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On 11/29/2020 at 5:07 AM, hekoman said:

I am attempting to repair a SRA-3S and I am having trouble trying to figure out the value of two of the caps on the first card. I can read on one of them that they are rated for 50V, but all other marking have been worn off. I tried looking online for pictures of the card, but I can't find any pictures online that are high enough resolution to read the values.

Any one that has one of these amps and can read the values on theirs would be greatly appreciated, Thanks!

PXL_20201129_032508446.thumb.jpg.cf1d7b9464db6da800573323b8b5cced.jpg

PXL_20201129_032727791.thumb.jpg.3b75b6f9afe0058053c8de2989ecd1e5.jpg

I have one unit, that is not working, but I opened it and it is obvious that both caps are 220 nF/50 V and they are input caps.

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Isn't everybody glad that I'm crazy enough to buy this stuff and have Kevin rip it apart?   

I have compared the 009 and 009S running from the same amp (T8000) today. The room was somewhat quiet, but I had only two source options: my iPhone (connected through Apple's lightning adapter direc

Ok...I had an interesting morning.  It isn't every day that one takes apart HE90 drivers.    Sorry no picks as I was too freaked out while handling something so delicate and well...fucking unobtainium

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What's the generally consensus revolving around which energizer sound best with which electrostatic earspeaker.

Blue Hawaii for 007

DIY T2 for 009 & HE90 & HE60

Anyone got impression how the the nanotube sound with the above?

 

 

 

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Hey guys, 

Im new here, and I was looking for an opinion. 

I recently got some L700s as an upgrade for my 207s, and I was thinking about upgrading the energizer as well. 
I am fairly confident at modding circuits, but I am unable to get non-stax branded amps. 

I am currently looking at used stax amps and found a few options. 
323A for 25000jpy
323S for 36000jpy
727A for 68000jpy

In your opinion, which will end up sounding the best keeping in mind that I am only driving lambdas?

Thanks for any input

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8 hours ago, Mach3 said:

What's the generally consensus revolving around which energizer sound best with which electrostatic earspeaker.

Blue Hawaii for 007

DIY T2 for 009 & HE90 & HE60

Anyone got impression how the the nanotube sound with the above?

 

 

 

I have two blue hawaii se (golden reference hv and lv psus) , two joamat mini t2 (with golden reference hv and lv psus) and a diy t2. I only have experience with them using sr007 mk2 earspeakers. The hawaii is very good, far far far better than the stax srm006 or anything modern stax sells. The mini t2 is better still improving bass, micro dynamics and detail. The diy t2 is fantastic its takes the mini t2 strength and improves on it and adds better macro dynamics, even better bass and detail. If you can get any stax amp get the diy t2. As far as I can tell the sr007 needs as much drive as possible to get the best bass and dynamics and the diy t2 has the drive.... (we are still waiting for Kevin Gilmore to design a single ended stax amp which uses 300Bs or 211s or something even more powerful... 🙂 )

In terms of build difficulty the blue hawaii is probably the easiest (there are two version the original uses obsolete components but the modern version only uses transistors which are still available new), the mini t2 amp boards are almost all surface mount (psu is still through hole) and require precision and a good hot air station. For checking a stereo microscope is very useful. It only uses modern components and costs a bit more than the blue hawaii to build. The diy t2 is not difficult to build (if you use resistors that can handle the voltages) it's just big and intimidating. In terms of build costs the diy t2 is by far the highest. (there are two versions of the t2 one which uses almost all obsolete and very expensive nos components and a more modern version which only uses two types of obsolete transistors.). Either way you need to be aware there are many people selling fake nos transistors which will fail and blow up immediately on switch on or if you are "luckier" fail slowly over time. So you either need a trusted source or a transistor breakdown voltage tester and transistor identifier and even then you are taking a risk... (almost every seller of nos transistors on ebay sells fakes or a mixture of fakes and modern "equivalents" relabeled as originals.

In terms of size I built the entire blue hawaii in a single 400mm deep case, the mini t2, transformers in one case and the amp and psu in a single 400mm deep case. Diy t2 transformers and psu in one 400mm case and amp in another 400mm case. (I had to modify the diy t2 amp board gerber files for the amp circuit board to make it fit)...

 

Edited by jamesmking
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9 hours ago, theweezle said:

Hey guys, 

Im new here, and I was looking for an opinion.

I recently got some L700s as an upgrade for my 207s, and I was thinking about upgrading the energizer as well. 
I am fairly confident at modding circuits, but I am unable to get non-stax branded amps. 

I am currently looking at used stax amps and found a few options. 
323A for 25000jpy
323S for 36000jpy
727A for 68000jpy

In your opinion, which will end up sounding the best keeping in mind that I am only driving lambdas?

