The 6550 Experience

His guitar slung across his back, his dusty boots is his cadillac.

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daveweyer
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Re: The 6550 Experience

Post by daveweyer » Tue Oct 30, 2018 9:28 pm

Yeah Tazin is right. The Dagnalls varied all over the map, and you could put a "stock" model in the amp and no one would know. Except the amp could output 125 or 130 watts, just what the technician in that article measured. And yes, the voltages could vary that much, say 20%. It's no big deal, and as I said, it was the absolutely easiest upgrade you could do because it required nothing but undoing some fasteners, and soldering some wires, doping a little finish on the connections if needed, and bam, hot amp.
The way the unit was wound, the particular batch of laminations, the copper put up, where the bobbin stopped or the winder, on paper-over-lamination styles, lots of variables, especially in the lower grade transformers, like the Woodward Schumacher transformers the amp builders all used in the USA, cheap, in other words.
Some modded amps had bigger transformers, but most had something which resembled stock units. I mean, you can't tell the difference visually between the same model transformers unless a manufacturer changed suppliers for brackets, covers, laminations, that sort of thing.I believe Tazin has pictures of a lot of those amps.
And Tazin, glad you are still with us!

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Re: The 6550 Experience

Post by frenchie » Wed Oct 31, 2018 3:36 am

Xplorer wrote:
Mon Oct 29, 2018 12:35 pm
Fantastic build Bill !!! And don't listen to these stupid agressive comments .... They simply don't know that this amp can be set differently and totaly produce the woodstok tone or BOG, also using different pickups on the strat.
1) The youtube clips of bill's amp DO sound like shit , and we didn't bash bill or the amp in itself just the totally out of place tweaking and playing of the demo guy ... neikeel agreed , but I guess he too is too agressive about plain truth for your softer mind all inclined to gently rub up and down the egos of key people that could pitch in to your internet show of social power ...
2) It's an interesting concept saying comments are agressive while calling them stupid , commonly stupid is used as an insult , that's a pretty obvious hallmark of you beeing pretty agressive yourself , but I guess a manipulative guy like you wanna irritate people so bad into a frenzy of internet fury while sitting back enjoying the show , thus polishing your image of the reasonable wise guy of the place , that you cannot help your own incoherence ...
3) Yes we DO know an amp has knobs that can be tweaked to achieve the bog tone ( another "between the lines" clumsy attempt at calling us stupid ) , that's primarily why we said the amp could at least be tweaked on it's launch clip to achieve what it's actually marketed to achieve ... Rather ... Go tell that demo guy how to use the fucking knobs of the amp he's demoing and to change pickups ...
4) First learn how to read comments properly , before trying to hop on your high napoléonian horse judging everyone conveniently deforming what everyone said in the process ... Reading is the main skill taught at school , showcasing your skills in that domain will help ya to appear a little less stupid ...

Xplorer ....the man getting his high irritating people into forum banishment since 2009

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axeman
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Re: The 6550 Experience

Post by axeman » Wed Oct 31, 2018 8:19 am

That comment Explorer made was directed towards me. When I make honest comments, they are only made as eye openers. I helped bill with his questions in sourcing parts on my YouTube channel. Society has changed drastically. Btw the Mexicans defeated neopolion haha. Pretty words are not always true, and true words are not always pretty. You could be super nice with someone instead and not be truthful, but you’ll confuse him or her on the long run and might end up causing harm by allowing said person they are ok, or right when they are truly wrong. Could you imagine “Bill it sounds great, keep on making them” and then Bill invest a lot of money. You can really mess someone up. Good luck Bill I hope you see past the forest and read between the lines.

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Xplorer
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Re: The 6550 Experience

Post by Xplorer » Wed Oct 31, 2018 10:28 am

Frenchie, the man who listens to himself talking so nice in English when agressively projecting his father issues on everyone since years. It's too bad, since you also have some interesting views sometimes. You know, peoples can also be nice by nature and enthusiast because they like it. btw, there's no social power to gain here, we're just all a forum. one more paranoid projection i guess ..

