Ain't Talkin' ... clip

[Jeremy1283]

That vid was helpful. What pre amp tube for v1 is the question. I need one to hold up and not breakdown early. Presently i have a sylvania nos 12ax7.

That tube is fine, just up the resistor at V1B. The lower the resistor the more clipping, the higher you go less clipping and more head room. Or if you want to refer to it as biasing, lower = hotter, higher = colder. Try it just to see what it does. Put a 720R in V2A and things get pretty mean. 12ax7wa's are pretty cool too, but you got to find the good ones.

This opens up a world of possibilities. ohh boy.

[awangotango]

how to DIME WITH CHIME. i.e. max out a stockish SL but still have some clarity and upper mid chime.

step one, set all controls to the heart of the sun and forget e'm

step two, no alcohol.

Start with /67/8 spec'd amp with both bright caps, no v2a, ralle filtering, either .02 or .1 output caps. flip a coin on that one. maybe consider your transformers tone and imagine what output caps they would want. YOu can always swap them for the other much later in the process. I pull two tubes and do not use an attenuator but you can leave them all in and use an attenuator if you want. i haven't found one that works well enough but I haven't tried them all.

the techs who really know how to dial in a SL do it with the help of waveform analyzers and they are not only able to hear, but see a clipped squared off wave vs a smooth one or a even order harmonic vs an odd. And they can balance the two. We just have our ears and so are at a disadvantage. It takes more time and you have to get lucky too so keep that rabbets foot in your back pocket as you mess with the amp. I just keep the chassis flipped upside down on teh cab and tweek/play tweek/play. dont' even take the guitar off. ( don't forget to short the big caps with a big screwdriver each time!). But the routine really is tweek/play/tube swap/rebias. tweek.play.swap.rebias. Some marshalls just got lucky straight from the factory and those are the 'magic' ones. They are not magic just a lucky synergy of particular tubes and particular values of parts. I would guess one out of 100 or 1 out of 50 would come out needing no changes


Also, a tip to make it easier for those who don't know or have forget. Start the bias/plate/cathode resistors (or any other resistor you plan on messing with) using the highest value you would guess would work. and then parallel over the top of it succesive 1meg or other large values and that will consistantly bring the overall value down with each mod. Use the equation to figure out what the drop will be so you can make it maybe 2k at a time. Then when you're done and happy if you want you can measure the stack and replace with a single value. So this way you're not unsoldering anything fom the lugs while tweeking, same thing with caps of course but you start with teh lowest value and add on top until smilin'


And another tip would be to start with a low 67 style feedback resistor or medium because it's near impossible to get a SL dimed with post '74 era feedback specs. It's too loose and falls apart. Ralle has done good work in this area. So now that you have a pretty clean feedback loop you can max out other places in teh preamp. Also, I would not have a bypass cap on v2a during this process. Just stock 67 bass specs but with both stock bright caps (one on mixer and the other on volume). Only add that v2a 'hair cap' cap after all your work has proven to not yield enough or needs tighteng/loosening. That cap is a lazy mans solution to 'gain' and often is not needed and I wonder if ed had it all the time either. I mean 1984 is a killer tone and I don't hear that cap there. Yes VHI and women and children probaly had the cap

That being said, as I said in paragraph one, the techs's I believe do not focus on the preamp when dialing in a SL to dime with chime. they are working in the power amp section getting even and odd order harmonics sorted out. Again, this is out of our area of expertise and so it requires some luck to get it all in place. All us novices know how to do is bias the power tubes or swap power tubes with different gain structures.....also that's another thing you can do is mix and match power tubes. I only use 2 in a SL these days so I swap literally whatever is on the bench and mix and match until I hear good stuff not caring at all what they measure. I do write on teh tube the current draw so afterwards I know what I ended up with but a non matched set can sound real good. You get some grind out of the power section but again, this will change the whole equation and you may need to go back and tighten somewhere else to balance things out again.

the basic point is that even within a pretty much 'stock' SL circuit, you have a tone of places you can tweek and many variable to consider so this is why mods are a joke imo. Mods are for people who don't want the spend the time tweeking teh stock specs or need more gain than VH. Say judas priest or post '87 metal, with some exceptions.
I'm currently listening to kill emall on original press vinyl. holy heck does that tone rip your face off. It's all midrange no bass or treble and man it's like being hit by a freight train. Now that's a tone that you can only get from a cascaded marshall, but still only that one pre tube cascade and no other mods are needed to a metal panel spec SL


And we still haven't dealt with filtering ! There is just so much to mess with in a stock 67/8 SL who has time for 'gain' mods.
Again i'd recommend starting with ralle/ed's filtering specs as it ends up being a good happy medium. Only mess with them after you've tried everything else.

[rgalpin]

cool. you've got me sold on the whole approach. nice. is there a place where the ralle filter spec you reference is documented? or if anybody knows it off the top of their head - please post it here?

