EHV 5150 III 4X12 cabinet

[Roe]

...There is no evidence that the 20 watt and 25 watt speakers with 003 Pulsonic cones differed in any way. They may have just changed the rating when it was evident that they weren't failing at the higher wattage. ...

can someone confirm this? -Jim?

[Scumback Speakers]

Thought I went over all of this stuff in my extensive Greenback ID thread on the TGP, but I'll go over some highlights out of an email I received from Duncan Boniface, former lead speaker engineer @ Celestion. This dates back a few years.

Here's the TGP thread: http://www.thegearpage.net/board/showth ... adid=67646

Duncan's email follows:

On them old speaker things, it IS all traceable (or at least WAS.....), but I never had time, and I don't know if they kept the records when they moved a couple of years ago. All this was recorded in the change note history, and that all existed in 2003 when I left but when they moved to a smaller factory some of that may have been thrown away (that was the management attitude ; if it's old, bin it).

A few useful bits of info though ;
1. Celestion used speaker names like they were screws. They could be used anytime for any reason. I counted over 40 speakers called G12-65 issued in 2 years, and G12M's were no different. Until the early 80's 'G12M' basically meant 'General purpose, 12" speaker, M magnet'. 'M' had meant 'medium', but came to refer to a specific size of magnet (though that varied a little as suppliers changed ; in my time they used TDK Japan, Pacific Metals Korea, Ssang Yong Korea and DMEGC China for that magnet). Speakers labelled G12M varied in construction and intention widely.
2. The progression in coils (though with some overlap) was ;
* Cellulose soaked Cartridge paper (about 15W on 1.75". Sweet and clear, very defined. Gets nasty with high gain, catches fire easily. Vox Blues, T652's)
* Kraft Paper (up to 30W on 1.75". A little less open, but more woody tone and nice growl when pushed. Still nasty with high gain, burns out easily though much lower flambe risk. G12M / G12H 55 and 75Hz classic versions)
* Fibreglass. (up to 90W on 1.75". More aggressive, and less open at low gain, but much better clarity with higher gain. Nice fluid treble. G12-65, Classic Lead, Mesa G12-90)
* Kapton. (over 100W on 1.75". Less open, much more aggressive, less detail. very crunchy, edgy sound. Less forceful character so good with effects, can work well with solid state, loved by the metal merchants. G12T-75 etc)
* Nomex (up to 70W on 1.75". Tries to be like the vintage paper with better power rating. pretty good, but lacks some detail. Vintage 30)


In rough time frames these go cartridge paper up to early 60's, Kraft to early 70's, fibreglass til around 78, Kapton after that. Nomex came into wide use in 1986.

3. I remember that Kapton started being widely used in guitar speakers in about 78. However, these were all new models as far as I could tell, and it wasn't back dated to older versions. There may have been special versions though for OEM customers that I didn't spot.

4. Another possibility is the cone ; over the years the cone tool got worn, the shape changed and the cone became less detailed, more aggressive and a little cardboardy in sound. This was used on the G12T-75, and the vintage tool remade in 86 for the G12M reissue. The original tool (UKM 269 G) was Mueller owned, and used by Celestion, Eminence and Peavey (and others). The Vintage tool was Celestion owned, and only used by them.

Of course, most of those cones now come from U-Sonic Power cone in Malaysia, from ex-UKM production Manager and Sales Director Tony Hewitt. He replicated the UKM 269 G and 269 vintage tools, and Celestion use these now on virtually all guitar speakers I think

5. The changes through tool wear (plus reduction in pulp formulations available and material changes) affected dustcaps and spiders. At one time Celestion made their own spiders, and that continued into the 70's in Ipswich but later was all outsourced (now almost entirely in China). These do affect the sound too.

The vintage pulp (Hard Delta' at UKM) was discontinued in favour of 'Black Sigma' in the 70's I think, and Hard Delta not reintroduced until the G12M RI launch. This was taken further with the Heritage models to get not just pulp but process more authentic to the mid 60's spec.

