ADA Depot - A Forum To Support Users of ADA Amplification Gear

Let's Get Technical => All PREAMP Tech Tips & Support => Topic started by: NorthShaun on March 07, 2014, 12:50:01 AM

Title: How long do tubes last?
Post by: NorthShaun on March 07, 2014, 12:50:01 AM

....and how often do you change yours?

I have an MP1 which has the 3TM mod with Hi gain teslas in which are about 2 years old.  Seem to be losing some 'bite' and tone!  Will swapping out the tubes help?

Please & thankyou!

Title: Re: How long do tubes last?
Post by: rnolan on March 07, 2014, 06:22:52 AM

Hey NorthShaun, how often to change the tubes is a little bit bit subjective (very much depends on how used they are), well simple answer, if your hearing some degradation (bight, tone), definitely go for some new tubes.  Modern tubes don't last as long as the older tubes as their not pumped as much so not quite as good vacuum. See attachment.
If I were you, I'd chuck in either 3 high gain low noise JJs (e.g. Ruby, GT, Boogie tested) or try either the New Sensor Mullard long plates or the new short plates CV4004 (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025/mullard-cv4004-12ax7.html), sit back and enjoy....

Title: Re: How long do tubes last?
Post by: NorthShaun on March 07, 2014, 07:22:55 AM

Cheers RNolan!

Deffo losing that 'bright tone', but it took a turn for the worse last night, so I've ordered some new hi gain JJ's!  Thought it was just my ears that were failing! :metal:

Title: Re: How long do tubes last?
Post by: MarshallJMP on March 07, 2014, 03:01:59 PM

I replace the tubes in my 3TM ultra+ every 3 to 4 months.They are still good but not good enough for the 3TM IMO.So i they get a second life in my other amps.So yes swapping them out will help.

Title: Re: How long do tubes last?
Post by: NorthShaun on March 08, 2014, 01:28:52 AM

Thanks guys!

Title: Re: How long do tubes last?
Post by: rnolan on March 08, 2014, 02:48:32 AM

Hey NorthShaun, happy to help  :) The JJs should do well for you.

MJMP, how much work are they doing in the 3 to 4 months, (just trying to get a perspective on it) and do you get a better run out of NOS tubes ?  Now you mention it, I'm hearing similar in my MP2 with the Mullards, they're still very good but had a particular sparkle early on, they've been in a while now and don't work that hard.
Cheers Richard

Title: Re: How long do tubes last?
Post by: MarshallJMP on March 08, 2014, 03:36:12 PM

Well i try to play 1 hour/day rehearsal on sunday (4-5 hours).Like i said they are not worn out, maybe a way over the top with this,but something is lost after a while.I always want a perfect sound (to my ears).

Now what i surely not recommend is using long plates tubes in a 3TM.Long plates are more prone to be microphonic so these are not a good combo with the high gain nature of the 3TM.Altough it might work it's always a bit risky.