Thanks for any input

I would choose the 727A and have it modified because it is slightly warm, while the 323S is more neutral. But the difference is not that big.
But there is also SRM-T1 and its close derivatives, the SRM-T1S and SRM-T1W are also available for reasonable prices and they sound good if they have good tubes in them, although for the best performance they need to be CCS modified as well to tame the bass hump (which I personally don't mind with some headphones) in stock form they can be even warmer than the 727A modded.

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I went to a dealer looking for speakers and I ended up hearing the 007 they had on demo just while I was waiting for my turn. To my surprise I really enjoyed the sound and sounded different than the 007s MK1 and mk2 I had.

To my ears the 007 has been always boring and the sound too soft/in the back, but this one was forward but still smooth, I enjoyed it. 

It was a silver one recently ordered from Japan and the serial number SZ2, wasn't suppose the new ones to be SZ3 ?

Has stax upgraded the 007?

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30 minutes ago, Spychedelic Whale said:

I went to a dealer looking for speakers and I ended up hearing the 007 they had on demo just while I was waiting for my turn. To my surprise I really enjoyed the sound and sounded different than the 007s MK1 and mk2 I had.

To my ears the 007 has been always boring and the sound too soft/in the back, but this one was forward but still smooth, I enjoyed it. 

It was a silver one recently ordered from Japan and the serial number SZ2, wasn't suppose the new ones to be SZ3 ?

Has stax upgraded the 007?

What were they running the 007's out of? Perhaps the difference might be down to the chain of hardware running it? Just a thought.

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On 12/29/2020 at 9:33 PM, Spychedelic Whale said:

It was a silver one recently ordered from Japan and the serial number SZ2, wasn't suppose the new ones to be SZ3 ?

SZ2 are current production. Also amps... I think I posted someone's FR graph here a year or so ago recording no difference from 252 on up to 717 at very high amplitudes with an 007a. This suggests to me that Stax amplifier differences lie in the ultrasonic region. On the other hand I haven't heard any amp other than 323S, and this puts me in contrast a little bit with others here.

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I would be very skeptical of any FR graphs for the 007's, they are next to impossible to measure correctly.  Ohh and that conclusion is completely false...  ;) 

I did order up a new 007A which should be here soon.  Let's see if Stax changed anything. 

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So I went ahead and modded my L700 mk1. I'm generally pretty skeptical of Lambda mods, but my yoke broke on the left side and I fixed it with duck tape and a coat hanger, and mysteriously my coat hanger solution ended up being far more comfortable than the stock setup. So I got to wondering if there was a way to custom-make a better yoke, and lo and behold, someone else has already done it.

These are 3d printed by Socas and they work pretty well. They allow for a wider range of motion for the earcup and they fix the problem of having too much pressure at the top of the earpad and not enough at the bottom. So if you're one of the people who, like me, can't wear the current generation Lambdas properly, this is a solution. You will need a Torx 6 screwdriver to get the screw out that holds the yoke in place, and after that it's an easy swap.

This does affect the sonics a bit. In the past I always read accounts of people hearing the L700 as overly warm and a bit congested and wondered what on earth they were hearing, but how... that's kinda how it sounds. The frequency response gets rotated clockwise, the highs are much smoother and more palatable, but the midrange shout and upper mid dip gets even more noticeable.

The solution of course is EQ. I'm not gonna post all of my settings since you really need to personalize your own EQ but -5db at 1150hz q1.41 and +2db 3khz q0.5 evens out the mids, then you also need to drop the peaks in the highs - which we all hear in different places - and adjust the lows to taste.

I have a MiniDSP ears now and will probably be able to EQ more accurately, but I thought I'd give a heads up to @yaluen and others who are in the same boat that there is a fix, and you don't need to write the current-gen Lambdas off (though I don't know if this works for the L300/500). This thing sounds very smooth and natural now, with great imaging and clarity but a bit lackluster impact in the lows, which I'm sure a more powerful amp than my 717 will fix.

Oh, and the Mk2? My opinion of it has turned pretty sharply downwards. I prefer my modded mk1 by a good margin.

L700_work.jpg

Edited by catscratch
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Hello all,

I'm planning on building a transformer box, so I came up with this bias circuit. I'm a complete novice at circuit design but I would be grateful if anyone could critique it or rip it to shreds. image.thumb.png.4f35d5fabfcae69642f13fcf2b13502c.png

V1 is supposed to be the 60hz output of a power transformer (I arbitrarily chose 700Vpp, but I tried it with 940Vpp and it seems to work too), and the zener string is 2x 200V and 1x 180V. Blue line is the sine source, red line the node right before the ballast resistor. The runtime of the simulation is 0.4 seconds. I know it's probably a waste of money to use a power transformer for a bias supply, but are there any issues with the idea other than cost?

