Nice Marshall Circuits link

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GroundhogKen
Moderator de forumus
Posts: 1379
(4/16/03 12:32 pm)
64.80.104.74
Reply | Edit | Del All  Nice Marshall Circuits link
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 I haven't scoured it for errors, yet, but this looks like a nice Marshall info page.

www.lastwordsmusic.com/cl...s_101.html


Ken
 
Craigzbrand
Junior tube assistant
Posts: 50
(4/16/03 2:59 pm)
165.235.87.69
Reply | Edit | Del  Re: Nice Marshall Circuits link
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 Wow, never seen that one. Thanks for that! Craig
 
seanman
I am not registered :(
(4/19/03 10:40 am)
68.53.127.89
Reply | Edit | Del  Marshall mod
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 I have a Bassaman with Hoffman board and would like to do the mod in the 2nd stage Rk. I do not know if you replace the 820 Ri with the .68uf, or add it. Could anyone help?


 
GroundhogKen
Moderator de forumus
Posts: 1388
(4/19/03 11:09 am)
66.67.155.173
Reply | Edit | Del  Re: Marshall mod
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 You must have Rk. Ck is optional. Put the .68 cap in parallel with the 820 ohm cathode resistor. Did I understand correctly what you were asking?

Ken
 
Seanman
I am not registered :(
(4/19/03 11:22 am)
68.53.127.89
Reply | Edit | Del  Marshall
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 Yes, Add/Put in with the 820 Ri. Thank you
 
bottle
I am not registered :(
(5/4/03 7:40 pm)
12.86.5.106
Reply | Edit | Del   Old Marshalls
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 The board, (looks like Dougs') the components, good quality caps and resistors, point to point to wiring, etc.
That is why the old Marshalls sounded so good. Compare to the garbage under the hood today! Great site.
 
clay finley
Junior tube assistant
Posts: 1
(5/8/03 11:27 pm)
206.66.15.150
Reply | Edit | Del  Re: Nice Marshall Circuits link
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 Hi Ken,

If you find any errors, please e-mail me. Also check out my amps while you're there. I have lots of detailed info on them. I have updated the page some, since this thread was started.

Clay


Edited by: clay finley at: 5/10/03 2:58:37 am
 
clay finley
Junior tube assistant
Posts: 2
(5/12/03 2:12 pm)
206.66.15.150
Reply | Edit | Del
  Re: Nice Marshall Circuits link
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 I added pics of a JTM45 RI (PCB), '69 SL (PTP) and a '74 SL (PCB). - enjoy ...
My Gear
Marshall Circuits

Edited by: clay finley at: 5/13/03 7:40:06 am
 
whittele
I only work on tube amps
Posts: 413
(5/20/03 5:40 pm)
68.58.209.80
Reply | Edit | Del  cool link got me to thinkin
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 I checked this link out and was especially interested in the whole slope resistor explanation. I put a 33K in parallel with the existing 33K and wow but a bit too dark. I swapped them out for a 22K and WOW. The buzziness of my (Hoffman) Combo 50 EL-34's) is gone and the mids are sweet and the harmonic content of the amp (especially during feedback) is incredible. Think Allman Brothers.

I also dropped the feedback resistor down to 56K to open the amp up a bit. NICE!!!

I assume there are no amp health issues with this swap. I did not smell any installed smoke leaking out and no fire....yet.

I love this place. That link is an excellent tutorial and so far every word is true.
 
clay finley
Junior tube assistant
Posts: 3
(5/22/03 12:14 am)
206.66.15.150
Reply | Edit | Del
  Re: cool link got me to thinkin
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 Thanks whittele!  

I also added another page for MV Marshall Circuits (models 2203,2204,...). All the standard mods are in there, along with bass mod and a resonance control.

I just found out about this forum recently. It's really cool.  
My Gear
Marshall Links

Edited by: clay finley at: 5/22/03 12:16:09 am
 
geoffreyreed
Junior tube assistant
Posts: 43
(7/25/03 12:09 pm)
64.12.97.6
Reply | Edit | Del  Re: cool link got me to thinkin
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 That is a really cool site!!!! was gratified to see my assessment of running filaments cool, verified, for comment on running amps in Japan. From the Marshall site listed above. ""I really can't stress that enough! Another thing to be aware of is that running tubes on reduced filament voltages is ok up to a point. It actually increases tube life to run filaments about 10% low. Too much lower and you can decrease tube life by causing cathode stripping."" Beautiful site!! Geoff
 
clay finley
Junior tube assistant
Posts: 4
(7/28/03 1:33 am)
206.66.15.150
Reply | Edit | Del
  Re: cool link got me to thinkin
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 Thanks
 
My Gear
Marshall Links
 
 
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