It may not display this or other websites correctly. Over the years, permanent magnets reduced in weight, and became stronger and more affordable to produce. For a better experience, please enable JavaScript in your browser before proceeding. This is what I watched , without the special efforts and without doubt: This is much different than, say, a 2000 ohm field. The manufacturing process is considerably slower due to the extra precision and difficult tooling required. (lets assume we are talking about field coils in very good shape), Some of the add-ons on this site are powered by. constant. That's why I suggested running the OT and everything else through the field coil, like the organo did. The field coil is the big coil on the back of the speaker. It would probably cost around $35 to have that done. The larger Xmax makes the modern speaker have less distortion at higher outputs. My guess is it's closer to the 1.5A that yours does. Pretty much all those old amps used the speaker electro magnet as a choke in the power supply section of the amp. And this FC speaker can get some highs that don't hurt,they somehow blend in with the rest of the sound which all ends up very sweet. The nominal voltage 250 IN / current 60 MA. In other words, does it attach to the speaker and is removable, or is it inside where it can't be gotten to? Separately worth mentioning this impasse has direction in the establishment of power supply units for the speakers on the ,as sources of current and stabilizers on powerful lamps and transistor.Creation experienced it on the best components showed that the natural sound when different measurement methods it is very severely affected,as well as the clarity decreases significantly.For additional costs to the lamp and the capacitors absolutely not justified.The only task,which has successfully resolved using such TBT,this achievement of the high stability of the current field winding.However, side effect,the sharp deterioration of the sound,outweighs all the advantages of the stabilization of the regime. I have the coil Klang and RF speakers were included in series. Some older speakers did mount the output transformer directly on the speaker frame, so it wouldn't be surprising if you had a field coil and an OPT right there on the speaker. No on/off switch, eitherwhen plugged in it was on, and when not plugged in it was off. The high voltage power supply has no correlation with the amplifier being used, it only powers the field coil. You must log in or register to reply here. I worried about that with the open baffles as well, but they don't have any perceptible speed concerns at allif anything, I would say that they sound even quicker than previous setups I've owned. And so I watched the last step , inserted in the straightener 5 cm ,which he himself considers its the best .and the miracle of the tweeter speaker in the noble wave merged with ideal and any signs of .It smoother hearing impression , which has inspired me that( which I incidentally as it has already been expressed in the article about the amplifier Medvedev).Some of the most highly conductors are beginning to educate low organized elements and conductors such as domestic production.More, they capture the power in the power source and declare themselves dictators. WebGet the best deals on Vintage Field Coil Speaker when you shop the largest online selection at eBay.com. For such speakers better power diagram is a direct connectionto the rectifier network,without intermediate transformer.Even the best transformer a feeling of pollution of the sound and reduce clarity.Rectifier element ,it must be so good,how much you can afford to. straightening, transformer and high quality of the condenser,defines not only the level of pulsation,but and voltage on the coil to the field winding.It is desirable to use -Oil capacitors,by selecting the typical and type by . Each lines I replaced the and correctly on Anton . power supply filter choke as well. My frame is marked 1000 ohm. This is why you will find many different It a radio or phonograph the primary No controls, since the Princeton steel guitar already had a volume control. For the new power supply units had fabricated special Shamanic Development socket.In the Square area of the red wood holes and insert the loop wire ,relying on directions,all connections with the now we have already customized our working environment and twist together. You must log in or register to reply here. No on/off switch, eitherwhen plugged in it was on, and when not plugged in it was off. The heat was enough to change the resistance of the coils. This was a feature that could be used to mute the bass depending on the placement of the radio in the room, and it's a quite desirable feature that you should try to keep if at all possible. It will need to be around 10 watts, maybe more. A field coil speaker is a loudspeaker that features an electromagnet rather than a permanent magnet. A single Jensen 8 field-coil speaker (permanent-magnet speakers appeared in 1947).

There are also some vintage German field coil drivers that sound quite good.

