Earth G-2000 Rebuild Pictures
Fri, 2008-01-11 15:39 — shiner555
Hey Everyone,
Just came across this site and figured a few people would dig this. I just compleatly re-built and hot-rodded(a little bit) an old Earth G-2000 that one of the guitarist's in my band got off of Ebay. When we got it, it was a total disaster...person on ebay didn't know what they were selling. After going through and replacing almost everything with some new improvements...the amp is a fire breather!!!
Future changes include dulling down the reverb circuit, adding a Master Volume, Post Phase Inverter, and possibly dumbling out the normal channel, adding a marshall/fender tone switch.
Check out the pix here: http://www.flickr.com/photos/mark2b2001/sets/72157603474069622/
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Question for the amp guru
Shiner555,
I was looking at the Blackface Twin schematic and comparing it to the Earth G-2000 schematic. I noticed that Fender installed seven diodes on the power transformer (TR1) whereas Earth installed three. Why?
Additionally, my amp has a 20uf/20uf/20 uf @ 450VDC can capacitor installed (OEM), but the schematic shows four caps where that unit should be. Am I missing something here? I looked at the one that you used by CA Manufacturing and it looks like a 20/20/20/20 @ 475 or 525VDC. Why did you choose that one? I heard that CA has a quality control problem with their can caps.
Lastly, do you know what the bias voltage setting is for the Earth G-2000?
Thanks in advance.
Craig
Happy Earth Super Guitar G-2000 Owner
Nice work on the amp.
Shiner555,
Thanks for sharing those photos!
Keep em' screamin',
Craig
Happy Earth Super Guitar G-2000 Owner
RE: Amp rebuild
Wow thats awsome! I have lot's of questions. Do you have a parts list that you would be willing to share with me?, And also did you do all the work your self, or have a shop do it? How much was it for the rebuild, with parts? Did you use any special tubes when you retubed it, or are you still using the vintage stuff? Sorry for sounding like a little kid with all the questions, but I don't know a hole bunch about all the electical stuff. I also have a G-2000 that I have been pack ratting with me since 1975, and it still works??? I think it's time to freshen it up, any help would be
really cool, thanks.
Hey Boatman! Let's see if I
Hey Boatman!
Let's see if I can answer a few of the questions.
1) As far as a parts list....well I replaced EVERY cap in the amp, as well as I added a couple of mod's to the power supply section to help with the sag. There is a diode trick after the B+ line, and then a voltage sharing tick across the rectifier diode's to make sure that all of the diodes in the bridge see the same voltage all the time. I still plann on doing some other Mod's to the reverb circuit as it is way to bright for my tastes....just haven't gotten around to it yet. I also upgraded and replaced the reverb xfmr with one from Mercury Magnetics...huge improvement. I would just suggest getting a schematic and going from there. I did you some different kinds of caps for tonal differences...but I kept the stock value. Oh YES! I almost forgot......the schematic for this amp is an exact rip of a blackface fender twin, however this amp actually had the silverface phase inverter section in it!! I put that back to blackface specs.
2) Yes, I did all of the work myself
3)As far as tubes, we only used all NOS Mullard tubes. Really expensive british tubes, but totally worth it. The amp already came with original Mullards, so we only replaced the ones that were bad. For the output we are running 6l6's, the name escapes me right now...they are the ones that came with the amp.
Cheers,
Shiner555
RE: Hey Shiner555
Hello Shiner555
Hey just wanted to say thanks for sharing that info with me, I do have the schematics for the black face, and silver face, it looks like it's time to do some home work, and shopping. My amp. also has the Mullards in the pre stage, and RCA 6L6's in the power stage. I do have the original G-2000 schematic on a PDF file, I can't remember were I found it . If you would like a copy of that schematic, to compare it with the black,and silver face. Contact me at ironman1@bwmail.us I would be glad to share it with you. I think this web site is pretty cool, it's nice to find some info on these almost non existing old amps. Thanks again for the info Shiner, Keep it loud, and keep'em ROCK'N.
later man.
G-2000 amp schematic
Hello Boatman1,
I was wondering if you would mind sharing your G-2000 schematic with me? You can send it to craig@forprettyhands.com
Thank you in advance, but if you do not want to share it with me, I understand.
Kind Regards,
Craig
Happy Earth Super Guitar G-2000 Owner
Amazing
Hey, just a short note. Nice to know these are still working after all these years and actually seems to be a following, sort of.
Ken S.
Former lead Technician and Sound tester for Earth Amps!
Bias setting
Hiya Mr. Ken S.
Thanks for hosting this blog! It's an honor corresponding with one of the original dudes!
Did you guys measure the tube current when adjusting the bias voltage? or did you just adjust them to a fixed voltage and then ensure that all the tubes were matched sets? Also, what were the biases set to?
Kind Regards,
Craig
Happy Earth Super Guitar G-2000 Owner