Fender vs. Marshall - just how diff will they sound ?

SlowGroove

SlowGroove

New member
Here is a Fender vs. Marshall question for everyone who love the vintage side of amp tones !

We all know that a Marshall JTM45 is very simmilar in circuit design to the Fender 4X10 Bassman.

So, just how diff, or simmilar, will they sound, IF, you AB a current '59 Bassman RI combo against a Marshall JTM45 head ontop of a well made all Pine dove-tail 4X10 cab, with the exact same *speakers as the Bassman ?

* Jensen P10R speakers

Will they sound miles apart, or will there be some similarities ?

Over to you . . .



James
 
Re: Fender vs. Marshall - just how diff will they sound ?

There will definitely be similarities, but they will sound a bit different also. They are different enough to sound different both when pushed into distortion and clean. The tone stack is different and the negative feedback is different not to mention the difference in the output tubes (assuming you have KT66 tubes in the JTM). The JTM will be a bit more midrangey when distorting methinks. The speakers could play a major role in how different they sound if they emphasize frequencies outside of the midrange.
 
Re: Fender vs. Marshall - just how diff will they sound ?

Gr8Scott said:
There will definitely be similarities, but they will sound a bit different also. They are different enough to sound different both when pushed into distortion and clean. The tone stack is different and the negative feedback is different not to mention the difference in the output tubes (assuming you have KT66 tubes in the JTM). The JTM will be a bit more midrangey when distorting methinks. The speakers could play a major role in how different they sound if they emphasize frequencies outside of the midrange.
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Thanx ;)

That is why i made a point to mention that this AB test will have the same speakers in the both cabs, to make even out the playing field a bit.

I take it the Marshall will have a slightly warmer clean tone ?


James
 
Re: Fender vs. Marshall - just how diff will they sound ?

SlowGroove said:
I take it the Marshall will have a slightly warmer clean tone ?
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Actually they would be comparable. The trick is going to be tubes. The KT66s are going to be throatier and meatier than a 6L6 is. The 4x10s give you a depth and swirl that a 4x12 doesn't have. Now using the same speakers that's negated, however the bassman is still a bass a bass tuning and the JTM does too but not quite as heavily tuned for bass. The Bassman is, IMO, more scooped than some of the other tweeds I've heard due to that tuning.

Luke
 
Re: Fender vs. Marshall - just how diff will they sound ?

Luke Duke said:
Actually they would be comparable. The trick is going to be tubes. The KT66s are going to be throatier and meatier than a 6L6 is. The 4x10s give you a depth and swirl that a 4x12 doesn't have. Now using the same speakers that's negated, however the bassman is still a bass a bass tuning and the JTM does too but not quite as heavily tuned for bass. The Bassman is, IMO, more scooped than some of the other tweeds I've heard due to that tuning.

Luke
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I do not know anyone who is still using the 4x10 Bassman as a Bass amp . . . not since the 60's any ways !
(is that what you mean by a bass tuning ?)


James
 
Re: Fender vs. Marshall - just how diff will they sound ?

I think he meant that the Bassman is more voiced towards actual basses?

Might be wrong though.
 
Re: Fender vs. Marshall - just how diff will they sound ?

SlowGroove said:
I do not know anyone who is still using the 4x10 Bassman as a Bass amp . . . not since the 60's any ways !
(is that what you mean by a bass tuning ?)


James
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One's perception and reality are not one in the same. The fact that guitarists love and use a bassman doesn't mean it is no longer a bass amp. The Bassman was designed and tuned as a bass amp. That makes the tuning different than other tweeds. The Bassman had a bit more headroom due to wattage, it was 4x10s so it was punchier and tighter as well. It was designed for use with a P-Bass so Leo sucked out some of the mids to keep it crisp sounding.

As marvar said the tone network is different resulting in the Bassmans being more effective at all volumes whereas the Marshall's tone network is most effective when the amp is running hard.

Luke
 
Re: Fender vs. Marshall - just how diff will they sound ?

marvar said:
the tone stacks of those two amps plot completly different, they will never sound that much alike- some similarities maybe, also you have to account for speakers, speaker sizes, and cabinet construction.
here- look at these graphs
http://www.guitaramplifierblueprinting.com/differences.html
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That is why i said in post #1 that the same speakers will be used, aswell as almost identical 4x10 open back Pine cabs.


James
 
Re: Fender vs. Marshall - just how diff will they sound ?

Marshall tone tends to be a bit tighter in the lows and crunchier in the mids.

