[TYATYA]

That is quite high on the volume pot, I need to use 11 or 12'clock on my 353X with the RR 1. I am using balanced xlr inputs, haven't really tried rca interconnects yet.

Output voltage of 353x is 400 while 007tA just 340V.
I use dual xlr too. Input voltage about 2.5V. My dap can give 4V but I prefer 2.5V

 

[PolloLoco]

Around May I bought a pair of Kaldas RR1 conquests that had squealing issues. On another forum, I'd read an account from a member who opened his early model up - to fix wiring that caused one side to cut out. So I figured I'd try the same. Aumkar's generous warranty replaced the squealing drivers - allowing the previous owner to keep the squealing bespoke drivers.

To make a long story short - I cleaned them out twice and rewired them, adding cables from Spritzer and my own Jerry Rigged Hifiman headband. That's why mine will look like Frankenstein RR1's in the pictures below. I contacted Aumkar with suggestions to improve the wiring and squealing issues on his product - and he informed me that all of the issues we discussed had already been addressed with manufacturing improvements. So if you buy one now - you can be confident in getting a reliable quality product, backed up by a solid warranty.

I realized early that I loved the sound of these, and it seemed that a lot of my squealing issues kicked off by my ears touching the stators. So I had Vesper Audio make me some custom pads by tracing the cups. I had them made out of leather, angled from 15mm to 20mm at the back (edited). I also increased the width of the pads from 10mm to 20mm (edited). I aimed to maximize the width without blocking the drivers. Peering through the vesper mesh screen - I might have blocked the drivers ever so slightly. The adhesive, which was a bit of a pain to install on headphone flaps - doesn't fit as deep as the custom Kaldas recessed fit. But overall - the pads look and fit great, with a solid seal.

Note: When I first wrote up this post, I thought I'd ordered 10mm to 15mm angled. In fact, what I got was 15mm to 20mm angled front to back.

I'll post my pictures below in case someone is interested in the same. Mine cost about $75 shipped. Changes in sound were subtle - but for me, comfort improvement was huge. I don't have to worry about moving these around at all, even while playing. Where before I'd got something like a rattling stax fart if I accidentally tapped them, or put them on too abruptly while charged. I've heard the original headband was firm - and that might be a problem with the additional thickness I added.

 

[PolloLoco]

I'd like to add some of my impressions on the sound. And there's no doubt - overall I love these. My entry into electrostats were a pair of Koss ESP95X, where I upgraded to Vesper angled pads, and a Stax SRM 717 amp. The 717 at a 450 volt swing is tied for Stax's most powerful amp.

I've recently learned the importance of direct back to back comparisons. Listening to the Koss one day, and the Kaldas on separate days - I thought the Koss might have an edge on detail, with better treble and soundstage. With the Kaldas RR1 having obviously better bass, and equivalent mids tonality. By doing a direct comparison - I realized my impressions were wrong.

One weekend I hooked both of them up to the SRM 717 and shuffled through my audio collection for about 4 hours. Swapping mid song as needed for comparisons. It became brutally obvious that the Kaldas RR1 sounded better in just about every factor except for treble and soundstage. The Koss are more comfortable, I regularly forget I'm wearing them - but remember that my RR1 are Frankensteins.

The biggest difference is an extra level of detail and impact. Even though the Koss had become my new standard for clarity, speed and detail - the RR1 made them feel like they had the slightest bit of veil. I think that helps the Koss sound ethereal, as opposed to truly analytical. Spritzer compared them and thought the Koss sounded "softer" - but I like my veiled, ethereal description more.

Bass quality and quantity goes to the RR1. Mids go to the RR1 because of that additional bit of detail and clarity, with thick warm notes. The Koss definitely have more treble energy. The Koss have a larger soundstage - though it's not huge.

Again - I have to caution that I'm going by memory and it's going to be inaccurate, but I also sold my Stax L300 with L500 pads in favor of the Koss. I feel like the Kaldas RR1 would be a decent improvement in everything but treble - but the L300's had shouty, peaky treble. The RR1 is a much darker, more pleasant and musical listen.

Overall - I think these are fantastic headphones and subjectively better than comparably priced electrostats. I told Aumkar that I hope to see an RR2 in the future.

 

[XNumbers]

They look great! I'll have to cop a pair of those pads too.

