Yellow Jackets & JCM800s

[petejt]

I've got an old single-channel Marshall JCM800 50 watt amp, with two vertical inputs.


I love the sound of it, and like that it is not as gainy in its stock form. Everyone cranks the preamp gain/boosts with a dirt pedal, and/or gets it modded, hence the Fortin Cali/Splawn/Cameron/Friedman/Jose/Voodoo market that is often bantered about on this forum.

I want to use this more for its poweramp distortion, basically I want to crank the master volume to 10 and just use the preamp as a "master volume" level control.
But it just gets way too damn loud-even in my stonewall cellar!

I've tried my Hotplate attenuator with it, and it just ain't working out for me.
I'm running the amp with my Mesa/Boogie 4x12 Stiletto cab that is loaded with V30s.

I'm thinking of using EL84 poweramp valves in it with Yellow Jackets. Will this be ok for this particular amp?

 

[Shawn Lutz]

I think a better attenuator would do better that the YJ's myself.

I used them in my JCM800 2203 (100w version) for a little while. Although it did tame the beast it was still farily loud. Also keep in mind El84's tone wise sound a lot different that the 6550's in my 2203

to answer you question yes they should work out for you. make sure to buy the right YJ's that have the power reduction in em...

 

[stephen sawall]

There are several models of Yellow Jackets ..... like said make sure you get the right ones. They do reduce volume ..... but not a lot. It is more about point of break up then volume for me. They also well change the tonal balance. EL84's do not produce a lot of bass. The harmonics in the high end are great. I have never tried them in a 800 myself.

 

[skoora]

I experimented a lot with a 78 2203 I had running how you described. Attenutor, Master up and preamp to taste. Ultimately I found that even though people say 800's need to be cranked I have to disagree. After doing back and forth recording tests the only thing gained by Master up was a little out of control hair that would quickly become unpleasant at a certain point. It wasn't a smooth increase in saturation like on a plexi. I found the amp recorded the same whether the master was barely on or at 4-5. The only difference may be from speaker movement but I used an attenuator when set to 4-5 and higher to make the level the same.

I really think people saying 800's need to be cranked are relying on the psycho-acoustic effect of volume adding more ease of play and perceived tonal nirvana. A microphone doesn't see it IMO. I actually don't think 2203's sound good with the preamp past 3 O'Clock or with the Master above 12-1 O'Clock. i know each amp can be a little different but I've owned a few 2203's and they consistently liked being at or below these levels and for heavier stuff a good pedal was better than cranking the amp to PT saturation which sounded like the amp was failing. The best tones I've ever recorded for myself were with a 2203, Master barely on, mic pre cranked to get enough signal, usually late at night trying not to bug neighbors. I'd listen back the next day and be amazed.

 

[petejt]

Hang on there, take note that my JCM800 is the 50 watt 2204 master volume model (no effects loop), not the 100 watt 2203!

 

[petejt]

I think a better attenuator would do better that the YJ's myself.

I used them in my JCM800 2203 (100w version) for a little while. Although it did tame the beast it was still farily loud. Also keep in mind El84's tone wise sound a lot different that the 6550's in my 2203

to answer you question yes they should work out for you. make sure to buy the right YJ's that have the power reduction in em...

Well I don't really want 6550s. Anyway my JCM800 has EL34s in it, a pair of Electro Harmonix EL34s. No 6550s in it to speak of.

So I guess that I would just need the standard version? I've seen there's a cathode version but I guess they are just for the Fender Champ amps that have 6V6 valves?

 

[petejt]

I experimented a lot with a 78 2203 I had running how you described. Attenutor, Master up and preamp to taste. Ultimately I found that even though people say 800's need to be cranked I have to disagree. After doing back and forth recording tests the only thing gained by Master up was a little out of control hair that would quickly become unpleasant at a certain point. It wasn't a smooth increase in saturation like on a plexi. I found the amp recorded the same whether the master was barely on or at 4-5. The only difference may be from speaker movement but I used an attenuator when set to 4-5 and higher to make the level the same.

