Would You all Check my Vero Layout of the ToneBender Pro MK2?

[fuzzymuff]

The only things I changed from the schematic were the 470R to a 1K for more volume and the electro caps to 47uf and 4.7uf as 50uf and 5uf were impossible to find or non existent any longer.  Looks correct before I solder the components?

[rousejeremy]

You need a trace cut where the E strip intersects with the E holes. The input jack is going to the collector of Q2 right now.

[fuzzymuff]

You need a trace cut where the E strip intersects with the E holes. The input jack is going to the collector of Q2 right now.

Ahhhh....jeeze!!  THANKS!!!!  Good eye!!

[rousejeremy]

No problem. Post samples when you build it.

[fuzzymuff]

I sure will.

How does it look now?  Thanks dude for catching that, saved me much frustration to find out after I soldered all the components..

[rousejeremy]

Looks good to me.

[digi2t]

If I may offer some words of "vero wisdom"... 3 tips....

TIP 1,
Being a vero addict myself, over time, I've developed a fairly decent way of verifying my veros vis-a-vis a particular schematic. The tools required are;
- Red highlighter
- Green highlighter
- Blue highlighter
- Pink highlighter
- Pen or pencil
- Copies of the schematic, and your vero

Sit at a well lit table or desk, with the schematic and vero, side by side.

First we'll outline our board power. Starting with the vero, use the red and green highlighters, and highlight all the positive voltage paths in red, and the negative paths in green. This includes any jumpers that you might be using to transfer to other rails.  Do not color any components i.e. resistors, capacitors, etc., only the rails or jumpers. Do the same on the schematic, red for all positive lines, green for the negative (or ground symbols), but stop at all components.

Now, we'll trace the circuit. Take a blue highlighter in one hand, and the pink in the other (doesn't matter which), the left hand will trace the schematic, and the right hand will trace the vero. Starting at the INPUT on the schematic (left hand), highlight the line and the first component you hit, C2 in this case. Now, with the right hand, do the same on the vero. Stop, and examine where the signal can possibly go from here. Is the required cut, or jumper, present? If no, then mark the error with a pen or pencil. If yes, then look back at the schematic, and continue to the next component, and so on. As you go from component to component down the line, always verify if it matches up with your vero, including if you require cut(s) further down a particular rail. After all, 90% of the time, missing, or misplaced cuts is where you'll mess yourself up.

Over time, you'll find that verifying veros in this manner will not only bring your error rate down close to zero, but will also develop your eye as to compressing the layouts to fit into smaller enclosures. Especially true if you decide to tackle more complex circuits. Don't get over enthused though... PCB still rules in the "space-saver" department.

TIP 2,
Don't try to reinvent the wheel. If a verified vero of the circuit you wish to build already exists, then use it. I know creating your own vero might be loads of fun (at least it is for me!), but when someone has been kind enough to have done tracing, layout, compressing, and debugging for you... well, you get the jist. You'll learn more by studying an existing vero, and trying to improve it, than starting from scratch.

TIP 3,
Try to keep leads short. This is the toughest puzzle I face when designing a vero. Part of this equation involves learning how to scale a component to your vero, and part is deciding what form of component, or component placement, you'll use. For example, C3. Can you use an axial cap instead, or is your heart set on radials? Personally, I would avoid having leads that long on a radial cap. The radial cap is top heavy, and would only put mecanical stress on the leads if the pedal got knocked around. If a radial cap is all you've got, how about adding a jumper/cut combo, to help shorten the span? If you can respect the caps lead spacing, and get it flat on the board, you've got the optimum support then.

I'm also a big fan of standing-up resistors. R4 for example; why use 4 holes, when you only need 3. Sometimes you have the space, but when you don't, stand'em up. Applies to diodes as well, but not axial caps! Thought you'd get me on that one, huh?

Non-electro capacitors come in all different shapes, sizes, and compositions. Ceramic, mylar, metal film, etc. One types value might be big and bulky, while the same value in another type might be a third of the size. Having an idea of how big a particular component is, in relation to your vero, could save you a lot of headache in arranging other components around it. C4 is 100nF? If all you've got is a Mylar cap, then Q1 and Q2 will have to bow out of it's way.

Of course, in some cases, you'll have to work the vero around the component. Case in point, box caps. They're not really conducive to having their leads bent out of shape when mounted, 'cuz quite frankly, it looks pretty stupid when they are. They look nice and purdy when they fit into a spot where the lead spacing matches, and they're nice and flush on the board. I'm not partial to them myself, except in rare cases where I'm trying to be really true to a particular circuit.

