dynaco st-400 manual
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dynaco st-400 manualPlease use the form below to log in, or click the 'sign-up' tab to create a new account. Please let us know if you have any questions or comment on how we run Hifi-Manuals. The ST-400 was first manufactured in 1973. The owners manual is used as an reference guide, instruction manual and instruction book. The service manual functions as a repair guide for troubleshooting and sometimes contains tips for refurbishing and modifications. The schematic is a technical drawing or diagram of your system, a perfect supplement to the Service Manual. This data is collected and thus shared with Google. Got it. They include 46 transistors, 47 diodes, 2 silicon controlled rectifiers, and 4 integrated circuits. The entire main amplifier is direct coupled. To this end, Dynaco has included more separate protective systems and features than have ever been employed in such a product. It has been designed as two independent 200 watt (at 8 ohms) amplifying channels with a common power supply having a high degree of inherent regulation. All files are provided under strict licence and reproduction without prior permission or for financial gain is strictly prohibited. If you have additional documentation please consider donating a copy to our free archive. Also Dynaco preamplifier and Dynaco loudspeakers and Dual 1249 record player. Very good sound. There were two fusions on the front. I think I had fusions of size 2 amp. To protect the loudspeakers when I blasted Pavarotti. This was very helpful. I just purchased this amp, and find this information Very helpful. Thanks again, moduck. That seemed to be a significant sound improvement. To purchase Stereo 400 spares or accessories, please contact the company via their website or visit an authorised retailer. Download all, before decompressing Did You find this Service Manual useful. Share it: Was this file useful. Share Your thoughts with the other users.https://www.atencion.com/userfiles/coolpix-s6000-manual.xml
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User ratings and reviews for this file: Date User Rating Comment Average rating for this file: 0.00 ( from 0 votes) Similar Service Manuals: DYNACO hfe dynaco af-6 schematics - DYNACO Dynaco-400-Rebuild -. For a better experience, we recommend using another browser. Learn more Facebook Email or phone Password Forgotten account. Sign Up See more of VTA Tube Amp Kits on Facebook Log In or Create New Account See more of VTA Tube Amp Kits on Facebook Log In Forgotten account.Below is a link. to a new solid state rectifier (in kit form) sold by Rick Green from Stuart, FL. This rectifier is similar to the Weber WS-1. Mr. Green's rectifier is made with heavier duty diodes than the Weber WS-1 and does have a thermistor included to give a delayed start. You can put the kit together in about 30 minutes. This SS rectifier will work well with any VTA amp or any original Dynaco ST-70, Mark II, Mark III or Mark IV amp. Check out this new rectifier kit at the Ebay link below. A couple of mistakes were found in the text. Anode should have been Cathode and pin 6 was omitted.Built a pair of VTA M-125 mono blocks with KT-120 tubes. Putting out 125 wpc tube power and weigh about 32 lbs each. Purchased them in kit form. Took about 10 hours each to build from scratch. Had been trying to find a perfect matchup with my Gill Audio Alana preamp and was running in to impedance issues with Class D amps and also a Schiit Vidar. It had only 22k Ohms impedance and my system was very quiet. These mono blocks have 270k each. Don’t think I’ll have any heat issues in my living room this winter ?? They sound absolutely amazing and punch way above their weight class for the price. Bob is awesome to work with. Answered all of my questions and also immediately sent out a replacement power switch when I needed one. Nice work Tom ! You have a great music room.Just go to the link below and click on the manual you wish to download. We have on this web page. 1. Dynaco FM-1 mono tuner manual 2.http://decamiones.com/userfiles/coolpix-s620-manual.xml Dynaco FM-3 stereo tuner manual 3. Dynaco FMX-3 multiplex manual for the FM-3 4. Dynaco Mark 2 power amplifier manual 5. Dynaco Mark 3 power amplifier manual 6. Dynaco Mark 4 power amplifier manual 7. Dynaco Mark 6 power amplifier manual 8. Dynaco PAM-1 mono preamp manual 9. Dynaco PAS-2 stereo preamp manual 10. Dynaco PAS-3X stereo preamp manual 11. Dynaco PAS-4 preamp owners manual 12. Dynaco SCA-35 integrated amplifier manual 13. Dynaco ST-35 power amplifier manual 14. Dynaco ST-70 power amplifier manual 15. Dynaco ST-70 Series II power amplifier manual 16. Dynaco FMA-2 insert amplifier manual I also have here on my computer a fairly complete collection of all the Dynaco SOLID STATE manuals. See solid state manual list below. 