I really think people saying 800's need to be cranked are relying on the psycho-acoustic effect of volume adding more ease of play and perceived tonal nirvana. A microphone doesn't see it IMO. I actually don't think 2203's sound good with the preamp past 3 O'Clock or with the Master above 12-1 O'Clock. i know each amp can be a little different but I've owned a few 2203's and they consistently liked being at or below these levels and for heavier stuff a good pedal was better than cranking the amp to PT saturation which sounded like the amp was failing. The best tones I've ever recorded for myself were with a 2203, Master barely on, mic pre cranked to get enough signal, usually late at night trying not to bug neighbors. I'd listen back the next day and be amazed.

So you're saying that it compresses a lot when cranked, so the notes bend into each other easier so to speak- ie making it "easier to play"?

Personally I'm not after a high gain sound. I don't want to boost the amp, I don't want to mod it for more gain, in fact I want it really clean-sounding. I just want a cranked poweramp sound- lots and lots of poweramp distortion with everything barking & crackling, but some nice solid thud to it. But still fairly clean, very clean. Ideally I don't even want the preamp volume to even near 12 o'clock. Basically I want the amp to crunch when I play really hard, and stay relatively clean when playing softly. Dirty-clean/gritty is ok, just enough for some extra character to a clean sound.

I'm hoping that a pair of Yellow Jackets with EL84s will more efficiently achieve that.

 

[petejt]

There are several models of Yellow Jackets ..... like said make sure you get the right ones. They do reduce volume ..... but not a lot. It is more about point of break up then volume for me. They also well change the tonal balance. EL84's do not produce a lot of bass. The harmonics in the high end are great. I have never tried them in a 800 myself.

Oh ok then, thanks. I don't want too much bass- just enough to keep it sounding solid with a nice thud. It doesn't sound very bassy anyway at the moment. The "thud" sound is pretty much right and I can get an awesome deep growly sound out of it, but it would be nice to get more of that poweramp breakup- lots of poweramp distortion. Some top end harmonics sounds good though- I like that sound of that.

 

[Shawn Lutz]

I think a better attenuator would do better that the YJ's myself.

I used them in my JCM800 2203 (100w version) for a little while. Although it did tame the beast it was still farily loud. Also keep in mind El84's tone wise sound a lot different that the 6550's in my 2203

to answer you question yes they should work out for you. make sure to buy the right YJ's that have the power reduction in em...

Well I don't really want 6550s. Anyway my JCM800 has EL34s in it, a pair of Electro Harmonix EL34s. No 6550s in it to speak of.

So I guess that I would just need the standard version? I've seen there's a cathode version but I guess they are just for the Fender Champ amps that have 6V6 valves?

you want get the power reducing type. They have two flavors, one that just convert to el84 and ones that convert to el84 and reduce power. you'll need 2 of them. primary difference between 2203 and 2204 is 100 watts vs 50 watts

 

[skoora]

Hang on there, take note that my JCM800 is the 50 watt 2204 master volume model (no effects loop), not the 100 watt 2203!

It would probably react the same way but I've never owned a 50 watter. The only 50 watt Master Volume circuit that was different was the '76. You also contradict yourself. You say you want it really clean but then want lots of power tube distortion. Distortion is distortion no matter where it comes from. It sounds like maybe a jcm800 is not the amp for you. You may want a Vox style amp or a Hiwatt.

 

[steve_k]

I've got an old single-channel Marshall JCM800 50 watt amp, with two vertical inputs.


I love the sound of it, and like that it is not as gainy in its stock form. Everyone cranks the preamp gain/boosts with a dirt pedal, and/or gets it modded, hence the Fortin Cali/Splawn/Cameron/Friedman/Jose/Voodoo market that is often bantered about on this forum.

I want to use this more for its poweramp distortion, basically I want to crank the master volume to 10 and just use the preamp as a "master volume" level control.
But it just gets way too damn loud-even in my stonewall cellar!

I've tried my Hotplate attenuator with it, and it just ain't working out for me.
I'm running the amp with my Mesa/Boogie 4x12 Stiletto cab that is loaded with V30s.