Axeman, oh thanks for the clarification, and "your amp sounds like shit", it's certainly the only choice of words to be truthful.... to be honnest, i couldn't read that between the lines and it just shoked me.
Myself, i told Bill that the demo could be better, the demo guy didn't really know what to look for but it's great anyway.
Btw, you're talking about Napoleon III .. Not Napoleon Bonaparte, THE ONE. Not the same guy ...

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axeman
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Re: The 6550 Experience

Post by axeman » Wed Oct 31, 2018 10:39 am

That’s nice many agree with me. I think you need to have children

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Xplorer
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Re: The 6550 Experience

Post by Xplorer » Wed Oct 31, 2018 11:26 am

axeman wrote:
Wed Oct 31, 2018 10:39 am
That’s nice many agree with me. I think you need to have children
ha ha, children ? i don't really want children ... And i don't consider you guys as children.
And after all, if you say you had all the best intentions in the world .. Me, i just found it rude and a tad egomaniac from you two guys. I won't interfere with you now, you have your way.

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axeman
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Re: The 6550 Experience

Post by axeman » Wed Oct 31, 2018 11:42 am

Do you want to be my dad?

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Xplorer
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Re: The 6550 Experience

Post by Xplorer » Wed Oct 31, 2018 12:32 pm

axeman wrote:
Wed Oct 31, 2018 11:42 am
Do you want to be my dad?
Nope ...

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Re: The 6550 Experience

Post by axeman » Wed Oct 31, 2018 12:38 pm

I was starting to like you. Bill if you need any further help or any phenolic boards please let me know.

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Re: The 6550 Experience

Post by Tazin » Wed Oct 31, 2018 12:43 pm

daveweyer wrote:
Tue Oct 30, 2018 9:28 pm
And Tazin, glad you are still with us!
Yep, still visit this BBS frequently to see what's going on. So it sounds like it's not imperative to have a higher voltage PT in order for the West Coast amp mods to work?

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Re: The 6550 Experience

Post by neikeel » Wed Oct 31, 2018 1:34 pm

Aspects of this thread are deteriorating, if I were a mod I would trim bits😉
I don’t think that using words like shit is helpful. Personally speaking I voiced my opinion that Bills demo did not bring the best out of the amp in terms of sounding like BOG not a bad rock amp. I always quite liked his own clips in which he played. Contrast those clips with ones Thorlief posted in fuzz thread and you will know what I mean. I would really like Bill to post some clips of him playing that amp dialled in playing the right licks through the right guitar. Then my sense of Ying and Yang will have balanced.
Not sure I want to delve into Frenchie an Xplorers issues.
Neil

