Anyone heard of tubes from "Penta Lab"???
Paul Bacchiocchi
>Hi:
>Recently, I bought couple of tubes here in Australia. and all of them
>are labelled as "Penta Lab ...... CA USA". It make me quite suspicious
>as a KT88 is half the cost of a KT66, and a EL34 is 40% of the cost of a
>6L6!!. and I never heard of this brand of tubes until I came here recently.
>but they are very easy to find here in shops that sell tubes. I was
>wondering whether they are relabelled stuff from the US?
>Just hope they are not "Penda~~ lab" !!!
>ZZ
I believe that the Penta tubes are made in China and distributed by
Penta Labs in the US. We used some 4CX5000s for a while and they cost
much less than the equivalent EIMAC tube and seemed to perform well.
Had one failure where the handle (part of the external anode) broke
off the tube, but suppose that could happen to anyone... if they only
would make a 1L6.
Cheers
Paul
-----------
Paul Bacchiocchi N1DGT
Analogic
Medical Division
CT Engineering pbacc...@analogic.com
home bacc...@ici.net
Views expressed are mine, and don't reflect those of my employer,
my wife, or even my cat.
S.T. Zhang
Kevin Fok
I've some NOS 6336C made by Penta Lab USA. Their logo is a tiger head and
their tubes are top grade. I don't know whether they actually made tubes.
If your finds are genuine then you've just hit a gold mine ! If they are
fakes (eg. re-labelled stuff) you'll find out very soon. Please email their
address to me, I'm interested to order a couple to examine. To do all of
us a big favour (most of us have been starving for tubes for years ! What
is that medical term for this 'tube sick' passion ?), please consider to
describe your new finds KT88, EL34 in detail (appearance & perhaps tube tester
observations).
thanks...Kevin
idk...@smart.net
> Hi:
>
> Recently, I bought couple of tubes here in Australia. and all of them
> are labelled as "Penta Lab ...... CA USA". It make me quite suspicious
> as a KT88 is half the cost of a KT66, and a EL34 is 40% of the cost of a
> 6L6!!. and I never heard of this brand of tubes until I came here recently.
> but they are very easy to find here in shops that sell tubes. I was
> wondering whether they are relabelled stuff from the US?
>
> Just hope they are not "Penda~~ lab" !!!
>
> ZZ
>
>>>>
THey also market some tube amps. The tube will indicate Md. or Calif. Either way its a low quality Chinese KT88. Jolida stopped
using them in their own amps. They now use Svetlana 6550's.
Art
Tremolux
better off buying Sovtek or Svetlana Russian tubes.
Regards.
Kevin Fok
tiger head ? I could not substantiate my claim about the Penta
Lab tubes that I said I had because I could not find them !
What I did find are some Los Gatos 6336A, they have a wild cat
logo. However, I have heard of Penta Lab tubes but just don't
remember where I saw the ad. I'm still interested in getting
more details about this Penta Lab tubes.
I hope I did not caused any confusion !
..Kevin
Kevin Fok
>s...@radius.rdt.monash.edu.au (S.T. Zhang) wrote:
>>Hi:
>>
>>Recently, I bought couple of tubes here in Australia. and all of them
>>are labelled as "Penta Lab ...... CA USA". It make me quite suspicious
>>as a KT88 is half the cost of a KT66, and a EL34 is 40% of the cost of a
>>6L6!!. and I never heard of this brand of tubes until I came here recently.
>>but they are very easy to find here in shops that sell tubes. I was
>>wondering whether they are relabelled stuff from the US?
>>
>>Just hope they are not "Penda~~ lab" !!!
>>
>>ZZ
>
>their tubes are top grade. I don't know whether they actually made tubes.
>If your finds are genuine then you've just hit a gold mine ! If they are
>fakes (eg. re-labelled stuff) you'll find out very soon. Please email their
>address to me, I'm interested to order a couple to examine. To do all of
>us a big favour (most of us have been starving for tubes for years ! What
>is that medical term for this 'tube sick' passion ?), please consider to
>describe your new finds KT88, EL34 in detail (appearance & perhaps tube tester
>observations).
>
>thanks...Kevin
>
is a very bad choice of word. I have absolutely no intention to
imply that Penta Lab sell/make/supply 'fake' tubes in any respect.
