I actually found i don't have a need for 15V with the AD823 I'm using, the standard rails should work just fine, correct me if I'm wrong. My current issue is in where to mount the IEC inlet and RCA jacks. I'm using the hammond chassis and a large IEC inlet that sticks too far to mount behind the transformer. I'm thinking of mounting the inlet essentially as close to the transformer as I can get, but am wondering whether I'm better off mounting the jacks on the left side of the back panel (closer to transformer but shorter cable run) or on the right of the back panel (longer cable run, closer to inlet, but further from transformer)?
I like Mogami cables for signal stuff, they have shielded 1,2 and 4 wire stuff in a range of stiffness and thickness
That is twisted shielded pair? When used for RCA ("single ended") do you use pair (both wires) for signal and screen as gnd or only connect screen in one end and then use the twisted pair as signal and gnd? one benefit of screened twisted pair is that you can get the best from both worlds when used "single ended"? …..both twisted and screened? ….so it will reject both "magnetic noise" and RF?
But don't think many use it that way?
But don't think many use it that way?
Well, I must of done something to break my whammy Today I replace the cheap mic cable and unsealing output wires with higher quality shielded mic cable. When I reassembled it, I got smoke in the PSU section :-(
When I add power, the resistors in the PSU section get extremely hot, very fast. Any ideas? Thanks.
When I add power, the resistors in the PSU section get extremely hot, very fast. Any ideas? Thanks.
Ug. I cannot find a short; at least it's not obvious to me.
Here are some images. Anyone see anything or have an idea how to find a short?
IMG_0841 | Allan Marcus | Flickr
IMG_0844 | Allan Marcus | Flickr
Here are some images. Anyone see anything or have an idea how to find a short?
An externally hosted image should be here but it was not working when we last tested it.
IMG_0841 | Allan Marcus | Flickr
IMG_0844 | Allan Marcus | Flickr
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I think R37 and R20. The smoke might have been the solder heating up. I unplugged it pretty fast.
There is continuity between the two AC inputs, so that's is not good.
I'm guess it's really hard to find this type of short. Is it possible the short is in the board? Should I remove one item at a time until the short is discovered? Or just start over?
I'm not sure how to measure that. When I connect the leads from MM on the ohm setting, it bounces around a lot.
I'm considering building a WHAMMY for both headphone and pre-amp use. I'll probably use a switching headphone jack, as suggested before.
An issue I see might be excessive gain, so I'm thinking about including a gain switch. Am I correct that I would have to switch both R1 and R12 (e.g. between 1K and 10k for unity)?
Any comments on performance on unity gain? Would I be better off building a buffer instead and stick to my separate headphone amp? Would be nice to have both in a compact package though.
Power amp is a Yamaha ax-596 in power amp "mode" (100W class AB), until I build something different.
I've built some kits before, but this would be the first "semi-free" build.
An issue I see might be excessive gain, so I'm thinking about including a gain switch. Am I correct that I would have to switch both R1 and R12 (e.g. between 1K and 10k for unity)?
Any comments on performance on unity gain? Would I be better off building a buffer instead and stick to my separate headphone amp? Would be nice to have both in a compact package though.
Power amp is a Yamaha ax-596 in power amp "mode" (100W class AB), until I build something different.
I've built some kits before, but this would be the first "semi-free" build.
You will measure some low resistance on the AC in it is the transformer primary. If R37 and R20 smoke you have a problem with the + supply. Connect a meter to ground and measure resistance on pin 1 and 3 of the 7815.
Between 1 and 3 on the 7815 measures 5Mohm and then slowly drops if I hold the probes there.