YJM100 - 'The Ultimate Plexi' thread!

[Holme]

Yeah I'm guessing all these extras must be heavy!

 

[indeedido]

Sooo, been through some valve-swapping.
Tested various power valves ranging from NOS 5881 over Sovtek EL34 through TAD KT88. The stock power valves are handsdown the best sounding to my ear.
Preamp stage saw some NOS JAN Phillips, TAD RT001 (which are basically the same Shuguangs as the stock valves from the look and sound of it), TAD 7025, JJ, Sovteks, Rubys, GT and what not but the stock ones V2 - V4 are the best so far IMO. At the end I just swapped the V1 for a selected TungSol 12AX7 which to my ears is currently the best new production valve in that position. I now have it in all my amps in the input driver stage. It has loads of chime and output without ever getting brittle, and it just doesn't get as muddy as with the stock JJ with booster off and volume 1 on 10.

Ok, so what are you guy's settings that you're the most happy with?
I find myself having all front panel pots on 7 most of the time except volume 1 which is somewhere between 3 and 10 depending on what sound I want. At bedroom level I sometimes roll back on the mids somewhat.
Booster gain on 5 (sometimes 7) booster volume full up.

What tonal difference did you notice when you tried the KT88 vs EL34? I know they will have more headroom, so did you notice less gain? Did it affect the brightness at all? I'm for sure going to try some 6CA7s but am curious about KT88s as I've never tried them but dig Jimmy Page's live tone with them.

 

[Quasar-Kid]

I was in the Las Vegas Guitar Center earlier today (I'm at the airport right now) and I was absolutely relieved that they didn't have a YJM in stock (to taunt me with)

Every time I walk into a new guitar center and they actually have a YJM I get itchy
a little nervous and slightly irritable - it's a far nicer experience when they don't actually have one sitting there (taunting me)


The YJM has become my nemesis

 

[Holme]

One day QK I think you'll have 2!

 

[Quasar-Kid]

One day QK I think you'll have 2!

You've moved up pretty fast to second on my list of Nemesis

 

[Fogdog]

Gee I hate being one of the first to discuss problems with the YJM especially since I just joined the Forum and this is my first real post, but here it goes.

I had less than five hours on the amp when one day I plugged in and engaged the boost and got, a as I would call it, a decaying flanger sound. Absolutely no sustain whatsoever. I messed with everything but no luck. Fortunately, everything else worked fine.

Luckily we have a repair guy nearby who is considered a genius and he does Marshall warranty work. It has been more than three weeks and my amp is still not ready. To be fair this gentleman is very busy and my YJM is just one of many amps & keyboards he's working on.

I had a quick conversation with him a week ago and he briefly said he found a loose wire and waiting to hear back from Marshall about some other issues which he had no time to discuss with me.

Can anyone shed some light on what might be wrong with the amp or the boost in general?

 

[Holme]

This is a new problem Fogdog or certainly one I haven't heard of before.
Hopefully it's a one off incident & you'll have your amp back soon!

 

[pleximaster]

My settings...

As usual with plexis and 4-holers I jump channels and set everything on ten more or less. The eq works better on the YJM than on old plexis, something actually happends when you turn the knobs. My settings on the YJM is about pres (8) bass (10) mid (10) and treble (9). Trebely? No! I play vintage les pauls and I run it through old basketweave cabs with pre rola 25 watters. These are very soft sounding and cant compare with new speakers notyet broken in.

then using a lot of epa I engage the boost set at noon.
best plexi

 

[Mat_P]

What tonal difference did you notice when you tried the KT88 vs EL34? I know they will have more headroom, so did you notice less gain? Did it affect the brightness at all? I'm for sure going to try some 6CA7s but am curious about KT88s as I've never tried them but dig Jimmy Page's live tone with them.

First, I checked it with a pretty worn out set of KT88 that also gave me a tube warning on initial autobias. Replaced the offending tube and all was well.
Second, you have to remove the tube clamps as they are too small for KT88.
The sound was allover bigger in the lower midrange and bass, let's say "sweeter" with considerably less focus on upper mids and treble. I didn't notice less distortion but I didn't run the amp much louder than football worldcup final tv level.
I wouldn't excpect too much power amp distortion with those tubes but as I said, not much difference at lower levels.
I would consider KT88 for this amp if it was my only one as the sound is probably more pleasing to the unexpecting ear (read: the ignorant crowd, what do they know about Marshalls) but that's not what I got it for. My KT88 needs are fully covered by my Pittbull Ultralead, that's the reason why I kicked them off very fast.

 

[olirc7usa]

listen to this awesome video with the YJM100

... when i heard this the first time, i ordered this head immediately !!!

[ame="http://www.youtube.com/watch?v=ecttTf1aH2s"]"I Am a Vicking" solo cover (Yngwie Malmsteen) - YouTube[/ame]

here's my amp :

 

[indeedido]

Thanks for the input! I'm a huge EL34 fan but now given the opportunity to explore a bit with an amp like this is forcing me to try other flavors I've not experienced. I'm going to have to breakdown now and try some! The tone chase never ends does it.

