| Author |
 Topic  |
|
Dirk
Platinum Member
Netherlands
1309 Posts |
 Posted - 01/20/2008 : 17:08:32
|
Well new....it's 26 years old for crying out loud.
I'm really a bassplayer but I sort of play guitar too as a hobby.
Having outgrown my Marshall vs30, which by the way is a decent practice amp I finally got myself a nice Marshall JCM 800 split channel.
It's the 4210 model, the 50 watt 1x12 combo, cause I wanted the smallest model for home use.
While it did sound OK in the rehearsal space where I tested it, at home we noticed a lot of woofy sounds.
Turns out the output tubes were toast and the original speaker needs replacement.
There's a little hole in it, I can see right through it.
I bought a Celestion Vintage 30 from some guy, that should arrive within the next few days.
My brother had some other used output tubes lying around that sound pretty good so far.
I just love the raw sound of those amps, especially the crunch channel. That's the sound of rock for sure.
It loves pedals too, my modded SD-1 sounds killer  and so does the CE-2b.
The only thing I need to look into is the reverb, for some reason it doesn't work.
Well, I'm off playing some more Guns N Roses and Aerosmith tunes.
|
Edited by - Dirk on 01/20/2008 17:10:00 |
|
|
DeFrag
Moderator
USA
3409 Posts |
Posted - 01/20/2008 : 18:58:45
|
| Congrats! That "sounds" like a nice amp. Are you able to provide a mic'd soundclip for us? |
 |
|
|
pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 01/21/2008 : 07:19:34
|
 Are they el-84's? |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/21/2008 : 10:45:15
|
Hi Dirk
Nice find.....
As for the reverb problem.
I have found that the cable to or from the Reverb tank can break or go open circuit.
Check them for continuity, if you have a multimeter.
These are usually RCA type connectors, like you find on home stereo equipment.
Also inside the actual metal reverb tank,
you will have to unscrew it, or take it out of its bag.
look at the very fine wires that are on the rear of the RCA sockets, sometimes these break off as well.
Maybe just the inner part of the socket has become worn, or has opened up just enough to not connect (open circuit)
If it's a valve driven reverb & recovery circuit, maybe the valve is faulty or even in some cases ---- missing.
usually a 12AT7 - if you don't have a spare 12AT7, just use a more common 12AX7 but just for testing proposes.
Hope you work it out - good luck & keep us informed.
Regards Dr. Bob |
Edited by - Dr. Bob on 01/21/2008 10:48:55 |
|
|
|
Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 01/21/2008 : 17:21:02
|
I tested the reverb unit with a little Park amp that had a similar tank and it worked fine.
I also replaced the tube with another ecc83 I had lying around, no luck either.
So, I'll probably end up opening the amp and measure the wires for starters.
Good news is, my new speaker was put on the mail today and should arrive tomorrow.
@ Pedals 4 pv: No, it's EL-34's. |
|
|
|
pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 01/21/2008 : 19:28:53
|
The Fire Inside |
Edited by - pedals 4 pv on 01/21/2008 19:30:00 |
|
|
|
StratoSphere
Double Platinum Member
Canada
2232 Posts |
Posted - 01/23/2008 : 00:09:29
|
is it just me or is the "Marshall" logo oversized?
bet it sounds great. those 80s Marshalls really cook! |
|
|
|
Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 01/23/2008 : 16:56:29
|
Actually, the amp on the pic isn't mine but similar.
Only mine says "JCM800 lead series" in the gold label, whereas this one says JCM800 50watt lead".
I think the logo looks so big, it's the same size they use on their 4x12's.
Sound update, I received my vintage 30 yesterday and it sounds a whole lot better already.
The old G-1280 speaker sounded like it was on the verge of blowing up, especially when palm muting with the gain above 7.
At least that's gone, but it's still a lot rawer sounding than my brother's 2210.
I don't know, maybe I should have bias checked? Any suggestions?
The reverb still doesn't work either.
Oh, and does anyone have a picture of the inside of a split channel amp? Cause I noticed some weird resistors soldered parallel across another one, maybe a previous owner tried to do some modding.
|
|
|
|
Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 04/29/2008 : 18:57:30
|
Wow, I had to save my topic from page 6, but I wanted to give a little update on this matter.
I was browsing the used amp section on the internet, and I found the exact same model amp as mine, from a guy in our village.
Since I'm still not satisfied with the sound of the overdrive channel, it barks and woofs like crazy with the gain anything above 3.
The clean channel is fine, and the crunch sound is nicely complemented by my SD-1 but off course in the long run, I did not buy a tube in the first place to still be using a distortion pedal in front of it.
Other than for boosting the front end when playing leads off course.
Anyway, I immediately called the guy, packed my guitar and went over there on my bike.
Wow that's another first, I don't actually had to fly half across the country just to check out some gear.
So I plugged in, turned all the controls to my normal settings at home and the moment I struck one powerchord I knew I had a winner.
I had the gain on 8, and it sounds like it's supposed to do but without the gnarly sound plus the reverb works just fine on this one.
In fact it sounds pretty similar to my brothers 2210 head, but a little less beefier due to a single 12" speaker.
I'm picking it up either tomorrow or thursday and so far I'm again as happy as child getting a new toy
Keep you posted, in the meantime, rock on  |
Edited by - Dirk on 04/29/2008 18:59:41 |
|
|
|
pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 04/29/2008 : 19:40:23
|
|
|
|
|
Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/29/2008 : 20:20:32
|
quote:
Originally posted by Dirk
Wow, I had to save my topic from page 6, but I wanted to give a little update on this matter.
