My really dumb tube mistake(s)


8 years ago, I bought a sweet sounding Line Magnetic amp for my office system which a few years ago died and had to go to the repair shop. $500 later it was back working, but then recently I noticed the sound was getting thin, I couldn’t bias the tubes and thought something else was wrong with it, arghh.

Then I noticed one newer tube was able to be biased and decided to replace all 4 KT-88 power tubes.
Presto, the amp sounded great again!

Like the boiled frog, the sound degradation had been so gradual my brain had gradually adjusted. But the new tubes brought it back to life.

So, then I thought, wow, maybe I should try the same thing in my primary system with my Primaluna monoblocks, switch out the Primaluna tubes for some new Gold Lions. Again - wow! What a difference. Like I bought new amps, much richer and fuller sounding.

Tubes wear out, even if they don’t blow out.
Yes, duh, it’s a good idea to replace them every 4 years or so and not wait eight.
cdc2
@sendthemall - Just keep the amp on all the time for SS. My phono stage doesn't have an on/off switch and a lot of preamps don't have one either. Doesn't use much power and always sounds great.,

And oh yeah, no tube worries.....
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The process is ongoing. The new tubes have about 75 hours thus far.


I’m hoping for the revelation to reveal itself soon.
@tvad 

If you're already at 75 hours, you're hearing it. Have you replaced the input tubes? They can have more effect than the output tubes.
An overlooked advantage of tubes is that they start sounding great within 30/45 minutes of turning on the amp and preamp.

My solid state stuff needed to be on for at least a few (3) hours in order to sing. This really is a super duper convenience and worth every bit of the fussing.

But then I have a Primaluna power amp so it's pretty fool proof.


elliottbnewcombjr
Similar obvious improvement: I just thoroughly cleaned the years old corroded rca jacks on my vintage McIntosh preamp. So old they are the close together ones, hard to clean but well worth it. I made a leather strap, put super fine steel wool on the inside of a loop, carried on like a professional shoe shine finale. Very glad I did it.

Don't just stop with the outside of the RCA's, clean the insides too! Power off and unplug the equipment. Spray DeoxIT or any other good, non-lubricant contact cleaner on a pipe cleaner, preferably white, and run it in and out of the plug until you can do it with a fresh one that comes out clean. It usually only takes a couple. You can grab the pipe cleaners at Hobby Lobby or just about any craft store.
Hello,
I auditioned the Rouge RP7 preamp. So good. It is on my wishlist. If I bought a tube piece of equipment. I think I would buy a second set of tubes. Break them both in to have the perfect backup. I heard on the Rouge RP9 they have NOS Russian tubes. Is it good to buy an expensive piece that is setup to run in NOS tubes? What happens when there are no more NOS?
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@ veerossi
TV-7D/U tester.
 It will not test the 805 
Yes on the 300b, 6SN7, 6SL7

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SET amps run at 100% duty cycle all the time. I wonder how fast that wears out tubes compared to a push/pull amp?
__________\\\\\\markpao: Can you please provide the name of the tube tester you have. Do you know if it will test 805, 300B, 6SN7 and 6SL7?
__________\\\\\\tvad: for 300b replacement tubes, please look at the Psvane Acme. They made a nice improvement in my Line Magnetic (along with the other rolled tubes on it)
When music turns lifeless, lacking, punch, drive, dynamics, air, bass, then is time to check which tube has gone bad, no need to blow if its an output tube. Or even if they cannot bias properly (output ones). For me it should be best to change all output tubes at the same time. A tube tester will not show when a tube is going to go bad but can give a good indication of its life. So if close to end of life readings, replace. Always have a spare set, you never know.

G
My system started sounding thin and lifeless last year. I got my tube tester out and went through my gear one at a time. Found a tube in my pre amp that tested very low. Changed it out and now back to amazing music. Not sure how I would have proceeded without my tube tester short of replacing one tube at a time until I found the bad one. Or, at a very high cost, replace all the tubes at one time.

