Tubes, Tubes, Tubes -- Resources for Rollers!

Discussion in 'General Audio Discussion' started by The Alchemist, Oct 7, 2015.

  1. gurubhai

    gurubhai Friend

    Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    261
    Trophy Points:
    63
    Location:
    India
    FWIW, Liquid Glass uses 6sn7 at input stage. The output stage is a solid state buffer.

    Regarding tube price in 1985, my tube supplier once showed me his ledger from 80s in which he sold WE 300b and 274b en bulk to a client from Japan for around Rs. 500 ( thats aboud 5 USD now ) each!
     
    Last edited: Jul 30, 2022
  2. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Friend
    Joined:
    Apr 15, 2020
    Likes Received:
    10,061
    Trophy Points:
    113
    Location:
    https://www.rhythmdevilsaudio.com
    Home Page:
    Are tubes more fragile/likely to get damaged when they’re moved while they’re hot?

    I just swapped tubes to compare by removing the first pair of tubes right after turning off the amp using some paper towel not to burn my hands and then I put the second pair in and it was so much easier to hear the difference without waiting 10 minutes for the first tubes to cool.
     
  3. WoodyLuvr

    WoodyLuvr Friend

    Friend
    Joined:
    Aug 17, 2021
    Likes Received:
    62
    Trophy Points:
    18
    Location:
    siam
    Concur. You are quite correct. Excellent call out good man. I was typing too fast and meant to say:

    "Yes, 6SN7's can and are used quite successfully as output (power) tubes... or as single stage tubes usually in hybrid designs like your Liquid Glass."

    I have edited my post accordingly. Respects.
     
  4. WoodyLuvr

    WoodyLuvr Friend

    Friend
    Joined:
    Aug 17, 2021
    Likes Received:
    62
    Trophy Points:
    18
    Location:
    siam
    No, but sensitive skin and hot tubes can result in a mishap (scratching, banging-up, or even dropping a tube) if one is not paying attention to what they are doing. I have always hot swapped my tubes with no known ill-effects to any of my tubes for decades now. With practice you will learn to pull then straight out with no need to wiggle or twist which are big no-nos in regards to handling vacuum tubes correctly... though sometimes it is hard to avoid as some sockets are real tight buggers.

    BTW: I always use white artisan gloves as does nearly everyone else I know... because tubes they can get kind of hot sometimes ;).
     
  5. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    1,307
    Trophy Points:
    93
    Location:
    Canada
    Yeah, I wouldn't be switching power tubes while hot, if only because I know for sure I'd burn myself! Small signal input tubes are probably fine though.
     
  6. dasman66

    dasman66 Self proclaimed lazy ass - friend

    Friend
    Joined:
    Mar 13, 2018
    Likes Received:
    1,663
    Trophy Points:
    93
    Location:
    NW Pennsylvania
    FWIW, Justin @ampsandsound told me once that it is a bad idea to power cycle a tube amp quickly... I don't remember why (?capacitors maybe?) and that the rule of thumb is that you shouldn't power on the amp again until the tubes are cool enough to touch.

    Not sure if this is specific to his amps, or a specific amp topology, or tube amps in general... but its the practice I've followed on all my tube amps ever since that conversation
     
  7. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    1,307
    Trophy Points:
    93
    Location:
    Canada
    The only thing I've ever heard in that vein is that some soft-start circuits might not reset in time. For example, this in relation to the Bottlehead Kaiju, "I should note here that once fired up, the amp will need to sit for about 20 minutes after you turn it off for the circuit to “reset” itself and function with the soft start."

    Maybe if you were able to switch things out in seconds charged caps might be an issue......?
     
  8. fastfwd

    fastfwd Friend

    Friend
    Joined:
    Aug 29, 2019
    Likes Received:
    813
    Trophy Points:
    93
    Location:
    Silicon Valley
    Off topic, but why 20 minutes? That seems like a terrible design for any universe where power outages are a thing. If the idea is to hold off the plate voltage until the heater is hot, the reset delay should be a few seconds at most -- and ideally zero. Right? Or am I missing something?
     
  9. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    1,307
    Trophy Points:
    93
    Location:
    Canada
    Yep, it seems really long to me. But it's really the only specific reason/situation where I can think of where you shouldn't try and quickly change tubes.
     
  10. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Friend
    Joined:
    Apr 15, 2020
    Likes Received:
    10,061
    Trophy Points:
    113
    Location:
    https://www.rhythmdevilsaudio.com
    Home Page:
    @dBel84 can you weigh in here? Do you have any thoughts on removing tubes while they're hot and swapping tubes and powering on the amp again after only a few minutes? (after any power down cycle is over)

    Interesting this hasn't been discussed before.
     
  11. Lickumms

    Lickumms Rando

    Joined:
    Jul 11, 2022
    Likes Received:
    15
    Trophy Points:
    3
    Location:
    USA
    Tested using HD800s and TORBalanced.

    Electro Harmonics 6SN7EH Gold Pins - Adds an airy spacious sound to music. Boosts the sound stage size a little over Class A amp. Bass is very tight and fast but sligtly reduced in quantity. Adds, what might be heard as, a slight dryness to the music from how clean and sharp everything is represented. Maintains all highs with no rounding or dullness.

