Installation of the efbtm bias circuit in a dynaco. Dynaco stereo 80 manual stereo power amplifier hifi engine. The st 120 was dave obrians favorite amp to test at the mcintosh clinics, because it truly demonstrated the huge difference between an amp with conservative specs and one with optimistic specs it measured horribly, and as often as not, didnt come close to meeting its published specs. Using biaset is a relatively safe way to set the bias on dyna amps with a digital meter, and some of the latest production dyna boards offer. It should be noted that the dynaco st70 has output transformer impedance taps at 4, 8, and 16 ohms.
The dynaco stereo 120 is an all silicon transistor basic power amplifier for use with separate preamplifiers such as the dynaco pat4 or pat5, or for use with tape recorders or tuners such as the fm5 or af6, which have their own volume controls. Despite the lower impedance of the paradigm speakers, the dynaco st 35 coped with it very well. I have done a search and did not come up with anything. Developed over many years, erhard audio is the only and official seller of. It uses octal tubes, which are right in line with the lovely classic sound of the dynaco. For more information about jims build and his impressions of the st35 kit, see the dynaco st 35 tube amp kit thread on the message forum. I would like to pool the tremendous knowledge base here as i am interested in. Dynaco st 120 amplifier restoration kit repair service fix recap capacitor. Dynaco dynakit stereo 35 st35 tube amplifier schematic and. Dynaco st 120 upgrade info techtalk speaker building. For those that need a little more power is the dynaco vta st 120. All parts needed for a complete upgraded dynaco st70 type kit except for the tubes. View and download dynaco dynakit st35 instructions for assembly and operation manual online. New dynakit st70 advice steve hoffman music forums.
Photos of a dynaco st35 tube amplifier kit from dynakitparts which was put together by jim wisconsin, usa. The perfect power tube for the dynaco st70 or vintage marshall amplifiers. The dynaco st 35 power amplifier has been the center of my music system since i discovered it in 1982. Both the zpc6 phono and zpc5 line preamps offer vastly improved circuits and performances over the original dynaco designs, with far superior sound reproduction. It can sing in romantic voice or with full twentyfirst century accuracy.
For those that need a little more power is the dynaco vta st120. The dynaco pas23 preamp upgrade kits we offer are the best available on the market. It uses the 7199 circuit from the original it is not a redesign using the inferior 6gh8. A very nice looking, straight dynaco st 150, this one dials in from sometime, mid production mid 1978. When i powered it up,not surprisingly, given his engineering background all the dynaco bits worked, but did not sound very good through those speakers. A customized dynaco st35 kit the st35, also known as the stereo 35, was released by dynaco in 1963. Acme silver plated iec receptacleneotech legenburg cryod upocc internal wiringcardas internal wiring where the rectangular neotech too difficult to work. Upgrade moduleshown installed on the photo to the left all triode fully direct coupled design cascode amplifier with split load phase splitter that preserves the musical midrange of the stock st 70 while significantly improving its bass tightness and high frequency extension over the stock board and dramatically increasing both. If the power supply doesnt work, then the amplifier. Schneider record player green mod turn table love the timeless style, how can. Dynaco stereo 120 manual stereo power amplifier hifi. I used one to replace my pair of dynaco mark ivs after performing lengthy comparative listening tests, and deciding that the smaller, cheaper st 35 provided inherently superior sound.
Dynaco vintage amplifiers and tube amps for sale ebay. The latest production dyna transformer for the st70 has a larger stack and is designed for the current 120 volt line power. Comments are closed, but you can leave a trackback. I built this from a kit along with a dynaco stereo 120 power amp. You can get seriously highend sound out of your dynaco stereo 120 power amp, pat4 preamp, or. You can build a point to point 3886 amp for peanuts and have just as good an amp since that is where the power comes from. This is the next step up from the original dynaco circuits. Despite the lower impedance of the paradigm speakers, the dynaco st35 coped with it very well. The later dynaco stereo 150 had a more conventional circuit and was touted as a big upgrade. This entry was written by admin, posted on may 29, 20 at 3.
There is a difference between the two amps besides the transformers. I can only say the best things about bob and the product that he produces. Make your dynaco stereo 120 power amplifier better than new with these kits. Triode, usa customer service mf 9am4pm ct 18007743201 email us anytime. The unit contains two 40 watt amplifiers on one chassis with a common power supply. When i got it from him a few years ago it came with the original klh speakers that he used with it. I recently came across dan joffes info online about the updated version for the dynaco 120, and thought it might improve the overall performance of my system, besides the fact i just love building electronic kits. Its the baby brother of the dynaco st70 and tends to be overlooked by many vintage amplifier aficionados. Theres no go figure with the st120s performance re the st70i had one to compare to, the box stock 120 was better in highs and low extension. The vta st120 uses three custom wound usa made transformers and is available as a kit amp or completely wired and tested. I used one to replace my pair of dynaco mark ivs after performing lengthy comparative listening tests, and deciding that the smaller, cheaper st35 provided inherently superior sound.
