The 6550 Experience

[bill bokey]

But I'll still carry on experimenting with my 3 amps, the fuzz, octavio and hopefully a vibe clone
And different sets of speakers as well, I just sbought a pair of Scumback H75

[Xplorer]

one thing you'll see in one movie is contradicting your statements. there's this guy ... behind the camera , commenting the new year's eve , with the sound, and he just walks with the camera.

[Xplorer]

But I'll still carry on experimenting with my 3 amps, the fuzz, octavio and hopefully a vibe clone
And different sets of speakers as well, I just sbought a pair of Scumback H75

[bill bokey]

I guess Im a little late to this thing but what does the west coast mod entail? Is it the fuzz mod you mentioned before or an amp mod?

There's a fuzz mod as well but this thread is about the amp mods Dave explained on the other thread.
High B+ (around 560V), 6550s in class Bish bias (25mA) and a 12at7 PI (with 2K2 screen resistors but some have tried with the usual 1K)

[Billy Batz]

But I'll still carry on experimenting with my 3 amps, the fuzz, octavio and hopefully a vibe clone
And different sets of speakers as well, I just sbought a pair of Scumback H75

I dont think it ever stops. Its just fun. I didnt want to sound anti experiment. I dont think I ever put that out there. Just not enough respect given to the extra rig stuff except the token nod every now and then.

Try the H55s too. I use my AlNiCo cab 90% of the time now but my H55 cab sounds huge.

one thing you'll see in one movie is contradicting your statements. there's this guy ... behind the camera , commenting the new year's eve , with the sound, and he just walks with the camera.

Now that is definitely something. When on which vid?

[bill bokey]

But I'll still carry on experimenting with my 3 amps, the fuzz, octavio and hopefully a vibe clone
And different sets of speakers as well, I just sbought a pair of Scumback H75

I dont think it ever stops. Its just fun. I didnt want to sound anti experiment. I dont think I ever put that out there. Just not enough respect given to the extra rig stuff except the token nod every now and then.

Try the H55s too. I use my AlNiCo cab 90% of the time now but my H55 cab sounds huge.

I don't have any other Scumbacks but I have a '69 1982B w/ T1281s
I should load a cab with Tayden 50W alnicos... never a played a Marshall through alnico speakers...

one thing you'll see in one movie is contradicting your statements. there's this guy ... behind the camera , commenting the new year's eve , with the sound, and he just walks with the camera.

Now that is definitely something. When on which vid?

Yep, I was gonna say the same

[Billy Batz]

I guess Im a little late to this thing but what does the west coast mod entail? Is it the fuzz mod you mentioned before or an amp mod?

There's a fuzz mod as well but this thread is about the amp mods Dave explained on the other thread.
High B+ (around 560V), 6550s in class Bish bias (25mA) and a 12at7 PI (with 2K2 screen resistors but some have tried with the usual 1K)

Lol. Thats pretty much my amp. My B+ is 560ish. IIRC I think I asked george specifically if he had a PT taht yeilded a huge B+. Its at least 540. Im pretty sure we got into the subject of biasing these 6550s cold back when. This is funny as hell. Its like deja vu. The 12at7 PI is interesting. I know Ive tried it plenty but maybe not in this amp for this purpose. I know what Im pulling out tomorrow. Would definitely make it easier to approach 10 ont he volume without too much breakup.

[Billy Batz]

I should load a cab with Tayden 50W alnicos... never a played a Marshall through alnico speakers...

I usually play my AC30 head through it. Though I often have both cabs going. That sounds really good. Theres a sweetness to alnicos that ceramics cant touch especially with an AC30. Playing that amp through a 4x12 ceramic cab isnt quite the same. Get both going with any amp sounds really broad and complex.

[Xplorer]

for the camera , go see this one : VTS_01_1_xvid_003

here you can find plenty of stuffs. it's not finished uploading heavy files, check again later.

https://drive.google.com/folderview?id= ... sp=sharing

[bill bokey]

I forgot the settings :
Volume 7
Treble 4
Mids 6
Bass 4
Presence 9

[Billy Batz]

I forgot the settings :
Volume 7
Treble 4
Mids 6
Bass 4
Presence 9

Settings for the mod?

