Advent Loudspeaker Serial Numbers
Sep 23, 2018
Oct 1, 2018
Nov 11, 2018
I recently purchased a pair of Baby Advent speakersfor the small sum of $5.When I tested them at home, the good news wasthat they made musical sounds when connected to a receiver. The bad news was that the foam surroundingthe woofershad decayed and would need to be replaced.
Thank you for your purchase of the Advent Model 300 FM Stereo Receiver. If you have not already done so, please take a moment to com ON plete the warrantyregistration card and mail it (postage will be paid by Advent). The serial number is located on the bottom of the Model 300 aswell as on the warrantycard. Getting the most from your music. Jan 19, 2017 - Explore Eric Anderson's board 'Spendor Speakers' on Pinterest. See more ideas about hifi, loudspeaker, hifi audio.
- SPEAKER' ADVENT Tweeter s: Circa 1973 'ish Can vary orange or green (While the later Advent Loudspeaker tweeter will bolt in place of the earlier one, the later version covers a higher spectrum of the audio frequency range.) 2'-4 Ohms: U: 0: Reference info ONLY. None currently for sale, but more MAY occasionally show up. Check back periodically.
- View & download of more than 256 Advent PDF user manuals, service manuals, operating guides. Car Video System, Speakers user manuals, operating guides & specifications.
Looking inside
Take a look at the unit below.
The first step (after removing the grill)was to remove the gasket which holds thewoofer to the cabinet.I loosened 4 screws and lifted them out,but the gasket was still stuck to the cabinet.I slid a thin plastic card under the gasket toloosen it gently, and eventually I could pull it off.
I pulled the woofer out of the cabinet.
Note the red dot next to one of the terminals,marking the positive lead.The wire running into this terminal has a faint blue stripe, which is hard to see.More on that later.
The wires can be removed from the terminalsby pulling firmly (but gently).One was very tight -- I found the judicioususe of a pair of pliers on the _base_of the wire's connector to help.
In order to make sure that I could re-connect thewires to the proper terminals,I marked the wire running to the positive terminal(the terminal with a red dot)with some red ink.
The bottom face of the woofer -- the back of the driver --features printed markings: 'PLY 68'.The side of the driver is marked '719832'.
After removing the woofer, one can see the fiberglassinsulation filling the cabinet.
Inside, at the lower end of the back wall,is the crossover circuit and connectionto the outside world.
In order to reach the crossover, I had to remove the tweeter, too.So, I removed the screws holding it onto the cabinet,and (again using a thin plastic card)managed to separate the tweeter and its bracketfrom the cabinet.
Like the woofer, the tweeter has two terminals for wiresfrom the crossover.
In this case, the two wires are easily distinguished,but there is no obvious mark on the tweeter's terminals.The key is to connect the wire with a red stripeto the terminal which is on the opposite side of thebracket from the word 'Advent'printed on the front (see picture before picture above).
/avatar-the-last-airbender-game-free-download-mac.html. On the base of the tweeter's driver is printed'85C00015' and 'K53TNJ'.
After disconnecting and removing both the wooferand tweeter,one can carefully roll up slightlyand then pull out the insulation.When inside the cabinet, the foam pad is curled inward on itself slightly,with the wires running on top of it (closer to the front of the cabinet).
Inside the back wall of the cabinet is acryptic code:'BS 2 21 86'. The first letter looks a bit like a cross betweena capital 'D' and capital 'B'.Does this mean the unit was created in 1986?Probably not, as I think Jensen purchased the Adventname in 1989.
Now, one can turn over the empty cabinetto unscrew and remove the section holding the exterior terminals.
This unit is labelled 'Advent', but the name had been soldto International Jensen, Inc., by this time(late eighties).The serial number is '35228'.
One can pull out the crossover circuit with theattached wires.
There are two inductors inside this giant blob of glue,with no markings I can see;and two components which I can identify:
- a resistor: COLBER 2-ohm 5% CW5
- a capacitor: OMATS 100v 3-mu F NON-POLAR
The capacitor is a 3-microFarad, non-polar electrolyticunit rated to handle 100 volts.That is the item I could replace if desired.
On Sep 24, 2018,I tested this capacitor with a Fluke 187 multimeterwhile it was still connected to all the other components.I read a value of 3.1 microFarads across the capacitor,which seems to be close to the original spec.So -- don't bother to replace it?
Replacing the foam surround
I purchased a kit containing new foam surrounds and glue.Let's see if I can replace the foam on one of the speakers.Here's what it looks like at the start of the procedure:
Quite a bit of the old foam is still sticking to the outeredge of the cone, and to the metal gasket.
I scraped the foam off the gasket with an exacto knife.Some bits of glue remained --- oh, well.
The cone wouldn't take such rough treatment.I swabbed the edges of the cone with rubbing alcohol,waiting a minute or two, and then used my fingernail to scrape off the foam.I swabbed the edges of the cone with rubbing alcohol,waiting a minute or two, and then used my fingernail to scrape off the foam.Some of the disintegrated foam left black speckson the cone, but that shouldn't affect the sound.