The vta st 120 uses three custom wound usa made transformers and is available as a kit amp or completely wired and tested. Restoration module this is an exact replacement for the original dynaco pc3 board fabricated from milspec materials. The dynaco st35 power amplifier has been the center of my music system since i discovered it in 1982. Follow any comments here with the rss feed for this post. Improve, renew, restore and repair your dynaco stereo 120, stereo 80, stereo 400, pat4, pat5, fm5 or af6 tuner, or sca80q highend sound on a budget. If the dynaco st 70 is great, then the heathkits are world class.
I recently came across dan joffes info online about the updated version for the dynaco 120, and thought it might improve the overall performance of my system, besides the fact i just love. I used them with two speakers stacked on a side for years until one of the st120s died. My uncle had the stereo 120, pat4 preamp, fm3 tuner, and a25 loudspeakers. A few years later i stepped up to the st 120 and although some would argue the st 35 was a sweeter little amp the 120 was pretty groundbreaking in its day. Some have said it sounds overly tubey, but man i am enjoying it i am running it with a ss dynaco pat5 preamp and spica angelus speakers, and they do a good job of bringing out what detail this old, original st70 has to offer. The sound stage is never ending with a solid 3d imaging. Here is the completed amp, with all of the new capacitors installed. The vta st120 is quite the chameleon among power amplifiers.
This may be a factory wired unit, or if not, the assembly is the same excellent quality. Replacing 7199 with 6gh8 and comparing thd in a dynaco st70. Dynaco vintage tube ampllifier technical articles, upgrade, restoration and repair resources for st 70, pas, sca35, st 35. I used it for about 6 months in 1990 until i bought adcom 555 that i traded up to vtl 100 mono blocks. I eventually sold both along with a pat4 but a couple of years ago i decided to get a used st120 to. We also had to repair the power switch circuit as one side of the switch had gone open. Developed over many years, erhard audio is the only and official seller of all these great upgrade kits, spare parts and more. The vta st 120 is a 60 watt per channel amplifier built on the same st 70 stainless steel chassis as the amp pictured above. I own a dynaco st 120 that i had upgraded by van alstine here in minnesota.
The dynaco stereo 120 was the first powerful 60 wattschannel transistorized stereo power amplifier in wide production. Vintage dynaco dynakit st70 stereo power amplifier. The heathkits have solid state rectification where the dynaco is tube rectified. Dynaco stereo 70 tube amplifier dyna st70 el34 amp dynakit good condition. Bob latino vta st120 sold garage sale the klipsch audio. The high end show 2016 in munich marks the relaunch and advanced design of the newest iteration of the dynaco stereo 70 st 70.
I thought my spicas would need more power, but they are sounding suprisingly good for the 35 watts going to them. I have a dynaco system consisting of pas3 preamp, fm tuner and st35 amp my father built in 64 or 65. Unfollow dynaco st 120 to stop getting updates on your ebay feed. Founded by david hafler and ed laurent in philadelphia, pennsylvania in 1955, dynaco was an american hifi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components its best known product was the st 70 tube stereo amplifier. This video describes the installation of the complete rebuild kit into a dynaco stereo 120 power amplifier. I had this one built 10 months ago with all the upgrades best capacitors attenuation pot so you dont necessarily need a pre amp sounds. Not to say the 120 was exceptional, just that the st70 wasnt either. A very nice looking, straight dynaco st150, this one dials in from sometime, mid production mid 1978. Dynaco st 120 upgrade info the schematic shows one lm3886 chip amp per channel. Dynaco tube amplifier technical articles and upgrades st70. The dynaco stereo 80 is an all silicon transistor basic power amplifier for use with separate preamplifiers such as the dynaco pat4 or pat5 or for use with tape recorders or tuners such as the dynaco fm5 which have their own volume controls. Lately the reputation of the st 120 has been rehabilitated. The transformer is free of resonances, has extended frequency response from 6 to over 60.
