[DrDustCell]

Am currently using the LF339 + HD650 (burned in) with just my laptop as source
 
THE BASS IS INSANE, and my volume's still around 75% (6th circle)
On some tracks, i have to EQ everything below 110Hz or else it would feel like I was experiencing the sendai earthquake in my senns!
...And some of them aren't even rock or electronica... (bass guitar in a jazz track)
 
I had been giving some thought about purchasing a DAC and the DT990 650Ω, but maybe I'll grab the K702's instead (for the time being), haha
 
It's also my first tube amp by the way. Beginner question, but can I swap the inner tubes and the outer tubes? How would that affect the sound? I kind of want to get started with tube rolling.

 

[alvin sawdust]

Read the rest of this thread for tube rolling ideas, phiero has listed a few.
Quote:

Am currently using the LF339 + HD650 (burned in) with just my laptop as source
 
THE BASS IS INSANE, and my volume's still around 75% (6th circle)
On some tracks, i have to EQ everything below 110Hz or else it would feel like I was experiencing the sendai earthquake in my senns!
...And some of them aren't even rock or electronica... (bass guitar in a jazz track)
 
I had been giving some thought about purchasing a DAC and the DT990 650Ω, but maybe I'll grab the K702's instead (for the time being), haha
 
It's also my first tube amp by the way. Beginner question, but can I swap the inner tubes and the outer tubes? How would that affect the sound? I kind of want to get started with tube rolling.

 

 

[phiero]

Okay..a note on some problems I had...
 
My amp's left channel had been acting a little finicky, and one day, it suddenly died.
 
I opened the amp, and after a bit of diagnosis, found that two resistors had burnt out... One 100Ohm, and one 430Ohms...I mailed Yuking09, and he expressed me the replacement parts within five days (awesome service, I must say).  
 
I am handy with a Soldering Iron, so the repairs were quick and painless. Now all back up and running. Enjoying the EF800 and RCA6AS7G Combo a lot

 

[alvin sawdust]

Quote:

Okay..a note on some problems I had...
 
My amp's left channel had been acting a little finicky, and one day, it suddenly died.
 
I opened the amp, and after a bit of diagnosis, found that two resistors had burnt out... One 100Ohm, and one 430Ohms...I mailed Yuking09, and he expressed me the replacement parts within five days (awesome service, I must say).  
 
I am handy with a Soldering Iron, so the repairs were quick and painless. Now all back up and running. Enjoying the EF800 and RCA6AS7G Combo a lot

Hey phiero, same thing happened to me with my 337se and yuking sent the parts straight away. Mind you, this sort of thing shouldn't really be happening in the first place.
 
Glad you got it repaired. Enjoying the EF800 and GEC A1834 combo in my amp. The EF800s seem to add just a little more air than the EF80s.

 

[ces456]

So, I did some tube rolling and, apparently, I screwed up!  I replaced the 339's stock driver tubes with 6AS7Gs and the stock amp tubes with EF800s from Telefunken.  I turned the amp on with my Pro 900 headphones connected and the volume at around 10 o'clock.  One of the 6AS7Gs popped (or crackled) (or both - snap, crackle, pop?) a couple of times along with some interior fireworks (lightening in a bottle).  It then settled down and now seems fine.  However, this little fireworks display seems to have fried the driver in the left channel of my Pro 900s - that channel is now substantially lower in volume than the right channel.  I thought it might be the tubes, so I tried another pair of headphones with the DV 339 and they worked fine.  I then tried the Pro 900s with my portable amp and had the same problem with the right channel.  Oops.  I guess one lesson to be learned here is to make sure the volume is turned all the way down when powering up your amp (something I usually do, but neglected to do in my excitement to try out the new tubes).  Anything like this ever happen to anyone else?

 

[Skylab]

Unfortunately, it sounds like you had a bad tube, which arced.  This certainly has the potential to blow headphone drivers.  Had it happen once to me - blew a DT990 driver.  After that, I bought a tube tester, and I test every tube I get before using them.

 

[ces456]

Skylab - Thanks so much for the reply.  I'm a noob at this (as I'm sure is painfully evident).  I take it this means I should replace the tube before it claims another headphone?  Last week was a bad week... Algorythm Solo and Stepdance stolen from my backpack, capped off by this.  The good news is that I was thinking of replacing (or maybe supplementing) the Pro 900s anyway and this provides me with an excellent excuse to do so.  Now what to get....decisions, decisions.
 
Quote:

Unfortunately, it sounds like you had a bad tube, which arced.  This certainly has the potential to blow headphone drivers.  Had it happen once to me - blew a DT990 driver.  After that, I bought a tube tester, and I test every tube I get before using them.

 

 

[Skylab]

Well, first off, are you sure you had the tubes in the proper sockets? The 6AS7G is actually the power tube in the 339. And a you sure the Telefunken tubes you got are an OK substitute for the driver tubes? I'm not familiar with it, which doesn't mean you cannot use it, but you need to be sure.

In any case, the tube that arced should be replaced for sure.

 

[ces456]

I probably got the terminology screwed up.  So here's a picture.  The 6AS7G replaced the big tubes in the middle and the Telefunken replaced the little tubes on the sides.  The Telefunken tubes required an adapter (which came with the amp), but others in this thread have used (and liked) them with this amp.
 
 
 

 

[Skylab]

Got it. So sounds like you got a bad 6AS7G, and it arced. That tube needs to go in the trash.

 

[ces456]

Thanks. Lesson learned. My next purchase will be a tube tester.

 

[reiserFS]

And if you can, don't buy from eBay. I have received two 6AS7G before that were tested good but nearly arced on my tester.
 
Quote:

Thanks. Lesson learned. My next purchase will be a tube tester.

 
 

 

[timoki]

ok.. n00b here.. I've added yesterday the 339 to between my LD DAC and HD800. Sounds really nice (could try it out in a shop here beforehand). Even though the stock tubes, seem to sound already quite good, but I want to try some tube rolling. Have been reading the thread here and it sounds all so interesting 

 
So I've a question, what is the difference between the 6AS7G and 6AS7GA? Because I can find a pair of GAS7GA brown base, but I'm not sure what is the difference to the 6AS7G.
 
Thanks a lot for the help in advance. 

 

[Ultrainferno]

Quote:

Originally Posted by timoki /img/forum/go_quote.gif
 
So I've a question, what is the difference between the 6AS7G and 6AS7GA?

As far as I know the 6AS7G is the tube shaped like a coke bottle. The 6AS7GA is the straight bottle
 

 

[timoki]

so does that mean they are of same quality just different shape?
 
(sorry for the maybe silly question)