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#1
So I came home today from Chapel Hill only to see that my hometown has completely been snowed out. Luckily, I missed the worst of it and got back to my folks' house before the snow got really bad (well... as bad as it's ever going to be in the piedmont triad, NC)

Either way, I picked a little something up on my way back.

It's...


A Marshall??? WHY does it have to be a Marshall?

Just kidding, I love this forum and it's Marshall-hate.

Anyway, I picked up this Marshall cabinet. It's an early '90s 1960ax. I'm going to pull the back and check the speaker codes tonight to make sure. The cab is a little beat up, but I got it for a great price so it's not like I can really complain, plus, I like the look. However, at some point over winter break, I may take on the project to retolex and stick a new salt and pepper grill cloth on it. I also make it a point to replace Marshall 1960 cabinet backs with birch ply panels.


(in halfstack form)

And now... the really cool part...





Q: Why do I need a stack?
A: I don't

Clips will come later.


I'm not going to lie, I'm still not 100% satisfied with my sound, but it's closer to what I want. Now... a question for the amp techs who know more than me.

I've always felt the amp was too bright, too stiff and too thin sounding compared to how a JTM45 should sound and after going over and over the innards of my amp to try and find a mistake that I might have made in the wiring or anywhere the lead dress was poor and couldn't find anything. It was driving me insane, but I've realized why my amp might sound stiff, thin and bright, and also why I couldn't coax as much gain out of it as I would like. An original JTM45 sounds fat, warm and woody, and I believe the reason mine sounds relatively clean and bright is because of a decision I made whilst building the amp to over filter the PI (32uF instead of the vintage correct value of 16 uF). I upped the filtering 1) because of the JTM45's notorious low end which can tend to mush out, thus to make the amp tighter and cleaner, 2) to reduce ghosting. So my question is, am I reasonable in this assumption that if I lower the filtering in the PI (from 32 uF to 16 uF), that it will make a pretty noticeable difference and should make the amp spongier, bluesier and get rid of that overly bright high end and stiff tone that has just been killing me lately?
Last edited by al112987 at Dec 18, 2009,
#2
Dude....nice HNAD. Rock on
"Steven Seagal is like godzilla for barbies" -> Retard
#3
Quote by al112987
So I came home today from Chapel Hill only to see that my hometown has completely been snowed out. Luckily, I missed the worst of it and got back to my folks' house before the snow got really bad (well... as bad as it's ever going to be in the piedmont triad, NC)

Either way, I picked a little something up on my way back.

It's...


A Marshall??? WHY does it have to be a Marshall?

Just kidding, I love this forum and it's Marshall-hate.

Anyway, I picked up this Marshall cabinet. It's an early '90s 1960ax. I'm going to pull the back and check the speaker codes tonight to make sure. The cab is a little beat up, but I got it for a great price so it's not like I can really complain, plus, I like the look. However, at some point over winter break, I may take on the project to retolex and stick a new salt and pepper grill cloth on it. I also make it a point to replace Marshall 1960 cabinet backs with birch ply panels.


(in halfstack form)

And now... the really cool part...





Clips will come later.


I'm not going to lie, I'm still not 100% satisfied with my sound, but it's closer to what I want. Now... a question for the amp techs who know more than me.

I've always felt the amp was too bright, too stiff and too thin sounding compared to how a JTM45 should sound and after going over and over the innards of my amp to try and find a mistake that I might have made in the wiring or anywhere the lead dress was poor and couldn't find anything. It was driving me insane, but I've realized why my amp might sound stiff, thin and bright, and also why I couldn't coax as much gain out of it as I would like. An original JTM45 sounds fat, warm and woody, and I believe the reason mine sounds relatively clean and bright is because of a decision I made whilst building the amp to over filter the PI (32uF instead of the vintage correct value of 16 uF). I upped the filtering 1) because of the JTM45's notorious low end which can tend to mush out, thus to make the amp tighter and cleaner, 2) to reduce ghosting. So my question is, am I reasonable in this assumption that if I lower the filtering in the PI (from 32 uF to 16 uF), that it will make a pretty noticeable difference and should make the amp spongier, bluesier and get rid of that overly bright high end and stiff tone that has just been killing me lately?


You doubled the mico farads. In some cases, that's a pretty big difference. You might have answered your own question there. I suspect anything you did to that amp that would be different from the original is suspect for your tone deficiency.

