[gibosi]

  The Chatham 6520, with 6AS7G style plates, both look and sound exactly like the Chatham 6AS7G. I have both and the only difference I can find is the writing on the tube base. I have seen 6520's with 6AS7G plates and top mounted getter but never tried those. Not sure about the 6520's with the 5998 style domino plates though, never tried those either.

 
For reasons we do not understand, the 6520 label was applied to both 6AS7 and 5998. Typically, the 4-digit number designation (6520) is the premium industrial version of the standard tube (6AS7). For example, 5654 and 6AK5. So the 6520 should be nothing more than the premium version of the 6AS7. Why this label was sometimes applied to 5998 is unknown, but perhaps in some industrial applications, the 5998 and 6520 were considered interchangeable.
 
I have the tube below, 5998 plates, steel grid posts and rectangular getters, but no date. I am guessing late 1950's. Likely because of the 6520 label, I managed to get it for a very reasonable price. I have it matched with a 5998 manufactured in 1957. Same construction and same sound.
 

 

[agnostic1er]

Thanks for the congrats about my order Lord Raven... but congrats should certainly go to the Feliks team and all the head-fi guys who initiated this project, rather than to me

Renderman, no specifics on the Sylvanias at the moment, Lukasz chose them following my wishes about the hoped synergy with the HD800.
You headfiers know this headphone needs an amp able to push a little the sub-bass area, tame the treble peek and add some flesh to the music/voices. That's what I said to Lukasz. BTW I ended with a light anaxilus mod on my HD800, taming the 6kHz without rolling off the top frequencies; not an easy task, I tested about 10 materials/combos, studiying Tylls discoveries... This present mod will stay on as it gives me what I wanted.
I'm not a tube roller addict (at the moment, lol) but why not after some times, so thanks for all the infos you are sharing.
As previously said I'll post my feelings after burn-in, so probably in september. See you later guys. Have a nice summer time!

 

 

[nephilim]

Update from the noise front: I brought my Elise to the garden shed and tried the socket there. It is directly connected with the distribution box and the least polluted spot on the property. While it became apparent how noisy it is outside I had a hard time to recognize the constant hum which has been bothering me for the past weeks. I would say the constant hum was gone by 95%. Of course if I crank up volume I get a hum, but that constant noise even at zero volume seemed to be mostly gone. So the issue is hidden somewhere in the house. I switched WiFi off - without effect. But as the hum is very close to 50Hz I guess it's rather the fridge or some other device which is less important for daily life than the Elise )
 
That was the good news.
 
What I just noticed again is that when I switch on the Elise with the headphones connected, the drivers (in the phones) seem to in/exhale once after approx. 20s. It's a very awkward sliding sound. I remember to have followed a discussion about the Schiit Lyr and that it sent DC to the phones while powering up or down (somebody even made a video of the driver membrane doing funny things). What I hear reminds me of this discussion. Have you noticed something similar? Do you always disconnect your headphones?

 

[Anathema123]

What I just noticed again is that when I switch on the Elise with the headphones connected, the drivers (in the phones) seem to in/exhale once after approx. 20s. It's a very awkward sliding sound. I remember to have followed a discussion about the Schiit Lyr and that it sent DC to the phones while powering up or down (somebody even made a video of the driver membrane doing funny things). What I hear reminds me of this discussion. Have you noticed something similar? Do you always disconnect your headphones?

 
General rule of thumb would be:
 
0. Unplugged headphones
1. Turn on amp, volume set to 0
2. Wait for it to warm up
3. Plug in headphones
4. Turn up the volume
5. Rejoice!
 
Same thing when turning it off: volume to 0, unplug headphones, turn off amp.

 

[Renderman]

  Update from the noise front: I brought my Elise to the garden shed and tried the socket there. It is directly connected with the distribution box and the least polluted spot on the property. While it became apparent how noisy it is outside I had a hard time to recognize the constant hum which has been bothering me for the past weeks. I would say the constant hum was gone by 95%. Of course if I crank up volume I get a hum, but that constant noise even at zero volume seemed to be mostly gone. So the issue is hidden somewhere in the house. I switched WiFi off - without effect. But as the hum is very close to 50Hz I guess it's rather the fridge or some other device which is less important for daily life than the Elise )
 
That was the good news.
 
What I just noticed again is that when I switch on the Elise with the headphones connected, the drivers (in the phones) seem to in/exhale once after approx. 20s. It's a very awkward sliding sound. I remember to have followed a discussion about the Schiit Lyr and that it sent DC to the phones while powering up or down (somebody even made a video of the driver membrane doing funny things). HWhat I hear reminds me of this discussion. Have you noticed something similar? Do you always disconnect your headphones?

Hi Nephilim, your symptoms (both the hum and strange sounds turning off the amp) sound very similar to mine. I tried just about everything I could think of including some high-end mains filtering. Here is what I did that finally fixed both problems at once:
 
1. Turn of the Elise
2. Unplug the power cord and wait for all the energy to dissipate from the capacitors (I would err on the side of caution and wait an hour)
3. Remove all the tubes
4. Look closely inside the holes in the sockets where the tube pins go
5. There are small metal flaps to be seen on either side of the pin hole, use precision tweezers to bend the flaps inward,
    about 0.5 to 1mm on either side. Be careful not to bend them too far as it might weaken or break the flaps off.
6. Clean the flaps for best contact with the tube pins (I used deoxidizer and cleaning alcohol)
7. Replace the tubes and enjoy the Elise
 
After this rather simple procedure my sound improved dramatically! Hum, even without mains filtering was reduced at least 10 fold to a level that was hardly even audible. The strange crackling noise (from my headphones) when turning off the Elise was also gone.
 