1. Dynaco AF-6 stereo tuner manual 2. Dynaco FM-5 stereo tuner manual 3. Dynaco PAT-4 preamp manual 4. Dynaco PAT-5 preamp manual 5. Dynaco SCA-50 integrated amplifier manual 6. Dynaco SCA-80Q integrated amp manual 7. Dynaco SE-10 equalizer manual 8. Dynaco ST-80 power amplifier manual 9. Dynaco ST-120 power amplifier manual 10. Dynaco ST-150 power amplifier manual 11. Dynaco ST-400 power amplifier manual 12. Dynaco ST-410 power amplifier manual 13. Dynaco ST-416 power amplifier manual 14. Dynaco DSC-1 stereo control unit 15. Dynaco QD-1 Quadaptor manual 16. It will take me years to scan and create all of the files I have access to. So if you use the search feature on our website and do not find your document simply use the Contact Form and ask for your document. More than likely I will have it. I will quickly scan and upload the file and then send you back a link so you can purchase. It may not display this or other websites correctly. You should upgrade or use an alternative browser. Curently their pushing my DQ-10's, very nice. Very clean and seems to have been serviced. All functional. Oh yeah pics! As far as value on the market, I honestly have no idea what it's worth.Super clean examples are fairly scarce i'd imagine.https://skazkina.com/ru/bose-radio-cd-player-user-manualThere is a fix online that covers the repair step by step with pictures(dynaco page I think).Generally thought of as a stout performer for most purposes. There are those that say the complexity of design with the Dynaguard limiting and complex power supply scheme can be improved on. Adding additional power devices and upgrades to the driving circuitry create an even bolder and more reliable unit for low ohmage speakers - the so called Double Dyna or later Dynaco ST-416 (with 16 total output transistors insteac of 8). But if yours is working fine and sounds good, best to enjoy it for a long while unless the update or upgrade bug hits you.I've never seen that one before.I was told the owner goes through all the electronics he sells, and does repairs for the locals. Also if I have any problems give them a call. We have 56 Dynaco Diagrams, Schematics or Service Manuals to choose from, all free to download.This Website contains a compilation of information already available elsewhere on the internet and therefore considered to be in the public domain. We make every effort to ensure the information contained here is as accurate as possible, but we will not be responsible for any errors or omissions, or anything resulting thereof. However, we do not accept any liability for any loss, damage or inconvenience, of any kind, as a result of downloading any information from this site. Always scan any information downloaded from the internet with an up to date virus scanner before opening the downloaded information. I have seen a post from audiobard (May 10, 2010) Originally Posted by audiobard. I have a copy on paper, but not yet in electronic form.I'll try to scan it as soon as I can and mail it to you if you are interested. Can someone send it to me. I am also replacing few parts for PC-28 amplifier circuit boards as per Kevin Baoles' article ( Dynaco Repairs For PC-28 Amplifier Boards ) Any articles on upgrading the PC-28 and PC-30?http://ferramentafranza.com/images/canon-ixus-230-hs-manual.pdfBoth of mine have been stripped to the bare bones and ready for reassembly after some painting or powder coating. Bypassing the Dynaguard seems to be a good idea if the amp is used strictly for stereo. I'm going to dig up the AA article when I get home, I'm sure I've read it. There's a lot of the original Ampzilla in these amps. CraigThe post on 22 is the main signal ground, so it's kind of sensible that there might be lots of wires tagged onto it. 7 and 8 solder bridged is quite sensible.the schematic shows that. D5 and D6 and the diodes that provide the Dynaguard limiting action, so.yes, with those pulled, the Dynaguard is disabled. Here's a