The Rola electromagnet is Sometimes they can be a little pricey because it was used on the 9S232 Walton tombstone. With respect , Anatoly , I I decided to compareRGN4004cordinary silicon cells diode in the .Result expected ,but as the palm. Three tubes. Atelier Rullit Aero full-range field coil driver with tube rectified power supply. The reason I asked about the original coil is because you can sometimes remove it and mount it elsewhere saving the hassle and cost of a new coil or high wattage resistor. I have more schematics of the organo but I think these will be what you need. And when it is said it is full range, it is truly is full range, going below 100hz on its own and well over 15K on the high end. WebSix watts. All Rights Reserved. All times are GMT. The City Public Works Department will be paving the street during this time. Hammond HX-119DA) between the old audio output transformer and the new speaker, or replace the audio output transformer. It might be interesting to use a variable DC power supply for the filed coil speaker in a guitar amplifier. The full-range driver is allowed to gently roll off at the frequency extremes. Hopefully there are others here more into design/building who may have comments. Then connect the voice coil of the field coil speaker to the amplifier Around 1920, permanent magnets that had the necessary strength were simply too heavy, too big and, most importantly, too costly. has to do it. be designed to use the total current of the radio. The Jensen The amount of current through the field coil will affect the speaker in the same way magnet strength would. Electrical/Mechanical Repair and Restoration, Replacing electro-dynamic with permanent magnet speaker, http://www.thomasrsammon.com/zenithconsole.pdf, http://www.thomasrsammon.com/zenithspeaker.jpg, http://www.thomasrsammon.com/zenithcoiltransformer.jpg. The Fora platform includes forum software by XenForo. Finally I realized Single-ended source toKlangfilm,on the upmarket to RGN4004 and compared it with rectifier. New / Toyota / Tacoma / TRD Sport / 3TMCZ5AN2PM583852. In connection with the fact that I have reduced the resonance frequency of the mobile system Klang and the same open box I picked up to listen to the optimum supply voltage bias 200 in the . Stay below about one volt. no lack of bass. warm, you will have to reduce the current. What voltages do you run the different drivers at? 2. It has two legs that are flat in one plane. It appears that there is no hum bucking coil so the other two wires that exit the output transformer will go directly to the two terminals on the PM speaker. The heart of the speaker is the main full-range field-coil driver produced by Atelier Rullit. Are you running the Rullit and tweeter passive and the bass active with dsp and a separate amp? A question first. There are several factors in play here that make this not such a simple prospect. The voice coil is attached to the actual cone (exterior part) that makes all the noise. Stock: Smart Price. When you first turn on me literally question always consulted vulgarity sound. The field coil was used as the choke for the power supply and was about 1K ohms in resistance. Do you have the original speaker? Two inputs on the back. WebGet the best deals on Vintage Field Coil Speaker when you shop the largest online selection at eBay.com. Field coil drivers use DC powered electromagnets as a motor to propel the cone, whereas a standard dynamic driver will use a permanent magnet for moving the cone. This speaker is a car audio 6" x 9". There should be two that go into the "pot" and two into the transformer. Wow, looks like a fantastic setup!

Both have thin paper cones and the outer suspension is formed Vintage Field Coil Speaker for sale | eBay I have a 1000 ohm 12 watt resistor in stock. Supravox 165EXC, I have the 165-2000 AlNiCo version. What is the mildly a note was present at the RF and has separated from the . how many powers supplies do you have, and are they all the same? Since the field coil doubled in service as a power supply filter choke, current passing through that coil carried a ripple current, 120 Hz in the case of a 60 Hz power line, and that ripple current would produce a low but discernible level of hum in The field coil is the big coil on the back of the speaker. I've seen people use a separate choke and I've also seen a simple 1K power resistor used to replace the field coil. Field coils also have stronger motors that are determined by current and voltage and this makes their power delivery more constant and stable. These speakers have an It might be kinda neat to bolt the transformer (and choke?) the resistance of the coils. No controls, since the Princeton steel guitar already had a volume control. You may hear a faint amount of audio with no power in the field coil This is much different than, say, a 2000 ohm field. can drive that impedance. These exotic drivers sound outstandingly transparent and musical, making their counterparts that dont use field coils sound veiled in comparison. This is a radio that is often parted out, so the speaker or speaker/acoustic adapter assembly is usually very easy to find on ePay. Secure it some way and keep it in clear for ventilation cause it will run hot normally. If you still have the schematics, they should tell you the speaker impedance..Now onto the more important piece of information. Enzo. The field coil of each speaker was drawing enough current to get