Is the JCM 800 2203 supposed to be this bright/trebly??

usablefiber

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Preface: For some reason my amp won't bias correctly. Tubes will bias extremely cold and I am not sure why. I don't know if this would be the problem.

I love some of the 800 tones I dial in on my amp, however I always find myself having to turn down the treble and turn the guitar tone knob waayyy down. When I do it sounds great but It really needs to tame it a bit as iif I don't it almost gets so trebly that it doesn't make musical notes but brittle sounding shrieks. This includes using humbucker pickups in the neck position.
 

MarshallDog

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What you describe Bro is typical JCM tone territory and I have experienced the exact same thing. They run at a much higher plate voltage than earlier Marshall's which is the biggest cause of this type of tone. That is why mine will probably be sold soon, I just love my JMP tone much more than the JCM. There are many tricks you can do to help improve the tone, just do a search on this forum ( bright cap mod) to start with.

As for biasing, if you bias it on the hitter side, say 70% max dissipation, that will help a little but not that much. I have JJ tubes help the most but it is still a bright ass amp hands down. If you can't get the bias up you may need to add a larger resistor across the existing fixed bias resistor assuming this amp was already converted from 6550 to el34 tubes.
 

NewReligion

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I have had this issue with many 2203/2204, both JMP and JCM. I will add that the speakers used will make a huge change. That is to say I really dislike the this circuit which is high ended and a bit buzy stock through a Marshall cab loaded with GT75's. Greenbacks were a little better. Using a vintage 30 loaded cabinet starts getting it in the tone zone IMO. And others swear by the 65's etc...

Remember that Marshall had Celestion design the vintage 30 speaker in 1986 for the thicker midrange sounds and approaching evolution of high gain to come.

I now use 1960BV cabs with all of my Marshalls for overdriven tones. Best tone solution I ever happened upon. Now I just mod the amps to taste, but you can't get there if your speakers do not cover the EQ freq.

Playing clean I love a great JBL/EV etc...

Probably gonna get flamed now, but my amps (All) sucked through 75's.

My $.02 David ♫
 
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dptone5

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I recently tried Classic Lead 80's. Much better than the 75's. Strong low end and very tight. Really liking them right now. Also, I use an EQ pedal to boost the low frequencies (100 and 200 Hz) when using my 2203X. Really tames the highs and helps the amp sound amazing!
 

Redstone

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I find my 2204 incredibly trebly compared to my YJM. I'm used to the having both channels going at once on the YJM so thats probably why I find my 2204 very trebly. Even with the presence on 0, middle on 3 and treble on 3, it is brighter than my YJM with the presence on 0 and everything else on 6. I've never really taken notice of how it sounds on the neck pickup of my LP or SG.
 

spacerocker

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Yes, 2203s are supposed to sound bright and agressive!

I think there are two types of Marshall fan - those who like the dark, middy tones of some of the earlier amps, and those (like me!) who like the bright Plexi/2203/800 type tones! (I have modded my JVM to capture exactly this type of tone on the Crunch channel)

Embrace the brightness! - it sounds killer in a band mix!
 
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damienbeale

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What you describe Bro is typical JCM tone territory and I have experienced the exact same thing. They run at a much higher plate voltage than earlier Marshall's which is the biggest cause of this type of tone.

This is aimply not true at all. The mid/late 70's 50w amps ram lower voltages, but the earlier amps ran much higher voltages than all of them

It is normal to run both presence and treble at around three to get a thick warm tone, but it still sounds like something is wrong here.
 

Voodoo Amps

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Preface: For some reason my amp won't bias correctly. Tubes will bias extremely cold and I am not sure why. I don't know if this would be the problem.

I love some of the 800 tones I dial in on my amp, however I always find myself having to turn down the treble and turn the guitar tone knob waayyy down. When I do it sounds great but It really needs to tame it a bit as iif I don't it almost gets so trebly that it doesn't make musical notes but brittle sounding shrieks. This includes using humbucker pickups in the neck position.

Plate voltage for the reissue JCM800 2203x is much the same as the older JCM800’s. There were some older 800’s that ran on lower plate voltage but these are more of the minority in the JCM800 single channel series. If the tubes are biased cold you can either A.) Purchase a quad of tubes that tests out in the middle-of-the-road so you can bias them properly or B.) Take the amp to a tech and have the bias supply Modded. It can be Modded to properly bias your present tubes or a tech can Mod the bias supply so there is enough bias adjustment to work with most tube types.

Mod – Here is a very simple Mod that we do for stock JCM800 2203x’s and it’s by no means reinventing the wheel but the disclaimer is that you should have a qualified and experienced tech do this for you as high voltage is present in this area - You can remove the (2) 56K’s that are located on the first filter caps in line off from the bridge rectifier in the high voltage / B+ supply. This will help to warm up the tone and help the amp to sound a bit more authentic to the late 70’s 2203’s or at the very least sound more like the original JCM800 2203’s that has the vertical inputs. Again, if you are not sure where this is please take the amp to a qualified tech as there is high voltage present in this area. This is a simple but effective Mod and it is 100% reversible.


I hope it helps
Trace
 

FutureProf88

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I have an '88 2204. I think that those amps tend towards the trebly side for sure. They are also VERY sensitive to speakers. NR thought he was going to catch flak for his post but I KNOW I will for saying this: One of the best cabinets I ever heard mine through was a Peavey 412MS with Sheffields in it. They were an amazing sounding combination. I sold that cab for a G12-65 loaded Marshall 1960A which I do like, but with the 800 I miss the tone from that Peavey cab at times.

