Nad - Holy Grail For Me- 1982 Jcm800 4010

  • Thread starter Jethro Rocker
  • Start date
    • This site may earn a commission from merchant affiliate links like Ebay, Amazon, and others.
Jethro Rocker

Jethro Rocker

Well-Known Member
Joined
Mar 11, 2011
Messages
12,301
Reaction score
21,987
Location
Saskatoon, Canada
Finally did it! Found a 1982 4010 combo so I bought it! Has a small tear in the grill sadly but no rust or anything on the iron. Has a couple Svetlana EL34 and an Ei smooth long in PI. I left it there. LOUD!!! Holy fuckin C, I need to get an attenuator just to control the volume. G12-65 speaker. MMmmm mmmm good. I think I might try a DR. Z Air Brake, I don't wanna get crazy here and I figured it would sound better at say 4 with the brake than 1.5 without.
Some quick snaps. Just rebiased. Dude took it to a tech friend. Bias was like 25 mV. Sigh...now it's around 36. 455PV.
P5090566.jpg

P5090559.jpg

P5090560.jpg

P5090562.jpg
 
Blueslicks

Blueslicks

Well-Known Member
Joined
Mar 10, 2011
Messages
1,681
Reaction score
1,056
Jethro Rocker said:
Finally did it! Found a 1982 4010 combo so I bought it! Has a small tear in the grill sadly but no rust or anything on the iron. Has a couple Svetlana EL34 and an Ei smooth long in PI. I left it there. LOUD!!! Holy fuckin C, I need to get an attenuator just to control the volume. G12-65 speaker. MMmmm mmmm good. I think I might try a DR. Z Air Brake, I don't wanna get crazy here and I figured it would sound better at say 4 with the brake than 1.5 without.
Some quick snaps. Just rebiased. Dude took it to a tech friend. Bias was like 25 mV. Sigh...now it's around 36. 455PV.
Click to expand...

What a score. Looks NOS FFS. Damn that is nice, like it's never even been used type of nice. And yes that is the holy grail of the 800 line IMO. They are like plexis in that; it isn't about the versatility at all, it's about the one core sound. I had the 1982 50 watt 2204 vertical input Canadian metal toggle head and matching G1265 equipped 4x12 A cab and it was a killer sounding rock rig. Mine burnt to a crisp in a studio fire.

Enjoy that thing!
 
Jethro Rocker

Jethro Rocker

Well-Known Member
Joined
Mar 11, 2011
Messages
12,301
Reaction score
21,987
Location
Saskatoon, Canada
Thanks man! I will! The tear in the grill bugs me a bit but...overall really clean. There was another around that still has warranty card and dust cover. An absolute time capsule.
It was a 4104 though and I don't need another bitchin heavy 2x12. Also, I wonder if it hadn't really been played what shape the caps were in....

This one if fun with an OD up front - versatile enough for me. I may re-tolex it in white.
 
RickyLee

RickyLee

Well-Known Member
VIP Member
Joined
May 22, 2010
Messages
10,295
Reaction score
3,709
Location
SoCal U.S.A.
Wow Jethro, congrats my Marshall Brother. That is soooooo sweet. And the G12-65. Oh yeah.

I was going to ask about the plate voltage when I started reading your post as you said it was loud, but you listed it. So your '82 has the higher voltage power transformer which is interesting. I have always been curious on when Marshall went to that PT on the 50W amps. My '82 4010 has the lower voltage PT and sounds quite a bit different than my '83 2204 and '84 4010 which is also a vertical input but has the D.I. jack on the back.

Shortly after I bought my '84 4010, I just had to have a second one and that is why I bought the '82 4010. I did run them in stereo for a few gigs. But that eventually wore off LOL.

EDIT/ADD: Can I get the date codes on your transformers? Mine date from JAN 81. Did you check that date code on the G12-65 as well?
 
RickyLee

RickyLee

Well-Known Member
VIP Member
Joined
May 22, 2010
Messages
10,295
Reaction score
3,709
Location
SoCal U.S.A.
Jethro Rocker said:
Nope I didn't. The one pocture shows a code on the speaker. Dunno if that's it. I'll check the trannys tomorrow.
Wonder why your 82 would be any different?
Click to expand...

