I have a business partner that was formerly in the optometry business.

I (as recently as 2 months ago) tried every single one of the multi-focal

contacts. Boy do they suck. In the morning driving, every stoplight turns

into 6 pointed stars.

Lasic is a very bad idea. After 10 years (especially when you are older)

it drifts badly, and is then not correctable. DON'T DO IT.

If you are near-sighted, when you hit about 45 you won't be able to

wear contacts anymore. You will see what i mean when you get there.

All current solutions stink.

I am pretty darn near-sighted, but correct very well with contacts now. Kinda counting on surgery having evolved by the time this stops working, or something else entirely.

DACs as eyes! DACs as eyes!

There was this boy with a wooden eye. He was, as you might imagine, very shy because of his deformity and the fact that his family could only afford a wooden eye.

Well, one day he worked up his courage and went to a dance. Across the dance floor, he saw an attractive girl with one flaw. She had a slight hairlip.

The boy screws up his resolve and goes over to ask her if she wants to dance.

When he gets over to her, he says, "I was wondering if you'd like to dance?"

She says, very eagerly, "Would I? Would I?"

So he says, "Hair lip! Hair lip!"

Thats a toned down version of the one I heard where she says "Would I!" and he says "Don't call me Woodeye Cuntmouth." The best jokes don't belong in Christmas crackers.

I am looking for some advice on a possible Stax amp upgrade. Right now I have a very old Lambda Pro and SRM-1/MK-2 combination that I have enjoyed for many years. A couple of years ago I added an SR-003 and SRM-252 II combination for use at work on my computer. I ended up using the SRM-1/MK-2 with the 003's at work now as that combination sounds better than the SRM-252 amp and naturally the in/on ear 003's are more unobtrusive than my Lambda's This driving by a Wavelength Proton 24/96 USB DAC that I like very much as well.

I have a bit of an urge to upgrade my amp at work. Any suggestions on how a newer tube amp would work with the 003's?

Thanks.

Well a newer tube amp for the SR-003 could be the DIYT2 but unless you have 18K sitting around that isn't really an option. The Blue Hawaii is also great...

Any particular reason why you'd want a tube amp?

No particular reason to get a tube amp. Just thinking that might be something to try. The 18k and the Blue Hawaii are a bit much for me right now.... Have upgrade fever but not quite that bad yet.

The best sub 1k$ Stax amp you can get is the 717 so that's what I'd shoot for. You can also do a once over on the SRM-1 Mk2 (replace caps with fresh ones and adjust the offset) which should give you a nice performance boost.

You can also do a once over on the SRM-1 Mk2 (replace caps with fresh ones and adjust the offset) which should give you a nice performance boost.

Could you explain this a bit more? I've only read about adjusting the bias from tubes via a screwdriver... Is the goal to reduce the DC offset or to increase the bias to 580V? And where do you adjust it? Which caps would you use?

The SRM1 Mk2 is a solid state amp, so no tubes to adjust there. You can adjust the DC balance (+ vs -) and the overall DC offset (+ and - vs ground) for both channels via pots inside the amp. Ideally you should have 0V on all four outs, realistically you can get the balance down a few hundred mV and the offset to something below 1V. Note these values tend to drift with time and temperature and should be adjusted with the amp warmed up and closed (with a thin isolated screwdriver through holes in the lid).

You can however not adjust the bias with the SRM1; just make sure you set it to the right operating voltage (240V for Germany)..

The SRM only has four electrolytes inside: three to flatten the high voltage after the rectifier and one for smoothing what seems to be a slightly more negative reference...

Edited June 13, 201016 yr by Cynric

The SRM1 Mk2 is a solid state amp, so no tubes to adjust there. You can adjust the DC balance (+ vs -) and the overall DC offset (+ and - vs ground) for both channels via pots inside the amp. Ideally you should have 0V on all four outs, realistically you can get the balance down a few hundred mV and the offset to something below 1V. Note these values tend to drift with time and temperature and should be adjusted with the amp warmed up and closed (with a thin isolated screwdriver through holes in the lid).

You can however not adjust the bias with the SRM1; just make sure you set it to the right operating voltage (240V for Germany)..

The SRM only has four electrolytes inside: three to flatten the high voltage after the rectifier and one for smoothing what seems to be a slightly more negative reference...

Thank you, yes I knew, that it has no tubes, that's why I wondered. Somewhere I read that a DC part in the voltage is no problem in electrostats.

Yep, I did set the voltage to 240V... I'll keep on reading... even though I study computer science my knowledge about electronics is really limited, but I'm starting to change this

I would use any good caps that fit, no audiophile nonsense for me. The stock caps are 15+ years old and way past their prime and since the PSU is unregulated it will have a large impact on the sound.

Are Stax the things that sounded almost as good as the LCD-2 Orthodynamic?

Hehe, I'd say it was the other way around.

The best sub 1k$ Stax amp you can get is the 717 so that's what I'd shoot for. You can also do a once over on the SRM-1 Mk2 (replace caps with fresh ones and adjust the offset) which should give you a nice performance boost.

Thanks. I will research these options.

A couple of years ago I modded a simple DAC and used motor oil filled caps. Do they have any use in the higher quality Stax gear? Thanks.

You could parallel them for the main PSU caps but then you'd need another box just to house the caps. All the modern Stax amps are DC coupled so no caps in the signal path.

The SRM1 Mk2 is a solid state amp, so no tubes to adjust there. You can adjust the DC balance (+ vs -) and the overall DC offset (+ and - vs ground) for both channels via pots inside the amp. Ideally you should have 0V on all four outs, realistically you can get the balance down a few hundred mV and the offset to something below 1V. Note these values tend to drift with time and temperature and should be adjusted with the amp warmed up and closed (with a thin isolated screwdriver through holes in the lid).

You can however not adjust the bias with the SRM1; just make sure you set it to the right operating voltage (240V for Germany)..

The SRM only has four electrolytes inside: three to flatten the high voltage after the rectifier and one for smoothing what seems to be a slightly more negative reference...

Oh to find out the pots pairs affect each other was mean. I had the DC balance to almost zero, then measured the offset and got an evil 60V...

But now all pairs are ~500mV which is fine.

Is the balancing technique the same as that for the tube amps? Could someone post a link to the SRM1Mk2 balancing technique?

The pots should be marked on the board, offset and balance. TO adjust the offset put probes on the + and - outputs and adjust for 0VDC. Of the offset put on probe to + and one to ground and adjust for 0VDC.

Hm, I found those: [url=http://cgi.ebay.de/5x-Elko-100uF-400V-85-C-30x20mm-RM10-Nippon-/230444408158]5x Elko: 100uF 400V 85

Caps have decreased a lot in size over the last 20 years or so. I have some 100uf/450V caps which are just tiny.

Those caps should work but they are designed for use in a chassis with low height clearance so they are wider then a normal cap would be. If they fit then they fit but do measure the pitch of the terminals on the Stax board (you can just remove the bottom panel to see them) but take care with the high voltage on them. Snap in would be correct.

Caps have decreased a lot in size over the last 20 years or so. I have some 100uf/450V caps which are just tiny.

Those caps should work but they are designed for use in a chassis with low height clearance so they are wider then a normal cap would be. If they fit then they fit but do measure the pitch of the terminals on the Stax board (you can just remove the bottom panel to see them) but take care with the high voltage on them. Snap in would be correct.

Alright, thats nice. I think I'll "build" a "discharge resistor wire" first, something which you people probably already have ( saw it here:

).

Even if i won't touch the cap during measuring, I think discharging it would be a safer bet...