I was browsing the used amp section on the internet, and I found the exact same model amp as mine, from a guy in our village.
Since I'm still not satisfied with the sound of the overdrive channel, it barks and woofs like crazy with the gain anything above 3.
The clean channel is fine, and the crunch sound is nicely complemented by my SD-1 but off course in the long run, I did not buy a tube in the first place to still be using a distortion pedal in front of it.
Other than for boosting the front end when playing leads off course.
Anyway, I immediately called the guy, packed my guitar and went over there on my bike.
Wow that's another first, I don't actually had to fly half across the country just to check out some gear.
So I plugged in, turned all the controls to my normal settings at home and the moment I struck one powerchord I knew I had a winner.
I had the gain on 8, and it sounds like it's supposed to do but without the gnarly sound plus the reverb works just fine on this one.
In fact it sounds pretty similar to my brothers 2210 head, but a little less beefier due to a single 12" speaker.
I'm picking it up either tomorrow or thursday and so far I'm again as happy as child getting a new toy
Keep you posted, in the meantime, rock on
Nice one... I had a JCM800 combo in the early 90s and sold it. One of my most regretted sales. I have recreated it somewhat with a JCM600 head and 1960A cab, but it's not a JCM800 combo - they have just a special sound. Congrats on your find!
Interesting comment about not buying a tube amp to put a distortion pedal in front of it... I thought the same too until I tried an MT-2 in front of the clean channel of the JCM600. WOW. With the headroom of a tube amp it sounds wonderful. Converted me! I am using a DS-1 (modded), the MT-2, and a digitech DF-7 (set to fuzz emulation) in front of the clean channel (errr... not all at once!). Soon to add an xtortion (thanks Zentropa!). I actually prefer the pedals to the Marshall drive channel. Plus I now run my POD into it when i want "glassy" overdrive.
|
|
|
|
FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 04/30/2008 : 12:53:25
|
If i understand you right,this means you now have two amps the same.... could be a nice little stereo set up...... |
|
|
|
Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 04/30/2008 : 14:56:02
|
Yes I do, and I will experiment with that a little.
I probably try to fix the first one, since now I have one for comparison that sounds like it's supposed to, and then sell it off.
A previous owner must've really f*#ked up by trying to mod it.
You won't believe how bad the overdrive channel sounds till you hear it, the reverb doesn't work anymore, and the amps loses power when something is inserted in the effects loop, the overall volume is also a lot lower.
I had to use the mastervolume on "8" to get decent volume, with my new amp I can put it on "2" getting the same volume 
However, the clean channel is a bit cleaner sounding and the overall noiselevel is a lot lower on the old amp so apparantly the modding was good for something
I replaced the speaker (this amp came with a Celestion GT12K-85 instead of the standard G12-80) with the Vintage 30 and it became even sweeter. |
|
|
|
FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 04/30/2008 : 16:08:16
|
Is the effects loop original to those amps.....?? could be the problem as i think that they usually go just bfore the output section.....it's possible if it's a mod that the person tried to use the reverb points to make an effects loop as thats where reverb usually goes in the circuit.....(i think...don't quote me..!!.. )this could be the cause of the loss of power....you say you changed some of the output valves..what about the pre amp valves..... a trick i learned especially with marshalls is that if the pre amp valve in V1 is a little old and dodgy,as a temporary solution try switching it with a preamp valve from one of the other sockets beside it.....preamp valves are usually pretty easy to find in music shops and not as expensive as output ones if you wanted to change it.....apart from that it could be the filter caps or the output tranny but i'm only guessing....personally i wouldn't be in a big hurry to sell it as these older amps are really well made and easier to fix than some of the newer ones..two little 1x12 combos in stereo is a pretty sweet setup..especially if they both have effects loops..you could run a stereo effect in the loop of the 'good' amp(if it has one) and use the second output of the effect straight into the return on the effects loop of the 'dodgy' amp..this way you could use the pre amp section of the 'good' amp.....and also see if the 'dodgy' amp works any better volume wise as the return input should be the last stop before the output/master volume..... |
|
|
|
Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/30/2008 : 16:17:51
|
If you end up selling it Dirk, I'll be wishing I was closer to the Netherlands
|
|
|
|
Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 05/01/2008 : 10:09:32
|
Hi Franzoni, thanks for the input.
The effects loop is standard on splitchannel amps.
I tried running a DD-3 in the loop of my good amp and sending the direct out to the fx return of the dodgy amp, with no result, just no sound.
Then I tried running the same signal into the input of the dodgy amp, yet no sound from the dodgy amp.
Then I tried running the guitar into the DD-3, the effect out the good amp, the direct out to the dodgy amp, as expected sound on both amps.
So for some reason the fx return doesn't function when there's a signal coming from a different source. (I do this on bass amps all the time and it works just fine).
And for some other strange reason the amps gives no sound when a send level signal is fed into it's guitar input, this gets pretty weird doesn't it.
A guitar player I know does this all the time, and it works just fine, you're just stacking preamps but this way he can deal with channel switching issues.
So I'll make sound samples and inside guts pictures of both amps for you guys. |
|
|
|
Topic |
|
New amp for me
