You just don't understand, I'm from Kalamazoo

900 · 10-14-2009, 05:51 PM

Just recently bought a JCM 900 2 x 12, have had some older SS Marshall's in the 80's / 90's but this is my first Marshall Valve and just sold my 9100 power amp and an ADA MP-1 but oh, the choices. Have been messing with Mesa's for a bit but finally decided the only clean is Fender clean and scored a Fender Twin ('68 silver face (blackface circuit) but then needed the nasty stuff so I came accross the 900 and figured I could A/B 'em. It sounds truley evil with my Heritage 150CM....

Quick question though, How do I score a manual, I've downloaded what's offered on the website but it doesn't tell me squat.

I need to know if the speakers were originally wired parallel ,someone has apparently rewired 'em, then where's V1 (preamp yes, but which side)

I'll certainly crank up the search function but figure these a pretty common questions.

Thanks

Richard

carnada · 10-14-2009, 09:30 PM

Quote:

Originally Posted by 900

Just recently bought a JCM 900 2 x 12, have had some older SS Marshall's in the 80's / 90's but this is my first Marshall Valve and just sold my 9100 power amp and an ADA MP-1 but oh, the choices. Have been messing with Mesa's for a bit but finally decided the only clean is Fender clean and scored a Fender Twin ('68 silver face (blackface circuit) but then needed the nasty stuff so I came accross the 900 and figured I could A/B 'em. It sounds truley evil with my Heritage 150CM....

Quick question though, How do I score a manual, I've downloaded what's offered on the website but it doesn't tell me squat.

I need to know if the speakers were originally wired parallel ,someone has apparently rewired 'em, then where's V1 (preamp yes, but which side)

I'll certainly crank up the search function but figure these a pretty common questions.

Thanks

Richard

try go get some help in the work bench

***Adwex*** · 10-14-2009, 11:34 PM

What are the choices for impedances on the amp's impedance selector switch, and what are the impedances of the individual speakers?

V1 is typically the tube furthest from the power tubes.

Wilder Amplification · 10-20-2009, 08:00 PM

Quote:

Originally Posted by 900

Just recently bought a JCM 900 2 x 12, have had some older SS Marshall's in the 80's / 90's but this is my first Marshall Valve and just sold my 9100 power amp and an ADA MP-1 but oh, the choices. Have been messing with Mesa's for a bit but finally decided the only clean is Fender clean and scored a Fender Twin ('68 silver face (blackface circuit) but then needed the nasty stuff so I came accross the 900 and figured I could A/B 'em. It sounds truley evil with my Heritage 150CM....

Quick question though, How do I score a manual, I've downloaded what's offered on the website but it doesn't tell me squat.

I need to know if the speakers were originally wired parallel ,someone has apparently rewired 'em, then where's V1 (preamp yes, but which side)

I'll certainly crank up the search function but figure these a pretty common questions.

Thanks

Richard

Welcome to the forum!

If they're 16 ohm speakers, they were more than likely wired parallel. You can only wire them series or parallel, and as long as the impedance selector matches the speaker impedance it really doesn't matter. You just don't want to wire two 4 ohm speakers in parallel (2 ohm load) or 16 ohm speakers in series (32 ohm load). Two 16 ohm speakers in parallel will give you 8 ohms, two 8 ohm speakers will give you 4 ohms in parallel and 16 ohms in series, and two 4 ohm speakers in series will give you 8 ohms.

10-14-2009, 05:51 PM	#1 (permalink)
900 Junior Member Join Date: Oct 2009 Posts: 3	You just don't understand, I'm from Kalamazoo Just recently bought a JCM 900 2 x 12, have had some older SS Marshall's in the 80's / 90's but this is my first Marshall Valve and just sold my 9100 power amp and an ADA MP-1 but oh, the choices. Have been messing with Mesa's for a bit but finally decided the only clean is Fender clean and scored a Fender Twin ('68 silver face (blackface circuit) but then needed the nasty stuff so I came accross the 900 and figured I could A/B 'em. It sounds truley evil with my Heritage 150CM.... Quick question though, How do I score a manual, I've downloaded what's offered on the website but it doesn't tell me squat. I need to know if the speakers were originally wired parallel ,someone has apparently rewired 'em, then where's V1 (preamp yes, but which side) I'll certainly crank up the search function but figure these a pretty common questions. Thanks Richard

10-14-2009, 11:34 PM	#3 (permalink)
*Adwex* Super Moderator Join Date: Sep 2006 Location: Long Island, NY Posts: 1,631	Re: You just don't understand, I'm from Kalamazoo What are the choices for impedances on the amp's impedance selector switch, and what are the impedances of the individual speakers? V1 is typically the tube furthest from the power tubes. __________________ http://www.youtube.com/MarshallLesPaul

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