Amperex and Emiac tubes 4-400a

Tubes Asylum Questions about tubes and gear that glows. This has been intriguing me for a while now, and I’ve tried searching the archives, but I haven’t found this particular question addressed. Its quite wide ranging, but please bear with me. As I interpret the Philips coding system, they would all have been made in the Heerlen plant in the Netherlands, using the same design, at the end of Would they all be identical, other than the inevitable variation between individual tubes? Certainly nowadays, Mullard and Amperex have a cachet that Philips never seems to have achieved going by NOS prices with dealers and on E-bay, etc.

Gi7b bias voltage

Some other sites call Amperex a European brand. They are what I like to call – Wrong. They produced receiving, transmitting and special purpose tubes. Eventually they did develop a close relationship with Philips a Dutch owned company to market European tubes. For a while they were arguably the biggest seller of European tubes in the US.

Never before seen Bugle Boy Tube: Amperex (Holland) labeled (eqiv. E88CC or better) w/ the Bugle Boy logo (w/ production & date.

Hey fellas, It’s time to add some new tubes to my collection as I’ve pretty much exhausted my supply of spares. The 12AX7 was originally intended as replacement for the 6SL7 family of dual-triode amplifier tubes for audio applications. This website uses cookies, which are necessary for the technical operation of the website and are always set. In fact, neither of them is as clear as many other available choices such as any ’50s US-made 12AX7.

I’m not familiar with the voltage or bias placed onto the 12AX7 sockets of your unitbut it may be conservative. This late s-early s military spec Sylvania 12AX7WA tube has long gray plates with copper grid posts and a halo getter. New old stock vacuum tubes worldwide, these mil-spec have limited availability and prices are subject to change.

Philips 12AX7WA: Great full range response, deep bass and more high end than the JJ, this tube seems to have a really flat frequency response curve. The 12AX7 is a high-gain typical gain factor , low plate current triode, and is therefore best suited for use in the preamplifier input and mid-level stages of audio amplifiers, guitar amps , mic preamps etc.

The tubes I tested had lots of gain while still maintaining very good noise levels and good tolerance for microphonics. Browse our daily deals for even more savings! Free shipping on many items! We are always adding product so please check this page often.

Dating amperex tubes

A lot of questions have been asked about when a tube is made, so here you go, a quick guide on how to decipher the date codes. The code is broken down into 3 or 4 characters. The first 2 characters are the most important ones since the factory code would show where a tube was made and year, well, this one is super important since sound changes quite a bit for the same tube from the same place depending on a year.

For 3 character codes 8 means , for 4 character codes, 8 means either or that depends on change code — more about that later. Date codes are usually done with acid, so they are burned into glass.

with energy subtraction, with important publications dating as early as During those early years, there was a close interaction with the Amperex to acquire their developmental “Frogshead” tube by June , which later emerged.

All Rights Reserved. Built with Volusion. Join our mailing list! Valvo Holland and Hamburg used color print and design for the special features as follows:. Military tubes: can consist of ALL the below attributes, including special alloys too expensive for commercial use. Also, tubes with special Military markings were pre-tested for tight tolerances and matched sections, and made with the more expensive earth metals, and better glass bottles that can withstand temperature variations in combat, etc.

Red Label: Industrial tubes designed for long heater hours, durability, high tolerance, shock and vibration resistance, special cathode construction. Yellow label: designed for long heater hours, durability, high tolerance. Green label: computers, designed for long heater hours, durability, high tolerance curve points, special cathode construction. Special switching filaments. Used in missiles as an on-off switch, Industrial tubes designed for long heater hours, durability, high tolerance, shock and vibration resistance, special cathode construction.

Nonetheless, all tube specifications change over time or don’t change from the original factory testing, whether for Military, Industrial, or commercial, and they have to be re-tested now and today! That’s why proper tube testing is necessary for any tube, regardless of what a color-code, or class of tube designates.

Telefunken ecc83

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I am gathering some tubes for sale on an auction site and matching pairs. I have some Orange Globe logo Amperex ECC88 tubes marked “GR.

To prevent damage to equipment, it would be wise to double check with a good tube manual before actually doing a substitution. I have always been intrigued by tube amplifiers, but most DIY kits are very expensive and use very high voltage. Individual test measurement results for each tube along with photos will be provided to you upon your order. My Hickcock tube tester definitely has 2 columns and the actual tube types on the left hand side are considerably away from those on the left hand side.

Find reviews, data sheets and specs to help upgrade your tube amplifier and preamp. Some tube amps are really good to use as tube testers when you understand what tube sockets correlate to which channel. Not sure if this is the right subreddit for this, but I really appreciate any insight you can give me! The Unit: Here’s the schematic – I wish i could find a cleaner copy. Most tube testers were not designed to evaluate balanced plate sections when testing a filament-type rectifier tube.

If in doubt, check with your amp or preamp manufacturer to see if this tube will work OK in your application. Next, if you have tube-driven effects on your amp, try a 12AU7 or a 12AT7 and see if you prefer the results to a 12AX7 tube in this part of the amp. These are all pin compatable with one another, the only differences being the gain factor of each tube. Click on here for a variable voltage filament supply to accomodate odd voltage power triodes 2A3, B, 50, etc.