..Kevin
Standard disclaimer apply to all my postings. My opinions are my
own, I do not represent my employer.
GGJaguar
and 6L6GC). All were Chinese. I called Penta and spoke to a rep that
told me that they don't deal in NOS tubes. I asked him about the origins
of my tubes and he said the "they get tubes from all over the world and
that they could be Chinese."
They were Chinese - I compared them to known Chinese tubes.
Not worth the bucks, so I sent them back to the dealer.
Regards,
GG
Marc Heijligers
| Penta Labs just re-labels cheap-ass Chinese firecracker tubes. You'd be
| better off buying Sovtek or Svetlana Russian tubes.
I'm getting a bit sick of all these anti-Chinese tube postings. There might be
some bad Chinese tubes on the market (and some severe problems were known with
some types about 5 years ago), but I know lots of people who are using Chinese
tubes for years and years without any problem, without any (measured) degrade
of performance and with superb sound quality. This means that there might be
bad Chinese tubes on the market, but the generalizations often posted are just
WRONG.
I do know two people driving Ford cars, and both had severe problems with
their gear. Does this make all American cars crap, and are we better of buying
European or Japanese cars?
Marc
Tremolux
Then take some Pepto Bismol. If you don't like my posts, don't read them.
Feel free to put me in your kill file.
David Josephson
>In article <4e9p08$3...@newsbf02.news.aol.com> trem...@aol.com (Tremolux) writes:
>| Penta Labs just re-labels cheap-ass Chinese firecracker tubes. You'd be
>| better off buying Sovtek or Svetlana Russian tubes.
>I'm getting a bit sick of all these anti-Chinese tube postings. There might be
>some bad Chinese tubes on the market (and some severe problems were known with
>some types about 5 years ago), but I know lots of people who are using Chinese
>tubes for years and years without any problem, without any (measured) degrade
>of performance and with superb sound quality. This means that there might be
>bad Chinese tubes on the market, but the generalizations often posted are just
>WRONG.
Marc, there are two basic problems. One is the bad quality control that
seems pervasive in all the Chinese tube factories, Shuguang particularly
but even the military shops in Beijing. Exhaustive testing by
the importer can put a bandaid on this problem. The other is a deliberate,
fraudulent misprepresentation in the case of the KT88. When you use a
type number for a known world standard, it is implied that your device
can be used just as the standard types are used. Mullard defined the KT88,
and the spec calls for a nominal plate voltage of 450 with a max of 750, if
I recall correctly. The Chinese spec sheet for their KT88 shows a nominal
plate voltage of 250 and an absolute max of 400! Plug them in a modern
amplifier with 350 or 400 volts on the plates and they go bang! A company
(in this case, the Ministry of Electronics Industry, export division)
that follows this practice deserves all the contempt they get. If they
called it a KT87, or a KT88 minus, or a KT88-for-low-voltage-guitar-amps-only,
you wouldn't hear so much bashing. But as it is, people get upset when
they are taken advantage of, (especially when their equipment is damaged
by this) and tend to forget that the same company makes decent low
level tubes and a few good power amp tubes such as the 807.
--
David Josephson / Josephson Engineering / San Jose CA / da...@josephson.com
Steven L. Bender
Lab"???>, 'ma...@boa.es.ele.tue.nl (Marc Heijligers)' wrote:
>I'm getting a bit sick of all these anti-Chinese tube postings. There
might be
>some bad Chinese tubes on the market (and some severe problems were known
with
>some types about 5 years ago), but I know lots of people who are using
Chinese
>tubes for years and years without any problem, without any (measured)
degrade
>of performance and with superb sound quality. This means that there might
be
>bad Chinese tubes on the market, but the generalizations often posted are
just
>WRONG.
with their 6550 / KT-88, etc., Chinese Tubes!!!
I'm waiting !!!!
--
Steven L. Bender
Roy Morgan
>
>I'm getting a bit sick of all these anti-Chinese tube postings.
..
I know lots of people who are using Chinese
>tubes for years and years without any problem,
Marc,
Would you please tell us more about this?
- The tube types your friends are using
- The equipment the tubes are used in
- What service conditions: continuous, occasional, home, commercial ...