 

[PolloLoco]

In July I added a used pair of Stax SR L700 stats to my collection, bought from a fellow head fi'er. Again - based on using one headphone exclusively each day - I came to the following conclusion. I felt the Stax were superior technically, but because of a more pleasant tonality - I liked the Kaldas RR1 just as much. Which on it's own, is amazing to say - since the Stax retail for $1500 new, and the Kaldas start at $500 new. That said, I realized after a direct head to head comparison - my first impression was wrong.

I did the same thing - shuffled through my collection for about 3 hours yesterday, swapping when a different type of music came up - or if I was really impressed with one or the other headphone. Since both were connected to my Stax SRM 717 at the same time, swaps were quick - I'd only have to adjust for volume. The Kaldas RR1 are much harder to drive at a decent volume. I used the internal switch on the SRM 717 to set it as a power amp, no volume control - and the preamp on my DAC needed to be at 29 out of 40 for the RR1. Comparatively, the volume needed to drive the Stax was 24 out of 40.

Treble - No contest. The Kaldas RR1 rolls off pleasantly. It's a much darker presentation. The Stax extends as far as my 42 year old ears can hear - and unlike my old L300 it's not peaky or shouty. I thought I would prefer the darker presentation of the Kaldas RR1. But switching on certain songs from First Aid Kit, Loreena McKennit, or the random classical track - it became clear that the music came alive with the Stax. The highs on those songs really needed the air the L700 provided. The music was exciting without being fatiguing. On a complex track like "Sweetness Follows" by REM, the mesmerizing bass of the RR1 makes the song sound 9 out of 10 exciting, but the L700 treble balance adds that last bit of excitement that puts them over the top.

Mids - Close, but the Stax L700 wins on detail by the smallest amount. The Kaldas RR1 soundstage is more intimate, but I pick up the slightest bit of more microdetail on voices with the Stax. On tracks with a lot of bass, the mids can take a small step back on the Kaldas RR1 by comparison. I found this on the random track "Even Though" by Sugar Ray.

Bass - Kaldas wins on quantity, Stax wins on layering and detail. I can make out individual percussion instruments better. I have not performed the blu tack mod on my Stax. I've never felt that I needed more bass than the L700's currently provide.

Soundstage - Kaldas RR1 is more intimate, L700 is larger, but not huge. I feel neither is subjectively better - for me it's a personal preference depending on how I'm feeling.

Comfort - My Frankenstein Kaldas RR1 win. If I have a complaint - it's the plastic assembly of the L700 housing, which like my L300's creaks when I move too much. I also have problems getting a good seal behind my ears with the L700. Where the seal from the RR1 Vesper pads is top notch.

Overall - comparitively, the RR1 is a much darker headphone. By comparison it's mellower and easier to listen to for long periods of time. But if you don't find it distracting, the L700 is more neutrally exciting, providing all the detail that you might not need. I was surprised to find out that I enjoy the L700 more than the RR1 after a head to head listen, which is not a knock on the RR1. The only songs I found where I definitely preferred the RR1 were overly complex tracks from Led Zeppelin where the cymbals and high frequency energy could be confusing or distracting.

For the Kaldas, I'd seen one bad video review from Max Settings which gets quoted on Reddit. I think most of his complaints, like channel imbalance might have been due to the manufacturing issues found in the early models. I wouldn't be surprised if the Kaldas RR1's he was sent had frayed internal wiring. I believe the review would have been quite different if he were sent one of the current versions.

While I was surprised to find that I enjoyed the L700 more than the RR1 - I really shouldn't be. The price difference is 3X. I still think the Conquest is an outstanding value at it's price. I've often read (I can't judge the accuracy) the Kaldas RR1 described as a mini Stax SR007, and the L700 as a mini Stax SR009. If true, I'd love to see a Kaldas RR2 tuned more like the SR009.

 

[talan7]

Kaldas should make an RR2 with a little more treble energy, details, and soundstage. Price it $200-$300 more, and sell it alongside the RR1. I would upgrade. I love my RR1 that much. I just got mine so I’m assuming most if not all manufacturing issues are resolved. Sometimes, when I first start them, the right side sounds ever so louder, but that goes away in a few minutes.

 

[Krassi]

Hi!
I am using my RR1 daily again after storing it a while in a closet with stax plastic cover always on.
I am using a SRM-t1 japanese 100volt modell with NOS toshiba tubes.

My problem is that if i turn the volume 100%-70% the bass starts to sound very bloated.
This is no problem with Jazz music but any techhouse and bass intensive music sounds really bad on high volume.

i use a khadas tone board thats running on 100% from windows.
If i turn it all very low its not loud enough.

i dondt have channel imbalance but i dondt have that praised great bass for a estat.
What could be the problem? because with higher volume it is very music depend.