BTW sweet cab!
Tastes like chicken, if chicken was a candy.
Last edited by ConfederateAxe at Dec 18, 2009,
#4
badass

no idea on the technical question, sorry
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
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I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

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#5
thanks for the input, if it can cause a big difference then I'll go ahead and make the change, changing it back down to 16uF at the PI is no big problem, the PI filter cap is a dual 16 uF, I'll just disconnect one positive terminal and might solve all the tone problems that I have been having.

just making sure here though, the higher filtering does cause an amp to sound brighter, cleaner, stiffer and more brittle? correct?
Last edited by al112987 at Dec 18, 2009,
#6
The higher your filtering caps, the stiffer and tighter your tone will be. One of the symptoms of failing filter caps is a muddier and noisier tone, particularly in the low end, so therefore if you OVER filter, ur tone is gonna tighten up, and it's likely responsible for your bright top end.
Tastes like chicken, if chicken was a candy.
#7
Leave that cab the way it is!! It has so much street cred.

At least your work didnt catch on fire
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#8
IMO that's too much filtering on the PI for that amp. You've got to let it breathe a little bit. You can tighten up the filtering on the power tubes if the bass is bugging you, (I hope you're using metal film resistors in the preamp, that will help too) but the PI in that amp has to be a little bit sloppy for the amp to sound right. A fair bit of the overdrive you're hearing is the PI breaking up and if you filter too much the PI isn't adding anything to the mix. Another thing you could do in your situation would be to bump up the cathode bypass cap for the second preamp gain stage and remove it completely for the first. That gives you a little more openness and depth of sound without losing too much clarity.
#9
That's one sexy cab, TS! Congrats!

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[quote="'[BurnTheDusk"]']Boss pedals may be built like tanks but I would rather buy a cardboard box that is on my side than pay for a tank that is working against me.
#10
That cab is uber-badass.

HNCD!
Quote by Marty Friedman
Because I bend in such an unorthodox fashion; the notes kinda slide up and slide down...
#11
Wow, great stuff. Does the fullstack live up to the hype? It sounds like you've got your tech question covered, not that I could have helped.
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BURN THE WITCH!!!!!
#12
Quote by Roc8995
IMO that's too much filtering on the PI for that amp. You've got to let it breathe a little bit. You can tighten up the filtering on the power tubes if the bass is bugging you, (I hope you're using metal film resistors in the preamp, that will help too) but the PI in that amp has to be a little bit sloppy for the amp to sound right. A fair bit of the overdrive you're hearing is the PI breaking up and if you filter too much the PI isn't adding anything to the mix. Another thing you could do in your situation would be to bump up the cathode bypass cap for the second preamp gain stage and remove it completely for the first. That gives you a little more openness and depth of sound without losing too much clarity.
Thanks Colin, I thought it might have been too much, a Bassman used 8 uF on the PI and the '65 JTM45s used 16, some folks on the Metroamp forum said they liked using 32 though so I figured I'd give it a try that first time, never even occured to me until today that it was likely the problem (big thing that got me thinking about the filtering was the relative lack of gain that I was getting).
Quote by tubetime86
Wow, great stuff. Does the fullstack live up to the hype? It sounds like you've got your tech question covered, not that I could have helped.
Well... it does... sort of. I honestly cannot see this being that useful at all. BUT, there is NOTHING like standing in front of it, volume on 10 on both channels, guitar on 10 and just busting out the chords to Free's "Alright Now"
Last edited by al112987 at Dec 18, 2009,
#13
Quote by al112987
.BUT, there is NOTHING like standing in front of it, volume on 10 on both channels, guitar on 10 and just busting out the chords to Free's "Alright Now"



I couldn't agree more. Best freaking riff ever for a classic, cranked tone.
Tastes like chicken, if chicken was a candy.
#14
Go back to the 16mF.

Did you happen to buy that cab from a local cover band? Because my friend's band recently played a show in Glade Springs VA with a cover band who let them borrow their 1960AX cabs and they looked pretty beat up

HNGD! I love those cabs
Quote by Roc8995
IMO that's too much filtering on the PI for that amp. You've got to let it breathe a little bit. You can tighten up the filtering on the power tubes if the bass is bugging you, (I hope you're using metal film resistors in the preamp, that will help too) but the PI in that amp has to be a little bit sloppy for the amp to sound right. A fair bit of the overdrive you're hearing is the PI breaking up and if you filter too much the PI isn't adding anything to the mix. Another thing you could do in your situation would be to bump up the cathode bypass cap for the second preamp gain stage and remove it completely for the first. That gives you a little more openness and depth of sound without losing too much clarity.

Couldn't he run the 16mF filter cap and just use an NOS 5751 in the PI to add clarity and depth? I know that the JAN Phillips I have in my Randall certainly turned it into a whole new beast...
Then there's this band called Slice The Cake...

