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 Post subject: Electro Harmonix tubes
PostPosted: 16 Feb 2017, 03:30 
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Joined: 16 Feb 2017, 03:24
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I found some new (just bought from internet) Electro Harmonix tubes faulty, i.e. bad amplification factor and distorted output even at very low volumes.
Did someone else experienced the same or was it only bad luck?
In your experience, should I rely to different brands?
Thank you in advance for your help.
Eugenio


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PostPosted: 16 Feb 2017, 08:02 
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eugeniom wrote:
I found some new (just bought from internet) Electro Harmonix tubes faulty, i.e. bad amplification factor and distorted output even at very low volumes.
Did someone else experienced the same or was it only bad luck?
In your experience, should I rely to different brands?
Thank you in advance for your help.
Eugenio


I am seeing and hearing rumors of the same with re-issue Tung-Sol tubes as well.

Anyone else?


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PostPosted: 16 Feb 2017, 08:05 
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Thank you Peter.
Good to know.


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PostPosted: 16 Feb 2017, 10:39 
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Joined: 29 Oct 2014, 12:32
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Location: Russia Komi republic
Yes, there was one problem with the KT120 - replaced under warranty.
In guitar amps, which brings to me to the repair or inspection - I have encountered problems with Electro Harmonix (very noisy, I met 2 burnt).
JJ more reliable, according to my observations. Least of all a problem with them. But - this is my statistics.

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PostPosted: 16 Feb 2017, 11:42 
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I have had persistent problems with new Electro-Harmonics tubes. This has run the gambit from noisy 6DJ8s, to buzzing 5U4GB rectifiers, to 6V6s with low output. I no longer but EH tubes unless I am willing to send back defective ones and wait for replacements, which may themselves have to go back.

I have never had an issue with JJ tubes of any type.

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PostPosted: 16 Feb 2017, 13:38 
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Hi, I have had problems with EH KT88s and as mentioned in aother thread problems with Tungsol KT120s and 150s. Never a problem with JJ tubes to date.

BTW, I don't like JJ's 5751 but all others are just fine.

Good listening
Bruce

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PostPosted: 16 Feb 2017, 23:26 
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Great! This just bolloxes my business >_<
JJ's don't work well in many of my builds (too low gain). EH and T-S were my feature tubes.

/me right pi**ed off!

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PostPosted: 17 Feb 2017, 09:14 
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Hi, Doesn't that just #@$%& Actually for small signal tubes like the 12AX7, 12AU7, 12AT7 family and 6DJ8s either EH or TS seem OK. I do get better sound (lower measured distortion) from the JJs though. For 5751 the NOS Philips is my tube of choice then the Sovetek. The JJ 5751 sound funky in my designs. New production Mullard small signal ones sound ok, but measure worse (about 3X) than the JJs and are about 1-3 db noisier in high gain circuits.

On the subject of tubes ....Psvane KT88s do not work in the Oddwatt amps. That is unless you like fireworks.

All this plays havoc with designers. Design something, then build it, then see smoke and fire.. :hot: ...then wonder what is amiss. :| Only to find out that the tube manufacturer is at fault. :evil:

Good listening
Bruce

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PostPosted: 17 Feb 2017, 09:19 
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Each and every day I play with tubes, I count myself blessed with having an adequate stock of NOS/NIB US/Euro 'golden-age' tubes such as will last me the rest of my natural life - and likely into the Grandkids' if they wish.


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PostPosted: 17 Feb 2017, 12:04 
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[quote="gofar99"
All this plays havoc with designers. Design something, then build it, then see smoke and fire.. :hot: ...then wonder what is amiss. :| Only to find out that the tube manufacturer is at fault. :evil:

a) Is at fault.
b) Is 8,000 + miles away.
c) Does not give a %^&*().
d) And makes their dealers 'deal' with the issue anyway.
e) Thereby forcing up prices.
f) Which they can then further exploit.
g) Rinse, and repeat.

Now, keep in mind that very nearly ALL modern tube manufacturing off-shore of the US is based on Soviet or Mao era tooling that was never very good in the first place. All leading to a nice warm and fuzzy feeling when purchasing these products.

WE still makes tubes on American soil, but using legacy tooling and jigs. I wonder what the break-even price and minimum volumes involved in actually starting up a tube manufacturing facility actually involves. The tooling alone must be horrendous.

http://vintagetubeservices.com/sylvania-factory-tour/

Do you imagine for one hummingbird heartbeat that the tubes you are purchasing today go through anything near this level of QC?


Last edited by Peter W. on 17 Feb 2017, 16:34, edited 1 time in total.

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