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. The next step would be to consider which Change Code the tube has been developed under. Usually looks like I61, etc. This is much more complicated since there is no standardization on that, each factory used their own codes.
Rarest of the Rare: Amperex Holland 7308 Bugle Boy Ever Verified by !
Full and chimey mids, a tight bottom end and greatly reduced hum and noise characterize this Fredenstein F Tube Microphone Preamplifier The F is a professional tube microphone preamplifier, using two double-triodes, one ECCS and one ECCS, in a single series rack module. The tube is unused and has NOS test values that match the factory specification very precisely and balanced systems.
The tubes have the typical plate structure of the Telefunken ECCS with reinforcement and of course the diamond bottom. To Contact Form. It is rumored that Tesla actually made many tubes which eventually were labeled, boxed, and sold as German Telefunken, and the ECC S is a prime example of this often-discussed practice.
Tube Type / Number: 6DJ8/ECC88 Actual Brand*: Amperex Printed Brand: Amperex Quantity: 2 Pieces-Matched Pair Matching Date Codes? Yes.
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
8560AS-2 Transmitting Tube, Misc Amperex & Eimac Brand, (NOS – Older Date Code)
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.
Matched Pair Amperex 6DJ8/ECC88 tubes Dimpled getter – Holland Pair Amperex ECC88/6DJ8 O-Getter Heerlen Holland Same Date Strong.
Gi7b bias voltage
Although it has an american designation, the industrial type , I’m not aware of any US based company who made this tube. This saves you time – especially when working on your own adjusting or List of bomber aircraft organized by era and manufacturer. Also, not so unconventional is the use of Lundahl step up transformers to provide enough gain for low output MC cartridges. Note that all Philips subsidary companies Mullard, Valvo, etc and allfactories that made tubes under Philips license used these codes Ei, Toshiba,Siemens, etc so it’s not limited to European Philips tubes.
Tests NOS Date Matched Quad (4) Amperex Holland 6DJ8/ECC88 Gray Plate Tubes. Buy it now, $, Time leftd 19h 31m.
The use of this valve will give more headroom and clarity and lower the gain on a over distorted valve amp. The larger plates combined with crimped construction may contribute to the background noise it produces. You aren’t actually getting 60 mu out of a 12AT7 in a 12AX7 slot, and you aren’t getting anything close to 45 mu from a 12AU7. Someone said that the 12AU7-A prefix “A” is better ‘coz gives longer life for all the tubes. They were really hyped about years ago on this forum and I bought a complete batch for my 2 amps at the time.
With hand selected quality and solid, proven performance, this JJ ECCs is a wonderfully refreshing addition to the 12AU7 family of tubes.
Amperex Bugle Boy 6DJ8 / ECC88 – phono grade, matched pair
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
s s s vintage Amperex boxes and pictures of the tubes. 8 in code means – () 9th week of is the date in white marking. Amperex.
Log in or Sign up. Steve Hoffman Music Forums. Is this the rarest tube you have seen? Poll closed Oct 14, Location: Raleigh, NC. Audio Tubes. It is just possible that for some reason the Bugle Boy labels were only sold in Canada? The Holland name sandblasted into the glass is only seen on Dutch Philips or Amperex tubes coming out of Canada. Your pictures do reinforce some facts that still tell the real thing from the fake: The fake or tubes NEVER have date codes or production codes on them.
Yours does, so I will concede that you have one of the very few real Bugle Boy tubes in existence.
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I’d had a long experience with the top Siemens, Amperex, Philips,etc so the Brent Jesse (Great resource for tube date and factory codes).
Below is my list of pre tubes, as I currently only have hybrid tube amps, the Schiit Mjolnir 2 and the Monolith Liquid Platinum. I have not expanded much into 12AX7s yet, just two pairs to try so far. Sylvania still has more balance, more inner detail in male Cohen and female without sounding whitish. Great defined slam and bass extension.
Sounds about same, considering different age of tubes. Images larger and less dense.