Featuring 60 watts or more per channel of tube power, the amps ability to run in either triode or ultralinear mode offers more versatility than most any other amp i know of. This board is a must for any serious restoration of the dynaco stereo70 to full stock condition. Specwise this was true, but i always found the st 150 less satisfacory overall. We hope this web page and the hints it offers could make it easier. Including our custom made transformers, which are made to original specs right here in the usa. Dynaco stereo 120 power amp instructions for assembly operation. Delivering the sound and performance of amps costing 4 times as much. I used it for about 6 months in 1990 until i bought adcom 555. Classic dynaco sca80q integrated amp just recapped with original box sweet. I own a dynaco st120 that i had upgraded by van alstine here in minnesota. Speaker recommendations for dynaco st 70 2channel home. For more information about jims build and his impressions of the st35 kit, see the dynaco st35 tube amp kit thread on the message forum. Find the right dynaco parts to restore, repair or upgrade your original dynaco vacuum tube amplifier. This goes for the dynaco st120 and its baby brother, the st80.
The unit contains two 60 watt amplifiers on one chassis with a common power supply. I have a st400 that i cannot find the trouble but it was a much more powerful amplifier. These amps smoked the dynaco from the beginning of the bandwith to the last and final note. Dynaco owners please comment audiogon discussion forum. I built my latino st120 amp 9 years ago and its still running strong. In later years, the company began to produce a line of solidstate audio components, commencing in 1966 with the introduction of the stereo 120 power amplifier. The high end show 2016 in munich marks the relaunch and advanced design of the newest iteration of. We left the old speaker output capacitors physically in place to preserve the speaker choke coils wound around them. Class d replacement for dynaco st 120 years ago i purchased four dyanco a50 speakers, two pat4 preamps, and two dyancost 120 amps. I used them with two speakers stacked on a side for years until one of the st 120s died. Pa060s power transformer nearly twice the lamination stack size of the original, a470s output transformers, c354 choke. The iphone desktop handset hammacher schlemmer from hammacher schlemmer. It is the very first generation of st120 amplifers that dynaco manufactured.
The phono preamp zpc6 as well as the line preamp zpc5 use 2x 12ax7s each. The st35 has output transformer impedances of 8 and 16 ohms. Class d replacement for dynaco st120 years ago i purchased four dyanco a50 speakers, two pat4 preamps, and two dyancost120 amps. Dynaco st120 restored with stainless steele chassis. It should be noted that the dynaco st 70 has output transformer impedance taps at 4, 8, and 16 ohms. A customized dynaco st35 kit diy audio electronics from. Dyna and hafler solid state amplifier rebuilds audio by. Dynaco st 120 upgrade info techtalk speaker building, audio. David hafler released the dynaco st35 twochannel power tube amplifier nearly 50 years ago as a lower cost alternative to the popular st70. Vtg dynaco dynakit catalog 80 120 amp 400 mark iii iii70 iii500.
Dynaco vintage tube ampllifier technical articles, upgrade, restoration and repair resources for st70, pas, sca35, st35. Dynaco stereo 120 manual stereo power amplifier hifi engine. Dynaco diagrams, schematics and service manuals download for free. I eventually sold both along with a pat4 but a couple of years ago i decided to get a used st 120 to. A few years later i stepped up to the st120 and although some would argue the st35 was a sweeter little amp the 120 was pretty groundbreaking in its day. Unfollow dynaco st120 to stop getting updates on your ebay feed. I have recently acquired a dynaco st 70 amp that i plan to pair with a bottlehead foreplay preamp i am going to build. We also offer an array of new select dynakit classic. A few months ago, i refurbished a dynaco stereo 120 audio amplifier for my. I have a dynaco system consisting of pas3 preamp, fm tuner and st 35 amp my father built in 64 or 65. Dynaco stereo 120 solid state amplifier repair journal. It is obvious the time and care that he has put into the design upgrades that this amp possesses. The heart of the stereo 35 is the special dynaco 2565 output transformer, a patented design tailored specifically to this circuit.
Founded by david hafler and ed laurent in philadelphia, pennsylvania in 1955, dynaco was an american hifi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components its best known product was the st70 tube stereo amplifier. If the dynaco st70 is great, then the heathkits are world class. Dec 14, 2016 david hafler released the dynaco st35 twochannel power tube amplifier nearly 50 years ago as a lower cost alternative to the popular st70. It is called a mosfet series d and he uses the case, connectors, power cord, switch and transformer. Dynaco stereo 120 repair information update my dynaco. Ignored for years by many tube enthusiasts, due to modest power output, its become a hot item since the start of the new millennium, with new releases of complete amplifiers, clone boards, transformers, tubes and other parts. All parts needed for a complete upgraded dynaco st 70 type kit except for the tubes.
I had this one built 10 months ago with all the upgrades best capacitors attenuation pot so you dont. The st 35 has output transformer impedances of 8 and 16 ohms. I can just sit back and pick out each person and instrument on the stage. We have decades of experience working with the dyna and hafler pieces, and continue to offer our latest.
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