Marshall Major: Differences between Lead and Bass models.

corey from doomshade · 07-02-2009, 12:16 AM

As stated above, I am interested in gathering the necessary info to modify my 1969 Major to Major Bass configuration. Cost is no object, as long as it's not much lol. Seriously, though, info, or a hook to a real amp tech near KC who's familiar with these amps would be appreciated. Tx. Corey PS, I am not altogether sure of the exact current setup of my two Majors. I may need a tech who can think outside the box.

felim · 07-02-2009, 04:11 AM

Schematics here if you don't have them already:

Marshall Amps Info & Schematics

Wouldn't have a clue as to an amp tech for you though...I live in Ireland.

PaoloJM · 07-03-2009, 07:05 AM

Quote:

Originally Posted by felim

Schematics here if you don't have them already:

Marshall Amps Info & Schematics

Wouldn't have a clue as to an amp tech for you though...I live in Ireland.

OP, sorry to but in.
felim, Where you from? I'm down in Cork myself

corey from doomshade · 07-04-2009, 12:55 AM

Maybe someone can tell me if the OP trannys are the same between the bass and lead models? How about on the Super Lead vs. Super Bass?

rockinr0ll · 07-04-2009, 02:21 AM

Cut the bright cap if it has one, most of the leads have those. Bass Models usually don't. Good luck.

pleximajor · 07-04-2009, 03:51 PM

v1 12ax7 in the bass share the same byass cap and bias resistor for each have of 12ax7 the lead doesnot..
bass has 250 pf coupling cap the lead had 500pf for treb..
coupling cap in driver v3 is .047mf in lead .47mf in bass

corey from doomshade · 07-07-2009, 10:42 PM

Sorry I've been on the road for a couple of days. I appreciate the replys and especially the boilerroom technical data. THAT'S why I asked you guys. Corey from Doomshade.

corey from doomshade · 07-07-2009, 10:46 PM

Quote:

Originally Posted by pleximajor

v1 12ax7 in the bass share the same byass cap and bias resistor for each have of 12ax7 the lead doesnot..
bass has 250 pf coupling cap the lead had 500pf for treb..
coupling cap in driver v3 is .047mf in lead .47mf in bass

Those capa

citors are amazing little things, aren't they?

felim · 07-08-2009, 05:11 AM

Quote:

Originally Posted by PaoloJM

OP, sorry to but in.
felim, Where you from? I'm down in Cork myself

Hey Paolo. I'm in Ennis. I've seen your username on boards.ie intsrument section a few times. You've even helped me out with a few posts

Reginald · 07-08-2009, 06:50 AM

Hi all folks,I'm Reginald and I'm a new member....sorry for my english...I'm italian...so
I saw in Major circuitry that there's the MAJOR AMP 200 (that it shouldn't be the model 1967 lead) ....What's this?
and what's differences from MAJOR lead model 1967?

joshuaaewallen · 07-08-2009, 08:09 AM

Quote:

Originally Posted by corey from doomshade

As stated above, I am interested in gathering the necessary info to modify my 1969 Major to Major Bass configuration. Cost is no object, as long as it's not much lol. Seriously, though, info, or a hook to a real amp tech near KC who's familiar with these amps would be appreciated. Tx. Corey PS, I am not altogether sure of the exact current setup of my two Majors. I may need a tech who can think outside the box.

Hi Corey...

I'm not much help on your thread about converting your Marshall Major...

However... You ma check with MartyStrat54 as to a tech near KC... I believe he is down in that area. Plus he's a pretty knowledgeable guy who's posted quite a bit of valuable info on the forum... I hope this helps in your search for a good tech.

pleximajor · 07-08-2009, 11:57 AM

im in st louis ....i can work on your major.....i have a 69 major

corey from doomshade · 07-09-2009, 11:33 AM

Hey thanks for the info, yaaaaaaaaaaaalll. First thing to do is find out what, if any mods have already been done. I'm going to try to post some detailed pics of my amp. One thing is certain, she's a powerhouse. Last night, after a "few" drinks, I sat with my 6string bass (active and really hot) and one 1510 Marshall cab, and just sat there and blasted myself with massive chords. It was around 100 degrees in here, and the air blast pumping from the speakers was fanning me pretty good. Channel one gain on 8, bass and mid pegged, treble and presence on 3. I probably should've worn ear plugs..................