warm. Trans Fi Salvation tt w SOTA motor/Farad LPS & Terminator LT arm w Zavfino Litz wiring/Bocchino RCAs, Soundsmith Straingauge SG200 cart w P.Downs LPS, Eera Tentation cdp, Nat Audio Utopia pre w Mullards/Mazdas 6DJ8 tubes & SE2SE SET monos w NOS '48 GE tubes, Zu Definitions 4 spkrs w Duelund caps/Lundahl transformers, Stacore isolation platforms, Symposium Isis rack & Rollerblocks isolation, Sablon Reservas & Elites cbls w Bocchinos connectors, Westwick 8kVA balanced pwr, Oyaides dedicated lines w Furutech duplexes, SR Black fuses, PET boards acoustic treatments. Open-baffle speaker, approximately 30 wide and 52 tall in live edge Walnut or Elm. I ended with 4x EY500 and LCLCLC. A field coil drivers flux field density will remain constant whenever voice coils move in the motors gap. A sound Klang I do not deface ,therefore proceeded immediately to manufacture a separate source. speakers. To use one of these field coil speakers, apply a DC current to the field coil. Incidentally I found that when the source of the residual magnetization dynamics continued sound,truth quietly ,but the main they were perfectly,and at all levels of experience. how smooth are the Rullits in the upper octaves? firmSiemens10 cm Could you have the original re-coned? loud as the permanent magnet speaker, you have enough current. So the diode sounds more clear, but can be heard in the sound some rigidity or you can say the rudeness field , then the stiffener no but clarity smaller . very from all conductors of the source and increases when the network as straight as possible into the and further to the coil of the bias of the speaker. structure was iron with room for a coil of copper wire. The center is attached around the voice coil form. Whats Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. WebI prefer to replace the old one with a new modern speaker I have in stock. WebA field coil speaker is a loudspeaker that features an electromagnet rather than a permanent magnet. WebA field coil speaker is a loudspeaker that features an electromagnet rather than a permanent magnet. Usually the current is the more important bit- so whatever voltage gets the current needed. I seem to remember that this can be done by replacing the field coil which sits on the speaker frame with a resister of the same value. With a sabbatical 5u3 with 50 and although the sound disappeared finesse ,but what the sharpness and especially at being discussed at the remained .me it is not unnatural and I returned to the inclusion through the diode semiconductor Bridge, by entering a small wires before plus the electrolyte that bridges longer not fly. Even in free air there was Field coil speakers must, in general, be built by hand and are less convenient due to their reliance on an outboard supply of power. WebThe Supravox field coils are very smooth and relaxed, open and effortless, and with a good bit of bass energy in an open cabinet. WebThe original WE 755A was an 8 alnico magnet speaker designed shortly after World War II. WebKeynote Speaker - Chairman, Decouple China PAC - Publisher, Boardman Report - Host, American Enterprise Radio 6d Meanwhile, field coils were more affordable, lighter and capable of producing sufficient energy by utilising a power supply that was big enough. New permanent magnet speakers will probably have 4, or 8(most common) ohm voice coils, so you will need to either add a matching transformer (e.g. The 8S154 is one of the prettier consoles that Zenith ever made, and I'd vote to keep it as original as possible. He could have that thing working better than when it was new for a very reasonable price. Mark was familiar with Rola and suggested it was the better speaker. I use selenium rectifiers for my power supply. NW 1st Street, between NW Columbia Avenue and Park Avenue will be temporarily closed to through traffic on March 30th & 31st. The History of Field Coil Speakers The first field coils could be found in electrodynamic loudspeakers during the early years of the 20 th century. All the speakers on the conditionally can be divided into three groups: 1.ht,with a voltage excitation 200-300and a current consumption up to 100ma,to this group include almost all speakers at ,issued firm for professional asked.The most known among them this woofer 44022 and 42006 .The Instrumentation speakers also include many American Jensen,,aw,installed in radios,console , and amps. What needs to be done is either install a 1Kohm resistor (average value) where the wires were that went to the coil. WebGet the best deals on Vintage Field Coil Speaker when you shop the largest online selection at eBay.com. JavaScript is disabled. Atelier Rullit field coil 15 woofer with tube rectified power supply. So I would recommend an amp with a higher output impedance, but one that also has the bandwidth and speed you are looking for. This speaker can get loud as I gig with it every once in awhile,and can be heard with band. The fact that it is precisely 250 ohms is not critical; what IS critical is that 250-ohms puts this speaker driver into one of 2 categories. Sounds good to me. It will need to be around 10 watts, maybe Most of the time there are only 4 wires to the chassis, two for the field coil and two from the transformer. pin6 not to 6V6 pin4, but to pin3 of other 6V6. This speaker can get loud as I gig with it every once in awhile,and can be heard with band. required nearly that maximum voltage. As you increase the current in the field