A trick that a tech I go to showed me is to invert the "normal" Marshall EQ curve. He said when he runs his JCM 800 he runs it Bass: 9, Mid: 7, Treble: 3, Presence: 6, Master as high as you can stand. It sounded very nice that way. Very thick but still had some upper midrange cut to it.

If you run much treble or presence you need to keep the other control low and then make sure that the Mids and Bass are both high up. Personally I don't like 800's scooped out and I think that makes them even tinnier sounding.
 

Ken

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my JVM to capture exactly this type of tone on the Crunch channel)

Embrace the brightness! - it sounds killer in a band mix!

I thought my DSL was stupid bright when I first bought it. EL34B's helped, but the big revelation to me was when I started hearing recordings with the band. What was too bright at home all of a sudden was a perfect tone in a band situation. I went from presence on 0 to what I've been doing lately which includes the presence on 10 and treble at 1.5.

Ken
 

MarshallDog

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This is aimply not true at all. The mid/late 70's 50w amps ram lower voltages, but the earlier amps ran much higher voltages than all of them

It is normal to run both presence and treble at around three to get a thick warm tone, but it still sounds like something is wrong here.

OK, I guess I should have been more specific as to what I meant which is both of JMP's a 1980 and a 1981 run at 390 V and 397 V respectively while my 1983 JCM runs at 466 V and they are all the 2204 models. I have also read on many forums that earlier amps than my two JMP's ran even lower voltages (not sure how far back this holds true for???) and I can't verify that because I have never owned or measured the voltages on anything older than mine at this point.
 

damienbeale

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OK, I guess I should have been more specific as to what I meant which is both of JMP's a 1980 and a 1981 run at 390 V and 397 V respectively while my 1983 JCM runs at 466 V and they are all the 2204 models. I have also read on many forums that earlier amps than my two JMP's ran even lower voltages (not sure how far back this holds true for???) and I can't verify that because I have never owned or measured the voltages on anything older than mine at this point.

The norm for your jmp's would be 360v if the wall voltage were closer to what Marshall presumed it should be. You'd find if you ran it over here rewired for the 240v tap you'd probably be around 365v. But the first jmps were much higher.
 

dreyn77

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Yeah My 5010 was bright and nasty today with a USA strat.

then I stopped kidding myself trying to make the extreme full power of the amp get me the sound.
I used the high input channel.
I left the pres on 10 and turned the B.M.T. way down.
turned the vol to the level I wanted to hear the sound at (yeah your 800 does the same thing!)
turned the gain to full.
clicked on the TS5 tubecreamer turned the gain and vol way down left the tone on full.
I set the amps B, M, T so that the guitars fullpower tone dial matched Edward V Halen's strat Humbucker tone on the first album (that's right, I was using the single coil guitar! I wasn't trying to match the Fuzzzz).
the amp has heaps more eq adjustment if needed and it wasn't.
and I played along to the album, then OH HO VH plays another guitar and it's a different tone. NO WORRIES all I did was turn the guitars tone pot way down to match the sound tone exactly.

Its really easy once you know how. Warm brown sound and there's NOT even a greenback or frankie or mumbucker in site!!!

Strat into cheapo tubescreamer into a NO MODS 5010 SS amp with G12 70 speakers.
the only thing that was missing was the crappy "Fuzzz" that the 68 amp does.
So I guess my version was heaps better!
I was really chuffed all day.
 

plexilespaul

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the 2203 are bright amps and that's their nature. when you are talking piercing high it's tech time.
i run mine with the treble and presence on 4 with g12-65's and the amp has a nice smooth crunch to it...high way to heck all day long:)
 

usablefiber

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Yea I figured out my amp had a problem for sure. Apparently I dislodged the bias trim pot when I attempted to bias. So it wasn't biasing the amp at all which is why my tubes just cooking ultra hot. I'm assuming the trebles were piercing because they were so hot the highs just shrieked. Anyways Its fixed and the amp sounds great.
 

SG~GUY

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#1-put a JJECCO83S in the V-1 position,..
#2-the treble resistor snip-(that vodoo spoke of works great)-
#3-speakers do play a large part ,..it's the entire signal path that matters,.the ole weakest link in the chain syndrome,..if all your using is a eq for a clean boost,...then you should be fine,...adjust the tone controls with your ears not your eyes,..my 2203KK bass-(10)- treble-(6.5)- mid-(4.50)- pres-(4)-,...green backs,..zero buzz,..(due to over-taxed-preamp)

the JJ803-S is a major help...i have had that tube in every marshall i have ever owned
 

Landshark

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Yea I figured out my amp had a problem for sure. Apparently I dislodged the bias trim pot when I attempted to bias. So it wasn't biasing the amp at all which is why my tubes just cooking ultra hot. I'm assuming the trebles were piercing because they were so hot the highs just shrieked. Anyways Its fixed and the amp sounds great.

I thought something sounded funny when you said it was not biasing correctly and you had a treble issue. Good on you for taking it to get fixed. Congrats on your 2203 being back in action!
 

plexilespaul

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#2-the treble resistor snip-(that vodoo spoke of works great)-

well it's nice for some applications for example when the cab has bright speakers in it but it cuts too much marshall yummy. i have a on/off bright cap switch on my jcm 2203 so i know exactly what it does.
 

SG~GUY

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well it's nice for some applications for example when the cab has bright speakers in it but it cuts too much marshall yummy. i have a on/off bright cap switch on my jcm 2203 so i know exactly what it does.

the switch is a good ..not for me ,..i clip um as soon as i get a marshall
 

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