ROSS Distortion vs. Distortion + layout for Liquid Drive?

[analog kid]

Will the ROSS distortion layout at (homewrecker.com)http://home-wrecker.com/ross.html, work and serve the same purpose as the layout for the DOD250/Distortion plus/Microamp at Tonepad http://www.tonepad.com/project.asp?id=6   In being used as the layout for the Liquid Drive project by Phillip at FuzzCentral??? He suggests the Tonepad layout(s) but I know that there is both a single and double opamp design there. I would like to build it with a double like 4558 or OPA2134PA and to MY EYES the layout here for the ROSS distortion LOOKS to be a perfect match for building the Liquid Drive, and easier modded pcb since tonepad's layouts are very TIGHT!!
So does anyone know if this layout would be a good candidate for building the Liquid Drive and how different it is to the Distortion+ layout??
Thanks everyone

[petemoore]

Schematics show V+ power to be connected to V+ At Pin 7 on a lm741 type single opamp.
 Look for power to be connected to pin 8 on a Dual Opamp.
  This will tell you if the tonepad layout is for a single or dual opamp.
 The tonepad layout calls for a 4558 dual.
 http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm
 type the part # of your active component ]I never tried entering a passive search], but don't trust the Jfet pinouts, IIRC 458's are different than say...just veryfy pinouts on IC's.
 Take a look at the data sheets on the item in question.

[Fret Wire]

The Homewrecker layout will work fine. This is the Tonepad layout you want. Modding wise, there's no difference between the two layouts, except the Tonepad layout has three clipping diodes.
http://www.tonepad.com/getFile.asp?id=6

The dual Dist./Micro layout (which uses a dual IC) works perfectly for the Dist. +, MicroAmp, DOD 250, Yjm 308, and Liquid Drive.

[petemoore]

Someone showed another way to hold the not used amps output at 0V.
 Using one side of a dual, connect the not used sides' inputs [-/+] to ground to keep cross talk from occuring.

[analog kid]

thanks, but I still am not getting , is there/what's the difference between the (DOD250,Distortion Plus) and the straight up ROSS distortion?? layout wise is there any difference? if not it seems to me that the best for the Liquid drive would be the Ross at homewrecker looks like an easier moddable pcb since it's not so tight as the tonepads and that it's made strictly for the dual op amps.OR is IT? I still don't have an understanding of the dual /single ops when they are the same package. Are the pinouts different?
Also speaking of Phillips liquid, this Ross layout looked right on for it since he describes a way of 'stablizing' the opamp by tying pins 6 and 7 togething and shunting pin 5 to ground right along with 4. AND  that's EXACLTY how the amp in this layout is already setup! the Micro/D-Plus layout's Opamp doesn't LOOK to have the same setup to me.

[Fret Wire]

The pinouts aren't the same with duals/singles. Go to Mouser and type in lm741cn (single) and RC4558 (dual). Look at their data sheets, it shows the pinout.

The basic difference between the Ross layout and the Tonepad layout is that the Tonepad layout is a multi-ckt layout. It can do the Microamp, as well as the Dist.+ based ckts. The Ross is made for a dual IC. Both layouts use only half of a dual IC, duals allow you more choices.

Moddable? 6 of one, 1/2 doz of another. With the Tonepad layout, you can take some leftover resistor lead and tie pins 6 & 7 together, perf style. Same with grounding pin 5. It's already set up for the liquid drive's three ge diodes. With the Ross layout, you have two solder two ge diodes in series, no biggie..just don't get them hot. And if you can't etch your own boards, you can order the Tonepad board.

If you perf or vero, both layouts are irrelevent.

[analog kid]

Quote: "With the Tonepad layout, you can take some leftover resistor lead and tie pins 6 & 7 together"
Ok , I didn't realize you could do that. I assumed that those pins, since they're NOT unused in that Tonepad layout as they are in the Ross , so I thought  they were in some other useage and couldn't just be tied off together. Those pins and "where" they were routed to was the reason I thought these layouts were very different!
So you are saying that the Tonepad layout we're referring to will accept either a single or dual amp without any changes being made. ?? I thought that there were TWO SEPARATE (single/dual) Layouts. something like "MAS"single and "AMPATOR" dual or something like that
MODDABLE?....
by that what I meant was , the ability to add in the power filtering components, Low Pass/HighCut rolloff,etc.... I draw my own PCB's based on the layouts and etch them so the tighter the design I'm going by the more difficult for me! Let Alone when improvising any changes into it!!
As for the Diodes.. I've already traced a modded version of the ROSS and didn't take that into consideration! Is it alright to just solder  two in series and stand them up on the board (as you would combining resistor values in series) or is that not a good idea with diodes??
thanks again

[Fret Wire]

Ok , I didn't realize you could do that. I assumed that those pins, since they're NOT unused in that Tonepad layout as they are in the Ross , so I thought they were in some other useage and couldn't just be tied off together. Those pins and "where" they were routed to was the reason I thought these layouts were very different!

