Mini T2 Switch off thump.
I have found that when switching off the mini t2 (golden reference LV and HV supplies) I get a thump on both channels around 3 to 4 seconds after pressing the off switch. I get no thump on switch on using a 45 second delayed HV so I guessed the LV was dropping faster than the HV at switch off. This was confirmed with a multimeter. Compared to the blue hawaii, the mini t2 drains the HV caps at a slower rate but drains the LV caps faster. I solved the switch off thump by replacing the standard 4700uF caps in the Lv supply with 22000uF. This provides significantly longer LV voltage on switch off and stops the thump. I used 30mm diameter Nichicon 22000uF 35V caps which just fit in place of the 50V 4700uF caps. I suspect 15000uF would probably work to.
regards and happy mini t2ing
Bob looks and sound exactly like he did when I visited his studio a decade ago in San Rafael.
Great to hear Don Was too. I see him around the Monterey Jazz Festival all the time (he's the head of Blue Note Records).
Gotta admit getting goosebumps with Ripple!
Table updated.
Blank in the GRHVxxx-bare column indicates that the participant has not responded on this thread to indicate the preference for bare or partially-assembled boards and is deemed to opt for partially-assembled board by default as previously communicated.
Heh, close enough. I've been gone from Chattanooga for over 2 years now, so I'm not as entrenched as I used to be. I DID, however, see Tom Hankins and Lee Scoggins at RMAF last fall!
-Brent
Here is a picture of my third mini T2.
Area for heat sink bracket screw holes cut away. Board now 160mm x 80mm and transistors mounted direct to heat sink. Inner dimension of case is 200mm x 161mm.
This is the way I’ve built my amplifiers for some years now. There simply is no room for terminal blocks – will only make things more complicated for me. The real thing - DIY T2 has no tblocks either (except for output to Stax connector).