This may seem like a dumb question, but can a tube tester provide the status of a tube prior to failure? 
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Sorry for the long post, but I felt the explanation would help.
This is a subject that is for me difficult to cover without explanation.

I personally look at tubes as an electronic Interface, that has a ease of use, as a method for carrying out exchanges. 

My personal experience from taking part in carrying out exchanges,
has on most occasions been done as part of group, with myself supplying the device to undergo Tube Rolling.  
Doing this has allowed me to experience quite a lot of Tubes, of which some are very well regarded.
I have heard well regarded Valves, that when placed into a Circuit, 
which have almost needed to be removed with immediate effect, 
as the SQ was not one that was wanted.
This was not a personal choice, but a request by a group in attendance.

If I recollect a Orange Print Amperex Bugle Boy was one such Valve used in a DAC,I knew of it, I was interested in it, when used, 
it was a very short lived audition.
On a later occasion, the exact same pair when used on a Phonostage,  were very well received, if a little thin in the presentation.

My experiences allows me to say that Valves with a Good Reputation and are to be found as recommendations, can fail to deliver a good result,
when used in a certain electronic interface.
So jumping into Tube Rolling without acquiring knowledge, seems to be a increased risk, to successfully finding a Personal Sweet Spot with the Valve selection.    

Tube rolling can prove costly, the cost can be impacted by Valve Selection, or accumulating Valves that have not met expectations, and then there are other pitfalls of being supplied Valves that are not measuring up to a usable standard.

I ordered during 2020 Two Matched Pairs of Same Brand 1960's ECC 83 from the same Vendor.
With the intention of producing Two Close Matched Sets.

It was agreed that I would have them Tested on a AVO Test Rig and a return would be accepted pending the test .
One Pair measured very high and slightly over the New Measurement,
(very pleased).
One Pair was between 50% to 70%, depending on the Valve
It took two further supplies of ECC83's that were still measuring quite low, before I got a refund on one pair.
Not all Vendors will be so tolerant.  
Prior to this, a Vendor sent me abusive mails for requesting a Valve return following a Test carried out at my end. 
  
If a modern $20 - 40 Rectifier Valve is claimed to have a similar 
 SQ / Performance of a $200 NOS Valve, and a person is entering into the world of Tube Rolling, the cheaper Valve would be the most cost effective place to start, if a Valve is to be exchanged. 
There should be a change in a performance that will allow an assessment as to the value of the addition.  

I have devices that use ECC88, ECC81, ECC83, 6SN7 and 845's
I have been supported by being loaned Valves that are Closely Matched NOS,  that have been Tube Rolled, those being all the above apart from the 845's. 
As a result some of my Valve Choices have been, more a case of having the Valve to be used already identified, and a purchase tested, to make sure the Valve is sold as described.     
Being fairly new to tubes and dealing with 2 reputable guys in the NOS tube business, I’ve had very good luck thus far until the other day. I got some 1958 Mullard 12AU7 long plates several months back that I put in my Primaluna Dialogue Premium preamp.
The other day I was showing off my turntable to a friend and I was knocking on the maple isolation shelf while it was playing showing how the table doesnt skip a beat.
It seemed like I could hear a door bell off in the distance. After some investigating found it was tube in my preamp one shelf below. As I tapped or even rubbed a finger on the glass it sounded like a ringing door bell. The tube is now crackling weeks later.
That’s my first experience with a tube going bad.
What I paid for a matched Octet of Mullard EL34 XF2’s has my fingers crossed on those.
Although I have seen several posts here and elsewhere about owners of Primaluna amps using current production Gold Lion KT88’s with favorable results. Maybe a second set of power tubes to switch out now and then would be a good idea to keep the hours down on the Mullards.
Not only should power tubes be replaced for reasons of performance, letting them go too long will cause damage to many amplifiers.  Typically amps with a manual bias.  We output tubes can go into a runaway state where they draw ever more plate currently.  Hopefully just the cathode resistor goes, but in some cases, the output transformer is the victim.  
pindac 

good to meet you.. that was quit a bit of information..

