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Too Many Tubes?

More as a thought experiment than as a description of an actual problem that may or may not exist...

Has anyone ever considred if there might be a problem with too many tubes in a given system? How many tubes is too many, and what might be some issues that could have a detrimental effect on system sound quality?

What do I mean by too many tubes?
1- too many physical tubes (by quantity). Consider an example where you have (let's say) 20 or more physical tubes distributed in your power amp, pre-amp, phono stage and DAC. Besides the obvious potential issues with heat and the cost of rolling and replacing so many tubes, what are the disadvantages (if any) of utilizing so many tubes?

2- Same question, but this time the concern is not the physical number of tubes but the variety of tube types used in a given system. Can anyone make an argument against (or for) using a large variety of tube types in a single system?

For years I used a system with a SS amp (Krell, then McCormack) and ARC tube pre and phono stage. The ARC gear used the same 6922 tubes, and it there was a well-defined (not necessarily great) sonic signature. It was also very easy to tell when a given tube was microphonic or going bad.

Lately, I have been swapping a lot of new (to me) used gear in and out, and the all-tube setups have varied from SET to integrated tube amps w/ phono to all CJ tube seperates. All good... well, mostly, but I have noticed that in the setups with many tubes and/or many tube types it is can be hard to pick out the characteristics of a single tube or tube type. I am not saying that that is good or bad - it just is what it is.

Comments?
br3098
mapman's avatar
mapman
22,588 posts
 
Old Armstrong stuff sound fantastic in my digital rig. Only three tubes in the signal path for digital in my system (the ARC sp16 pre-amp). There are 3 more (12AX7 I believe) tubes in the phono stage of the ARC pre-amp and that works quite well also.

I have a tube DAC I moved from my main system into my other system which is all SS otherwise.

I listen to everything from old jazz to classical to modern rock/pop and even hip-hop, so neutral performance for all genres is a big requirement for me.
6550c
393 posts
 
SETS are supposed to sound better than push-pull because of fewer tubes plus triods are just great too (as posted above)if you can live with no power. Also, most tube amps use SS rectification and only a few still use tube rectifaction, which is supposed to sound better and result in longer tube life in the rest of the amp. SS or Tube, the fewer parts, the better. This is not really my opin, just what I understand is being said by everyone. Straight wire with gain!
auxetophone
114 posts
 
Sure you can have too many tubes. If you have 100 tubes in your system, and they last 5 years on average, then 20 of them will need to be replaced every year - or one every two weeks. It could get pretty annoying trying to find the bad tube every other week. On the other hand, if you're up for that, then maybe you can't have too many tubes :)
markus1299
252 posts
 
I love the tube sound but problem for me is, I find an absolutely killer tube for my pre (Pope Holland 6SN7's) and know that in a few years I will never be able to dublicate the sound I'm hearing from these NOS, 1948 tubes. BUT!! I sure enjoy it while I have them.
ebm
9,311 posts
 
I had many tubes once used to listen to my system in my underwear.Now i only have tubes in phono section listen in my shorts now.
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