The Bassman will have more lows and while having plenty of mids, might sound 'scooped' compared to the marshall.

Both will sound great and i wouldn't believe anybody in a crowded bar at a rock show if they said they could tell them apart.
 
Re: Fender vs. Marshall - just how diff will they sound ?

My JTM clone has a HUGE bottom end. I'd say it's bigger than the blackfaced bassman I have to be honest. Mine was built by Scott_F, so it's not going to be exactly the same as a RI JTM amp would be.
 
Re: Fender vs. Marshall - just how diff will they sound ?

Empty Pockets said:
Marshall tone tends to be a bit tighter in the lows and crunchier in the mids.

The Bassman will have more lows and while having plenty of mids, might sound 'scooped' compared to the marshall.

Both will sound great and i wouldn't believe anybody in a crowded bar at a rock show if they said they could tell them apart.
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WOW . . . that close !

Thanx man !


Gr8Scott said:
My JTM clone has a HUGE bottom end. I'd say it's bigger than the blackfaced bassman I have to be honest. Mine was built by Scott_F, so it's not going to be exactly the same as a RI JTM amp would be.
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How would your clone differ from a 'regular' JTM45 then ?
Please do tell . . . just what was done to your amp ? Hot Rodded ?

Thanks

James
 
Re: Fender vs. Marshall - just how diff will they sound ?

Most RI 4-10 bassmans are running a plug in SS rectifier while almost all JTM45's run a GZ34 tube rectifier. The use of the plug in rectifier on the Tweed makes it tighter, cleaner, and louder, than it would be with a 5AR4 (GZ34) rectifier.

My JTM45 also has huge bottom end using KT66 tubes and 12" speakers. Compared to a 50 watt plexi with the SS rectification, the plexi needs to be run through a 4x12 to get the bottom of the JTM45 through a 2x12. Compared to my Jubilee you must Eq it very differently. To get as much bottom as the JTM45 with the bass knob on 2, you must turn the bass knob way up to about 6. Playing the JTM through a 4x10 cab I don't know how it would compare? I know that the old SF bassman I had didn't have the bottom end of my JTM45 through a 4x12, but that's a different amp than a 5F6A circuit.

Speaking of the diffrences between the Tweed and the JTM45 Ken Bran was qouted by Doyle as follows:

..I beleieve among other changes I changed the coupling caps to the output stage (will tighten or loosen things up quite a bit-my comment) and varied the amount of smothing on the HT line. The JTM45 also had a different harmonics content, and this was due to the large amount of (negative) feedback I had given to it....My workshop speaker cab had two Celestion Vox speakers, and I had always used Celestions...this and changes made by different make and tolerences of componants made up the marshall sound..By the way it was a bass amp we wanted. It was to replace the Leak amps we were selling for bass; but the guitar sound was to good to pass up

And in other detail comparisons Marshall engineer Steve Grindrod made a few comments:

For what it's worth, I have a Fender Deluxe reverb that I modified to the power amp to Vibrolux AA964 specs, but using JTM45 transformers-and guess what: it still sounds like a Fender

but he also stated:

the biggest difference apart from tranformers, is that while the power amp circuit is pretty much identical, the feedback circuit however, is taken from the 2-ohm tap on the bassman and the 16-ohm tap on the JTM45. With the amp running (clean) this means there are is nearly three times the voltage being fed back into the feedback circuit which must effect something (actually by my experience greater NFB increases clean head room-my comment) On overdrive feedback theory goes completely out the window particularly with valve amps and effects things even more. In real terms this means 1 the output impedance, loading, and (speaker) damping are way different, especially what's reflected back to the ouput valves (that are KT66 and not 5881) hence different harmonics ratio and different frequency/impedance sensitivity, and 2, the input sensitivity of the power amp is diffrent, therefore the ratio of preamp to power amp distortion is affected, giving rise to a totally fresh mix of harmonics

I think this all means is that even with the same speakers the amps don't sound the same at all. The JTM45 is comparitively higher headroom by my experience, but once finally kicked over the brink into overdrve it is a very different distortion voicing, and this matches the technical information these guys are giving.
 
Re: Fender vs. Marshall - just how diff will they sound ?

What marvar and Empty Pockets said is the most pertinent - the tone stacks and feedback design give Marshalls much more in the mid range than the Fender (we're talking "generally" here). End result is Fender have deep balls and singing highs where the Marshall honks and growls at you, everything else being equal. But the guys are right - the Marshall needs a 4x12 sealed back to show off it's sound - and immediately things are starting to change from the Fender's 4x10 open back.....

