Softone rc20 versatile audio interstage transformer. Crimson transformers can be found in all facets of professional audio. Where z p is the primary winding impedance, z s is the secondary winding impedance, n p n s is the transformers turns ratio, and v p v s is the transformers voltage ratio so for instance, an impedance matching audio transformer that has a turns ratio or voltage ratio of say 2. Resistance checks showed the primary winding is open. Hammond 124 series tube driverinterstage transformers, designed for general purpose or replacement use in pushpull or phase inverter tube driver circuits. As when using preamp output transformers, or interstage driver transformers, choke loads need to be very carefully sighted when used in small signal applications to avoid excessive hum field pickup. The coil is wound using our low capacitance, high internal isolation technique with internal multilayer isolation foil where layertolayer signal voltage is big. Resistive load on interstage audio transformers in tube. From the beginning in 1987, crimson has been committed to building premium audio transformers at reasonable prices.
At this point, if you find the word audio transformers on its left side, please click on the word or on a small picture on the other side to see the catalog 392k in pdf file. Interstage, driver transformers it is becoming increasingly obvious that applying transformer at every stage of an amplifier yields a great benefit in sound quality, provided off course the transformer in question is of an appropriate quality and design. New interstage transformers designed for singleended. Transformers in this category are hermetically sealed and of lower impedance than 1k ohms. Usually the driver stage is single ended class a, so theres a quiescent current in the primary. They have a 100v rating but many sets only run 90 volts anyway. For this reason we are looking to source mumetal screening cans in the near future to offer as an enclosure for these devices. It is becoming increasingly obvious that applying transformer at every stage of an amplifier yields a great benefit in sound quality, provided off course the transformer in question is of an appropriate quality and design. The signal has to be low impedant combined with enough current. Perfect drop in replacement for audio interstage transformer for gibson white panel amps that use a transformer for phase inverter. The original transformers are usually found with open windings due to the fine wire and high turns usedcoupled with age. Magnetic coupling in interstage transformer is the best energy transfer mechanism for low frequency audio frequency that can be best viewed same as the force working in most dynamic loudspeaker drivers.
Resistive load on interstage audio transformers in tube type amplifiers free audiobook. Please, follow these basic instructions to place your order. These transformers fill a broad application spectrum in the audio industry. Audio tube driver transformer 124 126 series hammond mfg. The quad split secondary arrangement each secondary section is 12 the turns of the whole primary means that as many as 4 tubes can be. We combine quality materials, expert craftsmanship and proven designs. Audio transformers were originally used in valve or tube amplifiers as interstage and output transformers. Although the stepup turns ratio of a transformer may provide noisefree voltage gain, some 20. Everyday low prices and free delivery on eligible orders. This is a universal replacement type it will replace any of the three audio transformers used 1st audio driver2nd audiophase splitter stage or output transformerby correctly connectiong the 5 lugs. Designed for general purpose or replacement use in single ended or phase inverter tube driver circuits. The hammond series appears to be a larger transformer.
Without the availability of precision transformers and precision is the key word here the clean, clear, accurate, and sonically pleasing reproduction of tube microphones, tube preamps, and tube power amps would not be possible. Audio interstage transformer specs antique radio forums. Transformer audio interstage, 10 ma equivalent to stancor a53c. Theres a couple of tricks available for battery set interstage xfmrs if you dont mind living on the edge.
About us the canadian vintage radio society is dedicated to the preservation, restoration, collection and enjoyment of antique radios and related items. Transformer audio interstage, 10 ma antique electronic supply. The quad split secondary arrangement each secondary section is 12 the turns of the whole primary means that as many as 4 tubes can be driven, each independently biased if wired for 1. The right on the photo is the r core audio interstage transformer in bare condition. The coils all a tap on the windings and the windings of the transformers also varied in resistance. So, is it possible to design a power amplifier that is coupling capacitor free. Audio transformers signal level, speaker level, tube audio. The armboard is mounted on the pd444 with the micro seiki armboard. Output and interstage transformers for tube guitar amps. Center tapped secondary may be used for pushpull grids. Eseries e328 pulse transformers and interstage coupling in whirlwind i jan1950. Transformer audio interstage, 10 ma antique electronic.
The design of chokes, small power transformers those used in tube amplifiers and preamplifiers and audio output and interstage transformers is such a specialist topic that even most electronics engineers would not even know how and where to start, let alone produce a finished, working transformer. Designed for general purpose or replacement use in pushpull or phase inverter tube driver circuits. The product is enclosed in the square case on the left. Impedancein audio transformers even mixing consoles especially in recording work, but also in many live sound applications all depend on transformers to match the high impedances of the tubes to useful interstage and output impedances. Original transformer primary went open after about a month when restored set started being used 23. I would like to know if somebody with more knowledge can explain the difference in. Transformer audio interstage, 10 ma ce distribution. Resistive load on interstage audio transformers in tube type. This is my homebrew method of rewinding 1920s audio transformers and those with. New universal interstage transformer, 20,000 ohm ct primary with 80,000 ohm quad split secondary. Also, if you need some more useful information but written in japanese about tamura transformers like how to connect terminals, characteristic figures, etc.