I've had mine for a week now and the honeymoon is still not over. I love it more and more each day. I've been playing around with the controls and it covers a LOT of ground. The interaction of not just the tone stack but the interplay of Vol I and Vol II with the epa is mindblowing. So many options really.

 

[John 14:6]

We practiced for Sunday last night at church and I got to play my YJM100 for the first time with a band, plus I got to get the EPA about half way up in the 50 watt mode. All I can say is that I have never been so impressed or pleased with an amplifier in all my years of playing guitar. This amp is the real deal. Of course it does all of the Yngwie and classic rock stuff to the tee, but it is also amazing for bluesy stuff too. I will have to take pictures soon and eventually make some recordings. Lincoln Brewster stuff like in these clips just pours out of the YJM100. Brewster played with Steve Perry in the 90's

[ame=http://www.youtube.com/watch?v=WXn-iwOHWMY]The Arm of My Savior - YouTube[/ame]

[ame=http://www.youtube.com/watch?v=OQl-FWStQ9c]Lincoln Brewster - Give Him Praise ft. Israel Houghton (Audio) - YouTube[/ame]

Lincoln Brewster "Yngwie Style."

[ame=http://www.youtube.com/watch?v=KCS1d04_iSE]bayside church christmas 2009 - YouTube[/ame]

 

[Holme]

Awesome clips & pics!

 

[Viking62]

Wheres the 50 watter!!!!

Built in

 

[indeedido]

Yes, it is also the YJM50 according to the manual. lol

 

[Holme]

2 amps for the price of 1! A 50 & a 100 watt.
So in theory it's 'cheap as chips'

 

[Quasar-Kid]

listen to this awesome video with the YJM100

... when i heard this the first time, i ordered this head immediately !!!

here's my amp :

Well this adds a whole new twist...
I was originally under the illusion that "there could only be one" total douche nozzle with a YJM (I'm talking to you Holmes)
but now there are two...
I'm perplexed as to which nemesis I shall despise the most (it's a tough call really)

 

[Holme]

Well this adds a whole new twist...
I was originally under the illusion that "there could only be one" total douche nozzle with a YJM (I'm talking to you Holmes)
but now there are two...
I'm perplexed as to which nemesis I shall despise the most (it's a tough call really)

 

[John 14:6]

Well, the YJM100 just got through its first live performance for both services at church today and it sounded incredible. We play 6 songs a service and the styles can vary. The YJM100 handled everything perfectly. I used my DOD YJM308 overdrive pedal which has been modded to Gray 250 specs with the gain set to zero and level maxed as a solo level boost a few times. I LOVE the amp's built in booster and the gain on that is set all of the way up. The noise gate on the amp is off the chart amazing. My amp is dead quiet too even with both channel volumes maxed. The noise gate threshold is not set very high at all and I can not even tell it is on other than the amp is completely quiet. The noise gate does not affect the tone or sustain in ANY way. Santiago is up there with ALL of the best amp designers around. Friedman, Bogner, Splawn and all of those boutique guys. Santiago designed the JVM also.

 

[Marival]

Well, the YJM100 just got through its first live performance for both services at church today and it sounded incredible. We play 6 songs a service and the styles can vary. The YJM100 handled everything perfectly. I used my DOD YJM308 overdrive pedal which has been modded to Gray 250 specs with the gain set to zero and level maxed as a solo level boost a few times. I LOVE the amp's built in booster and the gain on that is set all of the way up. The noise gate on the amp is off the chart amazing. My amp is dead quiet too even with both channel volumes maxed. The noise gate threshold is not set very high at all and I can not even tell it is on other than the amp is completely quiet. The noise gate does not affect the tone or sustain in ANY way. Santiago is up there with ALL of the best amp designers around. Friedman, Bogner, Splawn and all of those boutique guys. Santiago designed the JVM also.

Interesting setup. I also own a grey 250 clone, and I basically use it opposite to how you do, I use the built-in boost for a solo push and the pedal on 10/10.

To me, the pedal itself (provided it's a 250 grey clone) sounds much better dimed than the built-in booster (which is said to be based on the 308 circuit). Obviously it's up to personal preference, but I'm wondering if you tried it this way. Tell me what you think.

Incidentally, I've also read in a review somewhere that there was supposedly not enough gain on the built-in boost. I mean, really? Holy gain Batman. When I crank the built-in boost I can pretty much play the most obscene metal out there. In fact, I think there's more gain on it than one would need. I usually run it at 2/3 max if I use it as an actual gain boost instead of solo boost.


Also, KT88 demo is coming up when I get the other YJM heads. I think I'll keep one completely stock EL34. The other two will get KT88's and KT66's. I was thinking about 6L6's too, but I decided against those since they're not really related to the Marshall sound.