the TAE as a means of boosting a small wattage amp, so I assume they intend this point to apply when the original amps speaker is attached, rather than an extension
4x12 rated for >100watts. If a 4x12 was attached there would be no reason to limit volume.

Second, by this logic they are effectively suggesting the user judges power output to their speaker indirectly by using volume as a surrogate. I think we all know how difficult that would be without using a decibel meter. So it starts to get messy.

Im 80% sure that when these first came out I read a now edited version of the manual that specifically mentioned small combo amps in relation to volume. Either way, official Boss communication now states don’t use a speaker rated under 100watts...at all.

I no longer have a stake in the game having sold this on, but again this might all be of interest to those less experienced than mrkb.

monquixote

In the Deluxe reverb example they come with a C12K or a V Type and I don't think you could blow either of them up with a 100w solid state amp.

mrkb

Speakers arent as fragile as you think - a 100W marshall into a 25w speaker is ok for short periods:-

https://www.youtube.com/watch?v=DsSE-dSaJak

dunstanmus

Quite a few have fried on Other forums.

Nerine

I maybe talking out of my compost heap here, but I’m sure I’ve read that the way a solid state power section clips is not as smooth or as linear as a valve one. 
I believe there may be slightly more transient spikes involved when a SS power section begins to peak which would potentially harm a speaker more than a valve power section. 

If you’re below clipping volume, then I would advise that it’s just about using the unit sensibly. 

You wouldn’t turn the WTAE up to 10 whilst it was connected to a single 25w Greenback for example. 

Usual common sense general usage procedures apply, really. 

Handsome_Chris

I do not understand what the actually problem is wrt to experienced guitarists/musos.  I have a 200w valve head and a 3 x 500w solid state power amp, and both probably powerful enough to kill my 2x12 (v30s); however, I know how to use them without frying the cab, or fkn the amps.  

Are Boss basically saying one should not do what I am doing because one may be an idiot, fry their cab, and blame Boss?

TINMAN82

Handsome_Chris said:

I do not understand what the actually problem is wrt to experienced guitarists/musos.  I have a 200w valve head and a 3 x 500w solid state power amp, and both probably powerful enough to kill my 2x12 (v30s); however, I know how to use them without frying the cab, or fkn the amps.  

Are Boss basically saying one should not do what I am doing because one may be an idiot, fry their cab, and blame Boss?

I have no doubt Boss are playing it defensively and covering their backs with the official stance.

However it’s the 100watts into 1x12 (eg 25watt greenback) that I was concerned about. Most 2 x12 and all 4 x12 cabs would be fine. No doubt playing at home would never cause an issue.