In the end it seems it was just a bad connection between one or more tube pins and the socket. I really hope this provides you quick and easy relief and you don't need to spend lots of time searching for a solution. I know how frustrating it can be.
 
I wish you good luck fixing your Elise!

 

[hypnos1]

  Update from the noise front: I brought my Elise to the garden shed and tried the socket there. It is directly connected with the distribution box and the least polluted spot on the property. While it became apparent how noisy it is outside I had a hard time to recognize the constant hum which has been bothering me for the past weeks. I would say the constant hum was gone by 95%. Of course if I crank up volume I get a hum, but that constant noise even at zero volume seemed to be mostly gone. So the issue is hidden somewhere in the house. I switched WiFi off - without effect. But as the hum is very close to 50Hz I guess it's rather the fridge or some other device which is less important for daily life than the Elise )
 
That was the good news.
 
What I just noticed again is that when I switch on the Elise with the headphones connected, the drivers (in the phones) seem to in/exhale once after approx. 20s. It's a very awkward sliding sound. I remember to have followed a discussion about the Schiit Lyr and that it sent DC to the phones while powering up or down (somebody even made a video of the driver membrane doing funny things). What I hear reminds me of this discussion. Have you noticed something similar? Do you always disconnect your headphones?

 
Hi n.
 
That's great news re the hum...at least shows there should be a remedy somewhere!
 
Yes, 'fridges/heat circulating pumps/air-con etc etc can all be possible culprits - it shouldn't be too difficult to track down - hopefully!
 
And perhaps you might be suffering slightly from Renderman's problem, although as you haven't done much rolling yet I would hope this isn't yet the case, lol! (but certainly something to possibly look out for in the future...and as R says, if it is ever necessary to tweak those pin receptors in the amp's sockets don't be over-zealous with the tweezers!!).
 
Whatever, I do hope all is sorted very soon, so that there is nothing to spoil MAXIMUM enjoyment from your set-up...

 

[Lord Raven]

Where does all the air come from in my music?

 

[Renderman]

   
Hi n.
 
That's great news re the hum...at least shows there should be a remedy somewhere!
 
Yes, 'fridges/heat circulating pumps/air-con etc etc can all be possible culprits - it shouldn't be too difficult to track down - hopefully!
 
And perhaps you might be suffering slightly from Renderman's problem, although as you haven't done much rolling yet I would hope this isn't yet the case, lol! (but certainly something to possibly look out for in the future...and as R says, if it is ever necessary to tweak those pin receptors in the amp's sockets don't be over-zealous with the tweezers!!).
 
Whatever, I do hope all is sorted very soon, so that there is nothing to spoil MAXIMUM enjoyment from your set-up...

In my case it was not an effect of tube rolling mind you, this is a problem I had with the Elise ever since I got it.

 

[nephilim]

Thanks for all the good advice! I will get some Deoxit (cannot hurt) and try to track down the polluting element in the house. It seems that I will be able to get some nice c3g-s, too. Life is good. And even better with the Elise.

 

[nephilim]

Oh, btw... I just read that the spacer ring between the C3g's glass and canister is made of asbestos. So please be careful when wiping off the asbestos particles which (at least in my case) stick to the glass surface. Of course the amount is small but you never know )

 

[hypnos1]

  In my case it was not an effect of tube rolling mind you, this is a problem I had with the Elise ever since I got it.

Yo, R...you were indeed very unlucky...but am glad all is now well. At least your unfortunate experience has highlighted something that enlightens all of us, along with a very useful method of remedying if necessary...
 

  Oh, btw... I just read that the spacer ring between the C3g's glass and canister is made of asbestos. So please be careful when wiping off the asbestos particles which (at least in my case) stick to the glass surface. Of course the amount is small but you never know )

 
Good point n...can't be too careful with that stuff, lol!
 
ps. Life will get even better yet, I promise...I still can't believe the improvement in the Elise even beyond the 100+ hours (especially with the C3gs!...will be very interested in your findings if you do indeed get those 'S's...). I will also be interested to hear whether you ever experience the (debatable!) phenomenon I mentioned some while back - viz a noticeable leap in performance in a session compared to the previous one - and one that is not obviously down to different states of ears/mind/environmental factors/time of day etc. etc. (I stick by my belief, regardless!!

).

 

[CITIZENLIN]

  Hi guys,
 
Just received a mail from Lukasz 

 
"Good news, your Elise has just been finished and is being tested. Should everything be ok we will ship early next week (Monday/Tuesday).I tried a few tubes and decided to give you a pair of nice Sylvanias, i do hope you'll like it!"
 
Hope the heat wave we suffer from since 3 weeks here in France will stop in the next days, not a weather to listen to my HD800/Elise combo

Congrats!!!That's a great news. I am still waiting for email from Lukasz . I believe I put my order in before you. So should be any day now.  Cant wait to try Tung Sol 7236 and C3gs combo.

 

[agnostic1er]

  Congrats!!!That's a great news. I am still waiting for email from Lukasz . I believe I put my order in before you. So should be any day now.  Cant wait to try Tung Sol 7236 and C3gs combo.

I put mine 2015 06 02 but perhaps did Lukasz take it in account only at the time my returned Espressivo arrived safefully in Poland (2015 06 13)?...

 

[Shaffer]

I put mine 2015 06 02 but perhaps did Lukasz take it in account only at the time my returned Espressivo arrived safefully in Poland (2015 06 13)?...

That would make sense.

 

[CITIZENLIN]

  I put mine 2015 06 02 but perhaps did Lukasz take it in account only at the time my returned Espressivo arrived safefully in Poland (2015 06 13)?..

Hi agnostic
 
 
My bad,....Your order was before mine. I put my order on June 16th.  

 I got a good news too. I just got msg from Colin said C3gs adapters are tested and ready.