Dogears, set us straight! we've gone off the ol' plantation!!
She'd chomp you for comparing her to that thing! She has been a welcome addition to the crew. Cuts down on the dog walking miles for me, too. They wear each other out......
Last pic, I promise
Haha! I totally deserve it...
You are lucky to have such harmony between them both. It really is apparent in you pics/vids.
I installed preamp out/power amp in jacks in the back of my amp and i am starting to gather the components to build a dumbleator. I was looking at Tony Albany layout and i saw that the power supply had a transformer with 135-0ac secondary. I also saw that the voltages can go as high as 368.3 Vdc? How is this possible with a 135 Vac secondary? By my calculations they cannot go beyond 190 Vdc or am i missing something?
I am asking this because i have a preamp transformer lying around that deliver 220Vac/50mA on the secondary and has heater taps for a single 12ax7. After full wave rectification i should have like 311 Vdc max at idle. Is this transformer suitable or not?
Keep in mind that when you double the voltage, you also halve the current capacity. This is an important consideration when choosing a suitable Dumblelator PT.
Yeah i know. Thats why i dont understand why H. Dumble would do such a thing when he could just choose another type of transformer with different secondary voltages and power handling.
I know very little about the dumbleator and i dont really know how many units he has built. Did they all had this voltage multiplier (thats how we call it here)? Because i can only assume that on this one he used whatever transformer he had lying around.
I remember back when i was studying electronics we only used this type of circuit for reference voltages and only coupled to high impedance circuits so that the current draw would be minimum. Anyways just another thought.
turbo5speed wrote:Yeah i know. Thats why i dont understand why H. Dumble would do such a thing when he could just choose another type of transformer with different secondary voltages and power handling.
Because i can only assume that on this one he used whatever transformer he had lying around.
Cheers!
He did what he did using plenty of donor and surplus items. Keep in mind that even in a doubler config that Triad PT still provided 7mA, which is still very adequate for a 12AX7.
turbo5speed wrote:Did you bought the rack unit from tube-town also?
Forget it. Dumb question... just saw your post about your dumbleator
yes as you can see its a Hammond alu rack. The only mistake I made - its too high. So I had to cut it on one corner to shouvel it in Head and under the Amp (The PT of the amp is too high). So it looks nasty. But with the Front and back plates everything is hidden.
I could order a 5 cm high one but I orderd a 7 cm. But I wanted to finish so I cut the edge.
Yes I order everything from this shop and the forum there is very helpfully and friendly (to such newbys like me) too. Same like here, only over the pond