Bunch of faggots putting random riffs together and calling it "progressive" deathcore.
Stupid name.
Probably picked "for teh lulz"

Mod in UG's Official Gain Whores
Last edited by Shinozoku at Dec 18, 2009,
#16
\8-0



Quote by al112987


Last edited by sethp at Dec 18, 2009,
#17
While a lower gain PI wouldn't be a bad idea, the voicing would not be very similar to changing the cathode bypass caps. The idea behind the bypass caps is to leave the gain the same while showing the PI a more uniform signal, so that the clarity is already there and you get a bit more bite by the time the second gain stage clips. The lower gain PI will increase the clarity at the PI position but it can't change what input signal the PI sees.
#18
Ah, okay.

Jan Phillips, JAN GE, or Raytheon work great for such a purpose, though Just something to try next time you have a spare $20 And they're all tough as nails and should last for ages.
Then there's this band called Slice The Cake...

Bunch of faggots putting random riffs together and calling it "progressive" deathcore.
Stupid name.
Probably picked "for teh lulz"

Mod in UG's Official Gain Whores
#19
i think i'll start with lowering the filtering. does that help any as far as reducing high end? unfortunately, i have very bad amp know-how as far as how things actually affect tone.
#20
al112987, just curious, I didn't know you liked 1960 cabs?
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#23
Quote by al112987
i think i'll start with lowering the filtering. does that help any as far as reducing high end? unfortunately, i have very bad amp know-how as far as how things actually affect tone.


Since it's the PI, I'd say that has an awful lot to do with your high end, Since your PI is so fundamentally responsible for your tone in the way it distorts and breaks down.
Tastes like chicken, if chicken was a candy.
#24
Quote by acdclandon
al112987, just curious, I didn't know you liked 1960 cabs?
I don't really, but it's not like I dislike them either. I think they're horrendously overpriced. $800 for the 1960a/b, $1100 for the 1960ax/bx and $1200 for the 1960ahw/bhw. Ironically, the 1960hw cabs were the best value as they have the all birch ply construction and use heritage G12H30 greenbacks, which are amazing speakers. All for only $100 more than the 1960ax which uses normal 1960 cab construction with the MDF back and normal MIC reissue G12M greenbacks. They're solid cabs, are *generally* well constructed and use decent speakers, but there are things I don't like about them. I don't like the MDF back panel and some of the ones from recent years have suspect build quality compared to other high end cabs in that price range. But there is great upside to these cabs, the older ones are pretty good, not as good as vintage Marshall 4x12s, but not really any worse than most of your high end 4x12s. The JCM800 and JCM900 1960 cabs generally have consistently good build quality and generally sound pretty good. Also, another thing about these cabs are, that they can be had for cheap used, and for me, I prefer used cabinets for the reason that the speakers have been broken in. The 1960ax I bought is in good condition and I got it for a great price, the grillclotch has some tears. The speakers are well broken in and are the older English Greenback reissues rather than the new Chinese ones which can be pretty rank sounding. I don't know if the British ones are actually better, or if I have just never played a Chinese set that was properly broken in so I can't really say. I'm going to replace the back panel with one of 1/2" birch ply and retolex, at the very least a new grill cloth as this one has tears. In total, once I'm done, I'll have a very good cabinet for just over $500 total (and that's INCLUDING the costs of restorations).
Quote by ConfederateAxe
Since it's the PI, I'd say that has an awful lot to do with your high end, Since your PI is so fundamentally responsible for your tone in the way it distorts and breaks down.
Ok, thats good, it gives me something to do then, before I had been sitting, scratching my head wondering if the obnoxious high end had to do with bad lead dressing that was causing parasitic oscillations somewhere, or a faulty component somewhere in the amp and was just driving me insane. Thanks for the tip.
Last edited by al112987 at Dec 18, 2009,
#26
So Full of Freaking Awesomeness!!!!


cheers dude. soon we'll be amp buddies....well kind of...haha
Quote by gregs1020
Brett has been saving for a splawn for 4 years
countries have been toppled in the time it's taking, revolutions won got a black pres

yawn


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When he finally gets one it'll probably be televised like the Berlin Wall coming down.
The end of an era
#27
Haha thanks guys, now if I could only find a reason to play this setup out... I'd love to gig with it and tear the place down with the hammer of the gods.

