Please help! JCM 800kk arrived, and I'm 'very' under whelmed.

[Sidewinder]

UPDATE:

Hey everyone. I put a whole new set of JJs in the amp and set the bias at 37.2.

While it does sound better, there is still something very wrong.

The only way I can get close to good Marshall sound is on the beast mode with the preamp and master almost dimmed.

Just playing it normal without the beast mode (preamp and master at noon) there is no sizzle. Nothing. It's damn near clean sounding at those settings.

I'm very surprised by this.

What could the problem be?

 

[mickeydg5]

Did you notice anything strange, replaced or modified inside the chassis?

Was the other power tube set all good or was there a bad tube?
If there was a bad tube, it may have damaged another component?

Check out the chassis and components, post good pictures or take it to a technician for a once over.

Add
From what could be seen in the pictures on the other thread everything looked clean.

 

[Sidewinder]

I don't have a tube tester, so I don't know if any of the old tubes we're bad.

I did not notice anything modded or out of order. The innards looked pristine, and untouched.

 

[mickeydg5]

What type of preamp tubes are being used?

 

[Sidewinder]

These: ECC83-S/12AX7

www.thetubestore.com - JJ ECC83-S / 12AX7 Audio Tubes

These for power: KT-88

www.thetubestore.com - JJ KT88 Audio Tubes

 

[ShaneElvis]

Pre-War tubes , everyone is trippin over output tubes, Pre-amp is where your signal first gets boosted and broken up,!!! I had to do a lot of fucking around with my 59'RR tell I got my shit together. V1 failed causing the power tubes to get fucked up. I got Mesa Boogie 6L6 in the apocalypse position.
( hardcore randy rhoads fans and diehard Marshall fans hate my guts. )
but the 6l6 trumps the el34 tubes that were in there. Anyhow.... The pre-death tubes should probably be checked , that is the heart of the amp

 

[MartyStrat54]

New current production tubes does not guarantee anything. If you still have one of the original 12AX7's, swap out the preamp tubes one at a time and see if there is a difference.

Also, with the lights out, look at the tubes and see if all the heaters are lit up.

 

[mickeydg5]

These: ECC83-S/12AX7

www.thetubestore.com - JJ ECC83-S / 12AX7 Audio Tubes

These for power: KT-88

www.thetubestore.com - JJ KT88 Audio Tubes

Do you know if those tubes tested high or low?

I read a review on at the TubeStore which commented that some had gain like a 5751.

Roll some of the other tubes in the preamp slots and see what happens.

 

[Sidewinder]

"V1 failed"

Could you expand on that, ShaneElvis?

You usually do not know what is being sold or forwarded unless you ask for test results.
I have purchased new preamp tubes before that barely measured above JAN minimum specifications.
The JJ preamp tubes could read high or low. If all three are low it will tame or neuter the amplifier.

Like mentioned in the other thread, roll some preamp tubes.

I didn't know to ask for test results. I don't even know what to look for in numbers.

I don't have any other preamp tubes laying around except for the old ones, and the amp didn't sound any better with those.

What test numbers do I look for in preamp tubes? I'll order some more.

 

[blues_n_cues]

I don't have a tube tester, so I don't know if any of the old tubes we're bad.

I did not notice anything modded or out of order. The innards looked pristine, and untouched.

it's tech time.
I'm no tech by far but I do know that you can't always tell electronics malfunction by just a visual inspection.
I have a wireless that looks new out of the box but listening to it I swear it's taken a bath @ some point.

 

[bulldozer1984]

take it to a tech man..

 

[mickeydg5]

Like has been said, you may have to take to a technician.
There seems to be something going on in there based on your description which may or may not be tube related.

Give the story and what has been done so far.
The tech should be able to check all of your tubes and give test scores with a percentage of good/new for micromhos.

 

[Ken]

1 more reason for not buying sight unseen/heard.

I would bet 50% of tube amps sold on fLeaBay have some kind of issue, and I also bet 95% of those issues are old or bad tubes. Anyone buying a used amp sound unheard should retube it before complaining it doesn't sound right. Especially a KT88 tube amp since most musicians are pretty broke most of the time.