07-02-2009, 12:16 AM	#1 (permalink)
corey from doomshade Junior Member Join Date: Jun 2009 Location: Belton, Mo Posts: 19	Marshall Major: Differences between Lead and Bass models. As stated above, I am interested in gathering the necessary info to modify my 1969 Major to Major Bass configuration. Cost is no object, as long as it's not much lol. Seriously, though, info, or a hook to a real amp tech near KC who's familiar with these amps would be appreciated. Tx. Corey PS, I am not altogether sure of the exact current setup of my two Majors. I may need a tech who can think outside the box.

07-02-2009, 04:11 AM	#2 (permalink)
felim Member Join Date: Jun 2008 Posts: 64	Re: Marshall Major: Differences between Lead and Bass models. Schematics here if you don't have them already: Marshall Amps Info & Schematics Wouldn't have a clue as to an amp tech for you though...I live in Ireland.

07-04-2009, 12:55 AM	#4 (permalink)
corey from doomshade Junior Member Join Date: Jun 2009 Location: Belton, Mo Posts: 19	Re: Marshall Major: Differences between Lead and Bass models. Maybe someone can tell me if the OP trannys are the same between the bass and lead models? How about on the Super Lead vs. Super Bass?

07-04-2009, 02:21 AM	#5 (permalink)
rockinr0ll Senior Member Join Date: Feb 2009 Posts: 1,245	Re: Marshall Major: Differences between Lead and Bass models. Cut the bright cap if it has one, most of the leads have those. Bass Models usually don't. Good luck.

07-04-2009, 03:51 PM	#6 (permalink)
pleximajor Member Join Date: May 2009 Posts: 41	Re: Marshall Major: Differences between Lead and Bass models. v1 12ax7 in the bass share the same byass cap and bias resistor for each have of 12ax7 the lead doesnot.. bass has 250 pf coupling cap the lead had 500pf for treb.. coupling cap in driver v3 is .047mf in lead .47mf in bass

07-07-2009, 10:42 PM	#7 (permalink)
corey from doomshade Junior Member Join Date: Jun 2009 Location: Belton, Mo Posts: 19	Re: Marshall Major: Differences between Lead and Bass models. Sorry I've been on the road for a couple of days. I appreciate the replys and especially the boilerroom technical data. THAT'S why I asked you guys. Corey from Doomshade.

07-08-2009, 06:50 AM	#10 (permalink)
Reginald Member Join Date: Jul 2009 Posts: 75	Re: Marshall Major: Differences between Lead and Bass models. Hi all folks,I'm Reginald and I'm a new member....sorry for my english...I'm italian...so I saw in Major circuitry that there's the MAJOR AMP 200 (that it shouldn't be the model 1967 lead) ....What's this? and what's differences from MAJOR lead model 1967?

07-08-2009, 11:57 AM	#12 (permalink)
pleximajor Member Join Date: May 2009 Posts: 41	Re: Marshall Major: Differences between Lead and Bass models. im in st louis ....i can work on your major.....i have a 69 major

07-09-2009, 11:33 AM	#13 (permalink)
corey from doomshade Junior Member Join Date: Jun 2009 Location: Belton, Mo Posts: 19	Re: Marshall Major: Differences between Lead and Bass models. Hey thanks for the info, yaaaaaaaaaaaalll. First thing to do is find out what, if any mods have already been done. I'm going to try to post some detailed pics of my amp. One thing is certain, she's a powerhouse. Last night, after a "few" drinks, I sat with my 6string bass (active and really hot) and one 1510 Marshall cab, and just sat there and blasted myself with massive chords. It was around 100 degrees in here, and the air blast pumping from the speakers was fanning me pretty good. Channel one gain on 8, bass and mid pegged, treble and presence on 3. I probably should've worn ear plugs..................

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