[JimL11]

You got me curious, so I took a look. I think you're right this is the CCS mod. (I've attached a pic so if I'm wrong please do correct me.) Sorry for the confusion.

Yes, that is clearly the CCS mod. If you compare your picture with the stock internals in my previous post, you can see where the 8 plate resistors in the stock amp have been removed, to be replaced by four CC loads.

The good thing about that is it more than doubles the effective power of the 6CG7/6FQ7 tubes compared to the stock amp, giving it the same amount of voltage swing as the Stax solid state amps (the stock 006 amp, it is rated at 340VRMS vs 450VRMS for the solid state amps). It is still a bit less current drive than the solid state amps, but enough to effectively drive the SR007, as you have found.

 

[jsts]

Thank you so much for your help and guidance. I'm slowly drawing a circuit right now and I'm planning the parts. Then I'll be sure to let you know and show you pictures of what I can do.

Sketch of the CCS-mode board for the SRM-600. Moving forward little by little Mr. Gilmore, mr. Lin, thank you!

 

[Eich1eeF]

Sketch of the CCS-mode board for the SRM-600. Moving forward little by little Mr. Gilmore, mr. Lin, thank you!

Do I see that correctly that you are going to mount the CCS board by extending the screws already present in the vinicinity of the load resistors? That's a really nice solution.

 

[jsts]

Do I see that correctly that you are going to mount the CCS board by extending the screws already present in the vinicinity of the load resistors? That's a really nice solution.

Yes exactly. It seemed to me that this would be the right decision. Upon completion, I will definitely tell about the process and lay out the photos.

 

[Tugbars]

Okay, so I decided to take metal springs off from my 007.(mk 2.9) I don't know why but bass seems to have a little bit less presence after the changes, however the recession in 2-4khz region is no more. I actually am not sure if i want to keep it because 007's sound signature became closer to 009 right now. I can hear more micro detail but the thick bass and textured mids of 007 is no more. I'll use them without metal springs for a week and maybe I'll revert the changes.I could never think that bringing my ears closer to driver would bring such huge difference.
(tests have been done with KGSSHV Carbon + Soekris 1541)

 

[scottcw]

If I like the sound of Audeze LCD-2.1 and 2.2, will I love the SR-007? Not looking to spend anymore money, but my curiosity is piqued and I have a lot of listening time on my hands during shelter.

If the answer is yes, which version of the SR-007 should I look for? I've seen comment that the first version is best, the 71xxx versions are best, and the MKII are best. They can't all be best, can they?

 

[astrostar59]

If I like the sound of Audeze LCD-2.1 and 2.2, will I love the SR-007? Not looking to spend anymore money, but my curiosity is piqued and I have a lot of listening time on my hands during shelter.

If the answer is yes, which version of the SR-007 should I look for? I've seen comment that the first version is best, the 71xxx versions are best, and the MKII are best. They can't all be best, can they?

I had the 007 MK1, the 007 MK2 and the 007 Mk2.5 (2018 edition). Avoid the MK2 it is not good. But you have to build in the cost of an decent amp for the 007 as it is a hungry HP. And non of the current STax amps do it well IMO. You need a DIY KGSShv at least.

My view if look at the Focal Utopia or better, the Daina V2. That will give you superb mids and details, no fatigue and solid presentation. The 007 is slow in comparison, good in it's day, but things have moved on IMO.

 

[scottcw]

My view if look at the Focal Utopia or better, the Daina V2. That will give you superb mids and details, no fatigue and solid presentation. The 007 is slow in comparison, good in it's day, but things have moved on IMO.

Thanks, but the Focal is not an option. I'm interested in an electrostatic, otherwise I will stick w my Audeze.

 

[Tugbars]

SR007 and LCD4 are often compared to each other. https://www.innerfidelity.com/content/katzs-corner-episode-18-icelandic-wonder-page-2 Here is a nice comparison of both.
I think electrostatic treble performance is superior to any other tech out there.(which is subjectively the most important thing for me in sound presentation) So I have preferred SR007 over LCD4.

 

[astrostar59]

Yes electrostics are known for speed. But planar have caught up. And the soundstage on the LCD4 is better than the 007, possibly the angled cups, not sure. But sounds more convincing to my ears.
007 has an odd sound for a stat, like it is trying to be unstat like somehow. Anyone else notice this aspect? The 007 is an attempt at real world bass for a stat, but in doing that slows things down and sounds more closed in.
If we have the amp budget factored into driving an 007 to decent sound quality level, it becomes uncompetitive in recent years, been surpassed. YMMV. But you need a top amp to get the 007 to shine.

 

[Tugbars]

Perforated areas on 007 stators have very small openings and the area is surrounded with a thick ring.This design is like a doubled edged sword, because it's a not a completely open design(definitely less open than mesh stator designs) soundstage is compromised. However, thanks to this design 007 is acoustically very well damped and this becomes obvious with it's fantastic treble performance and bass performance. All these design aspects of 007 makes it absurdly hard to drive. I think without having a powerful speaker amp & trafo or KGSSHV Carbon, 007 isn't worth to invest in.

007 isn't the fastest headphones out there(not very far from the fastest though), however 007 stops better than probably all other electrostatic headphones. This results as top imaging & layering. (in a limited area though).

 

[Tacanacy]

What would you recommend for SR-007 Mk1 (and HE60), KGSS Klassik or KGSSHV?
I haven't heard these headphones before and I don't already own any estat amps to test the headphones with when they arrive. The only characteristic that I know I don't want in the amp is dry timbre.

 

[number1sixerfan]

The 007 (MK1 experience only here) are definitely unlike many of the stats.. but in good ways IMO. The 009's transparency/speed/detail is amazing to take in, but the 007 is an excellent contrast to it, being more musical, less fatiguing and with better bass presence and impact. Driving it properly is insanely hard and I probably wouldn't have it as my only headphone due to that reason alone ($$).. but if you already have a TOTL stat amp it's certainly worth owning to compliment a 009, HE60, L700 etc.

 

[joseph69]

Okay, so I decided to take metal springs off from my 007.

You didn't mention anything about the port mod, so I assume you didn't do it while you were in there. If so, why not?
It would've been just as easy to revere the port mod as it would to put your metal springs back in if you don't like either.

 

[dripf]

The 007 is more sensitive than other models according to its specs. On another forum, the 007 was level matched across different amps to a quite high 105 dB. There was no difference in frequency response between 252s and 717. It's time for big amp proponents to explain the value, and in clearer terms than "controls the driver with more authority".