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. Much which follows on the topic of audio transformers is of necessity somewhat over simplified to give a general overview. Transformer audio interstage, 10 ma antique electronic. They are homemade audio interstage coupling transformers. Hi all, started digging into this columaire8 and find the primary on the insterstage audio. I have intermittent cracking noise i pointed out to the audio interstage transformer t8. 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. This in turn has lead to improvements in tone and musicality, even if measured response has changed little.
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. Over the past years we have spent an increasing amount of time fine tuning the materials and winding techniques employed in constructing our transformers. I have a hallicrafters s76 receiver that i purchased and repaired about a year ago. It is no more used a lot, quality transformers are rare and so are their manufacturers. Tube amplifiers and interstage transformers audiogon. Jan 22, 2010 this may be critical on hi fi audio transformers but these old 1920s sets seem to be forgiving as noticed by the many different transformers that have been used sucessfully as replacements. Designed for general purpose or replacement use in single ended or phase inverter tube driver circuits.
A transformer schematic is depicted in figure 1 below. Wide bandwidth output transformers for single ended and pushpull vacuum tube applications. New tube gear mostly only have an input and output transformer. Our part number 124b is the same as our 124a except for 49% nickel laminations for greater fidelity.
Satellite tv equipment free delivery possible on eligible purchases. Merren audio provides custom wound transformers for both output and power applications including chokes. I should point out that my main interest is 1920s battery radios and that they are very forgiving. 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. Mouser is an authorized distributor for many signal and audio transformer. Interstage audio transformer too old to reply nelson 20040216 05. Transformers transform sound fx transformers transform sound effect, transformers transform sound fx, transformers sounds, transformers morphing noise, transformers transfor audio clips, transformers morph sound effects, tv audio sound bites free, noise mp3 download. View topic audio interstage transformers antique radio. Softone rc20 versatile audio interstage transformer. New universal interstage transformer, 20,000 ohm ct primary with 80,000 ohm quad split secondary. Previously only available as very expensive imports from the far east, interstage transformers are believed to be the only true method of driving output valves by many. For model audio interstage transformers for replacement, atwater kent mfg. Wide bandwidth output transformers for single ended and pushpull vacuum tube.
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. Transformer audio interstage, 10 ma antique electronic supply. The quad split secondary arrangement each secondary section is 12 the turns of the whole primary. Transformers in this category are open frame of various impedance. 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. Download hundreds of free audio books, mostly classics, to your mp3 player or computer. 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.
Connect the grnyel wire to the grn wire and the blkyel wire to the blk wire. This is a universal replacement type it will replace any of the three audio transformers used 1st audio driver2nd audio phase splitter stage or output transformerby correctly connectiong the 5 lugs. Center tapped secondary may be used for pushpull grids. The right on the photo is the r core audio interstage transformer in bare condition. The allen avionics agl series employ fullyshielded, 1. This is a universal replacement type it will replace any of the three audio. If youre antsy about that voltage you can always put this one on the detector and move a good detector one to the first audio.
I replicated the circuit faithfully with an exception of the interstage transformers. Hedgehog transformers are occasionally encountered in homemade 1920s radios. Interstage transformers can be made in different ratios, primary currents and voltage ratings. The original transformers are usually found with open windings due to the fine wire and high turns usedcoupled with age. I notice lots of old tube gear like pultec eqs, universal audio 175s have interstage transformers. The product is enclosed in the square case on the left. Audio interstage transformers from scrap canadian vintage. I was told by one tech the most influential transformer in a piece of gear is the input transformer. They have a 100v rating but many sets only run 90 volts anyway. A low current wallwart xfmrs can also do the trick. Audio transformers were originally used in valve or tube amplifiers as interstage and output transformers. Blablasise aetheradio smoothie insured financial wealth. May 25, 2010 when tested in a radio they performed as an audio interstage transformer and gave results very similar to that of a hammond 124a transformer. High quality audio transformers sjs electroacoustics.
Resistance checks showed the primary winding is open. Audio interstage transformer specs antique radio forums. If youre antsy about that voltage you can always put this one on the detector and move a good detector one to. It is a great receiver, and i have a lot of fun listening to it. Transformers in this category are hermetically sealed and of higher impedance than 1k ohms. I also read about the highly regarded amity and karna.
If you are looking to replace radiola iiia audio transformers, check out our universal radiola replacement unit. Moving coil, interstage and preamp output transformers. Audio interstage transformers for radio part atwater kent mf. I have used several in various radios with success. Transformer audio interstage, 10 ma ce distribution. Transformer audio interstage, 10 ma equivalent to stancor a53c. There are many ways in connecting a driver to a powertube, all with the same goal. I also read about the highly regarded amity and karna amplifiers that d olsen built and they have also interstage transformers. Original transformer primary went open after about a month when restored set started being used 23. The design of chokes, small power transformers those used in tube amplifiers and preamplifiers and. Somehow, it looks like some of the most expensive set amplifiers have interstage transformers like audio note or shindo.
New interstage transformers designed for singleended. Just had to play with the capacitor value to get the bass response back to original. 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. 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. Youtube, youtube channel, video marketing, youtuber, igtv, erika vieira, video, instagram electratone. Problem when i had this problem, robert casey suggested the capacitor fix. Used it to replace a driver transformer for pp 45s in a gm253 lowboy ca. Enameled copper wire is wound round the central half of the. 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. The signal has to be low impedant combined with enough current. Replacing any coupling capacitor with a well designed and correctly matched driver or interstage transformer yields an almost shocking improvement in sound and should be tried to fully understand. Home the canadian vintage radio society, and its bimonthly publication, canadian vintage radios, is dedicated to the preservation, restoration, collection and enjoyment of antique. I have numerous times in the past used the pt156 from aes. Our range of high quality audio transformers continuous to improve and expand.
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