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New Cavalli Audio Liquid Glass Amplifier - Fall Release - Page 40

post #586 of 664
Quote:
Originally Posted by dBel84 View Post

In theory, this should offer them some isolation from each other..dB

Yes putting my audio equipment all on their own circuit breaker on the main power panel will provide some isolation. That would be enough in some cases especially with a light dimmer on another circuit that I have. I then plug in all of my video and audio equipment into a large single double insulated isolation transformer. That way I avoid ground loops and certain types of AC noise on the line.  Any equipment that have motors in them refrigerators, AC, washers and even vacuum cleaners can cause problems with interference in delicate electronic equipment. The motor in a AC unit has to start with a heavy load on it causing a short term brownout due to voltage sag and a inductive “kick back” in the AC lines. http://static-course-assets.s3.amazonaws.com/ITE50ENU/module2/2.1.2.2/2.1.2.2.html

 Over time like a few years delicate electronic equipment on the same circuit can fail. That is one of the reasons that large data centers uses double conversion power systems with batteries that can take the entire floor of a large building.  

Amps like the LG or my Little Dot VI and the Schiit Lyr uses DC servo circuits due to not using output caps in the design. Tube uses high DC voltages and it is the job of DC servo’s to prevent high DC voltage from appearing at the outputs. LG has protection circuits that will sense a failure of the DC servo control due to large power fluctuations or an internal fault.

post #587 of 664

anyone have some tube recommendations for the he-500s?

post #588 of 664
I have been using the apc s20blk with good results. Not sure if you can still find one though.

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post #589 of 664

This amp is pretty damn amazing....can't wait to run with a proper source....just picked it up from Greed and am using the Gungnir as the source DAC and wow......makes the LCD-3/HE-6 sing with my USN CEP Amperex tubes from 1965 6922 e88cc with the large O getters....plate voltage 200v and 6.3 heater voltage......in terms of tube amp I moved from a Schiit Lyr to this......I'm a bit speechless.


Edited by sensui123 - 8/20/13 at 12:51am
post #590 of 664

I was wondering how long that would last on the FS section, you did well by nabbing it :) . It is a everything a totl tube amp is meant to be and you will have many hours of fun rolling out tubes ( or not - but the lure to do so is strong ) . I listen to mine every day and it never ceases to amaze me how the amp voices music depending on the tube being used, without losing any of the detail and dynamics. Keep us posted on how things evolve for you over time..dB

post #591 of 664
Quote:
Originally Posted by sensui123 View Post

This amp is pretty damn amazing....can't wait to run with a proper source....just picked it up from Greed and am using the Gungnir as the source DAC and wow......makes the LCD-3/HE-6 sing with my USN CEP Amperex tubes from 1965 6922 e88cc with the large O getters....plate voltage 200v and 6.3 heater voltage......in terms of tube amp I moved from a Schiit Lyr to this......I'm a bit speechless.

 

John was a pleasure to do business with. Sad to see the LG go, but it was time for a change. Hopefully the Stealth LG will bring John as much joy as it has me. Killer amp, and some very nice people here to help you out. GL

post #592 of 664

Likewise Eric was a true gentleman to deal with, very accommodating despite the late hour pick up.  I thought I was done with tube rolling but I guess the itch is starting back up again with this monster heh.  I'll definitely post more impressions as I get more time to listen.

post #593 of 664
Okay, I've broken it in with the stock tubes -which sound pretty good. I want to try some tube rolling and have some ideas. Can anyone recommend some good tube sources?
post #594 of 664

HF iers frequently sell tubes for reasonable prices on the FS section. There are many trusted tube dealers but if you want some of the more sought after tubes, prices will rise accordingly. ebay is not a bad place to look but you have to be aware that not all deals will be good. 

 

Bear in mind that the amp can roll a huge variety of tubes, so there are many options to try. Both 6.3V heaters and 12.6V heaters - this in itself will help you find tubes which sound great but are perhaps less popular. eg 12SN7 instead of 6SN7, 12AU7, ......

 

some of my personal favourites are the 6FQ7 RCA clear top, the 50's series 12SN7 - Hytron/CBS , the phillips miniwatt 12AU7.  but honestly the choices are fairly endless

 

..dB

post #595 of 664

All, I have an issue right now I'd like some feedback on:

 

Recently I purchased the Liquid Fire from another head fi member before I picked up the Liquid Glass from Greed......I have now put up the Fire for sale and decided to keep the Liquid Glass (for reasons I'm sure most of you would already know).  Thing is, in preparation for the Liquid Fire, I purchased a set of 4 Siemens E88CC platinum tubes from tubemuseum on ebay (he has a web store as well) as that was the recommendation.  Now, here is what happened with these tubes:

 

When they first arrived, there was no damage to the boxes, everything looked great until I opened the package (individual tubes packaged with peanuts per usual packaging).  One of the tubes had lost vacuum and the top metal splatter looked milky white.  I inspected further and found that a crack around the base around the pins.  I immediately contacted tubemuseum and after some picture sending, he has agreed to replace the tube granted I send the tube in.  Of which I mailed off the next day to him.

