Dirty Little Monster

RJ Guitars · Post by **RJ Guitars** » Fri Mar 20, 2009 6:53 pm

We've heard at least one indicator that a DLM was a hot-rodded plexi into a single ended KT88. It's likely that we will never know differently because it seems that there was only one, maybe two DLM's ever completed and only a handful of guys have ever seen one or know whats up with the circuit... so we can all take a stab at a best guess and have a lot of fun making up our own versions.

I sat down with a hand full of schematics last week and verified for myself... the preamp on the Rocket, the 59' Bassman, and the JTM45, they have a while lot in common and not much in the way of differences. You can consider those comparisons without much of a stretch to say that a Rocket preamp can be a contender for a "Hot Rodded plexi" front end... Thus the Rocket front end into a Single Ended KT88 matches up very closely to one of the few descriptions we've been given for a DLM.

FWIW and YOMV...

rj

mcrracer · Post by **mcrracer** » Fri Mar 20, 2009 7:00 pm

Thanks Rj,
I will put that on the To Do List!
I had already drawn up a schematic and a layout for a Rocket pre, a Liverpool pre, a Marshall 2204 pre and the Express pre...which I have built. Again not to copy Ken , but just to have some fun.

mcrracer · Post by **mcrracer** » Sat Mar 21, 2009 5:53 pm

Fired up tthe AMP today, first off I am a bass player not a guitar player. I know a few chords and can play a little lead. Hey maybe I am a guitar player! Anyway my impressions of this amp are... Massive gain and overdrive available. Lots of Volume.LOUD! I used two 12AX7 and one EL34. I have a KT88 I am going to try as well as a KT77 and a 6L6GC I have read much about how with a TW you dial in the amp and control your vol from the guitar . Down ---clean, up--- high gain crunch. Well it does work just like that . Pretty cool. I will have to get one of my real guitar playing buddies over here to put it through its' paces and see what it really can do. I still have to put the lettering on and install it in a cab. Pictures to follow. I just wanted to get it working well first. I will get some clips up as soon as I can.
Next up a Rocket front end. Thanks RJ for all of your help.

M Fowler · Post by **M Fowler** » Sat Mar 21, 2009 10:38 pm

mccracer,

I am anxiously waiting for pictures and further report on your amp, sounds like fun.

Mark

mcrracer · Post by **mcrracer** » Mon Mar 23, 2009 1:23 am

Ok guys here are a few pix. Still have not done the labels and final lead dress Tried a KT77, I liked the KT88 better. Still have not had a real guitar player jam it yet either.

mcrracer · Post by **mcrracer** » Mon Mar 23, 2009 1:24 am

One more

RJ Guitars · Post by **RJ Guitars** » Mon Mar 23, 2009 1:26 am

Very Cool! I'll be looking forward to some clips and further reports!

rj

M Fowler · Post by **M Fowler** » Mon Mar 23, 2009 5:17 am

Nice, that KT88 sure dwarfs the rest of the small chassis.

Thanks for posting pictures, always fun to see.

Mark

tweedeluxe · Post by **tweedeluxe** » Mon Mar 23, 2009 3:48 pm

is that a valve jr chassis? awesome!

mcrracer · Post by **mcrracer** » Mon Mar 23, 2009 5:54 pm

Yeah, I had a cheap source for them but that's over. Thanks guys. I used an Express preamp and so far there aren't any noise or hum issues nothing crazy. I must be lucky or blessed. OK Next up is the Rocket pre.

Zippy · Post by **Zippy** » Mon Mar 23, 2009 6:00 pm

mcrracer wrote:Yeah, I had a cheap source for them but that's over. Thanks guys. I used an Express preamp and so far there aren't any noise or hum issues nothing crazy. I must be lucky or blessed. OK Next up is the Rocket pre.

Hmmm, makes me wonder if you have enough - maybe increase R7 to get a lil' closer to the ragged edge???

mcrracer · Post by **mcrracer** » Mon Mar 23, 2009 6:07 pm

Zippy wrote:
mcrracer wrote:Yeah, I had a cheap source for them but that's over. Thanks guys. I used an Express preamp and so far there aren't any noise or hum issues nothing crazy. I must be lucky or blessed. OK Next up is the Rocket pre.
Hmmm, makes me wonder if you have enough - maybe increase R7 to g,
et a lil' closer to the ragged edge???

Hey Zippy
My Express schematic does not show circuit designations. Where is R7 and what values would you suggest? The soldering iron's HOT!

Zippy · Post by **Zippy** » Mon Mar 23, 2009 6:24 pm

mcrracer wrote:
Zippy wrote:Hmmm, makes me wonder if you have enough - maybe increase R7 to get a lil' closer to the ragged edge???
Hey Zippy
My Express schematic does not show circuit designations. Where is R7 and what values would you suggest? The soldering iron's HOT!

I was referring to the components as labeled in http://ampgarage.com/forum/files/tw_exp ... 08_334.pdf .

R7 is padding down the signal level between stages II and III. As RJ and I have been playing with turning the Rocker 66 into a test bed, I have become fond of the idea of adding trim pots on the board to dial these things in. I would suggest adding a 250k trimpot in series to the 150k resistor. Take a look at RJ's latest pics of the revised Rocker 66 for an idea of how to implement the trimpots.

http://ampgarage.com/forum/download/file.php?id=8141

If you are not into trimpots, I'd up to R7 in the range of 250k to 500k.

mcrracer · Post by **mcrracer** » Mon Mar 23, 2009 7:00 pm

Thanks Zippy, I will experiment and see what happens.

dayn · Post by **dayn** » Thu Apr 09, 2009 6:17 pm

Dirty Little Monster voltages and topology [class B single ended EL-34 output with real high voltages--like above 450VDC].

Also, I was told that this clip is a DLM on the solo:

http://postpunkbubblegum.com/audio/2ndBest.mp3

The Amp Garage

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DLM tidbits found on internet