The tube sockets, and tubes 2 x 12AX7 and 1 x 12AU7 , along with the tube shield bases have now been installed.

Can you help me with Bugle Boy date codes

European number is ECC This tube has a 6L6 feel to it when playing softly, however the EL34 sound starts to shine once you crank the volume on your amplifier. These are a very consistently made tube, sweet sounding, and very warm. Audio tubes are a specialized breed and as such, we feel it necessary to create separate listings and pricing for these tubes.

Lightly used, Like New s Amperex/Philips ECC83 Halo Getter Tubes with DARIO Miniwatt Label. *Heerlen Holland Production Date Codes 4xxx (first letter​.

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7025 Vs 12ax7

Bias, external 12V supply, fed via a diode to the ground side of the grid coil, with a 33k resistor going to ground from the same point, bypassed by a 1nF cap. New in Box. SB GI7B conversion. It will need a filament choke and bias applied from a zener or zener and transistor combo. The perf board in the lower left contains a pot for adjusting the bias and two turn pots for calibrating the grid and plate meter scales.

I was sorting thru my amperex tubes & noticed that I had two tubes, ostensibly made in holland without the manufacture/date codes on the base.

Did you mean: amperes 18 items? Skip to main content. Include description. Vacuum Tube Items NOS Tube Items Triode Items Preamp Tubes 52 Items Amperex 1, Items 1, Mullard 60 Items RCA 40 Items GE 15 Items Raytheon 11 Items New Items

6DJ8 / 6922 / 7308 & Equiv

The vacuum tube business was a very incestuous one, so much so that you can rarely trust everything that is printed on a tube. Often, the printed brand or printed country is incorrect. Vacuum tubes were simply a commodity that everyone needed like batteries or light bulbs are today. For the most part, back then no one cared when a tube was made or who made it, they just wanted a good product that would work and bring their radio, amplifier or TV back to life.


Amplitrex at reviews. I think since most of the uses today are for audio amp the Amplitrex AT will give a Passable test. What physical sizes of tubes will the AT test? The AT accommodates 7 and 9-pin miniature tubes, standard octal tubes, and 4, 5 and 6-pin small base tubes with a filament voltage between 1. The casings on each of the 9V batteries were loose and hung up on part of the door making it very difficult to open.

There are much better sounding tubes out there than the stock McIntosh re-branded tubes that come with the equipment. It has an usb socket to connect with a computer for control and printing of graphs or tube measurement labels. The new amp sounds really good — spacious, detailed, dynamic — with most of the stuff I listen to, acoustic, voice, strings, orchestra etc.

Most of the time, you need to manually adjust the test settings for each tube type in order to tailor it to your needs. They say they’ll run your tubes at operating voltages on an Amplitrex AT and check for microphonics, gas, leaks, noise, etc. We offered in writing on several occasions to re-test the tube on Amplitrex AT tester, and replace it.

Of course not, so don’t feed your precious tuner a tube not knowing the complete specifications! Keep in mind that no tube tester is as good as testing the tube in the device it’s being used in.

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As the RCA manual states that the characteristics may fall in a range above or below the bogey values. Kropotkin, I just received the RCA tube in the mail, popped it into my amp, and let me say that it’s the greatest thing I’ve ever heard. It gives my strat loads of texture when played clean, and the is sounding great, even at high volumes Super Reverb Reissue. I have many varieties of NOS ‘s they used to sell for around 5 dollars or less and I still like the Sylvania grey plate gold pin the best.

Sovtek – The Sovtek is an affordable alternative to the 12AY7 used in original Fender tweed amps and can be subbed for a 12AT7 reverb driver tube.

Δ 4H1 = manufacture date code for 6DJ8/ECC Example: GA8 Δ 4H1 GA = 6DJ8/ECC88 GA8 = 6DJ8/ECC88 #8 = manufacture series Δ = Manufactured.

For this digital tube tester, the 6DJ8 has a center value of 27 and noise floor dBV. This tube was manufactured for Amperex by Mazda. As you can see in the photos, we’re including a new box that will be labeled with the manufacturer and type. Gray Plate Silver Shield. Always checked for shorts, leaks, gas and Gm, Emissions or Plate Current where applicable. I have many other types of tubes. A for the U. S Amperex Tubes. Lower Noise and Microphonics and typically last longer.

They are pulled from a working system.

Ecc802s tube

Skip to content Amperex tube codes Posted: Mar Fri 22, am. Manufacturer Location; B Sylvania was a major manufacturer of tubes from the s when they were

Tests NOS Date Matched Quad (4) Amperex Holland 6DJ8/ECC88 Gray Plate Tubes. Buy it now, $, Time leftd 19h 31m.

Philips Audio T ubes. Valvo Amperex Mullard. Logos and Labels. Understand Codes. Common Labels Label Colors. Other Tubes. They sound very nice in SE amps and in also push pull mode. See my favourite EL84 amps in “my equipment”! And in fact they are very good. BUT I think that many people want them, because they never got the opportunity to test the rarer German and British types Important Note: Construction types on EL84s differ more on where they were made than as code may show.

Identified by:. Code: rX?

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