luvdunhill

edit: seems to me you're going to have arcing issues with the 5AR4 from exceeding it's PIV and in order to get that choke to work, you'll probably exceed the recommended input cap for the 5AR4 as well. If at all possible, I'd like to learn why this will work

"OTOH, if a pseudo choke I/P filter, with its "fudge factor" cap. is employed, you can safely draw a bit more current" there were more posts I found.. anyways, if there is an open Q&A at some point, I'd be interested to learn more.

yes. I looked at the 193Q and found some people saying that 220mA or so was more reasonable to expect. Here's one such post: http://www.audioasylum.com/cgi/t.mpl?f=tubediy&m=139326 I suppose I lack the experience in this area to weed through random crap on the web and pretty much believe everything I read

check out the EY500. I was going to use this due to the 6.3v heaters and avoiding the additional transformer.

sounds great! I'd be interested to see the actual current capabilities once it gets up and running

I'm assuming the 193Q is the first choke.. no way you're trying to use choke input, so I'm assuming there's a small cap before that. even so, I would be curious if you can actually get 300mA... I went down a similar road and pretty much gave up after simulating with psud2. needless to say, I'm interested to see how this works

seems like a perfect situation for tv damper diodes... Would you mind sharing the choke part number?

so, you have a giant trafo capable of 770 VCT and then tubes with 300v and 400v max plate voltage? where's all that extra voltage going? Assuming you're loosing 50v or so per rectifier...

perhaps a mechanism where you can turn on the heaters independently of the B+ line? I'm going to do this in the amp I'm working on... sorta a manual soft-start.

cool, thanks for the tip

I've come to realize that etch == "good for classical". This has been true 100% of the time for me. Also, etch is not good for "oversampling", and much more conducive to analog and non-oversampling sources.

any reason to turn one of the chokes 90 degrees?

oohh. I misunderstood. I was thinking a "key hole saw"

looks great! so, what's the trick to using a hole saw? Those holes look very nice, considering...

I've measured a few drivers in my day and this is definitely true. After around 24 hours of 10-20Hz the driver is pretty much ready to measure and simulate. For example, assuming you're talking about a nice Danish driver, things become real stable after this period. Given good mic calibration and good software, the predicted graphs get frighteningly close to the measured response once it's all said and done. Even measuring 6 months - 12 months later, things don't change all that drastically. Dunno about the cheaper drivers where the QA/QC process is not all that stable/

perhaps what you're thinking about is after loudspeaker break in, the individual Thiel-Small parameters vary (often a lot), but the the ratios of said parameters always stay pretty much in step.

hey, did you get the numbers off those chips? Just curious if they're BB INAxxx devices.

so basically, it's used for galvanized isolation.

probably they were forced to, due the massive amount of power lines in that general vicinity.

If you guys have any old classical records, please let me have them before you subject them to this steam torture.

what is the part number on the BB chips in the last picture, near the output coupling caps (i.e. IC727)? There are four of them. Opamps / Buffers perhaps?

same reason... lots of grill cloth.

just hang the MMGs from the ceiling. Do a search around, many people have done this (including myself). Having owned both of these models, why aren't you considering the MG12s?

sorry... it's about the best gin I've found around these parts. I'm not a huge gin drinker as I've had a few bad encounters with it

If I can be of any assistance on the Austin end, feel free to contact me.