Did you say "if you roll tubes, you can get good result, but you can have bad result too". I agree.. :-)

Regards
I am not an EE minded person, but share time with Audio Enthusiasts  that are adept at EE and build/modify Audio Devices.
In many cases I am able to audition equipment in a HiFi System I am familiar with, which helps when being asked to attend a home, with a purpose to take part in a Device Audition, and offer a assessment.

I have supplied ears for assessments and listened to SS Stereo and Monoblock Power Amps that have been built, as well as,
modified Versions of builds and Branded Amps, where changes are being made, with the intent to improve on such builds.
From my limited experiences, any perceived sound changes with SS,
are to me, being perceived as quite limited, even though a change to the SQ and Performance can be noticed.
I have heard SS Power Amps that I have been impressed by, any one of these could very easily be accepted to be trialled to be used in my system. 

I am a Valve Power Amp Owner for many years, starting with Stereo and today Monoblocks are in use.

I have again had the opportunities to assess Valve amp Builds and Branded Valve Amp's as well as a few other Devices modified to work with Valves.
The range of Valve Amp's I am familiar with are:
 Phonostage > Pre Amp > Power Amp's, Valve Modified CDP's and DAC's.
Apart from being familiar with adept EE minded Audio Enthusiasts,
another Plus Point is that a Friend can be described as having a specialist knowledge of Valves through their life experience, and is in possession of a Two Generation Collection of Valves, which has a vast catalogue.
This friend has always expressed generosity and been willing to aid others with allowing for Tube Rolling to be undertaken with a variety of very closely matched Valves.

Again my experiences are limited but have been revelatory.
One thing I feel very sure of,  is that a Valve Device can undergo perceived changes in the SQ and Performance that can be seen as a exceptional improvement over a previous guise, as a result of
exchanging Valves, if a opportunity to Tube Roll was undertaken,
this can make the observation even more apparent, as to how a selection of Valve will interface with a Device, the marriage will be for better or worse. 

I have also auditioned Valve Amp's, where Components have been exchanged in the circuit.
In one case a particular component (Copper Foil Cap's) was Rolled,
using different Brands,  and at one stage a selected component was perceived as a noticeable improvement over other respected Brands.
When this selected Cap' was in the circuit and Z Foils were introduced to the circuit, the perceived changes were phenomenal.
My limited knowledge would not be able to comprehend why their were such perceptions of improvement.

After such a impression, this device was taken to my friends to undergo 
Tube Rolling.
The Builder of the Device was present and was quite sure, prior to Tube Rolling,  his selected Valves were not to be improved upon.
Well he got a shock on two accounts when the Input/ Output Valves were
rolled, the Device found a new level with a Permutation that was used.
Then followed a few swaps of Rectifier Tubes and another level of performance materialised.

As for Valves vs SS, 
If one discovers a exceptional performing SS Device, that is what it will be.
I feel fortunate to have been able to hear SS Devices that have made such a positive impression.
In my limited experience, If the chosen SS Device is modified,  the perceptions of improvement on offer are with limitations, and opinions will vary on how noticeable they are.
These modifications will also be best carried out by a very adept EE minded person.
There is no doubt in my mind that others who have more experience than mine can dispute the above.  

 If one discovers a Valve Device that is offering a very satisfying performance, in my limited experience that will be a Device that can potentially offer much more.
The chances are that if a investigation is undertaken,
that is limited to Tube Rolling only, a opportunity will be arising, that can potentially offer a perception of improved performance, beyond a persons expectation.
When a Valve is perceived as offering a improvement, there is usually a unanimous agreement, what would be more of a discussion is how much the cost will be as a result of the valves availability.
 