BONUS TIP 4,
MOUNTING HOLES!!! Always design them into your layouts. Nothing worse than a board flopping around inside a box, just waiting to gound out against the casing. Lots of "It was working before I boxed it! Please help!" troubleshoot reads to be had here. Not a big fan of velcro mounting either. Proper screws and stand-offs. Make it bomb-proof.

Hope that helps.
Dino   

[fuzzymuff]

Thanks Digi2t.  Im new at this and learning.  Your tips gave me so new insight on a new approach to making a vero layout more thoughtfully .   Thanks!

[LucifersTrip]

The only things I changed from the schematic were the 470R to a 1K for more volume

just a quick note...
the MKII shouldn't need more volume, unless you are setting Q3C voltage to 4.5V instead of 7.5 - 8.5+ like it should be.

if you change to 1K, you will be changing the overall tone

[Electric Warrior]

just a quick note...
the MKII shouldn't need more volume, unless you are setting Q3C voltage to 4.5V instead of 7.5 - 8.5+ like it should be.

if you change to 1K, you will be changing the overall tone

right. my vintage unit is ridiculously loud 

[fuzzymuff]

The only things I changed from the schematic were the 470R to a 1K for more volume

just a quick note...
the MKII shouldn't need more volume, unless you are setting Q3C voltage to 4.5V instead of 7.5 - 8.5+ like it should be.

if you change to 1K, you will be changing the overall tone

I used a set of transistors that I got from small bear and used the resistor that came with it, 27K instead for R3 and the Q3C was measured indeed to 4.5V.  Perhaps, I should just ignore the 27K?  Why would small bear set it to 4.5v if the original spec was for 7.5 to 8.5v?

[Electric Warrior]

No idea, they tend to sound rather thin and lack volume when biased to -4.5V. Here are some voltage measurements from my vintage unit:

Battery: 9.67V
Q1 C -9.02 B -0.03 E 0
Q2 C -0.17 B -0.08 E 0
Q3 C -8.44 B -0.17 E -0.11

I found it rather easy to get into that ballpark using OC75s or AC125s in a stock circuit. No adjustments needed.

[fuzzymuff]

No idea, they tend to sound rather thin and lack volume when biased to -4.5V. Here are some voltage measurements from my vintage unit:

Battery: 9.67V
Q1 C -9.02 B -0.03 E 0
Q2 C -0.17 B -0.08 E 0
Q3 C -8.44 B -0.17 E -0.11

I found it rather easy to get into that ballpark using OC75s or AC125s in a stock circuit. No adjustments needed.

The set of transistors where mixed, and only one OC75 for Q3, the other two were some Japanese PNP Ge transistors.   Let me breadboard this again before I go any further in building this.

[fuzzymuff]

I did some search on the TB Pro MK2 and found a couple of different schematics on it with different resistor values.

[Electric Warrior]

breadboarding is a good idea
There were two different bias setups: the OC75/Impex version always had 10k at Q1's base and 47k on Q2's collector while the OC81D version had 100ks there. Mixed setups with 100k and one 47k don't seem to to exist in original units (and I've seen many).
If your clone sounds very compressed and the attack pot has little range, you'd better try the OC75 setup.

[fuzzymuff]

Will do...thanks!

[LucifersTrip]

you'll have a few options to increase Q3 collector voltage.

you can decrease the size of the resistor on Q3C for a quick change, but just like increasing the 470 to 1K, you will be changing the tone (unless you only need a very small tweak. say, 7 - 9K). so, that is not recommended

it's more common to increase the resistor on Q2 collector. the more you increase that, the lower the voltage on Q2C (or Q3 base) and in turn, will raise Q3C voltage.

a third method (if you don't want to alter stock values as much) is to choose Q2 with higher leakage. the higher leakage you pick there will again lower the voltage on Q2C (or Q3 base) and in turn, will raise Q3C voltage.  to test this, simply hold/pinch and/or rub Q2 with your fingers and watch Q3C voltage rise!

edit: you prob have ~ .4V+ on Q2C

the resistor from Q1B to ground basically sets the gain of the whole thing. to test that, just replace it with a 100K pot. start and 0K and turn up to hear the saturation increase!  remember, the MKII is not like a Fuzz Face where it really doesn't sound great when the fuzz is turned down. On a MKII, it should sound cool thru the whole sweep, from dirty to very saturated.

[fuzzymuff]

Hey Thanks LucifersTrip!  Great tips on the tonebender.  Thanks!