So things I can say were different / may have been different from G12M #1 and those in 1978...
1. Coil. As far as I know T1220/1221 ALWAYS used Kraft. However, the shape of the former changed in 1973, losing some sweetness and giving a harsher edge
2. Magnet. I think the first ones were from the UK. By 78 they almost certainly TDK Japan
3. Cone. The tool had worn, the process had been streamlined and automated for greater output, the pulp had changed, and the apex dip had changed from Shellac to 'Sub shellac' (an undefined, mysterious chemical) or Bakelite
4. Dust cap and spider. The tools had worn and changed shape, and the materials had changed supplier, weave and fabric type (probably all natural fibres in 66, acrylics by 78).

Have you tried the usual RI Greenback from Celestion to see if that's close ? It's certainly more aggressive than the Heritage or originals !

Dunx

End of Duncan's email.

OK, here's what happened in short. The 20 watt G12M's were rated at 20 watts due to the testing they had done up to that time (mid to late 66). They changed the glues that were used which were higher temperature and didn't melt as easily, then re-rated the speakers to 25 watts. The same thing happened with G12H30's, which is why you can find 25 watt G12H's early on in production 67-68, both speakers being re-rated at 25 for G12M's and 30 for G12H30's after 68.

Cones used. The Kurt-Mueller 1777 75 hz cones were used in the early 60's, then changed to Pulsonic 75hz 102 003 cones in 66. The 444 55hz cones were used in the early 60's then switched to 102 014 55hz Pulsonic cones at the same time (or with some slight overlap).

The sought after, to die for "Pre Rola" tone was not the Kurt Mueller 444 or 1777 cone, folks, it was the Pulsonic 003 75hz and 014 55hz cone models. These were used almost exclusively (Celestion used other cone makers for other speakers they made, too) from 1966-1974. The Pulsonic factory apparently burned down in 74 so Celestion was forced to use the Kurt Mueller cones again in 75. In the meantime, from early 74-early 75, there were some cones with an RIC1XXX # used. I am not positive if these are a Pulsonic derivative, variation, or a K-M cone. They sound like a cross between the Pulsonic and the KM.

After early 75, the 1777 and 444 cones were used FROM THEN ON. They had a more aggressive tone, and harsher high end, not as warm as the Pulsonic cones.

Along with the cone change came a paper fiber/formula change, from Hard Delta to Black Sigma, so the tone changed with the pulp/cone paper change.

Then they also changed the spiders/suspension, and moved to fiberglass voice coils in the late 77/early 78 timeframe, which was even harsher on the high end.

With the Heritage models, they have tried to recreate the paper/pulp cone of the 60's. As you can hear from the soundclips that Andy Z and Dan Boul produced for my Celestion Speaker Tone shootout 2.5 years ago, the results didn't sound like the 20 watt G12M I supplied.

Now for the things that you have to understand about all of this, and hopefully you'll understand it (almost) to the "inth" degre that I've come to.

1) If you get an old speaker, due to the varying processes and ingredients Celestion put in (note that Duncan says the G12M name was used for lots of general purpose medium weight magnet speakers, not just one) over their production time, it could either sound like God, or like ass. My experience is that there were only 1 in 20 that sounded really good, and only 3-4 in 200 that were "holy grail" tone speakers. The 20 watt I supplied and two I have from 1971 are in that group. The 71 25 watt G12M is what I supplied to Weber VST to replicate for my M75 speaker. I also supplied him with another identical model, cone, etc, that was 3 weeks apart to rip apart and autopsy for all the details he might need to replicate the parts, tone, tolerances, etc.

2) There have been significant improvements in voice coils in the last 30 years. Mine have Kapton coils, but improvements have been made that allow them to handle more wattage.

3) The cones used in my speakers are treated to sound old, have different suspensions and spiders than the other speakers Weber VST produces. They're not relabeled Weber Silver or Blue Dogs, etc.

4) The best recone company I've heard for the 1777 and 444 cones to date is Orange County Speaker Repair in Garden Grove, Ca. www.speakerrepair.com They have their own American made voice coil they put on a 1777 cone for G12M/H's and for the 444 as well. They are louder, and more aggressive, but if you want that type of tone of a quasi BlackBack to Pulsonic cone tone, they're the folks to call. Recone fees were $65 per speaker plus shipping last time I checked last year. The recone comes with a 1 year warranty.

