Plexi differences

mjmtri · 09-25-2009, 11:26 PM

What is the difference - or is there a difference btw the Plexi Lead and Bass heads? Does one have more gain, etc..

Thanks for any info you can give.
M

MajorNut1967 · 09-26-2009, 01:30 AM

The lead has a bit more gain because the first preamp tube has a hotter cathode circuit or even a split cathode. Also the tone stack is a bit different, but not all that much!

janarn · 09-26-2009, 08:00 AM

The earliest Plexis are almost identical amps.

Lead has a 500pF cap across the volume control
and a 500pF across the 470k on the same channel.

Bass has just the 500pF cap across the 470k.

PA has neither capasitors.

Later Lead models has a different tone stack, and split cathode from '69.
Bass and PA stayed the same.

mjmtri · 09-26-2009, 03:10 PM

thanks for the info guys
M

09-25-2009, 11:26 PM	#1 (permalink)
mjmtri Junior Member Join Date: Oct 2008 Location: Alabama Posts: 6	Plexi differences What is the difference - or is there a difference btw the Plexi Lead and Bass heads? Does one have more gain, etc.. Thanks for any info you can give. M

09-26-2009, 01:30 AM	#2 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: Plexi differences The lead has a bit more gain because the first preamp tube has a hotter cathode circuit or even a split cathode. Also the tone stack is a bit different, but not all that much! __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's

09-26-2009, 08:00 AM	#3 (permalink)
janarn Senior Member Join Date: Aug 2008 Posts: 408	Re: Plexi differences The earliest Plexis are almost identical amps. Lead has a 500pF cap across the volume control and a 500pF across the 470k on the same channel. Bass has just the 500pF cap across the 470k. PA has neither capasitors. Later Lead models has a different tone stack, and split cathode from '69. Bass and PA stayed the same.

09-26-2009, 03:10 PM	#4 (permalink)
mjmtri Junior Member Join Date: Oct 2008 Location: Alabama Posts: 6	Re: Plexi differences thanks for the info guys M

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