ceriatone B+

[geoff 1965]

can someone explain what ceriatone have done here with the TMB HT?

18wattTMBceriatone (1).jpg

290-0-290 into diodes then into the ez81 then a resistor/capacitor across the stanby switch!? is this just a way of boosting the B+,i did'nt know you could rectify prior to the rectifier tube.

[colossal]

The diodes are backup protection for the tube rectifier. The 100k across the standby allows a trickle of current effectively muting the amp but slow charging the power supply. The cap across the standby damps the switch pop, when thrown.

[geoff 1965]

thank's colossal, the layout shows 1N4007 but the schematic shows 1N4001 diodes,what's the difference?

27767572173_2b442802e2_b.jpg

[colossal]

You would not want a 1N4001 there. The peak reverse voltage for the 1N4001 is only 50V! The 1N4007 is 1000V. I would use the UF designation (Ultra Fast recovery diode). It has a smaller recovery spike than the 1N series and will be quieter.

[JMPGuitars]

They likely implemented it to make Merlin happy.

http://www.valvewizard.co.uk/standby.html

[Daviedawg]

I fitted the 100k across the standby switch when I built it. Not sure there is any real benefit unless you leave it on standby a lot. But it confused my 9 year old grandson who switched the amp on and could hear a faint signal so kept turning it up not being used to there being a standby switch. When I came to see how he was doing it was up at 10 but he was playing at just the right volume for the room!

Dd