|
Post by greenblues58 on Aug 28, 2014 11:44:35 GMT -7
Scored a mint 1984 Marshall JCM800 4210 split channel 50 watt combo on evilbay this week and it arrived today and its like new inside and out. Been gassing for one of these since my original first issue 4212 parted company in the late eighties for a stereo rack system. I have a number of technical questions / queries that I am sure I can get answers from here rather than post in individual sections. Firstly 1) it has its original G12M70 which I would like to swap out initially for my Celestion Gold but later a Creamback. Will this be okay with 50 watt amp driving a 50 watt speaker ?(I know a few of you do this with the EZG and a Gold)
2)I would like to run it occasionally with an attenuator will this be safe for the Brakelite which is rated at 45 watts max
3)It has its original tubes which are RDS ECC 83 x 5 off and 2 x ITT Lorenz EL34 never heard of either. Any information experience appreciated.
Thanks in advance for any advice.
|
|
|
Post by headshrinker (Marc) on Aug 28, 2014 12:30:51 GMT -7
No problem swapping the speakers. The gold will be fine. The brake lite should also be fine unless you have the amp turned up full and play it for a long time. Put your hand on it from time to time and see if it's getting real hot. A little hot if fine as it partially turns the signal into heat. Don't know about those tubes specifically but if they are original from 1984 they are likely much better quality than is out today. I would leave the preamp tubes in, except for maybe the phase inverter. If it's been played the power tubes likely need replacing. If not they may still be good and better than are out today. I would check or have the bias checked. I would buy one 12AX7 put it in the phase inverter spot and see if it makes a difference. If not put the old one back. If you know what bad power tubes sound like you should be able to tell about them. If not, I would probably do the same with the power tubes. Stick them in. If it sounds better keep them, if not, old ones back. Be sure and bias if you try the new ones. They likely don't match the ones in there.
|
|
|
Post by doctorice on Aug 29, 2014 6:41:38 GMT -7
At some point, how about a sound clip of that amp with the Corsa guitar? Please.
|
|
|
Post by Jaguarguy (Mike) on Aug 29, 2014 7:32:44 GMT -7
Those old Marshalls are fun! I've been having a lot of fun with my '79 2144 since it arrived a couple weeks ago. Factory-installed MV definitely makes it more useable!
|
|
|
Post by greenblues58 on Sept 2, 2014 11:34:36 GMT -7
Thanks for the advice fellas. I have had a bit more playtime with it over the weekend and it seems to be lacking in volume as my 1974x absolutely annihilates it so imagine what my Maz 18 does to it! There is also a big tonal difference and volume difference in the channels which I never had on my old one. I have put all good known valves in V1 to V5 ,which has helped its tonal properties somewhat,but I have no EL 34,s so have ordered a new set of stock spec JJ EL34 and will see what this does. If it does the trick,the originals are 30 years old so good chance they are shot,I will get it biased by my local tech if not then I need to get it investigated further by someone who can sort it for me( I know a couple of capable techs for this but couple hours drive) The previous owner has replaced most of the caps and a few resistors away from stock from what I now gather so getting original value stuff in would be worth while anyway. I have fitted the Gold,which necessitated me moving the reverb tank from the lower back panel to the bottom of the cab,and a brakelite. I already had an original matching 1933 1x12 (low res G12H Heritage in it)cab so now have a stack. Really fills the sound out with the Gold as well in the openback combo.
Doctorice would like to oblige you with a Corsa clip/soundbite but I have no means of recording. Can get my kids to try with a phone but personally wouldn,t know how to post it or get somewhere to share(far too technical for me) I can say it sounds nice with the Corsa on the clean channel on the edge of breakup despite lack of volume. Reverb is actually very lush and better than I remember my old 4212.
|
|