The old 50W JMP amps had the lower voltage PT. Marshall started the JCM800 line still using those same 50W power transformers. It was somewhere around 1982 that they went with the higher voltage PT's.

I am thinking the Canadian models might not match up to the change 100%. I have seen many other different things with the Canadian models besides the differences in switches, fuses ect.

My '82 4010 was an ebay score many years ago. It is in great cosmetic shape. But when it arrived, I was shocked by how it was so different tonally. Back then, I did not know how to work on amps or bias them and such. But later I learned about the voltage difference. It has lower output, even though it runs 6550's. Darker and woolier sounding as well. I do not think the voltage difference is much of the tonal thing, as I have a switch on my white Plexi/2204 build that allows me to switch between 400V/470V B+. The lower voltage barely reduces output but does not alter the tonal character of that amp.
 
Last edited:
Jethro Rocker

Jethro Rocker

Well-Known Member
Joined
Mar 11, 2011
Messages
12,301
Reaction score
21,987
Location
Saskatoon, Canada
jcm800gridlock post:1612212 said:
Congrats. A great amp and a great speaker. I owned early verticle input 4104 (your amp with 2x12 G12-65's).

Stay away from the Airbrake with that amp. I bought and Airbrake for my 800 and I was not happy with the amps tone or attenuation levels with the "Z".
Click to expand...
Too late...:( I got one already...
Now , in fairness, I dont want go attenuate enough to push the power section, just enough so I can play smaller venues and have some control. It gives a good whack of volume from 1 -2. This way I can set it on 3 or 4 and have some leeway. Don't want go spend an arm amd a leg on one.
It does really suck the punch out of it if pushed too far. I set it just so I still have punch and tone and can set the volume up a bit so it's not so touchy.
 
CQJR007

CQJR007

Member
Joined
Aug 30, 2014
Messages
79
Reaction score
46
Location
GB
Jethro Rocker said:
Finally did it! Found a 1982 4010 combo so I bought it! Has a small tear in the grill sadly but no rust or anything on the iron. Has a couple Svetlana EL34 and an Ei smooth long in PI. I left it there. LOUD!!! Holy fuckin C, I need to get an attenuator just to control the volume. G12-65 speaker. MMmmm mmmm good. I think I might try a DR. Z Air Brake, I don't wanna get crazy here and I figured it would sound better at say 4 with the brake than 1.5 without.
Some quick snaps. Just rebiased. Dude took it to a tech friend. Bias was like 25 mV. Sigh...now it's around 36. 455PV.
P5090566.jpg

P5090559.jpg

P5090560.jpg

P5090562.jpg
Click to expand...

I have the same amp, bought new in '82, it's never left me since
 
JohnH

JohnH

Well-Known Member
Joined
May 31, 2008
Messages
6,150
Reaction score
5,046
Location
Wilton NSW
Jethro Rocker said:
Too late...:( I got one already...
Now , in fairness, I dont want go attenuate enough to push the power section, just enough so I can play smaller venues and have some control. It gives a good whack of volume from 1 -2. This way I can set it on 3 or 4 and have some leeway. Don't want go spend an arm amd a leg on one.
It does really suck the punch out of it if pushed too far. I set it just so I still have punch and tone and can set the volume up a bit so it's not so touchy.
Click to expand...

It sounds like you may have the attenuation that you need. But, reading the thread, I' have a couple of comments . Airbrakes are simple resistive attenuators, but arranged differently to most others. As you turn down, I believe they may reduce mids due to increasing series resistance seen by the speaker. Most other simple attenuators instead suck bass and highs as you turn down.

Our design on the Workbench will keep your tone intact all the way down, and it's simple to build. You can just build as much if it as you need, e.g. just two stages (one -7db reactive and one more resistive) could take a 50W amp and deliver it at 10W and 2W. Add the -3.5db stage as well to add a 4 5W and 0.8W option.
 
You must log in or register to reply here.

Latest posts



Top