Ken

 

[Sidewinder]

I would bet 50% of tube amps sold on fLeaBay have some kind of issue, and I also bet 95% of those issues are old or bad tubes. Anyone buying a used amp sound unheard should retube it before complaining it doesn't sound right. Especially a KT88 tube amp since most musicians are pretty broke most of the time.

Ken

Who's complaining?

 

[JayCM800]

Sorry to hear, man! I also bought a KK sight unseen... it has always performed flawlessly for it's intended purposes (LOUD band rehearsal and gigs... not bedroom playing!) After a year and a half of use (not abuse), a power tube went out (a semi-loud "pop" while on standby at rehearsal...) After a re-tube and bias, it's been going strong almost a year now! I feel so confident on my amp that i never bring backup to gigs! LOL

I also bought online a Class 5 about a year and a half ago... I play that "Little Amp" at home every day! still on stock tubes! No rattles! No MV! No BS!

Maybe luck has somethin to do with it?

 

[Sidewinder]

Jay! Nice to see ya around man! Nice to meet ya too! I've read a lot of your posts in the JCM 800 threads. I was wondering when you might pop in...

Love your enthusiasm for the JCMs!

Anyways, ya, I can't wait to hear this mutha sing like it's supposed to. Maybe the previous owner couldn't be honest about the amp, or take care of it, but come hell or high water, this puppy will sing again. I Just got to find a good tech. Might have to head south or ship it out to someone.

I know what this amp should sound like, and I'm craving that bad.

Hey you have one of these kks. Tell me, shouldn't this amp be sizzling with the preamp and master on (5) with no beast mode?

I'm playing with a Gibson LP and 490 498 pickups. I can't imagine it wouldn't be singing at those levels. I have to dime this thing to get crunch and sizzle with no beast.

That can't be right? Right?

 

[JayCM800]

Jay! Nice to see ya around man! Nice to meet ya too! I've read a lot of your posts in the JCM 800 threads. I was wondering when you might pop in...

Love your enthusiasm for the JCMs!

Anyways, ya, I can't wait to hear this mutha sing like it's supposed to. Maybe the previous owner couldn't be honest about the amp, or take care of it, but come hell or high water, this puppy will sing again. I Just got to find a good tech. Might have to head south or ship it out to someone.

I know what this amp should sound like, and I'm craving that bad.

Hey you have one of these kks. Tell me, shouldn't this amp be sizzling with the preamp and master on (5) with no beast mode?

I'm playing with a Gibson LP and 490 498 pickups. I can't imagine it wouldn't be singing at those levels. I have to dime this thing to get crunch and sizzle with no beast.

That can't be right? Right?

No man, once you reach 5 on the master you surely feel the "punch" of the volume! Anything louder than 7 is a bit scary Shouldn't need to be "dimed" unless to crush, kill and destroy...

I wish it all works out well for you and your amp in the end. A qualified amp tech should be able to fix the problem, after all it's just(mostly) a 2203 circuit.

 

[Sidewinder]

I can easily tollerate the volume dimmed with or without the beast mode. It does get loud, but not crazy loud. My ATV150 is louder, and has a 'lot' more punch.

 

[axe arsenal]

I feel the need to tell that a KK doesn't sound as loud as an original JCM 2203.
I remember when I had my original one(s), that I couldn't put the volume past 3,.. didn't hear any drummer or whatever.
The 2203KK has less headroom than my 1986 2203 had, it distorts easier.
This is based on setting the preamp at 10 (and no "beast" knob involved).

 

[Reckless_Life]

Perhaps the amp has been tinkered with any way?

A friend of mine had his 2203KK modded for "more gain".

The result was that the amp had (a hair) more gain, but the bite was gone.
It sounded boomy, like a stoner, Black Sabbath sound.

We did a AB test with my amp, and well, imo, his amp tone was ruined.
Luckily the mod was reversible, so all is back OK now.

I wouldn't be surprised if the amp from the TS is not working optimally or maybe even has a failed mod, who knows... but a good checkup by a tech is never hurts.

I never played a ATV150, but I'm pretty sure that a 2203KK would be (AT LEAST) equally loud.