[Strat78]

Depends on what filtering Ralle was using that week. His old spec seemed pretty stiff, but he was cascading and also using his trusty JB, so I think he was trying to warm things back up: 20/20uf pre-amp, 50/50 screens, 100 mains and 50/50 PI (?). He even used a single 32 for the screens at one point when he was going in a particular direction. Think he was pretty much on board with the Friedman spec with a couple of cool twists last I heard.

[EJSLPlexi]

I still am floored by RALLE's "we die bold" clip using his 1400 wonder if he stayed with that tone?
it was dead ball's on accurate to the club days.
http://forum.metroamp.com/viewtopic.php?f=16&t=37837
and with some slight tweaking in sunset studio he would have nailed the VH I tone

[Jeremy1283]

All this talk of bias of the pre amp tubes. I dont understand how eds amp was bias if it has the same values we are using. Im confused.

[Strat78]

There is that pic floating around that shows Ed's pre-amp board, you can see the resistors for the pre's, well everything except the most important ones. I'm pretty sure V2A was an 820R resistor but you can't see what is under the philips .68 chicklet on V1B We have heard that it was a stock 820R, or a 820R Carbon Comp that drifted to 1.2k, or another person said it was 2.7k. Dave might have confirmed which was which but I don't remember. It's really that 820R position that effects the tone the most. But upping the 100k to 120k or 150k gives more gain too but I was not thrilled with that. These are all cool things to revisit from time to time. Maybe someone ells can explain why fixed resistors are used instead of little trimmer pots for the pre-amp tubes. I think Kevin uses a trim pot to dial that spot in, and replaces it with the same value resistor when he hits the sweet spot.

[awangotango]

first of all, the question implies that ed's marshall was super special. And it likely wasn't. It was just one of the good ones due to an accidental lineup of parts and values. Any marshall can be a good one if it's dialed in. Resistors drift wildly and start off wildly different from the factory. Add to that that each tube draws differntly and you can have huge difference in all 3 tubes compared to any other amp, even if you swap the exact tubes in it. As far as I see it, bias is the interaction of a given tube and it's feeding resistor network. It's not either or. It's both. But just swapping tubes can work fine. But to add more adjustablility, you can also mess with teh resistors. Without a wave generator etc it's all done by ear. With all the monkeying around ed did you think he didn't swap a ton of tubes in and out of his amps? by the time 1978 rolled around he found the combo that worked for him in that particular amp. You and I can do the same. You can go on ebay and get an RFT, a telefunken an amperex bugle, a sylvania. Get a few of each and you will find a trio that will work. Once you got that you can mess with the resistors to take it further.

the trim pot can be used in many places in teh amp to help dial it in. I seem to recall doing that with a feedback resistor. You need a pot with the right specs for one . I would guess depending on where it is it can be noisy for two. Ijust piggy back 'em. It is a hassle. It's a labour of love though. Nobody said dialing in an amp to dime with chime was easy. But if you're rabbets foot is working, it can be. If you don't believe in a higher power then it can feel like a lonely battle. And without a specturm analyzer to tell you where you are at in terms of odd/even harmonics, it can be tricky and hearing tone is just as much a talent as tapping. Ed had it all during the golden years. Ears and fingers and spirit.

[rgalpin]

... Ears and fingers and spirit.

inspiring analysis! nice.


there is one other element though... TIME! hahaha... you must have TIME.

i am determined to do this though. using this approach. i'm on the dime with chime train... both my SL's right now are messed up sounding pretty bad - one if just plain old garbage tone - the other has developed POPCORN - not sure where that is coming from but it's getting worse - so i am forced to record a project i'm working on with my old '72 Bassman. with both SL's just staring me down the whole time - but i don't have time right now to fix them - which basically means rebuild them since my troubleshooting electronics skills are ZERO - it either works or it doesn't. and don't look now but here comes Christmas - see you in 2015! hahaha...

strat78 - thanks for this: "20/20uf pre-amp, 50/50 screens, 100 mains and 50/50 PI "

[awangotango]

If anyone is pressed for time these days and you still own a tv, Dump that in the trash immediately and you'll find you've got time to burn. There's nothing but propiganda, perversion, and fals history on it anyway. And if still, no time, I don't know what df is charging these days but back in the day i recall sending $3-400. You'll only need to do it once. Otherwise you've got no choice but to do it yourself with your playing style.