 

[MrTechAgent]

Sounds like you're clipping out, especially given the range of the potentiometer.

It comes down to relative SPL preference of the listener but also down to the track. With complex passages containing a lot of LF information, Electrostatic drivers will clip out without proper supply to the Stators at high SPLs.

You may want to consider something SS like the Octave from Mjolnir Audio or the KGSSHV.

 

[Krassi]

Thanks for the fast Answer!
That makes sense!
i dondt have that mountain of cash to spend so i could first fully upgrade my srm-t1 by firschi.

Edit:
-6db mastervolume on the khadas tone board dac did the trick.
The dac did this clipping

 

[gikigill]

Just joined the club and initial impression is that the sound probably rates as high as my Focal Clear/Elear.

The detail in the treble and the transient response is just pure e-stat.

Running them off a Bifrost MB and ifi Micro Black Label powered by a 252 and the ifi seems to give them an added kick while the Bifrost is a bit laidback.

Now a $1000 RR2 which rivals a SR007 mk2/3 in its low end would push me over to invest in a KGSSHV.

 

[PolloLoco]

I just posted this on the Koss ESP950 thread. This weekend, for fun I made a Stax to Koss adapter, so that I could use my Stax terminated headphones with the Koss E90 amp. I've attached the picture below.

A friend had used the female end of my Koss extension to make me a Koss-to-Stax adapter. I saved the male end, and this adapter was a lot easier to make. I used Spritzer's advice and added a 4M7 resistor to the bias line - but otherwise, the female socket I was able to find online was much easier to solder to than the common male plugs. Without the resistor, I believe the problem is that Stax headphones are more likely to arc, thereby damaging your diaphragms.

The Stax cable I bought from Spritzer for the Kaldas RR1 fit flush as shown in the image. The pins on my Kaldas RR1 cable are longer and end up being exposed. In any case, both cables work just fine. I may add a cylinder or backshell to make sure pins aren't exposed in any case.

This might be useful for people wanting to dip their toes in the Stax or Kaldas headphones, without having to invest in an amp right away. The E90 did a decent job of driving my Kaldas RR1. The signature was brighter than I expected, and I used a tone generator to see if the E90 gave me more extension on the high end. It did not - I could hear a slightly lower max frequency with the E90 than with my SRM 717 (14.5KHz vs 15KHz). But the overall tonality was brighter, driving the Kaldas closer to neutral. The bass was still great, far better than my Koss ESP95X - but nowhere near as good as with my Stax SRM 717 amp.

The Stax SRM 717 provides better soundstage, a little more clarity, and deeper bass. Would I use the E90 as my primary amp? No. Would I use it at work as a secondary amp? Absolutely, if I'm eventually allowed to return to the office after this crisis.

 

[JLoud]

Thinking of selling my RR1's. These are the deluxe version with the longer cable and display box. If anyone is interested PM me.

 

[Hubert481]

Also selling my RR1 - longer cable - normal box - only selling in EU - just PM me if interested - located in austria

 

[talan7]

After some time with the RR1’s, I would like to see better bass extension in a RR2. The bass, which is very good and has good quantity, could use more extension. On songs with deep synth bass, the subass is pretty low. I’d like more rumble. So a RR2 with better extension top and bottom and bigger soundstage is what I’d want.

 

[MrTechAgent]

Hello @talan7 ,

Appreciate your inputs and everyone else above as well who have mentioned the so called "RR2".
I just wanted clear some confusion, there won't be an “RR2”. That's for many reasons -

1) Constant consumerism - I don't make Headphones for a living, I am lucky enough to be in a position to have multiple businesses which prevent me from being pressured like other Manufacturers to constantly launch new products for quick sales. I don't care about sales. My job is to optimise Manufacturing and Quality, not launch new products quickly. That is just never going to happen under my watch. Of course, there will be future products but the RR1 was always made to be a standalone product with no successors.

2) Product Value

New products tank the value of old Headphones and make them essentially worthless all while also damaging the Brand's value.
Furthermore, I am also against the concept of discounting. No product will ever be discounted under my watch. Discounting is a disrespect to the customers who have paid full price and also show's a Company's perception towards their own product.

So, for these reasons and many reasons I might have forgotten, there will not be an “RR2”. I always urge people to buy from other brands where they don't find similar limitations.
I have been a Headphone enthusiast for over 9 years and have owned some of the most important Headphones ever Manufactured, I personally think this industry needs more quality than quantity.