Stax Omega SR-007 Mk2

[slwiser]

I will ask this here...

Where is the best place to purchase these. Best price with warranty or just the best price. Are these so reliable that you need not concern yourself with the warranty?

As an alternative I am thinking about the "Stax srm-t1w stax tube amp/headphones" what price would be reasonable for this set?

Thanks

[tkam]

I got mine from moon-audio for $2050 (they are an authorized dealer so you get a valid US warranty). They get drop shipped straight from the US distributor in California.

[slwiser]

I have been talking with Drew already. His price is slightly higher now apparently at 2075$. I told him my time frame is near the end of June.

[spritzer]

Drew's price is very good as the SR-007A is about 1750$ shipped from Japan so if the warranty is important he's still competitive especially if you want the black model.

It's hard to gauge the price on the T1w as there aren't that many changing hands but it should be in line with the T1/T1S prices which is 800$+ for one in good condition.

[slwiser]

I have a SRD-7 Pro that I plan on using to power the SR-007. I am going to use a Nuforce Icon to power the SRD-7 Pro.

Any comments on this arrangement.

[spritzer]

I have a SRD-7 Pro that I plan on using to power the SR-007. I am going to use a Nuforce Icon to power the SRD-7 Pro.

Any comments on this arrangement.

I don't recommend the SRD-7's for use with the SR-007 as the transformers simply can't deliver enough juice for the phones so they will sound a bit dark and rolled off in the treble with a rather woolly bass response.

[slwiser]

What kind of power do the SR-007s need if the 8 watts of the SRD-7 Pro is not enough?

I had read somewhere where someone had posted a note saying that is one of the things they did with the Mk2 is make is more compatible with lower end drivers. Is this correct?

[spritzer]

What kind of power do the SR-007s need if the 8 watts of the SRD-7 Pro is not enough?

I had read somewhere where someone had posted a note saying that is one of the things they did with the Mk2 is make is more compatible with lower end drivers. Is this correct?

The watt rating of the SRD-7 is utterly meaningless here. We are dealing with voltage swing and when that doesn't cut it, current delivery. The simple fact of the matter is that the SRD-7's were never designed to deal with the load presented by any one of the Omega series so while they can provide the necessary voltage swing, the current is lacking due to the small transformers.

The newer model is more compatible with lesser drivers but it's no night and day difference. They are basically more "impressive" in those areas which the Mk1 was lacking with lesser amplification so they seem better.

[n_maher]

I will ask this here...

Glad to see you learned your lesson.

From what I've seen your options are few and far between and your only way to get a lower price is to either buy used or to import them and deal with limited warranty support.

[slwiser]

I am thinking I can live with a dark sound for a few months till I get in a position for a better Stax amp and I can be on the lookout for a used one.

I have really enjoyed my Stax Gamma Pro out of my SRM-1 Mk2 Pro. All these model numbers get confusing to me so I may right something not right. I also have used my SRD-7 Pro with the Berning micro-ZOTL with the Gamma Pro. This really sound nice. I am now trying to find some Muller banana couplings to connect my SRD-7 Pro banana plugs to my Nuforce Icon speaker out wires that are banana plugs.

I think Drew will get my business yet again.

[slwiser]

Glad to see you learned your lesson.

I am a bit dense with it comes to learning my lessons so don't hold you breath.

[n_maher]

You could also think about a DIY/custom built better version of the SRD7, couldn't you? I wonder what the Stax experts opinion's would be on how much better quality trafos would run you? Otherwise there isn't much to the thing internally from what I understand.

[CD44hi]

It's hard to gauge the price on the T1w as there aren't that many changing hands but it should be in line with the T1/T1S prices which is 800$+ for one in good condition.

Well funny you should mention this because all of the sudden there have been two on audiogon. The second one sold quickly. I heard the T1S once and it was not bad with the Lambda sig pro. Is the T1w similar in sound? I shall keep my eyes open....maybe I'll brake my no-electrostat run, heh.

[Jon L]

I am thinking I can live with a dark sound for a few months

Actually, I'm not so sure your NuForce Icon/SRD7Pro will be so dark. Haven't tried the Icon, but if it sounds like other NuForce amps I've tried, its sonic characteristics might synergize very well with O2. Worth a shot!

[slwiser]

Actually, I'm not so sure your NuForce Icon/SRD7Pro will be so dark. Haven't tried the Icon, but if it sounds like other NuForce amps I've tried, its sonic characteristics might synergize very well with O2. Worth a shot!

The Icon uses the same type of design internally as other Nuforce amps. I do know that. I plugged one of my dynamic cans into the headphone out and the Icon sounded very good with it.