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Re: The 6550 Experience

Post by daveweyer » Wed Oct 31, 2018 5:59 pm

Tazin, no it's not imperative to have a higher voltage transformer. I heard lots of nice lower powered amps, and if I didn't happen to have a hot transformer, I just did the mods without it.
You kind of have to imagine the zeitgeist of the day; here I was, this young cat who had somehow learned to build amps, trying to respond to the pressures of the moment, huge rock and roll backlines, demand for more and more power, demand for more and more sustain, demand for more and more reliability, demand for breakthrough tones and sounds, demand for something different to help musicians identify themselves among the thousands of competing bands.
In the mean time, I also wanted to distinguish myself from the thousands of other amp repair cats and modders, and come up with something that maybe others had missed, or didn't know about. I mean, it was pretty amazing to have Jimi call you from Stockholm or some such place and go into a rap about his sound or new idea he had--it kept my mind buzzing with possibilities, trying to interpret what he said into some tweak on an amp or a new FF circuit. And my whole day was filled with guitar gods asking me for this and that; it's surprising I got anything done it was so chaotic.
So the mods were kind of a progression, and developed from lots and lots of experiments I had done on my own amps. Every time Jimi or Neil, or some rock star would come in to West Coast, I had a new circuit to show them to see what they thought. The point of it all came down to modding everything important that came in to West Coast, sending it out in the field, and waiting to see what would happen. And you didn't have to wait long, you just can't believe the demand for services back then; the phone was literally ringing off the hook all day long, and every time I would look up, Lynette would say, "dave so and so wants to know when his amp will be finished, do you want to talk to him?"
And I would usually say no and ask her to make up something to tell him.
So small amp mods were very common. I think I mentioned that if an amp sounded just right to me, I would maybe replace the power tubes and set the bias, put a sticker on the back, and send it out, amp "modded". Maybe I would replace a bypass cap too, or HF compensation, often a 12AT7 PI. If you couldn't make it better, then what was the point, except to make extra money? I was just too busy for that in those days. West Coast had other employees who could generate extra income from marginal replacements.
At the time, I thought I was directing Jimi toward some idealized and refined sound, my own idea of the holy grail of guitar tone, but I could have been fooling myself. It might just as well have been Jimi directing me! We were both stoned half the time, well, Jimi ALL the time!

At least we have an expert on Jimi's amps here who can keep things in perspective. And I am not saying that just to be nice to somebody, Tazin is a valuable resource.

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Re: The 6550 Experience

Post by Tazin » Thu Nov 01, 2018 12:35 pm

Going on a bit of a tangent here so I apologize...I've heard some really nice clips posted here and I was wondering if anyone has taken into effect the tonal differences between using one 4x12 verse two 4x12's? Wouldn't that change the dampening effect on the amp since the NFB was fed from the speaker jacks on his '69 amps?

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Re: The 6550 Experience

Post by Xplorer » Thu Nov 01, 2018 1:21 pm

Wouldn't that change the dampening effect on the amp since the NFB was fed from the speaker jacks on his '69 amps?
Please, what is this technic ? feeding the NFB from the speaker jacks ?

With two 4x12, i think that shakti or Bill can do this, but not everyone, certainly not me.

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Re: The 6550 Experience

Post by daveweyer » Thu Nov 01, 2018 1:52 pm

Yes it does affect the damping. I hope others will chime in here too, at least with their observations about 2 cabs. Quite a bit is affected when using a stack; the amp has even less control over the speakers, even though the techs were supposed to switch the OT to 4 ohms, and that tap allows more current, supposedly giving the amp more control over the load. But as Bob Hovland, Vox engineer notes, when you have multiple speakers and they are connected in series-parallel, the amp can't really control them anymore because the other speakers act like a big spring to absorb any corrective current that is a result of the NFB. The speakers try to control each other, essentially playing each other. In a stack, the guitar becomes much more reactive too, because now there are these positive feedback loops between the pickups and the audio field--the guitar is really much more inside the loop. In short, the whole thing changes--there was more to the stack story than just volume, and speaker dissipation.

But you have to hand it to these guys here for their diligent reconstruction of the BOG sound; I have just been blown away by the amazing likeness, both in tone and dynamics. Now if these clips could be recorded with a stack, and without any kind of power soaking device we could see just how much that tone was affected. I certainly look forward to that test. One other wild card; there was no way to know just which speaker type was in the cabinets Jimi used at any particular performance. As many speakers as we replaced, and as many different types we used, it will probably remain impossible to know the exact combination of speakers he was using at any given gig. I mean, even re-coned speakers sounded and acted differently. And here is another caveat; this little gal from Oklahoma that re-coned speakers for us over in Pasadena, sometimes used a cone on the 12 inch speakers that had a little silver dust cover in the center, mainly so it would look like a JBL. Eminence speakers of the day also used that silver dust cover, claiming it helped the HF distribution. If you are looking for JBL speakers in his cabinets because of the silver dust cover, you may be seeing something else.How many permutations would you have to try to cover all those speaker cabinet possibilities? Probably about 92,000,000, so get going guys.

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