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Just buy this instead, much safer than working with mains.

https://www.aliexpress.com/item/1005001813099933.html?spm=a2g0o.productlist.0.0.41dab88epLfUCK&algo_pvid=27a95d58-360c-4aa9-943c-1a8140972e4b&algo_expid=27a95d58-360c-4aa9-943c-1a8140972e4b-43&btsid=0b0a557016094939405453680e2d15&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

Use a regulated 5V supply, and take the voltage between VCC (or GND, but VCC works better for me) and 200V as the bias (credit to Sajeev Ranasinghe (Nectar)).

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13 hours ago, catscratch said:

So I went ahead and modded my L700 mk1. I'm generally pretty skeptical of Lambda mods, but my yoke broke on the left side and I fixed it with duck tape and a coat hanger, and mysteriously my coat hanger solution ended up being far more comfortable than the stock setup. So I got to wondering if there was a way to custom-make a better yoke, and lo and behold, someone else has already done it.

These are 3d printed by Socas and they work pretty well. They allow for a wider range of motion for the earcup and they fix the problem of having too much pressure at the top of the earpad and not enough at the bottom. So if you're one of the people who, like me, can't wear the current generation Lambdas properly, this is a solution. You will need a Torx 6 screwdriver to get the screw out that holds the yoke in place, and after that it's an easy swap.

This does affect the sonics a bit. In the past I always read accounts of people hearing the L700 as overly warm and a bit congested and wondered what on earth they were hearing, but how... that's kinda how it sounds. The frequency response gets rotated clockwise, the highs are much smoother and more palatable, but the midrange shout and upper mid dip gets even more noticeable.

The solution of course is EQ. I'm not gonna post all of my settings since you really need to personalize your own EQ but -5db at 1150hz q1.41 and +2db 3khz q0.5 evens out the mids, then you also need to drop the peaks in the highs - which we all hear in different places - and adjust the lows to taste.

I have a MiniDSP ears now and will probably be able to EQ more accurately, but I thought I'd give a heads up to @yaluen and others who are in the same boat that there is a fix, and you don't need to write the current-gen Lambdas off (though I don't know if this works for the L300/500). This thing sounds very smooth and natural now, with great imaging and clarity but a bit lackluster impact in the lows, which I'm sure a more powerful amp than my 717 will fix.

Oh, and the Mk2? My opinion of it has turned pretty sharply downwards. I prefer my modded mk1 by a good margin.

L700_work.jpg

Nice! Have you tried the blu-tak mod? It gives the L700 MK1 much better bass impact.

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3 hours ago, Tachikoma said:

Just buy this instead, much safer than working with mains.

https://www.aliexpress.com/item/1005001813099933.html?spm=a2g0o.productlist.0.0.41dab88epLfUCK&algo_pvid=27a95d58-360c-4aa9-943c-1a8140972e4b&algo_expid=27a95d58-360c-4aa9-943c-1a8140972e4b-43&btsid=0b0a557016094939405453680e2d15&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

Use a regulated 5V supply, and take the voltage between VCC (or GND, but VCC works better for me) and 200V as the bias (credit to Sajeev Ranasinghe (Nectar)).

Those things are terrible, do not use them for a bias supply.  They are noisy beyond belief. 

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15 hours ago, Zoide said:

Nice! Have you tried the blu-tak mod? It gives the L700 MK1 much better bass impact.

No, or at least not yet. Hesitant to try more invasive mods. Haven't even port modded my 007 mk2 yet, though I probably will do that soon.

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On 1/1/2021 at 8:48 PM, spritzer said:

Those things are terrible, do not use them for a bias supply.  They are noisy beyond belief. 

Actually, if you adjust the voltage between GND and VCC to 800V or higher (the voltage between 200V and VCC/GND is around 500V at this point), the noise shifts beyond the human hearing range. Otherwise yes, they're really noisy. I'm using one for my transformer box - I can't hear any electrical or physical noise in its current configuration.

Edited by Tachikoma
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Howdy all, I was recently gifted an SR-30 and SR-30 Pro by a relative who had kept them in a box since 2008. I'm not an audiophile by any means, or knowledgeable about audio technology beyond "3.5mm jack goes in 3.5mm hole", but I'm making an effort to get these working again and maybe learn something new in the process. Is there anything I should know about these cans before I try them out? I'd like to treat them properly since they're over twice my age.

I should mention, I've got two SRD-4 Adapters for them and was also given a Pioneer SX-434 which I've plugged into my desktop through a 3.5mm to RCA splitter. I'm a bit frightened of the SRD-4s, as they terminate in open wires with bare metal. 

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