Thanks in advance:
--- Roy Morgan / Nist North / Building 820 - Room 562 / Gaithersburg MD 20899
(National Institute of Standards and Technology, formerly NBS)
301-975-3254 Fax: 301-948-6213 Internet: mor...@speckle.ncsl.nist.gov
---
David Lawrence
very good to me.
I have also found in an amplifier that Golden Dragon
12au7's compare very well to new old stock American
and Eastern European.
No problems with any of these tubes, although I know
that the situation could be different with some power
tubes.
Marc Heijligers
| Would you please tell us more about this?
|
| - The tube types your friends are using
E82CC, E83CC, E88CC, 2A3, 300B, EL34. I also heard positive rumours from other
friends about EL84 (I prefer the sound of the EL84 Sovtek BTW), ECC81, 211 and
807 tubes.
I know there were some severe problems with the EL34 Super tube a couple of
years ago due to a bad soldering junction inside the tube. After the problem
became visible (which I agree should have become visible in the testing phase,
not in consumer equipment at home) the tube has been withdrawn from the
market. I also know that the KT88 had some severe problems, but I'm not aware
of the current status. Maybe this is a bad tube, but again, this isn't true
for all the Chinese tubes from Golden Dragon.
| - The equipment the tubes are used in
Audio Innovations, Audio Note, VAA and DIY products.
| - What service conditions: continuous, occasional, home, commercial ...
Most of them are used in home conditions. Some are switched stand-by, and
therefore can be considered to be used continuously.
I'm succesfully using E82CC, E83CC and EL-34s for about 3 years in my Audio
Innovations amp, with no problem whatsoever. I must confess that the tube is a
bit dirty inside (due to lead oxidation), but this situation is stabalized
after one year, and I couldn't hear a difference in sound compared with rather
new EL34s. I did try out lots of other tubes (Sovtek, National, Philips,
Tesla, General Electric, Mullard etc.), and I think that only the General
Electrics came close w.r.t. the sound perceived (and my preference ofcourse,
but this is shared with lots of people). I buy my tubes at a place where I get
a warrantu, i.e. if a tube dies within half a year I get new tubes for free.
I heard that Golden Dragon (Shuguang)is shipping EL34M (a remake of the
Mullard) and a new EL34S (expected longer life) tube. Has anyone any
experience with these tubes? Can someone describe their sound?
Marc
Don Borowski
: | Would you please tell us more about this?
: |
: | - The tube types your friends are using
: E82CC, E83CC, E88CC, 2A3, 300B, EL34. I also heard positive rumours from other
: friends about EL84 (I prefer the sound of the EL84 Sovtek BTW), ECC81, 211 and
: 807 tubes.
: I know there were some severe problems with the EL34 Super tube a couple of
: years ago due to a bad soldering junction inside the tube. After the problem
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The only solder joints that I know about in tubes is the ones between the
wire leads coming through the glass and the pins of the (octal) base.
And this joints can be repaired with a bit of work.
So far as I know, the joints inside the envelope are all spot welds.
Donald Borowski WA6OMI Hewlett-Packard, Spokane Division
"Angels are able to fly because they take themselves so lightly."
-G.K. Chesterton
O'Connor
i.e. musical instrument amps. Most of the pro applications are combo-amps
where the amp chassis lives next to the speaker in the the same cabinet.
Needless to say, this is the worst environment for tubes to be in as they
will almost always fail mechanically before they fail electrically.
The poor inner support structure of the Chinese types lead to serious
microphonic problems for most users. The vibration often lead to the
opening of not-so-great-to-begin-with internal connections, resulting in
the usual flash or meltdown.
The tubes generally survived better in separate cabinets, away from the
speaker sound field. This is how things optimally are in a stereo set-up,
so it may be found that reliability is not so much of an issue. However,
the less than tight tolerances to which Chinese tubes are built, results
in a more variable tone from one device to another, and a different tone
compared to the usual old-stock reference tubes.
As a point of interest, I have found the general quality of Chinese tubes
to be inadequate. Russian tubes made by Reflector, and sold as Sovtek,
and those made by Svetlana ARE of consistent high quality.
Kevin O'Connor
John Allgaier
>To do all of us a big favour (most of us have been starving for tubes for years ! What is that medical term for this 'tube sick' passion ?),
>
>
Tube-itis in Tubular Hell(s)!