You're right. :oops: Shame on me for going over the schematic too quickly, shame on you for not picking it up when you were advised to read the data sheets. I should know better, and you should try to know better. :wink:  
The Ross & the Tonepad both use only half of a dual IC, they just use different halves. The Ross layout uses the "A" side of a 4558 dual type (uses 1, 2 ,3, 8 ), grounds 5, and ties 6 & 7 together. The Tonepad layout uses the "B" side of a 4558 dual type (5,6,7, 8 ), grounds 3, and ties 1 & 2 together. Both layouts ground pin 4, and use pin 8. That's the difference between the two layouts. Does it matter which halve they use? No!

So you are saying that the Tonepad layout we're referring to will accept either a single or dual amp without any changes being made. ?? I thought that there were TWO SEPARATE (single/dual) Layouts. something like "MAS"single and "AMPATOR" dual or something like that

No..No..No. I never did say that. The Tonepad layout we've been talking about is the Ampotor. Forget all other Tonepad layouts...remove them from your mind. It is a dual layout (means it supports two separate ckts), that happens to use a dual IC.

MODDABLE?....
by that what I meant was , the ability to add in the power filtering components, Low Pass/HighCut rolloff,etc.... I draw my own PCB's based on the layouts and etch them so the tighter the design I'm going by the more difficult for me! Let Alone when improvising any changes into it!!

No need to mod either layout for the IC's. They both tie off the unused halves of the IC's. They both could stand to have power supply filtering. You could mod either pcb for that, or add it in on your off board wiring. It's up to you. Personally, if a pcb is not what I want, I lay my own out from scratch.

As for the Diodes.. I've already traced a modded version of the ROSS and didn't take that into consideration! Is it alright to just solder two in series and stand them up on the board (as you would combining resistor values in series) or is that not a good idea with diodes??

You sure can, most of us do that all the time. Just remember not to fry them, especially the Ge diodes.

[analog kid]

sorry I didn't see your reply til now. I appreciate the help with it. I thought I saw something about that tonepads layout of the OP amp that was different!  I think we're on the same page as far as the other stuff though.  Far as which one to use It still seems to me that the ROSS layout at homewrecker is a better fit for The LIQUID DRIVE than the Tonepad. Even more so now . Since if you look at the changes to the crkt Phillip describes The pins he refers to in "stablizing" the Opamp  match exactly with the how it's wired in the ROSS layout. 4and5 grounded and 6and 7 tied off. So I wonder why he didn't USE the Homewrecker layout for his link?
QUOTE "No need to mod either layout for the IC's. They both tie off the unused halves of the IC's. They both could stand to have power supply filtering. You could mod either pcb for that, or add it in on your off board wiring. It's up to you. Personally, if a pcb is not what I want, I lay my own out from scratch"
Well for those of you who CAN! :wink:  Making changes to an existing layout is much more doable for me. IT takes way too much time and trial and error for me to  layout a very detailed pcb from a schematic . I'm just not there yet.
Putting the power filtering and protection is easier to add to the layout IF THERE"S ROOM EASILY MADE . I would like to figure a way to do it offbaord though. Pretty easy with a little pcb with the Cap/diode/resistor on it to wire offboard ??

[Fret Wire]

Pretty easy with a little pcb with the Cap/diode/resistor on it to wire offboard ??

Sure is. PCB, perf, vero, whatever you want. Then you could use the same little layout to add protection to all your ckts that don't originally have it. Same as mini board for an output booster on a wah, you can use the same layout to add one to all your wahs.

I don't really like using the resistor, I personally don't think it's needed if you use a good wall wart or power supply. But not knowing what a person might use to power the pedal, it helps. I'd go diode (anode to gnd), main cap (47-100uf), secondary cap (.1uf), in that order. Just my opinion, however.