[slwiser]

I don't recommend the SRD-7's for use with the SR-007 as the transformers simply can't deliver enough juice for the phones so they will sound a bit dark and rolled off in the treble with a rather woolly bass response.

Showing my ignorance again doing what I do by asking questions. I thought the lower impedance headphones had a higher current requirement. I see that the SR-007 Mk2 has an impedance in the 170k-ohm range while the Lambda series is more in the 130-140k-ohm range making the Lambda series having a lower impedance. This suggests to me the SR-007 needs more voltage swing compared with the Lambda series as opposed to current. It is possible the design of the SR-007 Mk2 simply requires more power overall than the Lambda series.

[spritzer]

You could also think about a DIY/custom built better version of the SRD7, couldn't you? I wonder what the Stax experts opinion's would be on how much better quality trafos would run you? Otherwise there isn't much to the thing internally from what I understand.

Sky's the limit here with electrostatic transformers from Sowter running at about 500$ for the pair but I'd really like to try the cheapest Hammond output transformer (less then 50$ each) and wire it up backwards to see how it behaves. There is always the Illusion unit but it's rather expensive and no thorough comparisons have been posted.

Well funny you should mention this because all of the sudden there have been two on audiogon. The second one sold quickly. I heard the T1S once and it was not bad with the Lambda sig pro. Is the T1w similar in sound? I shall keep my eyes open....maybe I'll brake my no-electrostat run, heh.

All the T1 amps share the same amp circuit (exact same PCB) but all the extra circuitry in the T1S and T1W does exact a small toll on the sound but it's nothing to worry about as different tube types matter a whole lot more.

Showing my ignorance again doing what I do by asking questions. I thought the lower impedance headphones had a higher current requirement. I see that the SR-007 Mk2 has an impedance in the 170k-ohm range while the Lambda series is more in the 130-140k-ohm range making the Lambda series having a lower impedance. This suggests to me the SR-007 needs more voltage swing compared with the Lambda series as opposed to current. It is possible the design of the SR-007 Mk2 simply requires more power overall than the Lambda series.

First of all, electrostatic elements act as capacitors so all rules for dynamics (resistive elements) go out of the window. Since they are big capacitors the impedance plot is like a ragged bell curve with the HF and LF tougher loads then the midrange. All electrostatics need voltage swing to make any sound but as the impedance drops in the treble and bass the elements draw more current to maintain the voltage swing. It's not a whole lot of current but at 300VAC it really adds up and most amps simply can't deliver it making the bass seem boomy and the treble rolled off and dark.

[Elephas]

I have an SRM-T1W and it works OK with the SR-007 and SR-007Mk2, but I wouldn't recommend it. The T1W seems to be a better match with the SR-Omega and Airbow SR-SC1.

I also have an SRD-7Mk2 and Illusion ESC-1001, but I haven't had the chance to try various power amps with the O2's.

For an O2, I think the KGSS at around US$1500 or maybe slightly less for a used unit is worth saving up for.

[luvdunhill]

I've always modeled amps in SPICE using a single 200pF capacitor as load and disregarded any resistive elements. I'm not sure if this is the best way to do things, but it seems to give believable results.

[slwiser]

First of all, electrostatic elements act as capacitors so all rules for dynamics (resistive elements) go out of the window. Since they are big capacitors the impedance plot is like a ragged bell curve with the HF and LF tougher loads then the midrange. All electrostatics need voltage swing to make any sound but as the impedance drops in the treble and bass the elements draw more current to maintain the voltage swing. It's not a whole lot of current but at 300VAC it really adds up and most amps simply can't deliver it making the bass seem boomy and the treble rolled off and dark.

Thanks for this explanation, I may have some understanding now.

Time to go get SPICE and play a little.

What does everyone think of this? http://cls.audiogon.com/cgi-bin/cls.pl?ampstube&1217214455

If I got this I would have to save up for the SR-007 instead.

[Tachikoma]

Unless you think the ED-1 is worth $900-1k, not a good deal. (The ED-1 is just a diffuse field equaliser for lambdas, and it won't necessarily do anything good to the sound)

[slwiser]

From deepak's thread where he is using his SRD-7 Pro he does note the rolled off highs. It is possible if this is really up there above 14 kHz that I would not notice it.

Thanks Tachikoma for the update on my question.

[slwiser]

How many watts do you think the SRM-007tII Vacuum Tube Driver will put out? I only draws 55w from the wall. At Class A eff. it really would not be much over 5 watts I would think? Which would suggest that it's current capacity is not that much either. Please enlighten me if this is not the case. Thanks