DefQon

Sorry for reviving this thread but I felt it best to consolidate all posts/faq's regards this beast in this single thread since schematics and other technical discussion have been made in the previous pages over a year ago. So I've managed to snag a 12S from a buyer who didn't know what it was for 100 quids (bloody bargain). The amp works fine except some hissing and collapse of the left channel, which seems to work intermittently. So I popped off the hood (which look's like somebody tried to scramble eggs on it), the pair of 51kohm 5watt red resistors on each output board have left scorched burnt marks but measure within the 5% of the specced resistance. Consulting with the schematics and pictures of the restored 10S pictures few pages back by spritzer, where you mentioned you had a voltage divider of two resistors in series for pro-bias output connecting the output stage green pcb slot connectors underneath, 22kohm and 220kohm was the 22kohm originally 2.2kohm? The spec sheets says 2.2kohm and my 12S particularly confirms this as well with a parallel 100uf 25v axial cap next to the 2.2kohm 1/4 resistor. What is the 100uf 25v axial cap for? I've disassembled the amp, cleaned the brass chassis and reassembled the slots, trafo and other stuff such as rewiring the sockets and have ordered parts only to rebuild the output and both power supply boards completely. Another thing on the schematics and the PS board underneath the amp, the rectifier is made by 4 RA-1 diodes and then another 4 round diodes (similar to the one I replaced in my SRM-1 except bigger) what can the RA-1 and other round diodes be replaced with? The usual 1N4007 suspects applicable in this case? Thanks

Mike are you able to do a kgst and megatron gb run of these board sets?

Lucky you most places in Melbourne is still between 240 and 250v. The last two properties i had including my current house my mains is 245vac.

Go back a few pages and look at the SR-3 drivers I posted. Same wire to same pin connection.

Is there any chance to up a limited pro-bias output at 470v to near 580vdc? I'm getting some compression distortion on the lower-end regions in sub-bass if I up the volume too much.

As expected. My two sets came in this morning. Holy shit these are small compared to my rev.04/0.6 offboards from Tran's GB. Very nice boards indeed. Thanks Michael.

I'd be interested in some brackets too if you manage to get a source who can do it. Conrad heatsinks are not responding to any of my inquiries.

I should receive mine in the coming week if John's received his.

Yep was talking about rinse aid specifically. Durability also depends on the place you live and store the headphones, here in Oz the weather is sometimes humid after a random hot to rainy weather change as its Autumn now.

Very nice. So far orange and purple or white are my favourite. The blue is getting a bit old.

That's going to wear off with channel imbalance settling after. I tried it as it's a very common home product. Till I got some gel.

Will do once I receive mine. @eggil: That was fast!

I got a quote from the Australian Stax distributor 2 years ago when I had my Sigma Pro's that I wanted to convert to Sig/404's, it was $380 for a pair of matched 404 drivers.

That quote will probably cost as much as the Sigma's itself.

Sell me the rk50.

All good recommendations personally. Buy a Stax amp for cheap with either o2 or 009 and build a kgst or megatron at the same time. Take your time building it with whatever amount of spending budget you want to allocate to it.

Any computer screen/lcd cleaner gel. I don't use the spray only the gel which stays on forever. Or you can buy some Staticide liquid solution which will be a permanent fix.

Yeah make sure when you're applying the antistatic goop don't apply too much pressure this stretches out the mylar (which you can re-tension using a heat gun but not back to Stax spec's). Use the least amount of pressure possible and evenly spread it out, let it dry then install the spacer back in otherwise the surface is still wet and sticks to the stator. You need to coat both sides.

Glad it worked out for you.

Looks good indeed. can't wait for my two sets to come in. Guess I'll be populating these faster with current parts then the 0.6 offboard I was planning to do.

You can easily fix the imbalance issues assuming the mylar membrane has seen too much sun light resulting in a complete sag like the pictures I posted Duffer quoted. To remove the 4 bronze pins don't use a flat head screw driver you`re going to be putting to much pressure and may end up cracking the plastic housing. Use a thin, sturdy but sharp Stanley or kitchen cutting knife and carefully pry it open with the sharp side in between the head of the pin and the plastic housing.

Looks legit. I have some old stock I got from a diy'er on diyaudio, bdent and a UK seller on ebay and there are some in the odd 50 bag of them that look like either of those 4686's.

It must be one strong cat. Best way to repair it is a donor cable or new connector. 6 pin normal bias cables are no longer stocked by Stax or its distributors.

Thick as a Brick aye? I know that fit's in line with the vast amount posters in the Stax thread on head-fi.

I hadn't thought of the ESP950 cable. How much are they and is anyone willing to ship one my way?