Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Preamps and Effects => Topic started by: THChrist on February 18, 2009, 10:18:29 PM

Title: JCM 900 SL-X Emulator/Simulator/Adaptation
Post by: THChrist on February 18, 2009, 10:18:29 PM
Hello everyone.
A few days ago, I was thinkin' about making some of the best emulators/simulators/adaptations of the classic ones. What I wanted to do is something like a JVM: 3 modes per channel. But, since 3 channels is enough for me (the JVM uses 4 channels, 3 modes per channel = 12 modes), my obsession led me to separate 3 groups for my project:

Channel 1 "Clean": Only Fender
A-Vibin' Champ
B-Professor Tweed
C-Bassboy 59

Channel 2 "Overdrive": Only Marshall
A-Plexizer
B-JCM800
C-???

Channel 3 "Distortion": Only Mesa/Boogie
A-Uno
B-Boogeyman
C-Dr. Boogey

As you can see (ok, ok, i'm a bit obssessive-compulsive, i know, please don't laugh) I needed a 3rd mode for the marshall, so i took the evolution of the jcm800, the JCM900 SL-X (http://www.blamepro.com/br01210.htm), which was an improved version of the JCM900 (without clipping diodes and with 1 aditional valve).

So here it is, another F4T project:

(http://i20.photobucket.com/albums/b228/Anti-Idiot/JCM900SLX.jpg)

Q : MPF102 (all of 'em)

I took ROG's Phase Inverter/Poweramp thingy, since it's almost the same as in the 1959SLP, JCM800 and JCM900. I wanted (and so did Marshall) this to sound like a hot-rodded JCM800. However, if you need some original values for the P.I., here they are:

VR7= B25k
R17= 1k
R18= 15k
C22= 47n

Also, most of the preamp emulators uses a 10k instead of the 100k (of the source-follower?) and since everybody's doin' it, and i just wanted to be popular, i did the same, he he he (R4 and R13).

Miller Caps: C13, 14, 15, 16, 17, 18, 20 and 23 (try values between 100p and 220p)

I'll try to upload some clips when i finish the emulator (yes, i said it).

Thanx to all who inspired me: the guys at ROG & DIYStompboxes (Marty, Electrictabs, Mojotron)

BTW, this thing doesn't have a name yet, so if you have something clever, please let me know

i have:

Markfour X (since this model is based on the MkIV)
eXploder
X-tender
and a lot of crappy names...
Title: Re: JCM 900 SL-X Emulator/Simulator/Adaptation
Post by: ubaid88 on October 06, 2009, 07:49:13 AM
can you share your pcb layout for this.
Title: Re: JCM 900 SL-X Emulator/Simulator/Adaptation
Post by: Brymus on October 06, 2009, 02:10:47 PM
SWEET,
You should post this at DIYstomboxes too.I bet the guys there will get a kick out of it.
Thanx for sharing.
Title: Re: JCM 900 SL-X Emulator/Simulator/Adaptation
Post by: THChrist on October 06, 2009, 02:20:59 PM
here's the v2.0

http://img97.imageshack.us/img97/9199/jcm900slx.png