5) Celestion has made attempts to replicate their 60's tone with the Heritages. They made a fair attempt with the 20 watt G12M, which actually is a 25 watt speaker. I believe they missed the mark on the G12H's, and I am privy to knowledge that they have changed the cones on that model from their announcement date and initial reviews to what they offer in them now. This is not surprising as Celestion (according to Duncan) and my own research, has done this over the years and as near as I can tell, they do not have to tell YOU, the consumer if they do.

6) To date, there have been several attempts by Celestion to recreate their Pulsonic cone era glory, with varying degrees of success. They did not do what I did, and go buy 400 old Celestions to research, test and listen to and decide which was the best one. They went on their old production notes & formulas, which rely on parts/paper/pulp/etc that are no longer produced or available. They did not source any superior speakers, nor listen to any to arrive at the tone they recreated. What they did (according to the Celestion rep) was find some old unused speakers in the factory, and replicate (as close as possible) what they heard there. As anyone who has been around this long enough knows, you need to break a speaker in before it produces it's best tone. Replicating the tone of a brand new speaker, without being broken in, and with the thick doping used at that time gives you the tone of a new speaker. This is what Celestion did for the Heritages. As you can understand, this is not the tone everyone raves about for Pre Rolas, they want the broken in tone that hundreds of hours onstage through a cranked 100 watt through two 4x12's produces.

Final thoughts... when I sent Weber VST the speakers I had replicated over 3 years ago, Ted had never had a fully functioning G12M Pre Rola in his hands, along with a dead one to autopsy that was 3 weeks apart in manufacturing. That was a first for him. I did the same for the G12H30 and the 10" speakers. I sent them for one reason, so that Ted would have a "holy grail tone target" to aim for with my speakers. He did an outstanding job.

This specification/build for the Scumbacks is not the same as the 1225, Stan Spec, or Pre Rola doping option you can get on Weber's site. Please do not be misled into thinking it's the same, it's not.

I hope that clears up the whole G12M/H cone, voice coil, construction thing with regard to the Celestion Heritages, etc. If not, email me.

[jnewlyn]

Jim, thanks for the post. Very good info. As you know, I have a pair of your M75's as well as a pair of the Weber "My Tone Series" Stan spec. I really can't tell the difference so I'm using one of each in the two 2x12's that I have. Despite that these are my own home made cabs (100% Baltic Birch) these are the best sounding cabs I've ever owned. Perhaps one day I'll happen across some Pulsonic coned Greenies but until then, you've made a speaker that in my opinion beats any Black Back or Greenback re-issue that I've ever heard. Kudos. Hope you had a good time at the amp show. It was nice to meet you there.

[908ssp]

...The sought after, to die for "Pre Rola" tone was not the Kurt Mueller 444 or 1777 cone, folks, it was the Pulsonic 003 75hz and 014 55hz cone models. These were used almost exclusively (Celestion used other cone makers for other speakers they made, too) from 1966-1974. The Pulsonic factory apparently burned down in 74 so Celestion was forced to use the Kurt Mueller cones again in 75....

What I'd I say? I got it from Jim in the first place. I knew you'd show up eventually.

[bmf5150]

the heritage are based off of the old pre rola 20 watter greenbacks.they have a different cone and doping that the 25 watt greenbacks.they do sound different.

That is not accurate I am afraid. Both 20 and 25 watt pre-rolas used Pulsonic 003 cones. There were also some very early 66 to 68 pre-rolas with 1777 cones but not the same 1777 cones which came about in 1973 and later. There is no evidence that the 20 watt and 25 watt speakers with 003 Pulsonic cones differed in any way. They may have just changed the rating when it was evident that they weren't failing at the higher wattage. After 1973 they were no longer pre-rola and those had 1777 cones which were brighter and they seemed to get progressively brighter as time went on including the reissues of the last ten years.

interesting,i did not know that.the celestion rep i talked to told me they where different?

[jnewlyn]

What were different? The 20 and 25 watters?

[bmf5150]

the cones as well as the dope treatment to the speaker.

[Scumback Speakers]

Details, details, details. They're important to the tone, bmf5150. The Celestion reps haven't been through or bought 400 of their vintage speakers, or they'd know the differences. Kinda like the differences between a reconed G12H30 and a Scumback in a posted soundfile, right?

