The ultimate DIY? A Stax SRM-T2!

[Dusty Chalk]

Manley (well that one did not end well)

What? I'm hoping you mean she got divorced (NTTAWWT), not that the company broke up.

[Craig Sawyers]

I'm pretty sure its a 1.5 amp slow blow. (for 110 vac) But it might be a 2 amp. Too lazy to go and look.

Definitely not more than 2 amps.

updated schematics with a couple of resistors labeled as to power, and default of .5 watt added.

I will have to look tomorrow on the fuse... Its never blown the fuse yet. Not even with 24 hours of CJ.

The normal time for a fuse to blow is at switch-on. Depending on where the mains is on its cycle, there can be a huge inrush current to build up core mangetisation, or capacitor charge up. Big power amps with 500VA - 2000VA transformers often have a soft-start circuit. A relay with N/O contacts and a several watt power resistor in parallel in the live. A timer circuit wakes up after a second or two, energises the relay and shorts out the series resistor.

Clearly not necessary wit the T2.

[struts]

Good news and bad news.

The good news is that onlinecomponents can supply the RK50 for $655 , the bad news is that the lead time is 12 weeks not 8

Meanwhile my build is s l o w l y progressing...amp, ps...amd yes, I realized the diode needs flipping and the resistors crossing...

[luvdunhill]

I realized the diode needs flipping and the resistors crossing...

and D2, D5, D8 and D11 are wrong in the PSU, should be zeners

[struts]

and D2, D5, D8 and D11 are wrong in the PSU, should be zeners

Yup, that one too. Thanks!

[luvdunhill]

Yup, that one too. Thanks!

We'll just have too see who sees sparks first, we are at just about the same point

[luvdunhill]

Excellent, I like the way you think. I was thinking aluminum remote too. One that would be a menace to hard wood floors, small children and pets.

edit: my Audio Space integrated has a really nice remote. I don't know if it's aluminum, but it's 2 pieces of heavy metal. We could probably find something similar from China.

yeah, the Rogue / BAT remotes are single piece with a removable back I believe

[Craig Sawyers]

why not just write an Ipad (or other VNC capable device) app for the remote

It was only a matter of time until a software jockey started talking dirty

[nattonrice]

I now have everything except 6 resistor values for the psu and the 4 caps that Inu mailed me.

Well that and the chassis which I'll get on Tues/Wed.

Almost time to start building my Soviet toaster

[kevin gilmore]

so, assuming such a touch panel showed up... would the designer be able to commission an "at-material-cost" billet titanium remote? heh

From the man with 4 billet machined aluminum krell remotes.

DEFINITELY...

Now the at material cost is ok, but i still have to pay for machine time at $72 an hour starting sept 1. (up from $68 ..)

Takes a while to machine titanium.

[kevin gilmore]

So here is the current plan. I should have 8 sets of tops and bottoms done by next tuesday (then i'm out of material till i get some more)

and the knobs by wednesday, then 8 sets will head off for polishing. When i get them back (3 to 4 weeks) i'll send half for anodizing

because that is the batch size the guy wants, (another 10 days) and then 4 will be available. When he drops off the 4, i'll give him the next batch.

After that there will be only one batch of 4 left.

So who wants one of the next 4 chassis. And include which kind of stax jacks you want. PM's ok too.

[qusp]

It was only a matter of time until a software jockey started talking dirty

yep, but I mentioned the device that must be hated

[Grahame]

The joy about software based controls, is that you can use any platform to implement a client that understands your control protocol. So you are not tied to a specific device / platform. Unless you want to be. Different platforms have different feature sets that you can exploit.

Dirty enough for you?

[morphsci]

Wrong thread

[deepak]

Because threads on Head-Case always stay on topic

I moved the posts because the T2 thread is actually worth keeping on topic.

[morphsci]

Heh, no I wanted to post in another thread but I hit post quick reply just as I realized it.

[deepak]

Heh, no I wanted to post in another thread but I hit post quick reply just as I realized it.

Heh, sorry Jim.

[kevin gilmore]

Correction... the screws that hold the heatsink brackets to the heatsinks are 3/8 long, not .5 long

[luvdunhill]

what does C1 exactly do? It's 1nF across the plates of the input stage tubes. Looks like some sort of filter or compensation? Can the working voltage be considerable lower, say 100v?

[kevin gilmore]

this just in, birgir likes his new knob.

C1 is a silver mica cap in the original. It lowers the differential gain after about 2 hz.

Ties in with the differential servo to keep the outputs at the same voltage.

i'm sure you could put a 250 volt cap in there. But the original is 500v.

If one of the input tubes shorts out, you really could get the better part of 250 volts

across that cap.

[Dusty Chalk]

One should like one's knob.

[Voltron]

Come on Tice. It's been like 5 minutes without a response to Dusty's quip.

[spritzer]

No, I love my new knob. Tice industries really should branch out into titanium...

[Craig Sawyers]

Paul Houlden hand delivered my transformers on Friday. Awesome - as a supplier to high end audio, what he does not know about toroid design is not worth knowing. These have additional insulating taping between layers to hold off inter-layer voltage - which considerably complicates manufacture. Wind a layer, take off winder, terminate wires and shrink wrap, put on taping machine and insulating tape layer, back onto winder; repeat as necessary.

These things are specifically designed for ultra low stray field and imperceptible mechanical hum irrespective of power line fluctuation.

The good news is that they nicely fit the chassis piercings. They are higher than the originals at 60mm (2.4 inches c.f. 1.6 inches), and are a thing of beauty.

I'll take some photos and post them - link supplied later.

Paul says that building identical units (physical size and secondary specification, except Paul's design is 7% regulation) for different primary voltages is trivial. Since he had to buy a quantity of cores to build mine, he is set up to build more.

[Knuckledragger]

One should like one's knob.

Sig worthy.