New Amp Day! JCM 800 [Photos/Questions]

[Adam SE]

Check out my newly acquired JCM 800 2210 head with 1960b cab. It's amazing! I love it so much. I've been saving up for this guy, and I owe some money now... but it was worth it. What a step up from a small Kerry King practise amp.

Some bad photos for you to drool at.

The tubes are ancient, at least 10 years I think, I should get some new ones and bias them.

Now a couple questions.

Is the the correct impedance settings? I have my cab set like so...

...and my head is set to 8 ohms.

My amp sounds a little harsh and maybe weak and fizzy on lower gain... is this a result of dying tubes? Or part of the amp? Also, my amp still doesn't have amazing definition, when I pick the low E constantly it drowns out whatever else I'm playing (think of thrash metal type stuff). I was hoping the amp wouldn't be drowned out by constantly picking the E. Again, is this another tube thing?

Time to go play Thanks for reading.

-Adam

 

[cicone]

Check out my newly acquired JCM 800 2210 head with 1960b cab. It's amazing! I love it so much. I've been saving up for this guy, and I owe some money now... but it was worth it. What a step up from a small Kerry King practise amp.

Some bad photos for you to drool at.

The tubes are ancient, at least 10 years I think, I should get some new ones and bias them.

Now a couple questions.

Is the the correct impedance settings? I have my cab set like so...

...and my head is set to 8 ohms.

My amp sounds a little harsh and maybe weak and fizzy on lower gain... is this a result of dying tubes? Or part of the amp? Also, my amp still doesn't have amazing definition, when I pick the low E constantly it drowns out whatever else I'm playing (think of thrash metal type stuff). I was hoping the amp wouldn't be drowned out by constantly picking the E. Again, is this another tube thing?

Time to go play Thanks for reading.

-Adam

Ouchie!!!!Please correct me if I'm wrong, but with your stereo cab set to mono you use the 16 ohm jack(which you did)and also set the head to 16 ohms. Either that's correct or I've been doing it wrong for years and haven't blown anything up yet. I'd wait for someone else to chime in.....don't want to be responsible for blowing up your new baby!

 

[MonstersOfTheMidway]

Ouchie!!!!Please correct me if I'm wrong, but with your stereo cab set to mono you use the 16 ohm jack(which you did)and also set the head to 16 ohms. Either that's correct or I've been doing it wrong for years and haven't blown anything up yet. I'd wait for someone else to chime in.....don't want to be responsible for blowing up your new baby!

Sup. Yeah, the ohms setting on the head and the cab have to match. If you set your cabinet set to MONO and place a speaker lead (not a guitar lead) into the 16 ohm input, then your head must also be set to 16 ohms and plug into the 16 ohms input. Just make the correction on the head and everything will be great.

You could play the cab in MONO through the 4 ohm input, and then make the corresponding connection at the head through the 4 ohm input if you head has such a connection. I say "if" because it looks like your head may have had some modifications; the backpanel looks a little different from what I've seen of the 2210 model.

Either way, make sure your cab is always set to MONO when you are using your 2210 head and that you are following the ohms rating printed above the inputs of the cab and NOT below the inputs of the cab. Hope this helps. Nice amp, cab, and guitar, by the way.

 

[cicone]

Sup. Yeah, the ohms setting on the head and the cab have to match. If you set your cabinet set to MONO and place a speaker lead (not a guitar lead) into the 16 ohm input, then your head must also be set to 16 ohms and plug into the 16 ohms input. Just make the correction on the head and everything will be great.

You could play the cab in MONO through the 4 ohm input, and then make the corresponding connection at the head through the 4 ohm input if you head has such a connection. I say "if" because it looks like your head may have had some modifications; the backpanel looks a little different from what I've seen of the 2210 model.

Either way, make sure your cab is always set to MONO when you are using your 2210 head and that you are following the ohms rating printed above the inputs of the cab and NOT below the inputs of the cab. Hope this helps. Nice amp, cab, and guitar, by the way.

Interesting you mentioned the cable---looked weird to me. You must use a speaker cable for the amp/head connection. A guitar cable can't handle the juice. Let us know what it sounds like with correct setting and cable---hopefully fantastic!

 

[Adam SE]

Thanks for the responses. This ohm thing is really tricky, and I know it shouldn't be. If I read correctly, you're saying to set my head to 4 ohms (if I can), and put the speaker cable in the left input?

The head is the Canadian version, plus I'm quite sure it has a mod, so it is definitely different than most.

Cicone, I believe I do have a speaker cable to connect the head to cab. Buddy at Long-McQuade said it was an "unshielded speaker cable". Here's what I'm using. This should be correct, no?

Many thanks,

-Adam

 

[Vince]

Set the head to 16 ohms... plug into the cabs mono input (should be 16 ohms)

The tubes may be good old stock tubes! Don't go replacing without knowing what you have. old German made tubes last far longer than new production tubes. Pull them out and see what is written on them. Definately check the bias on the power tubes.

As far as the E overpowering everything.... have you checked and adjusted your pickup height?

 

[cicone]

Thanks for the responses. This ohm thing is really tricky, and I know it shouldn't be. If I read correctly, you're saying to set my head to 4 ohms (if I can), and put the speaker cable in the left input?

The head is the Canadian version, plus I'm quite sure it has a mod, so it is definitely different than most.

Cicone, I believe I do have a speaker cable to connect the head to cab. Buddy at Long-McQuade said it was an "unshielded speaker cable". Here's what I'm using. This should be correct, no?

Many thanks,

-Adam

It's time to bring in an expert.

 

[Adam SE]

Set the head to 16 ohms... plug into the cabs mono input (should be 16 ohms)

The tubes may be good old stock tubes! Don't go replacing without knowing what you have. old German made tubes last far longer than new production tubes. Pull them out and see what is written on them. Definately check the bias on the power tubes.

