help with noise at startup volume turned down

[Hornet900]

What driver small tube are you guys using?  Could this affect anything    LO by the end of this I'll no more about the crack tube amp then I should! 

I'm looking to buy a 12au7 tube...  Ive ordered 2 TELEFUNKEN E80CC tubes and the resistors wont have them for a few weeks tho

[tdubl07]

What driver small tube are you guys using?  Could this affect anything    LO by the end of this I'll no more about the crack tube amp then I should! 

I'm looking to buy a 12au7 tube...  Ive ordered 2 TELEFUNKEN E80CC tubes and the resistors wont have them for a few weeks tho

Hornet your throwing down some cash on all those tubes! Haha. Nice! I replaced the stock 12au7 that happened to be real noisy with another 12au7 since I have quite a few lying around. All is well, no complaints with the 12au7. I have a JJ 12au7 in now. I also have a couple long plate raytheons lying around that I haven't thrown in yet. I'm pretty much set on the way this thing sounds now. It's awesome!

[Hornet900]

Thanks tdubl07  

yeah but I could be a drinker and go down the pub and spunk more!  yeah I've spent alot money   

once I heard the 5998 I was on a mission  , with the other power tubes I have I didn't really like the sound with the speedball upgrade , I found it brighter but then I only had a mullard and  the hewlett packards,

[tdubl07]

Thanks tdubl07  

yeah but I could be a drinker and go down the pub and spunk more!  yeah I've spent alot money   

once I heard the 5998 I was on a mission  , with the other power tubes I have I didn't really like the sound with the speedball upgrade , I found it brighter but then I only had a mullard other than the hewlett packards,  I like the hewlett packards more than the dead mullard with the 5998s

The amp sounds great guys with 5998 and the hewlett packard   just the volume at 0% bugs me

Yeah I hear ya, I just got over the 0% by never turning it all the way down  . I ordered a couple 6080's after my 5598 was noisy as well, and got a nice silent one. An old RCA. Both GE 6080's I have hum at all levels.  The RCA sounds great and is dead silent.  Anyway, maybe the guys will figure the 0% hum for us that are having the issue soon. Have fun and enjoy the hell out of this amp! I am  What phones you using? Just curious what's you weapon of choice? Haha

[Hornet900]

Well guys my second 5998 tube has been on maybe 2 hours now.... I just turned the volume down all the way and played with the headphone cable .... I held the headphone cable in my hands   and it went silent 

(the other tube I only had in for about 30 mins will test more)

Now its dead silent at 0% volume sometimes  ....it goes silent if i wrap my hands around the headphone sometimes and moving the cable about !!

This is the same thing that happens to my stock RCA 6080 tube though... takes ages for this to work.





edit:   now if I touch the cable it makes the noise! (well grabbing it in my hands)

confused me 

[ghost_rider]

What driver small tube are you guys using?  Could this affect anything    LO by the end of this I'll no more about the crack tube amp then I should! 

I'm looking to buy a 12au7 tube...  Ive ordered 2 TELEFUNKEN E80CC tubes and the resistors wont have them for a few weeks tho

I dont think its the driver tube. I tried 2 mazda 12au7s and the stock one(the stock one had a red marking but now it has no names on it anymore )

[Hornet900]

Hello Ghost  Thanks for that

My Number 2 tube is silent at 0% volume !  only if I move or grab the headphone cable in my hands the noise comes back.  And it seems to only make the noise half way up the cable now....not near the socket.

Think I'll order a new cable

tdubl07 I'm using a very old pair HD600s  and the cable is so thin . much thinner than the new HD650s I had. (stock cables

More edits:  just tried another pair of headphones Senns hd280 pro and the noise is still there 0% so not headphone cable       but it does go away messing with the hd600 cable now

[ghost_rider]

Hornet I am getting scared now.

Is there any chance that all 3 of my tubes are noisy and my amp is totaly fine? 