John :-)
Grego Sanguinetti
>I'm getting a bit sick of all these anti-Chinese tube postings. There might be
>some bad Chinese tubes on the market (and some severe problems were known with
on the bad side:
Yes, it's a generalization because as others have pointed out, many of these
people assume we are only talking about guitar amp tubes... Many of those
tubes have gotten a very bad reputation for very good reasons and should be
avoided.
on the good side:
Of the very commonly used tubes, the only Chinese versions I have found to
be reliable are the Sino 12AT7's. I have had good luck with them.
I have also had good luck with the 2A3's. They seem to be very consistant
and reliable. I know a number of people sucessfully running Chinese transmitting
tubes like the 211 and 845's but I don't have personal experience with these
yet.
-grego
--
---------------------------------------------------------------------------
Grego Sanguinetti, Lattice Semiconductor Corp. | Water, water everywhere,
gr...@lattice.com | but I'd rather drink beer.
Steven R. Rochlin
Marc wrote:
> I'm getting a bit sick of all these anti-Chinese tube postings. There might be
> some bad Chinese tubes on the market (and some severe problems were known with
> some types about 5 years ago), but I know lots of people who are using Chinese
> tubes for years and years without any problem, without any (measured) degrade
> of performance and with superb sound quality. This means that there might be
> bad Chinese tubes on the market, but the generalizations often posted are just
> WRONG.
Well, i'll speak up here. My feelings are that it's DEFINATELY
worth the extra few bucks for Soviet, or better yet N.O.S. tubes of
known quality. Mullard GZ34's are awesome !!! Grego, the Chinese 300B
Super cause ringing in my Wavelength Audio Cradinal amplifiers.
The WE300Bs i got are LIGHT YEARS AHEAD of the Chinese tubes. i will
NEVER try a Chinese tube in my Audio Note 211 based amplifier. GE VT4C
(211's) is all i use. The RCA's weren't as good at reproducing music
to MY ears in MY opinion. If the Chinese tube (KT 88, EL 34, 12AX7)
is THOROUGHLY TESTED and will meet up to the specs, then we may have a
good un'. Sonics are another matter to be .
> I do know two people driving Ford cars, and both had severe problems with
> their gear. Does this make all American cars crap, and are we better of buying
> European or Japanese cars?
Actually, i drive a Honda made in Japan (Del Sol), though i long
for a Ferrari. The Viper may be fast, but have you ever tried to do
"L" turns is one as compaired to, say, a Porche or Ferrari??? OK, i love Formula 1
type cars and not stop light to stop light automoblies. The Viper has a
good 0-60 maybe, but let's see it on a Formula 1 course. Yokohamma's are my
tire of choice by the way. The opinions expressed are mine and do not
necessarly represent anyone else. My opinion and working too darn hard
will get you milk that "expired" on January 24, yet still sits in my
refridgerator!!!
Enjoy the music,
Steven
Enjoy the Music
------------------------------------------------------
TUBES RULE!!! The streets will flow with the blood of
the non-believers. --- Cornholio
------------------------------------------------------
Reid Kneeland
>Kevin Fok <ke...@bnr.ca> wrote:
>>What is that medical term for this 'tube sick' passion ?),
>>thanks...Kevin
>Tube-itis in Tubular Hell(s)!
My vote would be for "thermionophilia". (In advanced stages,
"thermionomania".) Its counterpart would be "thermionophobia".
Of course, the PC crowd would just say that you're "differently
amplified".
=====================================================================
Reid Kneeland
re...@tti.com
Transaction Technology Inc., Santa Monica, CA, USA (310) 450-9111 x2499
The opinions expressed above do not necessarily etc etc...
Never trust a man who can count to 1,023 on his fingers.
Marc Heijligers
|
| >to MY ears in MY opinion. If the Chinese tube (KT 88, EL 34, 12AX7)
| >is THOROUGHLY TESTED and will meet up to the specs, then we may have a
| > good un'. Sonics are another matter to be .
|
| These are exactly the tubes to avoid, especially the power pent/tetrodes.
Fairy tails keep goin' and goin'.
