Ibanez LM7 "L.A. Metal" pedal

[e178453]

A friend of mine gave me one of these a while back, he didn't care for the sound.  Looked all over for a schematic with no luck.  Opened it up, there is a fair amount of circuitry there, too much for me to reverse engineer easily.  Heard somewhere this is actually a "10" series pedal.  Anyone point me to a schem?
scott

[tcobretti]

I have a strong yet unfounded suspicion that it is a Tube Screamer with a modified tone stack, which I believe is a standard Ibanez technique.  I did look around a little and couldn't find a schem.

[MikeH]

Isn't that a distortion/chorus sound in one box?

[tcobretti]

No, the TS is a classic distortion pedal.  I did find this hilarious quote about the LM7:

"this is the most difficult pedal ive ever picked up no matter what i do it sounds like crap, even when i dropped it sounded shitty."

I guess he didn't like it. 

I own an Ibanez Sound Tank Thrash Metal which is just a TS with a mid-scooped eq.  I made the eq work like a real TS and it sounds pretty good.  I also own an Ibanez FZ1 (I think that's what it's called) which is two TS's back to back.  I get the feeling that Ibanez is gonna get as much mileage out of that circuit as possible.

Here's an analysis of the TS.
http://www.geofex.com/Article_Folders/TStech/tsxfram.htm

[tungngruv]

I owned one for a few months. Sorry to say that despite playing it through good gear, I could not get a useable sound out of it. The name is very misleading. I ended up selling it, then buying an Ibanez SD-9 and Ibanez 9 series chorus pedal. That sounded a lot more "LA Metal" to my old ears.

[alfafalfa]

Hi,

I bought one cheap thinking it would give a nice crunchy sound but you're right : it's the worst pedal Ibanez ever designed imo !
So I ditched the whole interior and put a BSIAB 2 in it and a true bypass switch .
Now it very usable and people tell me what a great pedal the LA metal is !

Alf 

[Sir H C]

I like mine.  It is not metal, but you can get a cool distortion through it.  I have a 5534 chip in it (or is it the 5532?), has a grungy sound, not to bright but fun with a overdriven Fender Champ-like amp.

I know I saw the schematic somewhere but can not for the life of me find it again. 

[e178453]

Yeah, Ibanez missed with this one.  The kindest thing anyone has said about it is that it makes kind of an OK fuzz pedal.  Looks like either sell it or build something else in the enclosure.
Thanks for looking, scott

[analogguru]

Maybe it´s allowed to ask a question:

Is this a DIY-forum or not ?

If you are unhappy with the L.A. Metal why not modify it?  Christmas is coming soon.....

The L.A. Metal uses exactly the SAME pcb as the Fat-Cat (FC-10) - never wondered why there is printed  PCB-FC-0101A on the pcb ?

So, to convert the L.A. Metal into a Fat-Cat, you have to do (only) the following steps:

1.) Buy a 1k resistor, a 3n3 film-capacitor and a 3µ3 elko.
2.) Open the unit.
3.) Locate C6 (1n8), C12 (10µ), C16 (4µ7) and C20 (6n8) on the pcb.
4.) Desolder C6, C12, C16 and C20 (carefully, we need C12 and C16).
5.) Solder the 1k resistor in position R20, the 3n3 film-capacitor in C20, the 3µ3 elko in C12, the 4µ7 elko in C14 and the 10µ Elko in C16
6.) C6 stays empty
7.) control everything, especially your solder points.
8.) close the unit
9.) Now you are the lucky winner of an Ibanez FC-10 Fat Cat !!!

If you still don´t like the sound, you can by a LM 308, a ......, a.....  and make the rat-version you like.

But this is another story...

analogguru

P.S.:  for the technicians: C6 (1n8, huge!!!) is connected between pin 5 and 8 of the 5534 (frequency compensation).

[e178453]

Had no idea what to modify until now.  The changes you gave are easy enough!  Thanks for the info!  Going to start a new topic, ask for opinions on the Fat Cat.

[petemoore]

ask for opinions on the Fat Cat
  A fat Cat Schematic may 'moot' this.
  It's an opamp distortion, no clipping diodes, just raw OA clipping, of course filtering...Some people like it, some people don't. I've never tried it, some buiders reported...similar remarks to what surfaced^ about the LA pedal.
  Opamps slamming into their rails...could be cool, I never messed around with it much...tried it a couple different times, never a FC or anything verified though, just 'opening up' a DIST+ by lifting the diodes [kinda cool...] or making a Micro-amp distort.

[analogguru]

small update:

Peter Moore is right, the LM 7 does not have the clipping diodes, instead there is in Position D5 a 1M resistor.

so:

1a.) Buy two 1 N 4148 diodes.
4a.) desolder the 1M Resistor in position D5.
5a.) solder the two diodes in D5 and D6 (antiparallel !!!).

sorry that i forgot this.

analogguru

[e178453]

Thanks again!  Going to try and get these mods done in the next few hours and report back.
I am curious about what kind of components CR1 and CR2 are.  They look like ceramic capacitors but I'm thinking some kind of varistor.
scott

[analogguru]

CR1 and CR 2 are a resistor parallel with a capacitor - different from Pedal to Pedal its 47k or 100k parallel with 470p or 1000p.

good luck !

analogguru

[e178453]

Got the mods done, had everything I needed right here at home.  I like it!  I am not a good guitarist, but I think the circuit now gives me more range of control over the sound.  After the New Year, I will have a couple good players try it out.  They tried it in the original configuration so they will be in a position to give a useful opinion.
Analogguru, how do you know so much about this pedal?  Almost seems like you had one sitting in front of you, along with a book of Ibanez history!
Thanks to all,
scott

[analogguru]

Analogguru, how do you know so much about this pedal?  Almost seems like you had one sitting in front of you, along with a book of Ibanez history!
Thanks to all,
scott

Hmmm....:
1.) I am busy in music-electronic since more than 35 years (constructing and repairing).
2.) For this it is very recommended, always to have a look and understand what another people do (if you cannot "steal" a good idea, you will know what you better avoid).
3.) I cannot play guitar and i dont have one.
4.) But I own an LM 7 (not in front of me)
5.) when i bought this unit two years ago, the first thing i did, was to trace the schematic (like many other schematics)
6.) even when I have a "photograpic memory" i have the schematic in some seconds in front of me 

analogguru

[kusi]

hey analogguru,

does you email-adress work?

best greetings from switzerland, kusi