Will I blow a speaker with an Express?

[jcr1234]

If I build an Express clone from Ceriatone with 6v6's, Toneslut or Pacific trannies, and run it through a single Weber Blue dog or Scumback Greenback type speaker, am I gonna blow it?

I know that for example the Deluxe Reverb etc use 2 6v6's into one 12" speaker, but with all the talk about how loud the Express clone is do I need to re-think my speaker options?

[M Fowler]

It's a conservative 35 watts of power so match the speaker handling accordingly.

Not sure what each one of the speakers you listed are capable of. Typical Celestion greenback is 25w so use a pair. Typical Celestion blue alnico is 15w so you could run both as a 212 to cover the whole tonal spectrum plus handle the wattage? But the experts will chime in hear I hope.

[CapnCrunch]

What's the power rating on the Blue dog and the Scumback? You should probably figure the Express at about 40 watts full out. I'm with Mark. You will eventually (or quickly) blow a 25 watt greenback. Weber builds the Blue dog in several ratings 15, and 30 and maybe higher. Scumback offers a higher wattage version of their g12m clone. Anything 50 watts and higher and you should be good. Anything lower and you're asking for trouble eventually. Like Mark said, you can always go with a 2x12 and then you'd be fine.

[bcmatt]

I don't know how to register this, but I am still confused by it.
I built an express for a friend (Joe) with El34s.
He used it with the VVR2 turned off for a bit and he said he ripped a cone in one the speakers in his 2x12. He has a Veteran 30 (60 Watts), and a Classic Lead 80 in it. There's no way he should be blowing speakers, in a 120W cab, but he is notorious for wrecking things.
I don't really understand it.
Anyways, the way Expresses are meant to be played, I would generally try to stay well above 50 watts in speaker rating. And if you like to wreck things like Joe, go with a 4x12. But really, what do I know?

[M Fowler]

Well for example with my Express I usually run it through a 212 one 25w/green back and one G12H30 with no problems at all.

Sometimes I use my 412 with Vin 30.

Mark

[CapnCrunch]

It would be nice to hear from Jim at Southbay Ampworks about this. Generally a tube amp output rating is for "clean" watts. Most tube amps when pushed into clipping put out considerably more then their rated power. I have used this rule of thumb with no failures so far: double the rated power because most tube amps will put out at least 50% more then their rated power when pushed into distortion. A 40 watt Fender will put out more then 60 watts when dimed. A 50 watt Marshall will put out close to 100 watts.

I'm not an expert on the Express, but I'm guessing it doesn't put out more then 20 watts clean with 6v6's. I could be wrong on this, but that's how I came up with the figure of 40 watts above. I've heard of people running a single Celestion blue in a 30 watt or greater combo. I know from my own experience that the only way this works for more then a few minutes is if you run the amp at low volume. I crank my amps close to wide open, and then control volume and drive with my guitar volume. I don't use overdrive pedals either.

Most of the guys that I know that tout the 15 watt blue as "magic" because it can hang in there in an amp that is rated at twice its rated power are guys that play AC-30 derivatives in church. They play their amps at about 3 to 5 watts with distortion pedals though I was told this "rule of thumb" years ago by Ted Weber in an email exchange when I was getting ready to order several Weber Blue Dogs. It hasn't failed me yet.

[Scumback Speakers]

Hey...just checking in on this thread. Had to have my cable modem/internet reworked today by Time Warner...they had a bad line or something....anyway.

Ok, this is based on my clients and my experiences with speakers.

Trainwreck Express with dual EL34's, figure around double the clean wattage for it when cranked. Many people try to tell me they're 35w. Frankly I don't believe it. An Express kicks the living snot out of my JTM 45 clone with Mercury RS trannies for volume, so I think it's more like 50 clean with the right stuff (tubes/trannies/etc), so it's probably putting out way more than that, 80 or more, when cranked (vol @ 8-10). So you'll need a 100w 12" or two 65w models to handle it.

With 6V6's, that's a different animal...it might get to 22-25w clean, and maybe 40-45 dimed, so one 65w, or two 25/30w speakers should be cool.

