NIHD - New Impending Head Day

[DonP]

I didn't know that, thanks!

7025 is also the same tube.

[DonP]

Finally got a chance to be alone with the amp, and cranked the Gain to 10 and the Master to Intolerable

Definitely more punchy at higher levels. There's an audible difference between 4 and 7, and there's a "little extra" once you get to 8.
I quickly ran through a few different guitars - the Trans Red Warrior with the PATB1, the Halford with an Invader, the CS WR7 with the JB7.
The amp definitely needs a front-end slammer.


So, not knowing how long I'd have to dick around with it, I ran a cable from the Send of my MP-1 into the High Sensitivity of the head, picked some patches I never use and didn't mind losing, and started from scratch.

I backed the Gain of the head down to about 2 so that Cleans would be clean, the EQ to 5s, set the MP-1 Gains and Master to 5, the EQ to 0, Output knob to about 9'oclock, and brought the head Master up to about 3.

Totally knee-killing volume out of my 2x12.

So then I swapped the MP1 to the Low Sensitivity input, and was able to get the head Master up to about 8 to push the power tubes, then re-tweak the MP1.


I've read where a lot of people say the MP-1 can't do high gain. I'd like to know their definition of "high gain" because I got a fuck-ton of it.

I set up a Perfectly Clean patch and bashed the strings with a Jazz III, and there was no breakup, so I know the head Gain is not contributing any overdrive.

My MP-1 is unmodded. IIRC, the guy I bought it from almost 20 years ago said he put in GrooveTubes, and that it was otherwise stock.

With both MP1 gains set to 10 and the Voicing set to Dirty Tube, there's no chord definition, solos are smothered in fuzzy artifacts, and chug-a-chugs lose all definition. Major chords came out sounding like that one home-made live clip of Rhoads with QR

With the MP1 Gain 1 set to about 6 (just below clipping), and Gain 2 set to 10, it's still too saturated to play Sad But True cleanly, but solos on the upper strings/frets weren't as fuzz-covered. Nice sustain and definition, with minimal shrieking on double bends.

With Gain 2 on about 8, Holy Wars was totally do-able, as well as Disposable Heroes and One.
Speedy palm muted single-string rhythm patterns were articulate and well-defined. Arpeggiated lines on the wound strings were ballsy without sounding choked.

Scooping the mids of the MP1 (Mid on -12), I retained definition without turning it into a "bee in a bottle".

Since I didn't know how long I had before the noise-haters got home, I didin't get a chance to crank up any drums/backing tracks to see if I'd get buried in the mix with such scooped mids, and I only used one guitar - my black Warrior with a Parallel Axis Distortion in the bridge.

By default, the MP1's EQ is a tad on the bright side, so depending on the patch I used, I did have to back off either the unit's Presence or Treble a couple of notches. Setting the MP1's Bass to 6 and everything else to 0 made it too flabby for D-standard, but 4 was just right. I could still use the head's EQ to tweak it if I had to.


Probably won't get another shot until next week sometime, but I'm hoping to set up the camera and film different guitars and run through a few patches, with backing tracks. Definitely want to hear my NASL (Custom in the bridge), SoCal (JB bridge), and the WarAngel (Duncan Alt 8 - anxious to see how the "no volume control" works out with a real amp ).

Also want to see the Jazz'R (dual 59s) and SLS Custom (JB/59 hybrids) straight in - the alleged "Classic tone" of an LP straight to a Marshall will be put to the test there
Then there's the PL-2 with EMGs.
Need to get my Morton (dual P-Rails) up and running.

Just counted and I've got 22 guitars, and no two have the same pickups.

Don't know when it'll be, but it'll be a nice long day of Guitar Swapping and video editing and YouTubing

The MP-1 has 2 12AX7's. Each 12AX7 has 2 triode, each with a gain of 100. So 4 100 gain stages cascade is 100 x 100 x 100 x 100, or a theoretical maximum possible gain of 100,000,000. There's no shortage of gain.

You are doing as rockers did in the 80s. The MP-1 preamp (or pedals if you go that route) is defining the tone and the JCM800 is a big whooping power amp adding a little flavor to the mix with a little power tube and speaker distortion.

[Shawn Lutz]

While reading the online manual for the AM-4 at Line6's site, they mention the Brit 800 model is based on the JCM 800, and that some versions used diode clipping for distortion, and other versions used tube distortion.
How do I tell if my 800 uses tube distortion vs diode clipping?

I don't believe any 800 used diode clipping, JCM900's did.

[DonP]

I don't believe any 800 used diode clipping, JCM900's did.

Only the Silver Jubilee that I know of.

[jgcable]

You are going to find that the best way to get a high gain metal tone out of that amp is to slam the front end with something tried and true and vintage... Candidates are...

MXR Distortion +
Proco Rat
TS9 Tube Screamer
Boss DS1, SD1, HM2
Boss Metal Zone

I used an MXR Distortion + I would dial up a vintage gain tone on the amp so that if I dialed my guitar volume down it would clean up enough to be CLEAN. I would then dial up the MXR Distortion + to provide enough additional gain.

[jgcable]

The MP-1 has 2 12AX7's. Each 12AX7 has 2 triode, each with a gain of 100. So 4 100 gain stages cascade is 100 x 100 x 100 x 100, or a theoretical maximum possible gain of 100,000,000. There's no shortage of gain.

You are doing as rockers did in the 80s. The MP-1 preamp (or pedals if you go that route) is defining the tone and the JCM800 is a big whooping power amp adding a little flavor to the mix with a little power tube and speaker distortion.

I am one of those 80's rockers and I heard that combination many times live. Never liked it. Always sounded like a can of bees. I always thought the best tone was the purest. At that time I was playing out of a full stack Hiwatt 120 watt head with 2 Marshall cabs and an MXR Distortion + and a Phase 90 out in front. Thats it. The Hiwatt didn't have any distortion really. It just got CRAZY loud and saturated.

[Hellbat]

JG has it right. The right way to set up an 800 is to dial in a light crunch that cleans up when you dial the guitar back to 7 or so. From there Slam the front with a clean(ish) boost for extra gain.

Some pedals he didn't mention in the list because they aren't from the same era would include the MXR/CAE boost or boost/OD and the new TC Spark booster.

[roodyrocker]

JG has it right. The right way to set up an 800 is to dial in a light crunch that cleans up when you dial the guitar back to 7 or so. From there Slam the front with a clean(ish) boost for extra gain.

Some pedals he didn't mention in the list because they aren't from the same era would include the MXR/CAE boost or boost/OD and the new TC Spark booster.

I've used the MXR/CAE boost and my sound guy actually prefers it to the others I like to use with a JCM 800 which are the Retro-Sonic 808 and Fulltone OCD. Any of those sound good with it.

[Newc]

Gonna do some more tweaking when I get the chance, try to get the MP-1 to do the "clean boost" shtick.

Either way, the way it's set up now tickles my pickle, and that's what matters most

[zeegler]

I don't believe any 800 used diode clipping, JCM900's did.

Don't the 2205 and 2210 both have some diode clipping? I heard that somewhere.

[Newc]

I tried the MP-1 as a clean boost (set up a loud clean patch with minimal compression from OD1) but it just got louder, not smoother.
Even using the Clean Tube voicing, I get more of a heavy blues tone, but have to go with full-on distorted tube voicing to get the gain I'm after, and then I may as well just have a power amp.

Then again, I just realized I was running into the low sensitivity input. Shoulda tried it in the high input. Doh.