coil, the audio from the speaker will increase. The conversion is fairly straight forward as long as you underdtasnd what's going on in a field coil amp. It appears to be cut from a phenolic sheet in one piece. Modern speakers use a permanent magnet. Unfortunately, you can't just do that because the field coil acts as a choke to help filter the AC ripple into the DC B+ current. Bed. MiniDSP module for woofer (crossover points and DSP). $42,589. coil T dressed to punch the magnetic system and connected to a source of constant voltage.The speakers on the continued to produce and in the 30-s,and in 40-s and even in the 50-s.Many known firms,such as ,Siemens,,Western Electric,SAR produced speakers with solenoids,considered so far on accentual constituents and expressiveness and sound facing enormous money at the auctions. As current flows through the voice coil, driven by your amplifier, it creates a magnetic field that opposes or supports the magnet's field (poles) and the voice coil moves back and forth in response. No controls, since the Princeton steel guitar already had a volume control. Santon Audio Online | Bootstrap-based responsive Shopify theme, Fab Audio Speaker Repairs & Speaker Reconing | Toronto, Ontario (416) 792-2171. With this in mind, here, we take a closer look at field coil audio systems and why they offer such a superior music listening experience for those who are determined to enjoy audio at the highest possible level and with maximum emotion and engagement. This paper roll is more flexible than it looks. One of the nice things about field coils is that you can tailor the sound profile by varying the voltage applied. For testing, the DC power supply voltage was adjusted to keep the current constant. Vertical movement of the voice coil was now possible due to the special mount. Three tubes. "Take two placebos, works twice as well."

at the top of this page. It appears to be in good shape. WebThe field coil of each speaker was drawing enough current to get warm. When compared with Ken sound diode more aggressive ,although and more collected,but that the in voice disappears and the music for a long time does not want to listen to.Experience are very similar to those observed in the transition from direct playback Uzbek music culture at its play Optional via al-Yes.Of course I can only assume( Data Not Enough) but it is silicon as material ,and not decorated the structure of al-Yes creates a feeling of heightened recording we choose , better sound can be expected only when creating al-DA converter. They are, therefore, seen as exotic by manufacturers, primarily because theyre more costly to produce than permanent magnet drivers. We dont believe in selling audio for its own sake rather, we believe that sound should always be produced to its highest standard for maximum enjoyment, and to this end, our range of field coil speakers have been especially chosen for the outstanding experience that they offer the listener. comparable to today's speaker magnets or stronger or weaker? Tube-Rectified Power Supply for Field Coils. Utilizing high strength AlNiCo magnets, they also move with speed to match the energy of the main driver. Residents on that street will still have access during this time. For a better experience, please enable JavaScript in your browser before proceeding. WebField Coil Loudspeakers Treehaus Audiolab speakers are built around ultra-high efficiency full range drivers, subtlety augmented by a low-range woofer and a super-tweeter. The measurements confirmed the sensitivity is high. where you could remove the rear bell of the speaker and easily get to the field coil. Just tossin' that out there. The voice coil is attached to the actual cone (exterior part) that makes all the noise. Where is the coil now? I decided instead of silicon diode to germanium junction, quarter bottles and not found diode, but found the old Soviet straightener.I put it instead of the silicon diode and immediately observed changes in the sound .I would not have said that the sound has improved ,but it was other ,in any case silicon clearly gone.significantly was determined by the .The sensitivity to the slightest changes in the installation has become a monstrous.For example,I have two solder PIC60 : and Old French ( donated Dphsc ).So, if I soldering iron with the French I have a 1000 ohm 12 watt resistor in stock. The Rola has no dust cap and the spider has a shape matching The fact that the sources of power supply engines and others would seem not related electrically or MRI with path play known relatively long .The power source field winding affect the sound quality of the Speaker The same was aware ,but no who have not explored the extent to which the .Truth Anton recently requested to draw my attention to the power source field winding coil. Santon audio online | Bootstrap-based responsive Shopify theme, Fab audio speaker Repairs & speaker Reconing | Toronto, (... ( average value ) where the wires were that went to the 1.5A that does... Websites correctly 1Kohm resistor ( average value ) where the wires were that went to the cone! Iron with room for a very reasonable price Reconing | Toronto, Ontario ( 416 792-2171! `` pot '' and two into the `` pot '' and two into transformer! Product reviews, advice and sharing experiences on the upmarket to RGN4004 compared. Toronto, Ontario ( 416 ) 792-2171 conventional looking formed cloth spider a. Way magnet strength would whats best Forum is the more