I remember back in the early 90's i had a jcm900 it was ok and i went into a guit store an plugged into a circuit board 1987 4 hole. They had recently come out, the new revival series. I dimed it into a power brake and it was frickin perfect back inblack meets women and children. I couldn't believe it, It was like nothing i'd ever played through but I didn't know that amps were individual creatures. If I knew then what I know now I would have plunked down my savings and bought it on the spot because I'd not heard another reissue that came close to that one since. It must have had all the caps and resistors in order. The universe just put that one together right. Luck. To do that intentionally is possible but it seems to require Luck skill or time. WE do not have electronics skill, we admit, and time is at a premium, luck is up in the air and probably has somethind to do with karma so there's not alot we can do about it right now except live better and dropping any and all alcohol intake is my recomendation to anyone seeking better karma. It is an evul worthless liquid and all the worlds problems can be traced back to deals or people done under the influence of it's mind numbing affects. polyticians and big busniss men with their fancy 220k a shot steak and whisky lobby dinners being only one example. I propose it's easier to tune your amp when sober from booze. It not only clouds thinking but hearing as well. I cut it out 5 or so ago and haven't looked back. I'm not saying that is your problem but for some rason feel compelled to mention it since I know alot of guys imbibe the wicked ale. It doesn't help our soldering skills neither. If I sent a SL into df for dialin in these days i'd ask him to do it with two tubes pulled and a PT replacement of 570'ish volts. He already knows where to set the knobs if someone tells him that is what they are after, an amp that holds together dimed. The extra B+ helps with the chime. I'd also send it in with a dozen old pre tubes but that's me.



here's what it should sound like if you ask me. Id recommend you break out the turntable and play this album. They used a mix of a metal panel and a plexi. the compressed youtube clip doesn't do it justice. This album has serious stock non master tone. To my ears, it's pretty much what ralle had during his heyday.

http://www.youtube.com/watch?v=L6mZMFAu8BU

[rgalpin]

right on.

[awangotango]

http://www.youtube.com/watch?v=jS4NprloB-0


check out this tone. It sounds like a pretty cranked metal panel. Even in this low quality youtube clip you can hear that upper end chime and clang. It is very hard to get both the overdrive that this tone has while keeping the clean upper chime. You should hear this tone on a decent turntable with original vinyl ! yes it's two different guitar tracks, and likely two different amps but you can get a blend of it into one amp if you set out to do so.

tone check list:
chopped off bass - check
smooth overdriven mids - check
upper end chime and clang - check
minimal preamp distortion - check

Now imagine this tone but with the presence and bass cranked (which I don't believe he had), and you have the exact tone for unchained.



btw, for anyone interested in getting this tone, I can offer a few tips since this is my basic tone and is the sound of a SL which has been dialed in to chime while dimed and this is what it sounds like when you back it off back down to medium tone levels and maybe 7 on teh volume. Some tips. When I say the bass knob is cranked, it's not that the end tone is bassy. Contrary, you want to set up the amp so that even when the bass knob is jacked the end tone has no bass. It can be done by tube and compoment value choices and speaker choice. You want a worn out celestion m25. The older the better but you can use modern recreations. But if it has the modern extra doping i'd suggest you disolve some or most of it off. This loosens up the tone and decreases bass response.

The reason it's good to be able to use the bass knob instead of leaving it at 0 is because the 2 stage plexi really needs all teh gain it can get in order to get into ed territory and a bass knob on 0 is not only cutting bass it's cutting gain. So when you set up your amp while teh bass knob is at 10, you can then hang onto that gain but still get a tone with no bass. And all these old classic tones, including ed's, had absolutely zero bass. Cranking teh amp also cuts bass just by the nature of saturating teh transformers I believe so besides speaker and component choices, cranking the amp helps cut bass.

[rgalpin]

http://www.youtube.com/watch?v=jS4NprloB-0
Now imagine this tone but with the presence and bass cranked (which I don't believe he had), and you have the exact tone for unchained.

...

The reason it's good to be able to use the bass knob instead of leaving it at 0 is because the 2 stage plexi really needs all teh gain it can get in order to get into ed territory and a bass knob on 0 is not only cutting bass it's cutting gain. So when you set up your amp while teh bass knob is at 10, you can then hang onto that gain but still get a tone with no bass...

yup yup yup! great conversation - enjoying this stuff. awesome. i remember learning this a long time ago - but i never followed through by reverse tweaking the spec to sound great while dimed - especially including the bass knob dimed.

[rgorke]

Are you guys talking about adjusting the V1 plate resistors (100k) or the cathode circuit (2.7k/0.68uf) or both?

I have totally noticed the increase in gain diming the tone controls....especially trying to get the dutch treat tone.

[Strat78]

Seems like the cones start gripping the road a little better when playing very laud, but really, how many chances in a life time do we get to do that in todays world. I would argue that the 12xxx head is perfect. The thing to do is have a 50w head with a 2.7k V1b, 4ohm tap/100kNFB with a little push in front and mix both heads. The 50w has that great response when you really dig in: solidity to smeary squish like you hear in the RWTD riff leading into the second solo. This is why people like the 6-band, because it simulates this, but it is usually horribly abused as a certain dude demonstrated with his "case closed" clips.