Triad audio printed circuit transformers are used in line matching, telephone coupling, pulse trigger, interstage, output, isolation and input applications. The cvrs is a nonprofit society run solely by volunteers. Features designed for general purpose or replacement use in pushpull or phase inverter tube driver circuits. I have numerous times in the past used the pt156 from aes. Hashimoto brand tube transformer specifications click here to download the pdf specification file. Interstage transformers can be made in different ratios, primary currents and voltage ratings. The excellent magnetic properties of r core and precisely wound coil by the computerized manufacturing system achieve a wide bandwidth, low distortion, and low magnetic loss of the transformer. I was told by one tech the most influential transformer in a piece of gear is the input transformer.
When conventional design practice is applied to this type of transformers you easily get destructive capacitive coupling between the primary and secondary windings. Faq on interstage and line output transformers lundahl. I agree with charles1dad and larryi, most of the best tube amplifiers i have heard have interstage transformers. Over the past years we have spent an increasing amount of time fine tuning the materials and winding techniques employed in constructing our transformers. Hammond manufactures direct replacement transformers for popular tube amps from fender, marshall, vox, ampeg, orange, and yorkville traynor. Audio transformer and impedance matching transformer. Intended to be a permanent and accessible collection of manuals, technical specifications and. This will reduce the hf bandwidth and increase hf ringing. Our part number 124b is the same as our 124a except for 49% nickel laminations for greater fidelity. The use of tubes in a circuit requires transformers to match impedances from one audio stage to another.
Tribute amorphous core transformer set filament and interstage. Equal cathode resistors establish the bias voltage for the power tubes grids and the 10k load resistors give the interstage signal transformers something to bite on. Our range of high quality audio transformers continuous to improve and expand. Many of us tubeloving audiophiles secretly envy solidstate signalcapacitor free designs, wishing that we too could listen to our music naked, free of the sonic overlay imposed by coupling capacitors. Since the 1990s, the bitsavers collective has been scanning computerrelated documentation and materials as well as rescuing software from rapidlyfading media. Hammond puts a century of experience into manufacturing high quality magnetics for tube applications like hifi audio and guitar amplifiers. High quality audio transformers sjs electroacoustics. A transformer schematic is depicted in figure 1 below.
The graphs below represent the characteristics when the primary is in series connection for singleended input and the secondary is in parallel and inverted connection for singleended output using rc20 as input transformer 1. If you are looking to replace radiola iiia audio transformers, check out our universal radiola replacement unit. This allowed some mixing and matching of the parts. New tube gear mostly only have an input and output transformer. Satellite tv equipment free delivery possible on eligible purchases.
During the last year lundahl transformers have developed a new line of singleend to singleend 1. And like i said before, some of the highly regarded ones also have interstage transformers. It is no more used a lot, quality transformers are rare and so are their manufacturers. Get 3 audiobooks free now download our app and signup free for. Tube amplifiers and interstage transformers audiogon. I have intermittent cracking noise i pointed out to the audio interstage transformer t8. I dont know the advantages of nickle, but one important consideration for interstage transformers is their capacity for unbalanced dc current on the primary. The first chapter jumps right in and carries the heading. Used it to replace a driver transformer for pp 45s in a gm253 lowboy ca.
High performance audio transformers for audiophile applications from lundahl transformers. Interstage, headphone and line output transformers. Hi, i have seen that a lot of very expensive tube amplifiers use interstage transformers to handle impedance between stages. Triad produces a wide assortment of audio transformers for use in printed circuit designs. Audio interstage transformers from scrap canadian vintage. For sale is a set of amorphous core transformers from tribute in netherlands.
Since it reduces voltage, this transformer would be called a stepdown. While the ll1660, ll1692a, and ll1671 have been great transformers in my hands and in those of many others, there was performance to be gained by designing new transformers whose winding geometry has. Silver wire windings available at current market prices. Those that follow my work would be familiar with my affinity towards buidling single ended amplifers, e. Audio transformers audiophile applications lundahl transformers. Download scientific diagram integrated transformer model and interstage conjugate matching process. I notice lots of old tube gear like pultec eqs, universal audio 175s have interstage transformers. Yes, indeed, but it will require interstage signal transformers. May 25, 2010 in a silly moment i put two chokes together open end to open end. Resistive load on interstage audio transformers in tube type amplifiers interstage by tribute. I wanted to pick your brains and ask kindly if anyone here can explain to me how important is the interstage transformer in relationship to the overall sound of a tubed unitt. Transformers in this category are hermetically sealed and of higher impedance than 1k ohms. Assuming an interstage transformer winding ratio of 1.
Hammond 124 series tube driver interstage transformers, designed for general purpose or replacement use in pushpull or phase inverter tube driver circuits. Balanced interstage transformer monolith magnetics. Much which follows on the topic of audio transformers is of necessity somewhat over simplified to give a general overview. Add only the numerical characters of the item number. It looks like if you want your interstage transformer not to reduce the bandwidth or affect negatively the sound you need to buy a really. This in turn has lead to improvements in tone and musicality, even if measured response has changed little.
The output voltage of a tube stage is much higher than the bias needed for the next stage, we should eliminate the dc and let only the ac arrive to the next stage. It is no more used a lot, quality transformers are rare and so. Integrated transformer model and interstage conjugate matching. They started to look like a crude audio interstage transformer. These would work beautifully with 417a or c3g in a 2stage 45 set, for instance. Transformers in this category are open frame of various impedance.
1392 405 26 952 639 14 727 357 375 478 1486 209 941 1143 791 1235 908 383 570 908 6 332 100 518 575 1480 1526 1518 914 394 261 244 655 1315 175 990 602 1343 539 204 1044 571 811