If thats the case then it will be a very very sad day for me as those cost me a hell lot

But if thats the case then why do I still have that bad noise with the 6080WB? and these tubes sounded so good without speedball

[Hornet900]

I don't really no tho mate  Could well be Ghost      your noise problem sounds  bad like the 1st chatham 2399 I had,   these 2 new tubes are better..... well the one I'm running now can go silent playing with the cable  now  

I bet it would be dead silent without the speedball that's what's  puzzling  me.

I've just found a 12bh7 local to me so I'll try and get it tomorrow.  £15 I'll ask pickup http://www.ebay.co.uk/itm/new-old-stock-Brimar-12BH7-double-triode-valve-/171305214433?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item27e29621e1

anygood worth it?  which 12bh7 have you ordered Ghost?

[ghost_rider]

I don't really no tho mate  Could well be Ghost      your noise problem sounds  bad like the 1st chatham 2399 I had,   these 2 new tubes are better..... well the one I'm running now can go silent playing with the cable  now  

I bet it would be dead silent without the speedball that's what's  puzzling  me.

I've just found a 12bh7 local to me so I'll try and get it tomorrow.  £15 I'll ask pickup http://www.ebay.co.uk/itm/new-old-stock-Brimar-12BH7-double-triode-valve-/171305214433?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item27e29621e1

anygood worth it?  which 12bh7 have you ordered Ghost?

havnt ordered anything yet

I cant get near my dear crack for 3 more months so im waiting on what you guys get first. I think i will let you guys sort it out first and then when all is set, I will start buying the tubes

I gotta get my tubes from UK anyways as back home I wont find any tube in a few thousand miles and my home post office isnt the most caring one for handling tubes 

If none works then I think I will go with that E80cc mod to make it work. Either ways Im getting those 5998s to work with the speedball! 

[Hornet900]

yeah starting to feel like a guinea pig now     

The mullard I got from Jamie sounds good listerning to these 5998 now,, my second best power tube is the Mullard 6080 and works perfectly.

I hope this problem doesn't make the 5998 work  harder or something and rubbish them quicker  than the other tubes  



 

[Paul Joppa]

We still have not been able to reproduce the situation in the lab. But meanwhile this post just showed up:

http://bottlehead.com/smf/index.php/topic,6194.0.html

This suggests there's a shielding or RFI potential issue. As has been noted, that includes grounding and especially grounding to the chassis - but as I said, we still don't really know what is going on. But it's on our "active projects" list for sure!

There's a fair chance that most or all of the noisy 5998s are actually OK - don't sell them at a loss just yet.

[ghost_rider]

We still have not been able to reproduce the situation in the lab. But meanwhile this post just showed up:

http://bottlehead.com/smf/index.php/topic,6194.0.html

This suggests there's a shielding or RFI potential issue. As has been noted, that includes grounding and especially grounding to the chassis - but as I said, we still don't really know what is going on. But it's on our "active projects" list for sure!

There's a fair chance that most or all of the noisy 5998s are actually OK - don't sell them at a loss just yet.

Holding on to them paul, please fix it ASAP

[ghost_rider]

yeah starting to feel like a guinea pig now     

The mullard I got from Jamie sounds good listerning to these 5998 now,, my second best power tube is the Mullard 6080 and works perfectly.

I hope this problem doesn't make the 5998 work  harder or something and rubbish them quicker  than the other tubes

Hold on mate, you and I both are on the same boat. and dont worry we are gona make this baby sing again  Tung Sol 5998 and Mazda 12AU7s , oh heaven!

[Hornet900]

hehe   

I just turned the amp of for 30 mins let it cool down then turned it back on  and the noise is back    messing with the headphone cable is changing the noise but it wont go silent at the moment ( its been on 5 mins now  .( noise is like a fly buzzing around  and it changes to a kinda hum touching the cable and volume of the noise is louder then quieter.  All at 0% volume its fine if i turn it up.
Putting my 4 fingers around the headphone socket makes it go much quieter ...touching the top plate does nothing

Paul I did test another pair of headphones hd280 pros they have a big fat curly cable  much thicker than my hd600s

edit the noise is more like a buzzing humming sound kinda like a fly sorry