To achieve such a perception, is only a case of exchanging a single Valve or a Selection of Valves, depending on a Device, and generally does not require a EE minded person to achieve this is Valve Sockets are used as the connections. 
To the person considering Tube Rolling, if a single Valve Exchange is
a option, in most cases this would be the most cost effective, and would be a good place to start, i.e, a rectifier.
Note: Tube Rolling can be costly, so learning in advance of how a particular Valve might interface and offer a improvement would be time well spent.
                     
  

    
I agree that arguing the points of SS vs. tubes gets overdone, especially since tubes are simply better. Except maybe for Nelson Pass designs but I'm not sure...no...uh...wait...I'm sure. Tubes are better regardless of how they sound as it's simply due to the "betterness" part.
You’re in the wrong thread.
This is about tube amplification. 
No one here cares about owning solid state amplification, or opinions about owning solid state amplification. 

Didn't know it was your job to tell people what thread to open, and there is no need to inject nastiness. Yes, that's how it comes off. The need to explain yourself is your clue.
Yeah it is funny how you do not realize the sound falling off until you replace tubes and then have the wow moment, why did i not think of this before lol.
Roooooooll, another one, just like the other one.

Lets stick to the subject, roll another tube, just like the other one..:-)

Regards
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@baylinor I know where you are coming from.  My main system uses tubes and I'm always mucking about with them (enjoying every minute of it).  My bedroom system is solid state and gives me "set it and forget it" freedom.

@tvad Throw on something relaxing and chill. This hobby of ours is niche at best and there is no room for elitism and snobbery.  We need to keep the door open to all comers with a big "WELCOME" sign on the doormat.  Everyone's opinion counts, and yeah yours too.

Mark
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I wasn't aware I couldn't voice my opinion about the complexities of tubes. Sorry about stepping on your toes. I guess media bias has long reach.
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That's why I go solid state all the way, no need for the extra tube worries about quality and life degradation.  There are enough things for me to worry about in my vinyl system. Just me.
OP just googled those Davone Mojo's cool looking speakers I dig the MCM vibe! As far as tube wear goes I tend to have power tubes go bad before they sound degraded as I listen a ton. Pre-pandemic 8 hours a day and during more like 12+ so I work tubes hard.

But tube rolling to enhance quality is, almost, always a good thing. I am a big fan of those Gold Lions I use the KT77s in my custom stereo amp.
You know douglas, one thing that I found out. If a valve can make it the first 72 hours, they will usually last until they just run out of gas, (99.9% of the time). That last 10-15% can get a little wiggy, though. :-)

Sounding GREAT out of the box is always nice.. The OLD RCAs and Tellies always did it for me.. VERY consistent from day one.. PSVANE and a few of the Boutique valves can take 100+ hours to sound right..

Regards
We really need some critical analysis of when "break in" ends and the degrading affects of tube life begin.  ;)

Heheheheh... 


Live and learn.

When things don’t sound right, whatever the cause, time to jump into action! Regression testing rules! Switch/change one thing at a time until problem item is isolated. Having spare gear around to swap in when needed is key! If tube gear in particular  always keep spare tubes in good working order around!

That’s the nice thing about integrated gear and keeping things simple.....much easier to isolate a problem and get it resolved when it happens and eventually something will always happen. Good gear should last a long time and continue sounding good but nothing is forever.
I don’t see it as a mistake, I see it as getting every last mile out of that tank of fuel... Well done..

Regards..
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At the office I'm running my Line Magnetic 2161A integrated with some Davone Mojos. Which just need a sub to really sound amazing but that didn't go so well with the people in the office below, so no sub.

At home, using an amazing DeHavilland PreAmp with the Primaluna Prologue Seven monoblocks and a pair of Martin Logan Ethos speakers.
Great, thanks for posting your experience.

Similar obvious improvement: I just thoroughly cleaned the years old corroded rca jacks on my vintage McIntosh preamp. So old they are the close together ones, hard to clean but well worth it. I made a leather strap, put super fine steel wool on the inside of a loop, carried on like a professional shoe shine finale. Very glad I did it.

btw, what speakers?