FSSA amplifier build thread with review

fab

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Secondary PSU for front end

As for using a front end higher power supply voltage it has the following advantages:
1) increase max amplifier output power allowing only output stage losses
2) isolate front end voltage fluctuations caused by output stage.
3) clipping is caused by output stage only and not front end

The disadvantages are:
1) more complexity for routing secondary PSU wiring to minimize noise.
2) extra boards and space required in chassis

I have used secondary PSU for front end in several amps such as Goldmund Telos clone, VSSA-FAB, SKA-150GB....

My actual FSSA-1 and FSSA-2 amps do not have secondary PSU.
If I may suggest one can plan for space provisions in chassis for secondary PSUs for possible upgrade...;)

Fab
 
Thanks to both for replying

It is all probably good and well but quite expensive if you add it up... Ok, by far not as expensive as my speakers but I have seen other options for far less, inclusive ready built by audiophonics etc.... any reason for such price differences?

Any affordable option?
I would rather spend the money in the PS - all I want is a good protection, high reliability and low output resistance, the rest is fine for my engineer side but not really needed in my case, basic working tech would do the job...
 
I too find that the PCB's for softstart and DC protection, that are being offered, are expensive. Add exchange rate and freight and the boards end up being US$50 - $100 each:eek: If you're building multiply amps this is a large cost.

For years I have used the softstart kits with thermistors from Ebay, without any problem. They now come with remote control and a temperature control switch.

For DC SSR protection you might want to look at this link:
SSR for speaker protection?
 
You could also adopt the circuit of the diyaudiostore solution. In this case it's shorting out an CL60 for security reasons after a short time... But use it only if you know what you're doing. There are lethal voltages in the game.
 

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