TSSA - The Simplest Symmetrical Amplifier

[Salas]

So if we don't want auto protection extra circuits maybe it can be done to switch manually the delay thing, or double it as a remote main bias ''on'' from standby, using a far away preamp?

[Lazy Cat]

Originally Posted by Salas

So if we don't want auto protection extra circuits maybe it can be done to switch manually the delay thing, or double it as a remote main bias ''on'' from standby, using a far away preamp?

TLP accepts the same signal (delay-on from protection circuit) as there would be mechanical relay on a PCB.

+ 12 V trigger signals from preamp or HT system via remote connector, turn on power supply's soft-start circuit, which is the different thing. Trigger signal puts on the whole amp from stand-by mode to on mode. After that sequence is done and if everything is OK, protection circuit sends internal 12 V remote signal to amp's PCB to turn output power transistors on.

[Lazy Cat]

Originally Posted by Idefixes

I think i have enough transformers (500Va 2x36Vac) for dual mono .... take a look picture under



Don't know what futur is made from so i think to had 2x10000µf per board.



I have been waiting for modification

Marc

Transformers are super duper ones now you can make it as dual mono power amp.

I hope the sch mods can be implemented to existing PCB.

[Idefixes]

Hi LC i take note from you modification a will work today later on for routing

Originally Posted by Lazy Cat

Hi Salas

No, TLP627 serves to switch output transistors on/off, practically replaces an output relay.

This systeme seems quite interesting could you details more.

Marc

[Lazy Cat]

Originally Posted by Salas

So if we don't want auto protection extra circuits maybe it can be done to switch manually the delay thing, or double it as a remote main bias ''on'' from standby, using a far away preamp?

Yes, simple solution is to switch TLP manually on some while after the amp is already on.

But I don't suggest to eliminate TLP from the PCB, since than you would have to send high Z loop 3,5 mA sensitive current signal across the long wires. Not recommended.
There's always some spare DC potential to turn TLP on, just adjust serial resistor for higher/lower voltages drive signal.

[Lazy Cat]

Originally Posted by Idefixes

Hi LC i take note from you modification a will work today later on for routing

OK, use empty areas over power transistors if needed. I think it can be done in an existing PCB format, just optimization and filling in the empty areas. Good luck

[Idefixes]

Originally Posted by Lazy Cat

OK, use empty areas over power transistors if needed. I think it can be done in an existing PCB format, just optimization and filling in the empty areas. Good luck

I made me, during home car travel for lunch, the same reflexions, to keep the size board i have to use the space over output bjt but than then can't be "sandwiched" by screewing between PCB and heatsink.

Marc

[Idefixes]

Originally Posted by Lazy Cat

This update enables TSSA BIGBT HP to be even more universal:
- serial diode MUR160 plus 22 ohm resistor in power supply rails helps to improve PSRR
- +/-OPT pins enables to connect separate power supply for the front-end (MUR160 and 22 ohm are omitted)
- power supply LED indicators for both front-end and output stage are present
- serial compensating resistor added to NTC (serves to calibrate NTC thermal response)
- serial resistors added to SK75 heatsink's GND connection (serial RC filter)
- 1 uF/63V decoupling capacitors added close to VAS transistors supply rails
- TLP627 input now accepts 12 V remote signal (serial resistor added)
- LT1034 replaced by TL431
- R2-R9 values stated for +/-50 V power supply rails

And that's about it.

In the moded schematic you swap the two 10R resistors connected to IR led to 100R right?

Marc

[Lazy Cat]

Originally Posted by Idefixes

In the moded schematic you swap the two 10R resistors connected to IR led to 100R right?

Marc

Temporarily, now are back to 10 ohm.

[Idefixes]

LC could you take a look at the schematic i attached. The ground i split in to that joining at one point. Is the ground point repartition silly or Ok.

Marc