Marshall tsl 602 problem

[Rod]

Hello, Jon!

Yes i do understand now, because the AC voltage at the input of the BR1 that comes from the PI invertor tube is rectified at BR1 to DC, and this should have at the output of BR1 a DC voltage of around 6,3 volts.

Thanks a lot guys your lessons here are vey precious, im learnig alot with all your tips.

[Mick Bailey]

Rather interestingly the Hayden Speakeasy runs the preamp heaters at 5v of an L7805 regulator. When I spoke to Dave Green he said when he designed the amp you couldn't get a regulator to output 6.3v. Not correct of course, but If you've ever dealt with Dave you'll know it's pointless to argue.

[g1]

said when he designed the amp you couldn't get a regulator to output 6.3v. Not correct of course, but If you've ever dealt with Dave you'll know it's pointless to argue.

Not to mention that even if it were true, it's pretty simple to set the ground pin on a 5V regulator up on 1.3 (or whatever) volts.

[Mick Bailey]

The second he said this I thought 'What about the diode trick?' Three diodes and a regulator and you have 6.3v output.

[Rod]

Hello again!

So i just now desolder de bridge rectifier from the pcb and received a new one, but my question is how can i have sure that the problem is in the bridge rectifier?
Im asking this because with the multimeter negative probe on the + side of the br, and with the multimeter positive probe on each side ~ of the br the suspect br displays a value. So how can i have sure that the problem is really the br?

It seems that the BR tests fine, but can fail under load?

[The Dude]

............It seems that the BR tests fine, but can fail under load?

Yes. That has been my experience. It could also be solder connection issues. I don't risk it or mess with it. As long as you have the amp torn apart and have access to the solder side of the board, it doesn't make sense to risk the amp coming back. You may as well just replace the BR IMO. Also, when soldering in the new part, leave it standing off the circuit board a bit to help keep solder joints from getting hot and cracking.

[Rod]

Replaced the BR, now the tubes ligth up but theres still no sound , what should i check now?

[Rod]

I found that i had a bad preamp v1 tube.

I remenber you guys said that preamp tubes runing bellow they recommended voltage would have a short life so i replace the v1 tube and the amp now has sound