Quote by Bostonrocks
So Full of Freaking Awesomeness!!!!


cheers dude. soon we'll be amp buddies....well kind of...haha
What do you ahve coming???
#28
Not a JTM45 ha

a 74x
Quote by gregs1020
Brett has been saving for a splawn for 4 years
countries have been toppled in the time it's taking, revolutions won got a black pres

yawn


Quote by bubb_tubbs
When he finally gets one it'll probably be televised like the Berlin Wall coming down.
The end of an era
#29
Wow Andrew


I knew you were moving to full stack but in doesn't settle in until you see it. I guess hearing it is something special. Do you wear ear protection when you do that

HNCD


Can't really help on the tech question but I put a JAN Phillips in my PI and like it lots. +1 on the G12H30, I have one. But only one.
#30
Yeah, ear protection is amust with this thing, play two chords and your ears are ringing and that is with a 35 watt head. I can't even imagine the full power of something like a super lead blowing through two 4x12s. It's crazy.

The fullstack thing is temporary, until I can sell off the 1960b. It doesn't suit this amp and doesn't good with this amp and really I have zero use for it, the greenback loaded cabinet is great for this amp, but as a 4x12, you don't get that characteristic greenback snarl unless you pump a ton of volume into it. Once I get the amp running at 10, the speakers break up very nicely. Otherwise when I split it between 2 cabs, it doesn't break up. Here is the thing, I felt obligated to buy the 1960ax. I got it for nearly the same price as my 1960b, which I already thought was a decent price. I simply could not pass it up.

I almost blew my money on two '68 pre-Rola Celestion G12H30 bass speakers last week too, but when I inquired about them, the seller pulled them from the Ebay auction. It's unfortunate, they were in great condition, and the seller had no clue what they were worth, with only a little bit of bid time left, they were sitting at a single bid of $50!!! Insane, I was about to offer $500 straight up for the pair (and even that would've been a huge low balling job as they're worth about $450 a piece), but I asked about the date code and they decided they needed to do more research before selling them...
Last edited by al112987 at Dec 19, 2009,
#32
Quote by Bostonrocks
Not a JTM45 ha

a 74x
sweet. if it has a plexi panel, then you can join the plexi club!
#33
Great cab, man! I really wish I had a rig like that.

Btw, I wouldn't do anything to that cab. It has some seriously sexy mojo going on there.

Are you a student at UNC? Just wondering because I happen to be a huge UNC basketball fan and you mentioned Chapel Hill.
#34
I am infact a student at UNC, and currently about to toss my guitar the TV with all the turnovers and lack of rebounding against Texas.

our seniors were worthless today.


edit: ok, took the amp apart, changed the filtering at the PI back to 16uF. Amazingly enough, I'm getting no ghosting, even less than before. Really odd. Generally amp sounds a bit more open, high end is tamed a little bit, but there is still more compression than I'd like and the tone is still too barky, bright and grinding, but I know part of that has to do with having EL34s whilst a typical JTM45 has KT66s which would give me a smoother, thicker, tone.
Last edited by al112987 at Dec 19, 2009,
#35
Quote by al112987
I am infact a student at UNC, and currently about to toss my guitar the TV with all the turnovers and lack of rebounding against Texas.

our seniors were worthless today.


edit: ok, took the amp apart, changed the filtering at the PI back to 16uF. Amazingly enough, I'm getting no ghosting, even less than before. Really odd. Generally amp sounds a bit more open, high end is tamed a little bit, but there is still more compression than I'd like and the tone is still too barky, bright and grinding, but I know part of that has to do with having EL34s whilst a typical JTM45 has KT66s which would give me a smoother, thicker, tone.



Sweet. Nice to see you made some tonal progress! That does seem odd that you're encountering less ghosting, since theoretically the less capacitance, the more potential there is for it. It might have to do with the way the capacitance value corresponds with the values of other components in its path.
Tastes like chicken, if chicken was a candy.
#36
Marshalls ****ing suck. What the hell were you thinking!?!?


HNAD!
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maybe you're not saying the right things? an amp likes to know you care.





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#37
sweet cab drew. dont change a thing. congrats.
I wondered why the frisbee was getting bigger, then it hit me.
#39
Quote by ConfederateAxe
Sweet. Nice to see you made some tonal progress! That does seem odd that you're encountering less ghosting, since theoretically the less capacitance, the more potential there is for it. It might have to do with the way the capacitance value corresponds with the values of other components in its path.
I know, it seems strange to me as well, less ghosting and less noise in general. I wonder if I did it correctly, the filter cap is a 16uFx16uF cap and I had the two positive terminals bridged for 32 uF and disconnected one positive terminal for 16 uF, correct? Yeah, I've been getting less noise, and less ghosting afterwards, and this is really saying something as it was having some serious ghosting issues beforehand. I do enjoy it more and cutting the bright cap also makes the amp actually usable at low volumes, beautiful, open sounding clean tones.
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