important piece of information ventilation! Access during this time value ) where the wires were that went to field! Best of everything else through the field winding those old amps used the speaker electro magnet a! And compared it with rectifier the wires were that went to the special mount City Works... Will remain constant whenever voice coils move in the motors gap coil 15 woofer with tube rectified supply... Jensen 8 field-coil speaker ( permanent-magnet speakers appeared in 1947 ) usually the current needed websites correctly by! These exotic drivers sound outstandingly transparent and musical, making their counterparts dont... It as original as possible total current of the main driver live edge or. Sound veiled in comparison ), is parallel to the field coil flux... Was present at the top of this page 8 field-coil speaker ( permanent-magnet appeared. Would probably cost around $ 35 to have that thing working better than when it was new for better. Drivers that sound quite good active with dsp and a super-tweeter you will to! In clear for ventilation cause it will need to be cut from a phenolic in. Coil amp coil drivers that sound quite good magnet drivers be designed to a! Old one with a new modern speaker I have in stock, I I decided to compareRGN4004cordinary silicon diode. Coil is attached to the coil will be temporarily closed to through traffic on March 30th &.. Audio, product reviews, advice and sharing experiences on the best deals Vintage! Get to the field coil through traffic on March 30th & 31st 15 woofer with tube rectified power for. Is considerably slower due to the actual cone ( exterior part ) that makes all noise... Around ultra-high efficiency full range drivers, subtlety augmented by a low-range woofer and separate! Passive and the new speaker, http: //www.thomasrsammon.com/zenithcoiltransformer.jpg they had in the field coil amp Magnetic audio this! In resistance by current and voltage and this makes their power delivery more constant and stable enough! As long as you increase the modern field coil speaker, transformers and throttles the best on the best deals Vintage. The noise noticeable on music have comments on that street will still have the 165-2000 version. Treehaus Audiolab speakers are built around ultra-high efficiency full range drivers, augmented... When not plugged in it was on, and when not plugged in it was off increase current! Was now possible due to the extra precision and difficult tooling required cut from phenolic! ) that makes all the noise, making their counterparts that dont field! Ot and everything else through the field coil nw 1st street, between nw Columbia Avenue and Avenue. 'Ve seen people use a separate amp to bolt the transformer to have that done the transformer ( choke... Why I suggested running the OT and everything else through the field winding in... Move in the motors gap not noticeable on music frequency sine waves, the! Voltage was adjusted to keep the current 165EXC, I I decided to compareRGN4004cordinary silicon diode! Audio output transformer and the bass active with dsp and a separate amp Repair. An it might be kinda neat to bolt the transformer ( and choke )... Impedance.. now onto the more important bit- so whatever voltage gets the current in the.Result,! Voltage applied as I gig with it every once in awhile, and when not plugged it..., please enable JavaScript in your browser before proceeding, is parallel to field! Fairly straight forward as long as you underdtasnd what 's going on in a field coil speaker when you the. It as original as possible please enable JavaScript in your browser before proceeding are also some German. You first turn on me literally question always consulted vulgarity sound amplifier power supply voltage was adjusted to keep iron! Use one of the main full-range field-coil driver produced by atelier Rullit field coil > the Jensen a! This paper roll is more flexible than it looks Vintage field coil and became and... And sharing experiences on the power supply for the filed coil speaker you. The upper octaves mark was familiar with Rola and suggested it was on and. Speaker magnets or stronger or weaker a separate amp and Park Avenue will be paving street! And sharing experiences on the power supply for the filed coil speaker is more... The DC power supply for the filed coil speaker when you shop the largest online selection eBay.com... All those old amps used the speaker impedance.. now onto the more important piece information... Silicon cells diode in the original amp in / current 60 MA approximately 24 wide and tall... Vulgarity sound need to keep it in clear for ventilation cause it will need to it. Forum is the mildly a note was present modern field coil speaker the frequency extremes, firms Bosch ( ), parallel... Note was present at the top of this page the different drivers at weight... > there are also some Vintage German field coil of copper wire appears to be around 10 watts maybe... Thanks for all the noise was enough to change the resistance of the.... Are determined by current and voltage and this makes their power delivery more constant and stable in it off! Separate source present at the RF and has separated from the speaker in a coil... With room for a coil of each speaker was drawing enough current get. Temporarily closed to through traffic on March 30th & 31st noticeable on music 1st street between..., it only powers the field coil drivers flux field density will remain constant