[jnewlyn]

Details, details, details. They're important to the tone, bmf5150. The Celestion reps haven't been through or bought 400 of their vintage speakers, or they'd know the differences. Kinda like the differences between a reconed G12H30 and a Scumback in a posted soundfile, right?

Yes. Sometimes the smallest detail makes the biggest difference. Jim, do you make a 20 watt type?

[Scumback Speakers]

Details, details, details. They're important to the tone, bmf5150. The Celestion reps haven't been through or bought 400 of their vintage speakers, or they'd know the differences. Kinda like the differences between a reconed G12H30 and a Scumback in a posted soundfile, right?

Yes. Sometimes the smallest detail makes the biggest difference. Jim, do you make a 20 watt type?

Nope. The reason I didn't is because I didn't have access to a dead 20 watt to autopsy for the differences between it and a 25 watt, which I feel is essential to knowing if there are differences. And i wasn't going to sacrifice my one working 20 watt G12M for the cause, cuz then I'd have no tone target to reference, either.

The 20 watt models only ran from 66-69. As DunxB pointed out, the G12M name could have been put on just about any build/spec/variation, and since there were so many, I'd only feel comfortable doing a 20 watt if I could find one within 3 weeks of the date code of my "holy grail" 20 watt speaker. One of mine (the 8 ohm) is 5LB, November 5, 1969, for example, but the 8 ohm models are exceedingly rare. My 16 ohm is in a cabinet in storage so I don't have it's date code handy.

If someone would like to send me a dead 20 watt Pre Rola to have autopsied, then that would settle it, huh?

As a matter of fact, one of my clients says his 20 watt G12M just died, so he's sending me that frame. If that's the case, then I'll know soon enough.

[jnewlyn]

Mmmm. Cool stuff. There's a guy back east doing 20 watters. I don't remember his name but I think his company is Alien Transformers or something like that. I don't know where he got his 20 watter info but the one reliable source I know of coins them as pretty much dead nuts to the originals. In fact as I think about it, I think his name is Jim Garrity, or McGourty or something close like that. I wonder if he had an original 20 watter to do his by.

[908ssp]

I seem to remember that McGourty had a found a stock of original cones. I thought they were the Pulsonic cones.

Now he says he has cones made to his spec.


http://www.alienxfmr.com/ALIEN/Alieninstars.html

[jnewlyn]

Hmm. Really? If he found a stock of original stuff, he could very well duplicate it. Interesting.

[908ssp]

No that logic doesn't follow. There are lots of original cones. They are in every Pulsonic cone speaker so having new ones or used ones makes little to no difference. Having a sample has never been the issue. Making them as per sample has, that is not as easy to do as it is to say. Then picking the final product out of a host of samples so it sounds like you want, that's what Jim and Ted did to make Scumbacks.

[jnewlyn]

Yeah, I hear you. Was just kind of thinking on the spot in that last post. Well, for what it's worth, this is how I get that older cab/more musical tone without those harsh or brittle mid highs. I built my own 2X12 cabs out of 100% Baltic Birch. They sound just as good as any Marshall cab I've ever had and I've had quite a few. I bought a pair of Jim's Scumbag M75's and a pair of Ted Weber's, Stan spec pre Rola types as well. Both sound better than any Black Backs, Green Backs (original and Re issue but none with Pulsonic cones) that I've ever owned. So far, I think the best celestion speaker I've ever had/heard is probably the G12-65 but again, I've never had the Pulsonic coned Greenies. Anyway I've beat the shit out of the Webers and Scummies with my 100 watter for quite a while and thought that, that was as good as I can ever make it, but it wasn't. IMO, I'm hearing those speakers give me that early warm VH/ZZ Top tone simply by tuning the cab with the grill cloth. Yep, the GRILL CLOTH. You have no idea if you've not taken a couple of hours to try different stuff. Even throwing a towel over the cab and playing. Just amazing how things change. I think an old cab with thicker cane or weaved type stuff makes more difference than most folks care to take time to notice. Not to mention that as they age, they collect dust, dirt, sticky beer/soda spills, etc. and over time, that will change things. Not saying here that those Pulsonic speakers didn't play a roll, I'm certain they did but I also think that tuning the cab, so to speak, play a more important roll.