The Stax SR-L500 and SR-L700 Impressions Thread
Dec 5, 2018 at 4:51 PM Post #1,141 of 1,866
Does anyone have thoughts on L700 with iESL and iCan?

I thought about it, but decided it's a fair bit of coin and I'd rather put it towards one of the "higher end" energizer/amps for the Stax.

Currently using the 353x with the L500 and will continue to until I'm ready to upgrade,
 
Dec 5, 2018 at 5:38 PM Post #1,142 of 1,866
I thought about it, but decided it's a fair bit of coin and I'd rather put it towards one of the "higher end" energizer/amps for the Stax.

Currently using the 353x with the L500 and will continue to until I'm ready to upgrade,
Hi I thought about the iFi iESL that it cannot be much more special than the Woo Wee or the Mjolnir Audio SRD-7. I guess I'll have a real energiser. By the way Woo audio sais on its site do not use the Woo Wee for a SR-009 or 009S then why use it on a L700??? I'd like the people of iFi to build an energiser for that price. Best wishes.
 
Dec 5, 2018 at 5:39 PM Post #1,143 of 1,866
I thought about it, but decided it's a fair bit of coin and I'd rather put it towards one of the "higher end" energizer/amps for the Stax.

Currently using the 353x with the L500 and will continue to until I'm ready to upgrade,
Hi I thought about the iFi iESL that it cannot be much more special than the Woo Wee or the Mjolnir Audio SRD-7. I guess I'll have a real energiser. By the way Woo audio sais on its site do not use the Woo Wee for a SR-009 or 009S then why use it on a L700??? I'd like the people of iFi to build an energiser for that price. Best wishes.
 
Dec 5, 2018 at 7:44 PM Post #1,144 of 1,866
Does anyone have thoughts on L700 with iESL and iCan?

So I've posted my thoughts on the iESL before. Briefly, it's a step-up transformer plus bias supply. Stax uses a voltage multiplier circuit consisting of diodes and relatively small capacitors (0.1 uf) for their bias supplies, which is simple, inexpensive and works well because the bias supply draws essentially no current, so the bias voltage is more than sufficiently stable. In fact, if you take an old Stax converter box which uses AC power, and pull the AC plug, the headphones will continue to play for some minutes. In addition, the current Stax bias supplies use a 5 megohm safety resistor, so in case the diaphragm accidentally touches the stators, there isn't enough current discharged into the diaphragms to do damage.


The iFi iESL uses a battery in its bias supply, which carries a large charge, and lacks the safety resistor, so if the diaphragm should accidentally touch the stator, for example if it is overdriven, then there is a likelihood that enough charge could go into the diaphragm to damage it. In my younger days, I once decided to discharge a power supply capacitor by putting a screwdriver across its terminals. The resulting spark put a 2mm divot in the blade. A plastic diaphragm is less sturdy than a steel screwdriver blade. Thus, it is an expensive solution to a non-existent problem which could potentially damage the headphones. IMHO this is poor engineering, I'm sorry to say (I imagine the iFi people will disagree).
 
Dec 7, 2018 at 5:41 PM Post #1,147 of 1,866
I would also personally recommend tubes for an L700. They do fine with solid state but tubes make them more enjoyable. Of course that is only my opinion and others would argue the opposite side of the coin.


I confirm, my L700 sounds super with SRM-006tS
 
Dec 24, 2018 at 2:01 PM Post #1,148 of 1,866
Hi,

İ am reading lots of positive things about L700+srm353x combo. İ'm planning to buy this setup. any suggestions other than this combo for a starter? Changing amp or headphone?

Mjolnir octave2 or 3 +L700

Or

Srm353x + L700

Or

L700+ srm006ts kimik2

Or

Anything better for me under 2500 usd?

Too many choises
:)

And what is l700 PRO, what is the difference between l700 and pro?
 
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Dec 27, 2018 at 6:41 AM Post #1,153 of 1,866
Best with T1
Hi I use the SRM-T1-S which is a balanced T1 but I understood it is more or less the same as the SRM-006Ts and I am happy with mine but I advise the SRM-006Ts because it is newer so you donot have the capacitors issue. You can refurbish the T1 by renewing the capacitors to get what the SRM-006Ts already is. A relatively new amp. I was thinking of a 100Volt SRM-007tA with a step down adaptor from 230 Volt EU which should be a bigger and a bit better T1S but at least it is new. I hope with the EU trade deal with Japan the taxes will be lower. Ebay sells them cheaply. Best wishes Yoram
 
Dec 27, 2018 at 2:09 PM Post #1,154 of 1,866
I haven't heard the SRM-007t vs a T1, but I am not all that convinced that the 007 is worth the money. The reason is that the 007 uses the same antiquated output design as the T1 - specifically, it uses plate resistor loads. The problem with plate resistors is that, per Ohm's law, V = IR. Since the plate resistor is lower impedance than the headphone, this means that the majority of the signal current generated by the output tubes is wasted, burned up as heat in the plate resistor. The lower the value of the plate resistor, the more signal current gets burned up. Not only is this inefficient, but it also increases distortion, due to the increased amount of current variation needed to drive the headphones and plate resistor. The plate resistor values are 66 kilohm in the T1 versus 47 kilohms in the 007. Granted, the 007 has double the number of output tubes, but this only buys a 40% increase in standing plate current. It should be remembered that Stax did originally recommend the T1 to drive their Omega headphones, although they did later introduce the T2 for that purpose, and the Omega is considered more difficult to drive than any Lambda headphone.

However, a better technical solution to my mind than buying a 007 is the constant current modification to the T1 (or 006). This effectively eliminates the current wastage of the plate resistor, which more than doubles the amount of signal current available to drive the headphones. At the same time, the decreased amount of signal current needed decreases distortion. Also, the parts cost of modifying a T1 is around $100, so the overall cost should be significantly less than the cost of a 007, even if you pay somebody to do the mod for you.
 

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