luvdunhill

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Thanks guys! With any luck I'll finish up a conference proposal today and come home to last few parts needed for the Houston meet on Saturday!

a bunch of Bantam boards ...

insanity... FPE can go down to 0.5mm material remaining without marring the front. Add on another 0.5mm that is unusable due to the tap. That leaves a hair over 1.5mm remaining. Cue up some M2.5x.45 standoffs at Mouser that I'll use. I should get 3 useful threads. yay!

leaving? I just got here. Once again, I'm anti-FOTM! I have three portable amps now.. PPAv2 with battery pack Millet Tube Hybrid Portable Baby Stax yay!

Lamm is epic fail. even worse is their phono stage.

you say that.. I was looking at some of the Hammond pricing and you can drop big bucks on them... $500 and up easily per transformer.

But, that's 4-5 VRMS from input leg to input leg. So, in a four channel amp each board would see half that.

x2 what nate said, and x1 on why would you want to do the above?

is that a Jameco 4.7uF/500V cap in there (the first pic)?

silver transformers is nothing compared to custom silver foil inductors.. pricing is crazy on both. Electra Print offers a nice partial silver stranded secondary (PSSS) transformer option here: Electra-Print.com Partial Silver Stranded Secondary Transformers .. not that I've been considering it or anything

doesn't the center stretch more than the sides, as it travels further?

nope, it doesn't matter how the primaries are configured, you can get the same amount of the current and voltage out of the secondaries. That's the beauty of universal primaries.

...only problem using this on a design is that it basically means all 220V people are out of luck But, it's nice to be able to rearrange some wires and get double the voltage output,

Nate: Did you ever post the other psu schematic? I'd rather like to take a look at it, if possible.

ah, the menacing popcorn smiley... oh course, if someone got a hold of it and used 220V, that would be really exciting

Hey, I was thinking about using the 220 taps on the primary side here in the US in order to half the voltage on the secondary side of a transformer. Can anyone think of any reason not to do this?

so, what's a piece of gear with a 2SJ109V in it worth? infinite?

that's not all that uncommon. Looks like a CCS before the opamp, that could be doing it.

yeah, I agree with the both of you. Problem is, they won't be symmetrical... gah, I dunno what to do. I'll talk to FPE.

I'd bet the batteries + reg is just as clean. I don't know if the supply Kevin was referring to in the comparison used a regulator after the battery, but that's a good question. I thought that there was an AA commercial battery power upgrade for these units? edit: what's the current draw?

sorry, I wasn't clear. The front panel has some extrusions to support the case assembly. I think it might be possible to get the entire panel fabricated at FPE, but I'd have to really think hard about it as I'd need to work in some angle brackets and a flange for the case lid. Too much to think about at the moment, as I'm really really wanting to get this baby singing soon. I totally agree about the thread. In fact, the VFD I'm using requires 2.5mm screws to mount, so I'm consider going with M2.5 or a fine threaded screws everywhere to get more threads. Think this might work out? The FPE bottoming taps or whatever they use are very nice and there is very little wasted space. That being said, there is not much to work with so ....

oh I see. I wouldn't go with anything more than an Elpac... I mean, the money for a sigma22 could much be better spent on, say tossing the amp and building another one.. i mean, improving the circuit (somehow)... Looks like opamps for voltage gain and then solid-state current gain into class A? solid-state output stage. Also, lots of 'styrene.. I like that. edit (again): why not try battery power?

problem is, that the pre-made panel I will be processing is only 2.5mm thick, and it has extrusions that are required for the case assembly. I'm hoping I will be able to get enough thread from the blind holes in the rear to mount the 4 PCBs needed on the back..

well, long story short is that a very large case from FPE is very, very expensive. The top alone was going to be around $200... so, I had to improvise. The case I got is a bit of a because, it is too deep to fit in my rack, or probably anyone's rack. That being said, here's what I've decided for the front panel: