[Mach3]

I have an slightly off-topic question to you, Do STAX 009BK also sound different(in a better way) to you than 009S as well. That was my experience and I'm curious if it just me who thinks like that? If you've listened to 009S, let me know.

Pretty sure I have had other member ask me the same question.
I do prefer the BK over the S. It's not the earpads that make it sound different to the non S or S.
I've already confirm this with Spritzer, his finding was exactly like mine.
Main reason I prefer the BK over the S is because the wider soundstage, detail and sparkle similar to the non S.
It's subjective from person to person, as I seen comments from other that still prefer the S the most.
But all the people I know that listen to all 3 agree the non S is the weakest of the 3 in overrall sound presentation.

 

[number1sixerfan]

Pretty sure I have had other member ask me the same question.
I do prefer the BK over the S. It's not the earpads that make it sound different to the non S or S.
I've already confirm this with Spritzer, his finding was exactly like mine.
Main reason I prefer the BK over the S is because the wider soundstage, detail and sparkle similar to the non S.
It's subjective from person to person, as I seen comments from other that still prefer the S the most.
But all the people I know that listen to all 3 agree the non S is the weakest of the 3 in overrall sound presentation.

As far as the 009 (non-S) being the weakest link of the 3, any further thoughts as to why? I have it and I love a lot about it. Top tier for sure, one of the best.. but there's something a bit weird with the tonality of it I can't put my finger on and just a bit lacking in bass/bass impact. I don't want to give up any of the soundstaging, detail or imaging though. Had a chance to grab the 009s, but I wanted to start with the base 009.. intend to have one of the variants long term, just want to make sure it's the right one.

 

[jsts]

JimL11, you are as always great Thank you for the clarification. It's just that I am considering modifying my SRM-600 and I am afraid of losing the "valve" sound.

@JimL11, I rely on your help. Regarding the CCS-mod for the SRM-600.

I set out to achieve maximum aesthetics when implementing this mod. The money is not worth it, the question is to make everything as beautiful as possible. That is, for example, to abandon the use of a white ceramic insulator for the IXCP10M90S MOSFET by replacing with a ISOPLUS version technology that does not require additional insulation. Like this:

Question: Can I use IXTJ4N150 (TO-247) with Electrically Isolated Tab instead of IXCP10M90S (TO-220)?



Heatsink (4 pcs) are planned as follows (30mm X 20mm X 19,2mm):

 

[kevin gilmore]

no you cannot replace with that part. you need a depletion mode part.

 

[JimL11]

The IXTJ4N150 is an N-channel enhancement mode MOSFET, whereas the 10M90S is an N-channel depletion mode MOSFET, so you can't substitute. Also, your heatsinks amount to 16 fins, each fin 17.5x30mm with a total length of 60mm. In my mod I used a heatsink with 19 fins, each fin 20mmx 60mm, with a total length of 120mm. Granted that might have been overkill, but it fit in the same area vacated by the plate resistors, and it is more than three times the surface area of the four small heatsinks you propose. Better too large than too small, as too small at a minimum compromises component life due to excessive heat, and at worst results in instant destruction of the MOSFETs.

To be honest, I don't understand your concern about "aesthetics" over function since the mod is inside the chassis and would be invisible from the outside. You have to use white thermal grease anyway between the MOSFET and the heatsink, which is going to look a bit messy, so what's the big deal about a white ceramic insulator? If the white color bothers you, color it black with a Magic Marker. :-^

 

[kevin gilmore]

no don't color the insulator with magic marker. bad idea. but on the isolated part you could have used the correct size silicone washers.

And the heatsink is a 2.5 watt heatsink. Not big enough.

 

[JimL11]

no don't color the insulator with magic marker. bad idea. but on the isolated part you could have used the correct size silicone washers.bein

And the heatsink is a 2.5 watt heatsink. Not big enough.

Sorry, I was being sarcastic about the Magic Marker.

 

[jsts]

Mr. Gilmore, mr. Lin, thank!

I apologize for my ignorance, I'm not an engineer at all, I just know how to hold a soldering iron in my hands. Hobby.

Bummer, with ISOPLUS technology no depleted mosfet`s are produced... Apparently, I have to look for black insulators and black ceramic/PEEK screws.

Regarding radiators, according to my calculation, one 10M90S dissipates about 1 watt maximum and the radiators I have indicated should be enough. Or am I wrongly calculated?

 

[JimL11]

Mr. Gilmore, mr. Lin, thank!

I apologize for my ignorance, I'm not an engineer at all, I just know how to hold a soldering iron in my hands. Hobby.

Bummer, with ISOPLUS technology no depleted mosfet`s are produced... Apparently, I have to look for black insulators and black ceramic/PEEK screws.

Regarding radiators, according to my calculation, one 10M90S dissipates about 1 watt maximum and the radiators I have indicated should be enough. Or am I wrongly calculated?

No, you are incorrect. What you need to calculate is the amount of power that is actually dissipated by the CCS. The 10M90S data sheet gives the maximum amount of power that a "naked" (i.e. without heatsink) 10M90S can dissipate before it burns up as 1 watt. However in the T1 CCS, the 10M90S is running about 5 mA of current at about 325 volts (assuming that the output is sitting at 0 volts and the B+ is at 325V. The lower MOSFET DN2540 actually only has a couple volts across it which we will ignore) Power dissipation is therefore V times I = .005 x 325 = 1.6 watts. However, if you choose a heatsink that will just accommodate 1.6 watts the circuit will blow up. The usual engineering rule of 3 means you want to choose a heatsink that will at least accommodate 5 watts, and more is better if you have the space. On the SRX Plus board KG specified 42x35x25mm heatsinks (I think Aavid 5328), for my mod I bought a 60x150x25mm heatsink from China for about $10 and cut it down to size. Later I painted it black to improve heat radiation, but even in its raw aluminum form it was fine, and of course once the cover is on you can't see it.

And you apparently have a very different view of esthetics. When I look at the inside of box of electronics I look at how neatly and logically the components have been laid out, how the wiring is arranged, how consistent the soldering is (i.e. no clumps of solder, no dry joints, etc.). I pay no attention at all to whether the colors match, since that is up to the manufacturer. AFAIK, there is nobody that makes black PEEK screws or black insulators. No offense, but focussing on that seems to me a bit like choosing a partner based on their hair color.

 

[jsts]

When calculating the size of the radiator, I used this calculator.

It shows, that the heatsink I proposed can dissipate ~4.4 Watts = that at dissipated power of 10M90S in SRM-600 = 0.006 x 350 = 2.1 Watts = heatsink has reserve ~2 times.

Yeah, it's not a "engineering rule of 3", but... In SRM-600 there is no space from the sides, and the remaining space is a little less than in T1. I wouldn't want to do a very tight assembly and expect to keep at least 1.5cm distance from the original parts and the motherboard.

As far as aesthetics is concerned, I completely agree with you. At the same time, I try to find details and colours that match the original solutions in the amplifier. For example, I see a modification like this (photoshop

 

[jsts]

Or, for example, this Avvid 5811 radiator:

As I can see, at an ambient temperature of 70 degrees(C) and a power of 2.1 watts, the ambient temperature of the MOSFET will be increase to 110 degrees, which fits into the specifications (+150 C) and safe for him. Am I wrong?

 

[526731]

This "aesthetics" thing has potential.
I mean if you're set, or think you're set, but still itching? "Aesthetics", the new frontier.
(never mind what the term actually refers to, which even native speakers seem unable to grasp for some reason)

My techdas is silver but my airtangent is black. Aesthetics.
Cannot abide that, let's waste a 5digit figure and sort that. Aesthetics.
My Wadia is black but the furutech reference silver. Aesthetics.
And so on.

It does have traction..

 

[zeitlos]

Hi guys,

can you help me out? I once owned a STAX L700 (together with the STAX 007II tube amplifier). Sold both and now have a Paltauf Headphone amp (really lovely gear https://www.analog-forum.de/wbboard/index.php?thread/145439-it-s-a-paltauf/) and the STAX 007 Mk2 headphone. Even though I was fascinated with the clearness and also the sound stage of the L700, I somehow wanted to have something maybe not as analytical or more corporal. Hard for me to describe. More laid back, however also more involving if it comes to vocals. Listening to the STAX L700 always was kind of exhausting (even though I didn't notice this while hearing, but when I stopped hearing). So my new combo is basically more the way I want it to. The 007 Mk2 has more bass (even though I wouldn't say the L700 really lacked it, it was okay), nice voice and a fuller sound, which I prefer. However, what I am struggling now since I got it is that everything seems to be a bit distanced. This really is a problem for me.
I really like this combination since I can listen to it for 2 or 3 hours without getting exhausted or fed up. However, it never really gets me. I cannot remember even once rocking with my feet while listening. So I listen to it but it doesn't reach my heart, doesn't make me joyous. And that's not what I was looking for when I invested that much money into my headphone gear...

So is there a way out?
Some people say buy the L300, it goes straight into the ear (which sounds good). However, I fear that I might lose otherwise....
Some say the new L700 Mk2 might now be what you are looking for. Can anyone confirm this? How does it compare to the old L700? How to my 007 Mk2? And maybe how to the L500 Mk2 which is also on my list now.

The 009 is not my league price wise

I really hope that here someone can help me out. I mean, I really do have a fantastic headphone amp, but still it's not the fun I expected when buying it Although for sure both, the headphone amp and the STAX earspeaker basically are fabulous gear.

 

[JimL11]

When calculating the size of the radiator, I used this calculator.



It shows, that the heatsink I proposed can dissipate ~4.4 Watts = that at dissipated power of 10M90S in SRM-600 = 0.006 x 350 = 2.1 Watts = heatsink has reserve ~2 times.

Yeah, it's not a "engineering rule of 3", but... In SRM-600 there is no space from the sides, and the remaining space is a little less than in T1. I wouldn't want to do a very tight assembly and expect to keep at least 1.5cm distance from the original parts and the motherboard.

As far as aesthetics is concerned, I completely agree with you. At the same time, I try to find details and colours that match the original solutions in the amplifier. For example, I see a modification like this (photoshop

Or, for example, this Avvid 5811 radiator:




As I can see, at an ambient temperature of 70 degrees(C) and a power of 2.1 watts, the ambient temperature of the MOSFET will be increase to 110 degrees, which fits into the specifications (+150 C) and safe for him. Am I wrong?

The problem is that those calculations tell you the temperature at the heatsink, but not the temperature at the chip, which is what really matters. Remember that the heat from the chip is transferred to the case, which is transferred to the insulator through the thermal grease, which is transferred from the insulator through more thermal grease, which then reaches the heatsink. At each step, the temperature drops, or, in the reverse direction, the temperature increases. So a "safe" temperature at the heatsink could easily mean the chip vaporizes in a few seconds. Take a look at the size of the Aavid 5328 I mentioned above which Kevin Gilmore specified. That is known to be safe for the SRX Plus, which is 7mA at 350V. I would not use anything significantly smaller to be on the safe side. Of course, I prefer to build something that I am confident will last for years of use, which means being conservative and building in as much extra capacity as I can fit in. I suggest that you fit the largest heatsinks that can fit, not the smallest that the calculations suggest will do the job. And you don't need 1.5 cm from the board to the heatsink, it can be touching the board - which gives you another 1.5cm of height for the heatsink to fit in. If Kevin Gilmore, who is a MUCH more experienced builder than I am, says the heatsinks you chose are too small, I would believe him more than I believe your calculations.

 

[number1sixerfan]

Hi guys,

can you help me out? I once owned a STAX L700 (together with the STAX 007II tube amplifier). Sold both and now have a Paltauf Headphone amp (really lovely gear https://www.analog-forum.de/wbboard/index.php?thread/145439-it-s-a-paltauf/) and the STAX 007 Mk2 headphone. Even though I was fascinated with the clearness and also the sound stage of the L700, I somehow wanted to have something maybe not as analytical or more corporal. Hard for me to describe. More laid back, however also more involving if it comes to vocals. Listening to the STAX L700 always was kind of exhausting (even though I didn't notice this while hearing, but when I stopped hearing). So my new combo is basically more the way I want it to. The 007 Mk2 has more bass (even though I wouldn't say the L700 really lacked it, it was okay), nice voice and a fuller sound, which I prefer. However, what I am struggling now since I got it is that everything seems to be a bit distanced. This really is a problem for me.
I really like this combination since I can listen to it for 2 or 3 hours without getting exhausted or fed up. However, it never really gets me. I cannot remember even once rocking with my feet while listening. So I listen to it but it doesn't reach my heart, doesn't make me joyous. And that's not what I was looking for when I invested that much money into my headphone gear...

So is there a way out?
Some people say buy the L300, it goes straight into the ear (which sounds good). However, I fear that I might lose otherwise....
Some say the new L700 Mk2 might now be what you are looking for. Can anyone confirm this? How does it compare to the old L700? How to my 007 Mk2? And maybe how to the L500 Mk2 which is also on my list now.

The 009 is not my league price wise

I really hope that here someone can help me out. I mean, I really do have a fantastic headphone amp, but still it's not the fun I expected when buying it Although for sure both, the headphone amp and the STAX earspeaker basically are fabulous gear.

In my opinion your best bet would be to own a few different stax models to rotate if you can. There is no perfect stax headphone. Even their top of the line models all have strengths and weaknesses both. Even with the 009, I'm very happy to have the HE60 and MK1 because there are things they do better and as an entire collection it feels almost perfect. But listening to each headphone, I can easily point out where I'd want them to be a bit different or better. This isn't limited to Stax either, this really just applies to the hobby across the board imo.

There isn't a model (at least that I'm aware of) that blends the sound of say the MK2 and the faster and more detailed, brighter models..especially if bass is a priority. I have the L300 and it's a downgrade across the board entirely although a very, very good value for the money. Maybe look at getting the L700 back?