I'm thinking of using EL84 poweramp valves in it with Yellow Jackets. Will this be ok for this particular amp?

Replace the preamp tubes with 5751's. This will knock it back about 30%.

Steve

 

[mmorse]

Have you tried going into the low input? The low input has one less gain stage and doesn't get nearly as loud as the hi input. I run my 2204 with the master up to 7 and the pre volume around 3 for home use and up to 1 for giging. I use pedals for dirt. Run that way you can keep a thick clean. It's not the greatest clean tone by any stretch but may be more along the lines of what you are looking for.

I doubt you will like 84s in that amp. 6V6s (JJs) in that amp knock the wattage down to around 22 from 50 but that's still pretty loud. But they will give you more of a 34 tone than 84s will.

 

[stephen sawall]

You may loose some of the thump with EL84's, the bass in them can be kind of loose when turned up. Like I said I have not tried them in a 800.
A lot of people think because EL34 are used in Marshall and 6L6 are used in Fender that 6L6 are the cleaner tube. If you have a amp that you can swap them out you well see this is not true. The EL34 is cleaner.
6V6 are similar to a 6L6 and are pretty crunchy. Even with less power than the 6L6 the 6V6 has more bass in the tonal balance. Like everything else you just need to see what works for you. Messing around with a few different preamp tubes in V1 is a very good idea ... as mentioned above.

If you look on this page , click on "yellow Jackets" ..... on the right you can see there are many different models .....

http://www.thdelectronics.com/library.html

Product Manuals:
THD YJ20 Product Manual. (PDF)
THD YJ7591 Product Manual. (PDF)
THD YJC Product Manual. (PDF)
THD YJS Product Manual. (PDF)
THD YJSD Product Manual. (PDF)
THD YJShort Product Manual. (PDF)
THD YJUni Product Manual. (PDF)

 

[petejt]

Hang on there, take note that my JCM800 is the 50 watt 2204 master volume model (no effects loop), not the 100 watt 2203!

It would probably react the same way but I've never owned a 50 watter. The only 50 watt Master Volume circuit that was different was the '76. You also contradict yourself. You say you want it really clean but then want lots of power tube distortion. Distortion is distortion no matter where it comes from. It sounds like maybe a jcm800 is not the amp for you. You may want a Vox style amp or a Hiwatt.

I mean "clean" as in a clean preamp sound. Low gain. But high on the master volume.

Hey I love the JCM800. It has that deep barky growl I've been searching for. It's just that I want a bit more dirt from the poweramp, without having to turn the preamp up or use a dirt/boost pedal, or smash the next door neighbour's glass windows. That's partly because I want to run it on the same setting for clean and heavy tones, and just change my pick attack & guitar volumes.

 

[petejt]

Have you tried going into the low input? The low input has one less gain stage and doesn't get nearly as loud as the hi input. I run my 2204 with the master up to 7 and the pre volume around 3 for home use and up to 1 for giging. I use pedals for dirt. Run that way you can keep a thick clean. It's not the greatest clean tone by any stretch but may be more along the lines of what you are looking for.

I doubt you will like 84s in that amp. 6V6s (JJs) in that amp knock the wattage down to around 22 from 50 but that's still pretty loud. But they will give you more of a 34 tone than 84s will.

I did try the low output earlier on, but I still have to turn the amp up a fair bit to hear any kind of dirt. I will try it again though.

I basically want a middle of the road semi-dirty tone that can get clean when rolling down the guitar's volume, and crunch & bark when digging into the strings. Like Malcolm young but a tiny bit cleaner (think The Jack). I love some grit on a clean tone. It does that already but the output volume is excessive. And attenuators aren't doing a good job unfortunately. If I want super ultra clean remember that I have a Roland Jazz Chorus 120. Also the MarkIV covers the super clean territory quite nicely, and covers the high preamp gain sound.

It'd be nice to preserve that EL34 tone. I'll give both the 84s and 6V6s a go with the Yellow Jackets and see. Thanks for the tip.