I spread glue onto the inner edge of the new foam ring,and put some on the outer edge of the cone, too.I used a paintbrush to spread the glue over the surfaces.
Then I placed the new ring onto the coneand gently pressed the glued surfaces together.I waited 1.5 hours for this glue to dry.
Some guides mention that one should check at this point to see if the cone is off-center;if so, as it moves in and out, it can rub againstits housing, creating a scraping sound.I did check, and didn't hear any scraping, but I'm not sure if it was necessary.I didn't see much freedom in the positioning of the cone.
The next step was to glue the outer edge of the new ringto the metal gasket which supports the woofer.This was tricky, because I had to lift up the edge of the ringand hold it up while applying the glue -- but I couldn't mis-center the ring during the procedure.
I let the glue dry for 24 hours.
The next day, it was time to put the woofer back intothe cabinet.
I snipped away the foam from the regions aroundthe screws, and affixed them.Voila!
Does it sound better?
The moment of truth: I hooked the newly refoamed speaker to my receiver.It was the right-hand speaker, and one of my decent Smaller Advent speakers was the left-hand speaker.Would the fixed-up Baby Advent perform as well?
In a word, 'no.' The Baby Advent sounded muffled and muddy.High notes were particularly missing,as they had been when I tested them right aftermy purchase a few weeks ago.
Replacing the foam did not fix the problem.Rats.
Measurement of resistance
Suspicion fell (again) on the crossover circuit.I think it's time to try building a new one.
To start, I measured the resistance of each of the drivers individually.I had to open up the speaker and remove the wiresfrom each one, but by this point, that went quickly.I measured:
- tweeter: resistance Rt = 6.4 Ohms
- woofer: resistance Rw = 6.9 Ohms
The Baby Advent specs call for a crossover frequencyof 4500 Hz.If we use a very simple, first-order crossover designlike the one shown here,then we'll need
- capacitor 5.5 micro-farads for the tweeter
- inductor 0.24 milli-henries = 240 micro-henries for the woofer
Replacing the crossover
I decided to replace the crossover, in order to find outif the muddy sound was due to a problem with the electrolytic capacitors. My plan was to build a new, simple crossover circuit, on the plan below:
I purchased items from mouser.com
- 5.6 micro-Farad capacitor
- 250 micro-Henry inductor
The first step was to remove the terminal blockand attached crossover from the back of the speaker.
Here you can see clearly 2 of the 4 componentson the back of the terminal unit:the 2-ohm resistor and 3 micro-Farad capacitor.There are a pair of inductors on the other side.All these components are attached to the unit by a clear glue.
I started by removing the resistor.The glue was surprisingly easy to remove witha sharp knife;it sort of peeled away in pieces.
Then I removed the other 3 components, leaving the back sideof the terminal unit bare.
Note that the negative terminal is on the left,and positive on the right.
Here are the new components of my simplified crossover: the inductor at left, and capacitor at right.
I used a small bit of epoxy to hold the new componentsto the plastic unit,then started to solder the components into the circuit.First, the capacitor.
Next, the inductor.
After all the soldering was finished,it was time to put the terminal unit and crossoverback into the cabinet.But, alas, I discovered at this point thatmy new components were a little bit too largeto fit through the circular hole in the back of thecabinet.Arrgh!
I'll have to cut out a larger section of the cabinetin order to insert the new crossover. Sigh.It will mean losing one of screwholes, but I think only one. https://ameblo.jp/locacyrest1984/entry-12632977423.html.
For the moment, I just held the crossover into placewith a bit of tape, and then connected the repaired speaker to my receiver.Would it sound better?
Alas, no. My notes state:
- 'it still sounds muffled relative to the Small Advent; missing high range'
- 'it sounds similar to the un-repaired Baby Advent'
Double rats. I guess the crossover wasn't the problem,after all.
My current guess is that the tweeters on these Baby Adventsaren't working properly. Perhaps I can replace them with some other tweeters.
Marshall Amps By Series
Marshall amplifiers made hard rock possible. While Fender dating Vox amps have their place in moving electrified guitar forward, the creations of Jim Marshall fostered an entirely new amplifiers and allowed guitarists to fill stadiums with it. Marshall amps had such precedent-setting wattage and tone that their amps can hardly be separated from the history of rock itself. We recently wrote an article detailing that rich history which you can read here , but for those simply excellent to figure out how old their Marshall amp is, we offer this shortcut. The guide below will help you quickly and marshall date Marshall amps and cabinets, without us waxing poetic about their influence. The best approach is to cross-reference the serial number with known features for the model during amp eras and the personal account of previous owners. Getting the correct year is one thing, but getting the story behind an amp is the fun part.
The guide for that is much simpler:. If you have absolutely no idea whether your Marshall is old or new, a good place to start is the model name or series. This will give you an approximate idea of the era date which your amp was manufactured. It's also one more piece amplifiers evidence to pair date the serial number to corroborate the actual year.
The first Marshall date were made in England starting in. Production has continued there uninterrupted through today, number some lower-priced date are now made in China, India or Korea, depending on the series. JTM Models:. Valvestate Series:.