The 12AX7 is NOT a power tube, and is rated very high by many many people
(although there are probably enough people who will be able to give another
preference in this case, but hey, where is preference all about?).
The EL34 is not a tube to be avoided. Actually, in my and some other amps it
seems to sound superiour to other EL34s. I did compare with some Sovteks, but
these were of no serious competition.
I never, I repeat, never saw any problems with my EL34s and those of lots of
friends. Nevertheless, the tubes me and my friends buy are tested beforehand,
and we get a 6 months waranty. I think this should be a standard procedure for
ALL tubes. I've also seen other brands of tubes die, among which European, US
and Soviet tubes.
Marc
John Beach
<Much deleted>
>Yokohamma's are my tire of choice by the way. The opinions expressed
>are mine and do not necessarly represent anyone else...
I thought Yokohamma's were _tubeless_. So why are you mentioning them
here on rec.audio.tubes? <G>
(Sorry 'bout dat.)
John Beach
Grego Sanguinetti
> Well, i'll speak up here. My feelings are that it's DEFINATELY
>worth the extra few bucks for Soviet,
yes, in almost all cases. however I don't share the same sweeping
generality about NOS tubes. Lots are complete junk, overpriced at that.
There are alot of very good eastern block tubes on the market. I take
them very seriously. I do also have a large inventory of NOS to compare
to.
>known quality. Mullard GZ34's are awesome !!! Grego, the Chinese 300B
>Super cause ringing in my Wavelength Audio Cradinal amplifiers.
I have heard that from others also. I am not into 300's so can't
speak on those. I have had great experience with the 2A3's and know others
that have good experience with 845's... You definately have to pick the
right tubes if they are of Chinese origin! Too bad about the 211's as
I would like to try a 211 amp.
>to MY ears in MY opinion. If the Chinese tube (KT 88, EL 34, 12AX7)
>is THOROUGHLY TESTED and will meet up to the specs, then we may have a
> good un'. Sonics are another matter to be .
These are exactly the tubes to avoid, especially the power pent/tetrodes.
-grego
LarrySB
>I'm getting a bit sick of all these anti-Chinese tube postings. There
might be
>some bad Chinese tubes on the market (and some severe problems were known
with
Marc,
I understand your frustration, as I get tired of similar non-sense about
circuit boards vs. eyelet cards, silver wire, etc.
But, I have had problems with chinese manufactured 6550 on a consistent
basis. Number one, these tubes do not appear to live up to the ratings
for the type number, especially voltage. This is especially true in
circuits which operate close to the upper edge, both hi-fi and guitar
amps. AR, Marshal and some others specifically.
I have also had problems with 12AX7 types and microphonics and noise.
While I have heard some that were very good, they were prime hand-picked
tubes from a large lot.
--
Dr. Nuketopia
Technology Director of the World-Wide Monetary Conspiracy
All opinions strictly reflect the party line
Henry A. Pasternack
: But, I have had problems with chinese manufactured 6550 on a consistent
: basis.
I ordered four GE 6550s from New Sensor four years ago. They sent
me Chinese by mistake (and changed me for GE's, to boot). For a variety
of reasons, I never sent them back. Last year, I tried to use them.
One tube was dead out of the box. The filament lit, but the tube drew
no current.
Hurrah for the Chinese tube industry.
-Henry
Marc Heijligers
| I ordered four GE 6550s from New Sensor four years ago. They sent
| me Chinese by mistake (and changed me for GE's, to boot). For a variety
| of reasons, I never sent them back. Last year, I tried to use them.
| One tube was dead out of the box. The filament lit, but the tube drew
| no current.
|
| Hurrah for the Chinese tube industry.
And hurray for New Sensor, which seems to ship their tubes untested.
Marc
Adam Baum
>LarrySB (lar...@aol.com) wrote:
>: But, I have had problems with chinese manufactured 6550 on a consistent
>: basis.
> I ordered four GE 6550s from New Sensor four years ago. They sent
>me Chinese by mistake (and changed me for GE's, to boot). For a variety
>of reasons, I never sent them back. Last year, I tried to use them.
>One tube was dead out of the box. The filament lit, but the tube drew
>no current.
> Hurrah for the Chinese tube industry.
>-Henry
Adam Baum
punchy bottom end and overall liquidity thats tough to beat.