[bill bokey]

I'd like to try this topic one more time given the solid belief that Jimi used his FF at full fuzz.
I have been on stage where Jimi performed and observed the following settings; gain-7. treble-4, mid-6 bass-4, presence-9, fuzz-2, gain-10.

When the FF units would show up at West Coast, the fuzz controls would always be turned down, and the amps would all turned to "11". The longer you stand in front of super loud amps, the more you need as your hearing desensitizes.

And you might want to try daisy chaining (even if the second amp isn't switched on) as it has an effect on gain

[bill bokey]

About Jimi's settings:
If YOU got to be on stage where Jimi was playing would YOU pay special attention to his settings? I thought so.
This was important to me for other reasons at the time; I wanted to have a baseline to use when I set up the amps and effects at the shop so I could compare changes I made.
The problem with my line of thinking at the time was that as any performance progressed, Jimi changed the settings to accommodate what he was feeling, and so there was no ACTUAL Jimi setting which typified his sound.
Still I used that setting when I made a change in an amp or fuzz or wah, rather enjoying playing his guitar through it.

[Billy Batz]

I just didn't know what you meant posting settings. I don't get too crazy with knowing eq settings either. The thing I have a hard time with is volume. If it is a stock bright cap the amp is pretty close to perceived total loudness pretty damn low. It just gets bigger sounding.. Ichange how I set the amp up all the time. Either I'll have it on ten with little to no bass. Or dime everything and back off the volume to clean up the muddiness. I always figured Jimi was probably the same way because sometimes it's a muddy mess and sometimes it was an ice pick with his sound.

I had a box I made one time that was just a simple volume pot on a stonp switch I made to be a preset roll back for clean sounds. At one point I added resistors to duplicate the total voltage divider aspect of coupling 3 sets of inputs when daisy chaining. It was interesting but not very useful. For one the resistances are different for each amp in the chain. The third amp would see the biggest reduction of the signal obviously. A large series resistance attenuates high end in each amp down the line. Which amp would be micd? Is it actually a reamping situation at times Dave talked about?

[shakti]

Interesting remarks in these last posts. And further to that, I made some interesting observations last night (which are probably old news to you seasoned guys).

I have two amps which are very similar; both are Super Lead clones using NOS parts and the same transformers. But they are set up slightly differently;

One has 465 V plate voltage, EL34s biased at 65%, split cathode, V2 bypass cap, 32+32 preamp filtering, 12AX7 phase inverter
The other has 510V plate voltage, 6550s biased at about 28 mA, shared cathode, no V2 bypass cap, 50+50 preamp filtering, 12AT7 phase inverter

So basically one is a stock Super Lead, the other has some West Coast mods. I definitely prefer the West Coast mod for the BOG thing, but the interesting thing here is what happened when I tried to daisy-chain these amps. What happens is that each amp fills in and covers up any "deficiencies" in the other amp. On its own, the West Coast mod amp can seem a touch shrill at certain settings, but you need the clarity and cut it gets. Whereas the EL34 amp is a touch muddy for most BOG sounds. But when you mix them, something magical happens; the clarity remains, but the fatness increases a *lot*. Much more than you would expect based on what each amp sounds like on its own.

What this all tells me is that chasing the magic tone and thinking that one amp alone can provide it is a futile search. I think we have the DNA all in place; 6550s is a part of the recipe, but the other subtle details (actual plate voltage, V2 bypass, shared/split) are mere details in the larger picture. And it's fairly likely that the three amps at BOG were not identical. Even if the circuits were, they are going to sound slightly different anyway, and fill each other in and fatten up the tone to where I think you'd have great trouble deciding whether the cathode was shared or split, whether the PI tube was a 12AT7 or 12AX7 or whatnot.
I am only guessing, but I think that three amps with West Coast mods set up like mine, and daisy chained, in the right room, would sound scarily close to BOG.

BTW, do we know if all three stacks were used, or was one a backup? And do we have stage photos or footage from each night that show the amps/logos? Perhaps we can in fact determine from the logos if an amp was switched between the two nights? Most of the logos had their idiosyncracies, in that they were either missing completely, partially broken, or fully intact after life on the road.