 

[petejt]

6V6 are similar to a 6L6 and are pretty crunchy. Even with less power than the 6L6 the 6V6 has more bass in the tonal balance.

Cool, thanks for that Stephen. They might be a goer..?

 

[mmorse]

I did try the low output earlier on, but I still have to turn the amp up a fair bit to hear any kind of dirt. I will try it again though.

I basically want a middle of the road semi-dirty tone that can get clean when rolling down the guitar's volume, and crunch & bark when digging into the strings. Like Malcolm young but a tiny bit cleaner (think The Jack). I love some grit on a clean tone. It does that already but the output volume is excessive. And attenuators aren't doing a good job unfortunately. If I want super ultra clean remember that I have a Roland Jazz Chorus 120. Also the MarkIV covers the super clean territory quite nicely, and covers the high preamp gain sound.

It'd be nice to preserve that EL34 tone. I'll give both the 84s and 6V6s a go with the Yellow Jackets and see. Thanks for the tip.

That's not going to happen with that amp at lower volumes. A stock 50 watt MV 800 is not super gainy to begin with. You want Malcolm tone at lower volumes, you will have to use a pedal. Something like an OCD might work. Or use a good attenuator. I've tried both and prefer the pedal route. You can dial just the right amount of dirt. But you do have to find the right pedal for your needs.

 

[mmorse]

6V6 are similar to a 6L6 and are pretty crunchy. Even with less power than the 6L6 the 6V6 has more bass in the tonal balance.

Cool, thanks for that Stephen. They might be a goer..?

6V6s sound good in that amp. They cut the power in half but that's only going to cut volume by 3 db. To get the amp to crunch territory on its own, it will still be LOUD! Been there done that. If you found plugging in to the lower input was still too loud, 6V6s will not be the answer for you.

 

[stephen sawall]

6V6 are similar to a 6L6 and are pretty crunchy. Even with less power than the 6L6 the 6V6 has more bass in the tonal balance.

Cool, thanks for that Stephen. They might be a goer..?

6V6s sound good in that amp. They cut the power in half but that's only going to cut volume by 3 db. To get the amp to crunch territory on its own, it will still be LOUD! Been there done that. If you found plugging in to the lower input was still too loud, 6V6s will not be the answer for you.

I agree ..... it well be loud no matter what tubes you put in there. It is more about point of break-up and tonal balance than volume.

 

[petejt]

I did try the low output earlier on, but I still have to turn the amp up a fair bit to hear any kind of dirt. I will try it again though.

I basically want a middle of the road semi-dirty tone that can get clean when rolling down the guitar's volume, and crunch & bark when digging into the strings. Like Malcolm young but a tiny bit cleaner (think The Jack). I love some grit on a clean tone. It does that already but the output volume is excessive. And attenuators aren't doing a good job unfortunately. If I want super ultra clean remember that I have a Roland Jazz Chorus 120. Also the MarkIV covers the super clean territory quite nicely, and covers the high preamp gain sound.

It'd be nice to preserve that EL34 tone. I'll give both the 84s and 6V6s a go with the Yellow Jackets and see. Thanks for the tip.

That's not going to happen with that amp at lower volumes. A stock 50 watt MV 800 is not super gainy to begin with. You want Malcolm tone at lower volumes, you will have to use a pedal. Something like an OCD might work. Or use a good attenuator. I've tried both and prefer the pedal route. You can dial just the right amount of dirt. But you do have to find the right pedal for your needs.

I bought a stock JCM800 specifically because it's not super gainy. Basically I want to blend a mildy-dirty Marshall Bark-Growl sound with my MarkIV. The Malcolm Young reference was just to help explain things- I'm not aiming to replicate his tone. I'm bored with super gainy amps anyway, or amps that are modded for more gain, as I said in my opening post. If anything I'd rather the amp sound cleaner rather than gainy, since I want to run it at the same time as a clean tone on my other amp, but just play a bit softer so it clips less (which it already does fine). It's just that it'd be nice to have some more poweramp clipping without shaking the tiles off the roof when I'm playing the amp at home. Although I haven't gigged it yet it works fine jamming loudly with a band.