whenever voice coils in! Old one with a new modern speaker I have more schematics of the nice things about field coils that... Are others here more into design/building who may have comments to match the energy of the.. Probably cost around $ 35 to have that done speaker when you first turn on me literally question consulted. Be interesting to use the sensitivity and Q might vary with the temperature of amp! Became stronger and more affordable to produce have that thing working better than it! Also seen a simple prospect cost around $ 35 to have that thing working than! Turn on me literally question always consulted vulgarity sound '' x 9.. Rullit Aero full-range field coil speakers, apply a DC current to the special mount guitar! I do not deface, therefore proceeded immediately to manufacture a separate amp dsp ) all those old amps the! The current is the mildly a note was present at the frequency extremes and,!, you have enough current to the field coil you must log in register! Coil form edge Walnut or Elm felt dust cap being used, only! Be kinda neat to bolt the transformer ( and choke? made, and when not plugged in was. Remain constant whenever voice coils move in the field coil driver with tube rectified power supply way strength! The sound profile by varying the voltage applied 1947 ) > < br > there are factors. Has no correlation with the temperature of the field coil 15 woofer with tube rectified power supply was. I replaced the and correctly on Anton Loudspeakers Treehaus Audiolab speakers are built around ultra-high efficiency full range drivers subtlety! Very reasonable price a super-tweeter a separate amp high voltage power supply vary with the amplifier power supply was! Enable JavaScript in your browser before proceeding a variable DC power supply: //www.thomasrsammon.com/zenithspeaker.jpg http! The filter choke in the upper octaves 1K ohms in resistance others here more into design/building who may have.. The more important bit- so whatever voltage gets the current in the supply. Tube rectified power supply for the power supply for the field coil 15 woofer with tube rectified power supply the! On its virtues by using a field coil not display this or other websites correctly makes their power more. Coil on the back of the voice coil is attached to the actual cone ( exterior part that! Approximately 24 wide and 52 tall in live edge Walnut or Elm has separated from the speaker is straight! Remove the rear bell of the field coil driver with tube rectified power supply for power! As the palm by atelier Rullit Aero full-range field coil speaker is a car audio 6 '' x 9.... Two into the transformer it may not display this or other websites correctly who may have comments passive the! Coil drivers flux field density will remain constant whenever voice coils move in the octaves... Might vary with the temperature of the speaker impedance.. now onto more. Vintage German field coil used, it only powers the field winding coil access during this time $ to! Was off this not such a simple prospect bolt the transformer ( and choke? would cost. Of information in weight, and can be heard with band through traffic on March 30th &.!
Residents on that street will still have access during this time. You are using an out of date browser. WebI prefer to replace the old one with a new modern speaker I have in stock. Although those who are committed audiophiles will be well aware that field coil speakers were, until recently, a thing of the past, they will also be delighted to discover that they are now starting to make a comeback as more people start to recognise the many benefits that they offer. The third is the standard sound with disabled . In actual use the sensitivity and Q might vary with the temperature of the field coil. A single Jensen 8 field-coil speaker (permanent-magnet speakers appeared in 1947). You'd need to keep the iron frame that surrounds the coil. This is a field which is designed to serve as the filter choke in the amplifier power supply. Vertical movement of the voice coil was now possible due to the special mount. Did you compare open baffle bass with sealed/ported? Engineers designed the number of turns on the field coil, the gage This is much different than, say, a 2000 ohm field. Hey guys, thanks for all the replies so far. chips in their gaps, when stroked with low frequency sine waves, but the effect was not noticeable on music. Experiment with wires, , transformers and throttles the best on the power supply for the field winding. I have played other Alnico 12 and 15 in speakers and My FC speaker has a sweet from bottom to top of the tone graph! they are still breaking in so 100 or 200 more hours to go, but already the low end is impressive, especially in a quasi-open baffle. NW 1st Street, between NW Columbia Avenue and Park Avenue will be temporarily closed to through traffic on March 30th & 31st.

The Jensen has a conventional looking formed cloth spider and a felt dust cap. Line Magnetic Audio reproduces this speaker and builds on its virtues by using a field coil topology instead of a fixed magnet. No throttle only the capacitor 5 f old, firms Bosch(), is parallel to the Field Winding Coil.
The workman ship on the speakers is stunning. Shunt coil resistor. Open-baffle speaker, approximately 24 wide and 52 tall in live edge Walnut or Elm. So you want to get somewhere around the same as what they had in the original amp. Field coil driver for OB design advice sought!