 

While I was waiting for the replacement tube, I rolled in a pair in the Liquid Glass to see how they sounded.  It started off with some slight hiss/scratch on the left side but I figured it would clear up like some tubes after getting warm, and it seemed to have done it.  Not too bad but I preferred my previous Amperex USP CEN set along with other Mullards I tried instead.  The settings were set on 6.3V heater voltage and 200V plate voltage as recommended on 6922 types of tubes.  I listened to the tubes for 45 minutes in 1 sessions and turned off the amp. 

 

Fast forward a day....I come back to the amp and see that 1 of the tubes had lost vacuum.   I inspected it and it showed the exact same symptoms as the one that was cracked out the box, there was a crack around the base where the pins are.  I messaged Mark @ tubemuseum again and he proceeds to say that there has to be something wrong with the liquid glass and that it was putting up a heatervoltage of higher than 6.3.  And that he doesn't cover abuse and I'm "clearly" abusing his tubes.  Although I have had no problems rolling in other 6922 tubes.....I am no noob when it comes to these tubes as I've acquired a huge collection of 6922 tubes from my Schiit Lyr days.

 

So now I ask you gentleman, do you think the Liquid Glass is defective in that the 6.3 heater voltage is actually not what's being put out?  Maybe Alex can help answer this.  Any thoughts are welcome, now I have to sort out this situation with this ebay seller.


Edited by sensui123 - 8/26/13 at 8:13pm
post #596 of 664

If you have the setting on the heaters set to 6.3V , it will pretty much be 6.3V. You could check by using a multimeter to be sure but if the tubes glow the normal intensity and the amp sounds good, then it would be very difficult for the amp to put any other voltage on the tube heaters. In your message however you mention plate voltage - this is the 200 or 300 volt option. You correctly said earlier that you run these tubes at the 200V setting which effectively places 100V on the plate. If Mark at the tube museum is questioning the operating conditions of the tube at these settings, have him email Alex and he can set him straight. The amp is not abusing the tubes as this was the intended use. Are you letting them cool slightly before removing them? It sounds like you know your way around tubes, but just checking. 

 

..dB

post #597 of 664

Yeah the tubes are glowing like they normally do and have been in my other amps.  I'm sorry about the heater/plate voltage mixup on the lingo above, I edited it to avoid confusion....writing the note too quickly.  The heater voltage is set at 6.3v and the plate voltage is set at 200v.  Like I said, when I first ran those Siemens I heard a hiss/scratch on the left side but I let it go because from having tube amps, sometimes tubes need to warm up to be free from random microphonics.  They sounded ok, nothing special compared to my other e88cc stuff so I didn't listen long and turned in for the night. 

 

I am now listening to a set of Mullard cv2493 to test the tubes with the HE-6, it sounds pretty nice actually, nice lush mids.  Going to listen for a couple hours here and leave the amp on overnight to test this.  Plate voltage on 200v and Heater Voltage on 6.3v.

 

Thanks for the response dB, I know better than to change tubes hot off the grill.  The Siemen that cracked had been left on the Liquid Glass all night in the off position before I returned to see one of them looked white on the head (loss of vacuum) and that's when I took it off to inspect.

post #598 of 664

I have used several 6922/6DJ8 tubes in the LG, never had a problem..dB

post #599 of 664

I left a set of Mullard cv2493 in the amp all night with the HE6 playing music for 10 hours straight and it seemed just fine.  I turned off the amp this morning accordingly.  I don't think the amp is having any issues, seems like Mark from tubemuseum is sending me another set of the Siemens with better internals and older vintage.  I am sending all 4 of these tubes back to him for inspection.  I'm glad at least he's willing to try to work this out.

post #600 of 664
Quote:
Originally Posted by sensui123 View Post

I left a set of Mullard cv2493 in the amp all night with the HE6 playing music for 10 hours straight and it seemed just fine.  I turned off the amp this morning accordingly.  I don't think the amp is having any issues, seems like Mark from tubemuseum is sending me another set of the Siemens with better internals and older vintage.  I am sending all 4 of these tubes back to him for inspection.  I'm glad at least he's willing to try to work this out.

 

I'm sorry that you are having troubles John. I rolled pretty much every variant of tube compatible with the LG (a lot as you know) and did not experience any issues. I honestly don't think it is the amp, but I maybe wrong. Did you have a chance to test the voltage plates to confirm? 

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