TSSA V1.6 docs and buyers list

[Siberia]

The bulb tester is before the soft start. It only tripped once, so far. I didn't tried to bring it to 30 mV strictly next time. Just observed a very bright light bulb and went above 20 mV on R30.

 

[sonnya]

if the voltage after the bulp goes below 85VAC the softstart reset and releases the relays.

and a 40W bulp is 1.3Kohm. => 30mV bias is 600mA => two channels is ~180mArms => 180mA * 1.3K => 230Vrms drop across the bulp.

 

[buzzforb]

Your the man, Sonny.
Did you get my response to your email.

 

[sonnya]

Siberia - Let us know when you have tried without the bulp.

 

[Siberia]

To be honest, I'm puzzled. Should I go without the soft start, or without the bulb? I was adjusting one channel only and it looked very bright. That should've been only 117Vrms across it?

 

[sonnya]

Let the softstart in the circuit and remove the bulp.

If the softstart is broken i will replace it.

 

[Siberia]

I'll need a fresh head for another setup. That means tomorrow. Thanks for guiding and all.

 

[Siberia]

I have managed to bias both channels and get the offset below 10mv. Not without a little smoke though, at first. I can only suppose, one channel trimmers were not set right at the beginning. Otherwise, I have no explanation why that smoke appeared after some 30 sec after powering it up. I guess it was C6, because when measured with laser thermometer, I've got 60C even sometime after a shutdown. Now everything looks OK. Different power resistors are hot. Just above 60C. Otherwise they measure the same bias voltage.

Should I check something more before hooking it up to the main system?

 

[sonnya]

mmmhh. Sounds like a good explanation, i cannot see why else.

I think C6 get heated by the other parts.

 

[sonnya]

How does the AMP Sound Tomas ??

 

[Siberia]

I have to go through all kind of events (nothing DIY related), untill I hook it up. Treasuring the moment. Will let you know. I hope it's over the weekend.

 

[buzzforb]

did you pull the bypass caps? 4 big ones across the center?

 

[Siberia]

Not yet. An orthodox way is to listen first, pull out later?

 

[buzzforb]

Cant argue with that.

 

[Siberia]

How much of the bias drift is tolerable?

 

[buzzforb]

I have not experienced any.

 

[Siberia]

Mine shifts +- 1mV during the warm up

 

[sonnya]

1mV is okay. Up to +/-50mv

 

[Siberia]

We are talking about the voltage measured across R30, right?

 

[sonnya]

1mv is 20mA .. That is fine