Oh, and James - my '62 bassman 6G6-A went to a rocker in the Czech Republic for nearly £700 and has been replaced by a Traynor YGL-3 Mk.III combo with old Greenbacks - it's a Fender Twin Reverb on Marshall steroids - best of both worlds - yah ever get a chance to - try one.
 
Re: Fender vs. Marshall - just how diff will they sound ?

Lake Placid Blues said:
My JTM45 also has huge bottom end using KT66 tubes and 12" speakers. Compared to a 50 watt plexi with the SS rectification, the plexi needs to be run through a 4x12 to get the bottom of the JTM45 through a 2x12. Compared to my Jubilee you must Eq it very differently. To get as much bottom as the JTM45 with the bass knob on 2, you must turn the bass knob way up to about 6.

Speaking of the diffrences between the Tweed and the JTM45 Ken Bran was qouted by Doyle as follows:

..I beleieve among other changes I changed the coupling caps to the output stage (will tighten or loosen things up quite a bit-my comment) and varied the amount of smothing on the HT line.

For what it's worth, I have a Fender Deluxe reverb that I modified to the power amp to Vibrolux AA964 specs, but using JTM45 transformers-and guess what: it still sounds like a Fender
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Oh boy - a looser JTM45 is something i deff want to hear !
I can not stand tight low ends. That is also why i do not like 90% of todays modern voiced amps !

So the JTM45's have massive amounts of low end, compared to most other (Jubilee, Plexi'x and what not) Marshalls then ?


Thermionik said:
Oh, and James - my '62 bassman 6G6-A went to a rocker in the Czech Republic for nearly £700 and has been replaced by a Traynor YGL-3 Mk.III combo with old Greenbacks - it's a Fender Twin Reverb on Marshall steroids - best of both worlds - yah ever get a chance to - try one.
Click to expand...

Thank you . . . i will deff if i come across one ;)


James
 
Re: Fender vs. Marshall - just how diff will they sound ?

SlowGroove said:
Oh boy - a looser JTM45 is something i deff want to hear !
I can not stand tight low ends. That is also why i do not like 90% of todays modern voiced amps !

So the JTM45's have massive amounts of low end, compared to most other (Jubilee, Plexi'x and what not) Marshalls then ?




Thank you . . . i will deff if i come across one ;)


James
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I checked the published schematics of the Fender 5F6-A vs those of the JTM45. Although Bran seems to remember there being a difference in coupling cap values, the schems show them to be the same. Additionally there's no difference in the tone stacks between them either.

There are crucial changes between the JTM45/Tweed and the later plexis with solid state rectifiers though. The tone stack on the SS rectified Marshalls uses a 33k slope resistor and 500pf treble cap, instead of the 56k and 270pf treble cap as on the 45/Tweeds. The coupling caps in the power amps are different too. These coupling cap changes will make the SS rectified plexis considerably tighter. The SS plexis also took the negative feedback from the 8 ohm tap (with EL34) and used a different NFB resistor. The combination of differing coupling caps, power supply (higher voltages and much higher filtering) and rectification methods, tone stack, and NFB changes made the SS rectified plexis different. A tighter, brighter, but dirtier, sound.

The SS rectified amps for bass such as the 1992 (100 watt) and 1986 50 watt as used by Duane Allman kept most of the JTM45 specs in these small details, because of the bigger bottom end. These models are interesting because they combine the SS rectifier and power supply, and EL34's, with the JTM45 type specs.

Some Marshall JTM45's also used 470k mix resistors (as does the re-issue) and higher value bright caps on the treble channal compared to the Tweed.
 
Re: Fender vs. Marshall - just how diff will they sound ?

empty pockets said:
marshall tone tends to be a bit tighter in the lows and crunchier in the mids.

The bassman will have more lows and while having plenty of mids, might sound 'scooped' compared to the marshall.

Both will sound great and i wouldn't believe anybody in a crowded bar at a rock show if they said they could tell them apart.
Click to expand...

big +1
 
Re: Fender vs. Marshall - just how diff will they sound ?

just fwiw.... Both these amps used carbon composition resistors which change value depending upon the temperature in which they are exposed to. (take a reading for a true CC resistor and then heat it up and see how far it drifts off, you might be surprised..)

5F6-A's chassis has the tubes facing downward, the JTM45 has the tubes facing towards the top. Why does this matter?? Heat rises! Marshall's usually have tubes facing up, Fender's usually face down.

Just one small thing to think about.

Jeff
 
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