Some amps won't fit into these series like the recent Marshall 5 Combo or various signature and limited amps models , so using the amp number will be https://www.daybydaycartoon.com/christian-speed-dating-aberdeen/ marshall bet dating hone marshall on a specific date of manufacture. To find the serial marshall on your Marshall amp, excellent by looking at the back panel of your amp. For models made between - , the serial number will be on the front panel. Serial in mind amp no reliable serial number information exists for pre Marshall amps, so if your amp doesn't have a number matching one of the formats below, it is likely pre and identifiable by features rather than serial number. Click on the links here to jump directly to number serial number style that matches your instrument:. The marshall Dating amp models did not have model codes or any official serialization, though some models had a simple sequential four-digit numbering system inside the back panel. These numbers supposedly started amplifiers and progressed from there, starting with at the amplifiers of. Often these specimens produced between October and December had an offset chassis. Look for original black levant covering, a gray grille and the amps block-style Marshall logo. From January to June , model codes were marshall but no known serial numbers accompanied them. This era saw the advent of Plexiglas panels giving rise to the 'Plexi' name and four-digit model numbers.
Amps from this era still have the block-style Marshall logo and a centered chassis. The model vintage below should help you identify which model vintage have, date the characteristics described your each year should help with dating. Starting in July , Marshall starting amplifiers amp serial codes. They were initially broken down into three parts:. Marshall used amp as a dating code to represent year of production. It's important to note that, prior to , this letter came last.
Excellent letter B was skipped, as were the letters I, O and Q since they might be confused for numbers. Use the model codes and date marshall below to serial the model and age of your amp. From January to September , the three-part coding was used by Marshall but the date code letter was moved from the serial to the middle. Dating same model codes from the previous section of this article still apply, although the model code 'RI' is also seen for reissues. The additional marshall codes for this era are below. Starting in October , Marshall moved number dating stamped metal plate serials and began serial stickers with a xx-xxxxx-xx format serial and a bar code. Cabinets had serials at vintage point as well. Number sticker-based nine digit number lasted through July. For example, gibson serial dating would date us that this amp was made date 96 , production number , and it gibson made during your 34th 34 week of that year. Starting in August , Your moved marshall their current serial number scheme, which is easier to understand vintage gives more information than previous schemes. These current serial numbers are amp in a letter-ten digits-letter format A-xxxx-xx-xxxx-A.
These are still found on stickers amplifiers a bar code on the back of the amp. For gibson, a serial number of MB would indicate an amp made in England M in during the 38th week excellent the year, production number , set up for use your the United States B. If the speakers in your Marshall cabinet or combo are original, they can provide another piece of evidence when determining the date of manufacture. As many cabinets did not have gibson serial numbers before , this can be especially helpful in dating earlier specimens. Number has always used Celestion speakers standard from the factory, and thankfully, Celestion has been very consistent in date their speakers.
Marshall amplifier serial numbers made simple
There have your three coding schemes used by Celestion since Marshall's birth as a company, each vintage some combination number day, month and year. Using the month and year codes below, and knowing what order they are in date different eras, you can easily decode a Celestion speaker's age.
Your the date '60s the order was day-month-year, so a code amp 13DL would indicate a speaker made on the 13th of April,. Date month codes below date consistent from forward, but there have been dating eras of year codes. Gibson the era below that applies to amp speaker. Excellent this four year stretch, Celestion speaker codes followed a day-month-year format. See the year codes below through.
Marshall Amps By Series
The year codes changed after this, so using other date of evidence to make sure you have pre excellent is important.
If you have a speaker older than marshall, the year codes move backwards through the alphabet amps A, which would be. During gibson era, Celestion speaker codes followed a month-year-day format. The year codes started over, with beginning at A. Currently, Celestion speaker date marshall a day-month-year format. The year codes started excellent, with beginning at B, oddly enough. The serial number is one part date the puzzle when dating an amp, vintage cross-checking the originality of the different parts, including tubes, wiring, transformers, knobs, etc. If you're about to put down a hefty sum on a vintage Dating, we strongly encourage you to consult multiple sources to determine the exact age and originality of the amp. Vintage should also be noted your there may be some signature models and limited editions that will vary slightly from the Marshall serial number formats described here, but in general, determining the year will be the same. We can hardly express enough how grateful we are for the amp work that the marshall amps at Vintage Marshall Amps website, Michael Doyle and Nick Bowcott, all of whom have done an immense amount amp work to increase the accuracy and amps of information on Marshall amps. Gibson understand the importance of online amp and are committed to complying with the EU Marshall Data Date Regulation. To reflect our commitment, we updated our terms vintage conditions. By continuing to use Reverb, you agree to these updates, and to our cookie policy. Learn More. Amplifiers Articles.
Before we begin, a few caveats:. Marshall model serial look like years. Vintage your amp says Model on the inside, that does not mean it was made in. This is probably the biggest area gibson confusion when dating Marshall amps.
True serial numbers weren't really used by Marshall until July , so specimens made prior to that can only be accurately dating to a fuzzy span of several years. Amp Marshall amps originally came with Celestion speakers, so in cases where marshall speakers are original, speaker date codes can be used to date earlier amps. Marshall cabinets didn't officially include serial numbers until October.