Breadboarding Brittania

[bilo01]

Hi, I'm trying to breadboard the Brittania schematic and I'm totally new into reading these.
I'm a bit confused how to connect the "VREF" points. Are they going directly in the +-rail or should they be connected together?
The same goes for the 9V(T) point and GND(T) point. How should i connect those.



This must be a dumb-ass question but just trying to learn here.

Thnx for any help on this.

[Kipper4]

The power supply is in the bottom left hand corner of the schematic.
Anything marked Vref goes to Vref in the power supply. IIRC there's only one such connection and that's to the op amp.

Edit R18 is also connected to Vref.

Anything marked V+ goes to V+ in the power supply.

Vref is half the 9v supply so 4.5v
Created by two equal value resistors (one connected to +9v the other connected to ground, )Vref is the connection(node) between these two resistors.

When bread boarding
Make some power supply rails
V+ rail
Vref rail
Gnd rail..

On my breadboard I made a perfboard filtered power supply that has these rails, I think I made the filtered power supply from Beavis audio site.

[bukas]

it is assumed they are connected, but for sake of simplicity of schematic these lines are not drawn. they can be refered to as grids, nets or rails.
now, vref is usually 4.5V so you do not connect it to - or + rail, it is net on its own. vref comes from R25,R26,C23 and C24 section which is powered by +9V net, this section creates vref. when you finish assembly power on circuit without IC and check the vref voltage with multimeter. reading between vref poin and gnd should be 4.5V, if not you did something wrong.
then you have two A points that need to be connected to. gnd points are connected to metal enclosure or piece of metal at one point where you connect negative terminal of battery or dc adapter, gnd IS metal enclosure or piece of metal so it is a must.

look at some clips on youtube how to read schematics and start thinking about vero or etching

[bilo01]

Thnx for clearing that out guys.
I'm in the process of etching the PCB now actually...

[duck_arse]

it will be much easier to get something as complex as this to go on the breadboard if you build it in stages, get each one working as you go along. start at the "in" and build across to R4. test, trim the Q1 drain voltage, listen w/ audio probe. then add right of R4 across to Q3/R7. test, trimm, probe. working? why not? fixxe, then add the tone stack across to the top right. test, probe. does the stack work as expected?

now add the Q4 section across to D6/D7. test, etc. now youre ready to add the opamp section, and it's finished, and working. and seeing as you've scribbled notes all over the circuit from metering and probing, you'll know what goes where on the pcb, and it'll work FIRST GO!

of course, you built the power supply section in bottom left first on breadboard, didn't you?

[deadastronaut]

when i breadboard something larger i tend to put the schematic in photoshop and mark off the bits ive put in as i go....(draw lines in a colour)

it just makes sure i haven't missed a connection anywhere, and it works first time, every time...

have fun, breadboarding is great for tweaking...

[bilo01]

I really love this forum for pointing me in the wright direction every time. I'll save it all and learn