    Shuguang CV181-Z(50 Years) Premium Grade - Sounds almost identical to a class A power amp. Adds the slight warmth of Class A power, compared to Class D, removes anything offensive from headphones and songs. If you want to know what a Class A power amp sounds like use these in your tube amp. Rounds out the occsional terrible peaks that can occurs with HD800s.

    Sylvania 6sn7gt 3 hole "Bad Boy" - Adds warmth to sound. Slight reduction in sound stage creating a more intamite sound. Excellent boost in the impact, rumble, and power of the sub bass. A little boost in lower mids presence. Closest thing to what I would call a traditional "tube" sound.

    Ken-Rad VT-231 Black Glass - Bass King. Greatly improves bass impact, power, and presence on all ranges without muddying it or losing any quality. No real noticeable change in sound stage. If bass is what you want this is the tube to go with. Warmer sound, almost dark, compared to the "Bad Boy". Slightly dulls out the higher end peaks.
     
  12. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Friend
    Joined:
    Apr 15, 2020
    Likes Received:
    10,061
    Trophy Points:
    113
    Location:
    https://www.rhythmdevilsaudio.com
    Home Page:
    Occasional? :confused:

    [​IMG]
     
    • Like Like x 2
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  13. Lickumms

    Lickumms Rando

    Joined:
    Jul 11, 2022
    Likes Received:
    15
    Trophy Points:
    3
    Location:
    USA
    Haha, maybe occasional is not the right word. Perhaps "Constant" or "Always Occurring" is better.
     
  14. dBel84

    dBel84 Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,773
    Trophy Points:
    113
    Removing hot tubes.

    Biggest risk is burning your fingers. Other risks would be to crack the glass by placing it on a cold surface or hard surface as it would be at higher risk. Small risk for oils on fingers to transfer and get burned into the glass - you can sometimes see fingerprints etched into the glass. But otherwise, no real risk assuming amp is designed to shuch down voltages pretty quickly which most are.

    Turning amp back on after a minute or 2, no problem. "rapid cycling" refers to some idiotic tendency to flick power switch on and off multiple times, if you are 2, this is fun. If you are high, this is fun. But the amp (both tube and most amps, especially class A, will not like it and you could damage the amp) for tubes it is more a matter of cathode stripping and risk for arcing.

    Good designs build some degree of latency into the power cycle which prevents this from happening.

    @rhythmdevils - The process you describe is perfectly reasonable

    .. dB
     
    • Like Like x 6
    • Epic Epic x 4
    • List
  15. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Friend
    Joined:
    Apr 15, 2020
    Likes Received:
    10,061
    Trophy Points:
    113
    Location:
    https://www.rhythmdevilsaudio.com
    Home Page:
    I get a lot of tubes that have some scratchy sound that comes and goes in one channel. And some with no sound in one channel or very scratchy all the time. I think like 20% of the tubes I get on ebay have a problem to some degree. Is this normal? I'm wondering if the Liquid Glass is more sensitive to tube issues than other amps.
     
  16. RestoredSparda

    RestoredSparda Friend

    Friend
    Joined:
    Jan 7, 2021
    Likes Received:
    612
    Trophy Points:
    93
    Location:
    Wisconsin
    I sometimes take off one of my socks and use it as a protective glove to swap hot tubes. But only when I'm really impatient. Lol.
     
  17. dasman66

    dasman66 Self proclaimed lazy ass - friend

    Friend
    Joined:
    Mar 13, 2018
    Likes Received:
    1,663
    Trophy Points:
    93
    Location:
    NW Pennsylvania
    Personally, I'd say that 25%+ of the ebay tubes are old, used up and represented as new. IMO, you're probably doing a little better than average...
     
    • Like Like x 2
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  18. Lickumms

    Lickumms Rando

    Joined:
    Jul 11, 2022
    Likes Received:
    15
    Trophy Points:
    3
    Location:
    USA
    I've never had any noise problems with the tubes I bought off of eBay. Just have to be sure to buy from someone who has good reviews and, if you can find them, someone who post the actual test results of the tubes. If you are buying untested tubes you are risking the gamble on if the tubes are old or not.
     
  19. Slade01

    Slade01 Rando

    Contributor
    Joined:
    Jul 15, 2020
    Likes Received:
    60
    Trophy Points:
    13
    Location:
    New Jersey
    From my experience, it is a little bit of both the condition of the tubes from ebay, and how sensitive your amp is to tube issues. Many vintage tubes that I have bought that end up being scratchy can be resolved when simply cleaning the pins (usually with deoxit). Usually the more worst cases where there is no sound at all or loud popping (I usually experience this with octal tubes) require to re-solder the pins.

    But 20% seems about par for the course. I always have to remember that these are 80+ year old pieces of tech, so if 80% of these items are still working to their full capability, its nothing short of impressive.

    And yes of course (in my opinion) that some amps are more sensitive to the tube issues more than others based on how they were designed. The classic Darkvoice 336se amp is notorious for the humming issue that requires at times up to an extremely long burn in period for the tube to settled down. That same tube in a Bottlehead Crack or Eufonika H5 for example, from the get-go, would otherwise be dead silent. I'm pretty sure that some amps mitigate some of those tube issues better than others.
     
    • Like Like x 3
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • List
  20. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Friend
    Joined:
    Apr 15, 2020
    Likes Received:
    10,061
    Trophy Points:
    113
    Location:
    https://www.rhythmdevilsaudio.com
    Home Page:
    God damnit why are the best sounding tubes the noisiest?
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List

Share This Page