As far as the E overpowering everything.... have you checked and adjusted your pickup height?

They are Sovteks, well the power tubes are... not so sure about the preamp.

Thanks for the tip about the pickup hight, that should definitely help.

Cicone, what do you mean? This is my first tube amp, so pardon my ignorance.

 

[Vince]

Sovteks are "new" production tubes. JCM800's like SED Winged C's. I would swap them out and bias them. Also, putting a TungSol 12ax7 in the V1 (the first preamp tube socket from left to right) will help your overdrive sound tight. These are the best new production preamp tubes out there in my opinion.

 

[Adam SE]

Yeah, I would have had to have been lucky to have nice NOS tubes in my amp. But these ones will suffice until I make an order for new, fresh tubes with a bias.

Thank you for the recommendations. Unfortunately the SED Winged C's are a little out of my budget for now. I was thinking of trying Eurotubes. They seem to know they're stuff. I know some people here aren't fond of JJ's, but they have a nice full kit for retubing that I can trust.

By the way, my head doesn't have a 16 ohm setting capability, partially why I'm confused.

 

[MonstersOfTheMidway]

By the way, my head doesn't have a 16 ohm setting capability, partially why I'm confused.

Sup. No 16 ohm setting? Then take a good look at the back and see what options you have for connection the amp. Most amp heads have multiple ohms selections so that you can use it with one cab or two. For now, I say to play it safe and use just one cab. I can't see any detailed pictures of your amp's connection options, but see if you can post picture of where you make your cabinet connections at the back of the head. It may be possible that you do have a 16 ohm connection option, but it might look a bit different.

 

[SigurdTheGreat]

JJ... beware. "Trust" doesn't equal good, inspiring tone.

 

[Vince]

Yeah... JJ's are good for Fenders but not so great for Marshalls.

Save for the SED's. They will last a good long time too.

 

[Adam SE]

Theres the back panel. I have two inputs and one dial, and I'm only running one cab. The dial for the ohm settings has the options for 4 and 8. The toggle is a mod, that is a high output/low output switch. I don't know exactly what it does, but it does change the tone.

I didn't realize that JJ's are not so good for Marshalls. If the SED's really are that good, I'll save up for 'em.

 

[Vince]

I'd have an amp tech look at it and he should be able to find a 16 ohm tap off the power transformer and wire it for ya. Should not cost more than a bench charge.

 

[Paramedic006]

+1 on the 16ohm setting. +1 on the =C= power tubes. Those new Russian Svetlana's sound great in an 800. I did try a tungsol at V1 and there is a difference. Also don't fall for that matched balanced set crap. Marshall's sound better with "unmatched" sets. I get my 2203 JCM800 1987 on Monday. Nice score man.

 

[MonstersOfTheMidway]

Theres the back panel. I have two inputs and one dial, and I'm only running one cab. The dial for the ohm settings has the options for 4 and 8. The toggle is a mod, that is a high output/low output switch. I don't know exactly what it does, but it does change the tone.

I didn't realize that JJ's are not so good for Marshalls. If the SED's really are that good, I'll save up for 'em.

Sup. I can't get a real good detailed look at the output connections or dial, but I think I see the two loud speaker outputs and the dial, as you mentioned. If that is the case, I'd suggest that it's wired for 8 ohms if you are using TWO 8 ohm cabs, AND it is wired for 4 ohms if you are using ONE 4 ohm cab. It is possible that it could be wired for just one 8 ohm cabinet, but given that there are only two loud speaker outputs and one dial with 4 and 8 ohms settings, my best guess is its wired for TWO 8 ohm cabs or ONE 4 ohm cab.

My suggestion is play it safe and set it to 4 ohms on the dial, make the connection with a speaker lead at the back of the head at the 4 ohms output, set your cab to MONO and plug the speaker lead into the 4 ohms input. Remember to set the cab to MONO and match the ohms rating that is printed ABOVE the cab's inputs (you will be using the left input when you are looking at the back of the cab).

I'd have an amp tech look at it and he should be able to find a 16 ohm tap off the power transformer and wire it for ya. Should not cost more than a bench charge.

Great suggestion. If the tech can add in the 16 ohm option, you might also need a new switch or dial, but that won't cost much. Take it to a tech and have him/her check out that circuit. It is possible that the modification has affected your ohms selection options that were originally available on your amp. Ask him or her what modification has been performed on the amp and what are its intended effects? It's possible that the tech might not know much about the mod, so talk to the person from whom you purchased the amp and ask them about the modifications as well: who performed the mod?; does the modification have a name?; what is the effect of the mod?; does he have the original parts? Having a modification done to an amp is not a bad thing, but it's good to know your particular amp's history.

 

[Vince]

The switch is probably a half power switch by either turning off a set of tubes or switching from Pentode to triode mode. This never works well on a Marshall and I would put it back stock personally. Make it sound very sterile.

 

[dugger]

Gaw that thing looks nice! That toggle mod might change output wattage. If so, probably should turn the amp off before flipping it back and forth.

 

[Adam SE]

Extremely helpful post Monsters, thank you very much. I set the cab and head both a 4 ohms. However, I noticed that when I made the amp "thump", i.e if I were to chugg the low E with a high bass setting, something would buzz, and it sounded like it was coming from the cab. Also, when I flipped the standby switch, it popped, it didn't do this when I was at 8 and 16 ohms.

I think the mod is cool, I would say it makes the same amount of difference a pick-up does. It really gives an attack on high-output.

I also read that others have tried to find a 16 ohm tap but failed to do so. I don't think it will be possible to have a 16 ohm setting on the head.