EL 34's seem to almost double in power when cranked, whereas 6L6's get about 50% more, not double, so a dual 6L6 Fender probably puts out 60-65 cranked, with 40-45w clean. With this amp, you'd be on the ragged edge with two 30w speakers, or one 65w speaker.

I've had too many people call me to get speakers reconed at 65w after they tried to run two 25w G12M's with their 40-50w amps to believe they can handle it for long.

So my rule of thumb (experience of frustrated clients) is advise you to get twice as much power handling as your amp's rated/clean power.

No one likes the smell of burnt electronics and voice coils...well, at least no one I know of.

[skyboltone]

I've measured one of my two hole Liverpools at 54watts into 8 ohms in full feedback/sustain. Plates go red very quickly but don't seem to suffer from the abuse. That measurement has to be taken with a grain of salt though because the multimeter is only looking at a portion of the harmonic spectrum.

To properly analyze the power you need single tone or a spectrum analyzer.

[geetarpicker]

I would mention it does depend on the build specs. I've compared my original Express side by side with an original JTM45 (that was on a variac at about 110v to match "period voltages") and both amps were very similar in volume. My Express has a 6.6k Pacific OT which perhaps tones it down compared to 5.2k builds. I've played a ceriatone Express that with 6v6s was louder than my Express is w/EL34s! So power wise these things can vary a bit. I've played my Express quite a bit on a single 65watt scumback M75 with no issues yet fingers crossed. I've used it on 1 original G12m but only when attenuated at least 4db. It seems two alnico blues can handle a Liverpool, but not wise to try that with an Express. That said most of the time I play my Express amps on 25 watt G12Ms or 25 watt M75s in sets of 4 simply as I don't own a 2x12. I either go 1x12 or 4x12 all in sealed cabs.

[paulster]

Many people try to tell me they're 35w. Frankly I don't believe it. An Express kicks the living snot out of my JTM 45 clone with Mercury RS trannies for volume, so I think it's more like 50 clean with the right stuff (tubes/trannies/etc), so it's probably putting out way more than that, 80 or more, when cranked (vol @ 8-10).

Factor in the low plate voltage (400-410V) and the deliberately high impedance at the OT (6K6 compared to Marshall's 3K5) and 35W clean isn't that far from the truth. However the voicing of the Express with its really strong midrange makes it sound louder than it actually is.

I've had my Express EL34s cranked through a single 65W M75 with absolutely no problem, and I wouldn't do that if it were going to risk causing a problem. In terms of output it's nothing like a 50W Marshall (that I wouldn't subject a single one 65W M75 to).

6V6es will also bring the power output down, although I'm not a fan of them with the Express.

[JamesHealey]

Paulster I'm pretty sure that 35W clean is the case, but i'll tell u now when I measured the peak output on my amp cranked it was 60w cranked.

I'm running a slightly higher plate voltage though about 490v compared to the 410v usually seen on wrecks, so I expect the lower voltage ones to be most deffinatly NOT putting out 60w or above.

[Scumback Speakers]

Ok, I guess there are all kinds of plate voltage/tranny options on an Express. I was basing the volume of what I heard on the one that Billy Yates brought to the LA AMP Show in 2007 next to my demo amps. At a volume of 2.5-3 it was totally dominating my JTM 45.

[paulster]

Jim

Was that the Ken Fischer tribute amp, that Billy has had, or has? If so then that has a different output transformer (5K2 rather than the usual 6K6), which makes for a much more aggressive amp and is closer to the 'optimal' impedance for EL34s, so should definitely produce more power.

[M Fowler]

I have to correct my first post as I did not mean to emply using two blues cab for the Express, but looks like that's what I typed sorry.

My experience is, do not use them, they cannot handle an express.

I tested my DR Z 212 openback Celestion blues with two of my express AMPS one 5.2k and the other 6.6k and no way is that a good option.

Anyone use the EVM12L single cab with their Express?

Mark

[funkmeblue]

I have a boogie 1x12 theile with an EV. Sounds great for cleans and has tons of bottom but doesn't "give" in the highs. I usually run it with an open back boog cab with either a celestion mc 90 or a tone tubby ceramic. Not a true express, I used 6sl7's.