V6 amplifier

[sajti]

I did some changes on the amplifier pcb, based on the experience of the first version. There will be 4 series connected resistor in the feedback chain, to reduce the dissipation on each of them.
I put small connector to the pcb to use for bias monitoring, which makes the settings more comfortable.
Change the values of the DC balance setting circuit, the old version was able to set up to +/-3V which was hard to adjust down the mV range.

Sajti

 

[r_merola]

interesting project

Very interesting project. I am curious to see your audio impressions as I never tried Current Feedback amplifier.

Could you please show us your housekeeping circuit details?

Tks
Ronaldo

 

[sajti]

Housekeeping schematic attached.

There are the 3 common function:

- 2second turn on delay
- DC protection
- overtemperature shut down

Sajti

 

[thimios]

Housekeeping schematic attached.

There are the 3 common function:

- 2second turn on delay
- DC protection
- overtemperature shut down

Sajti

Pcb?

 

[sajti]

Here is the picture of the pcb.

There are some minor changes, as I had many BC327, so I use them instead of BC516. Works very well, only 0,1V loss on it... All values are on the pcb to easy implementation. Output relay is Omron G2RL2 12V coil version.

The pcb is Pcbway friendly designed. You can get 10pcs. for 5USD+delivery. Gerber is available if You need.

This pcb has connection to the housekeeping psu pcb, which contains small EI tansformer, and inrush current limiter, driven by the turn on delay circuit.

Sajti

 

[sajti]

I use this binding post:

Dual Female Banana Plug Terminal Binding Post for Speaker Amplifier LW

The pcb was desingned for it.

Sajti

 

[sajti]

New amplifier pcb just arrived...

Sajti

 

[r_merola]

Nice Board

You do a really nice looking board.
I would like to propose you to use larger tracks than you use to do. It will improve the overall board quality and reliability in the project in general.
Thank you for schematics and PCB from housekepping circuit
Regards
Ronaldo

 

[sajti]

I would like to propose you to use larger tracks than you use to do.

The critical wires are 5mm wide, and they are enough, even with 4 ohm load. There was no significant voltage drop, or heating.

Sajti

 

[r_merola]

The critical wires are 5mm wide, and they are enough, even with 4 ohm load. There was no significant voltage drop, or heating.

Sajti

Yes, I saw it.
Please, understand it was a suggestion to improve your nice work.

I know is easier to use thin tracks as it can run in small areas, but no doubt with larger traces you will have best final work.
The board become more reliable (with even less voltage drop in signal tracks) and you can make more changes in the board during development without board damage.

It is a point of view, of course you are own of your work
Regards
Ronaldo

 

[sajti]

We will see, once it will be up and running.

Sajti

 

[sajti]

All parts are soldered. Only the heatsinked parts are missing.

Sajti

 

[sajti]

Ready. I hope, that it will make some noise in the end of the next week, when I back from my holiday...

Sajti

 

[Walkalone]

Sajti,
Please tell me manufacturer name of your HEXFRED diodes? These HEXFRED diodes that are available on Mouser, but i wonder why its price that's too different between Vishay and Infineon/IR. Vishay diodes are expensive than Infineon/IR about 2x price.

 

[sajti]

I use Vishay, but not from Mouser. I bought from a local dealer. Cost is about .75Euro.
Sajti

 

[thimios]

Nice!
Where is connect the speaker gnd ,on amplifier board or on power supply board?

 

[sajti]

Nice!
Where is connect the speaker gnd ,on amplifier board or on power supply board?

From the amplifier pcb. There is star gnd point on each amplifier pcb.
Sajti

 

[thimios]

From the amplifier pcb. There is star gnd point on each amplifier pcb.
Sajti

Do you believe that is the best option?
Did you test FFT this way?

 

[sajti]

Do you believe that is the best option?
Did you test FFT this way?

Yes I believe, that it's the better solution with dual mono psu.

Sajti

 

[Walkalone]

Do you believe that is the best option?
Did you test FFT this way?

Your way make me feel a little bit embarrassment when you said connecting Speaker GND back to power supply better than connect to power amp board. However, many commercial expensive amp that are also use same as it.