link to one of the schematic variations that's out there: Here's the other variation: Good luck wrestling with the beast. All the best. DanThe meter lights are not working and the meter needles are not moving. Are the meters not functional after bypassing the Dynaguard system. All the best, JacquesResources saved on this page: MySQL 15.79 vBulletin Optimisation provided by. Learn more - opens in a new window or tab This amount is subject to change until you make payment. For additional information, see the Global Shipping Programme terms and conditions - opens in a new window or tab This amount is subject to change until you make payment. If you reside in an EU member state besides UK, import VAT on this purchase is not recoverable. For additional information, see the Global Shipping Programme terms and conditions - opens in a new window or tab Delivery times may vary, especially during peak periods and will depend on when your payment clears - opens in a new window or tab. 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User Agreement, Privacy, Cookies and AdChoice Norton Secured - powered by Verisign. Or share your ideas and experiences. AudiophileI have acquired a Dynaco 400 stereo amplifier and it has some problems. Upon pulling off the top cage cover and before plugging it in to my dim bulb tester I noticed it had a transistor that was hanging off the PC-29 board on the very top by one metal leg only. I looked at the service manual and it was labeled Q6 on page 39. Upon searching for the part number I could not find it listed. I searched again and on page 23 found the number Q106 a transistor MPSU56 and the part number 567043. Am I correct in assuming this is the correct transistor to replace the one that is hanging off. There are no numbers on the one in the amp. I really can't go any further until I replace this part. I also plan on re-capping it. In normal operation the relay driver grounds the low end of the relay RY301, allowing current to flow through the relay coil, and thus closes the relay to connect the power amplifier to the loudspeakers. If there is excessive DC sensed at the output of the power amplifier, the relay driver circuit senses this and shuts off, thus opening the relay and disconnecting the loudspeakers to prevent damage. Later it was increased to reduce premature triggering of the relay circuit at high output levels. I would suggest checking the amplifier WITHOUT speakers connected, first by the Preliminary Tests on Page 27 of the Dynaco Stereo 400 manual. If you get it powered up, especially check the DC voltage at eyelets 10 and 11 on PC-29. These are the centerlines of the complementary-symmetry output stage (eyelet 10 right channel, eyelet 11 left channel). I am thinking that someone may have messed with that Q106 because the relay wasn't closing. But the ACTUAL reason for the relay not closing to begin with would more likely be an output stage failure. AudiophileThat helps a lot. If they are already blown, you probably already have shorted output transistors and very likely, damage on the driver boards. I'd power up such an amp through a VariAC but you're going to power it up through a light bulb to absorb excess current, as a precaution. Good luck! GP49 I am going to power it up as soon as I get the part installed I was referring to in my first post and plan on using a dim bulb tester. I am going to order that part today along with some other items I am in short supply of. Most of the time if a non-Dynaco technician replaced the fuses, they'd use glass ones because that was what was usually kept in stock. GP49 Joined: April 19, 2006 So far, all of them have 6-ampere AGX type fuses on top of the relay plate. I have yet to encounter one with ceramic fuses installed. MarkAfter looking at them for too long, with no responses from registered letters sent to the owners, I took them home and used them myself. After about ten more years I sold them off and as far as I know, they are still running.Joined: April 19, 2006 Exactly how did you bypass the PC29 board, anyway?If you do this, the Stereo 400 will no longer be usable with the Dynaco PAS preamps; its input impedance will be too low. I disconnected the twisted-pair wiring at eyelets 19, 20 and 22 of PC-29 to eyelets 1 and 2 of each PC-28; and ran an extra twisted pair, one signal and one ground, from the input jacks way down on the heatsink, to eyelets 1 (signal) and 2 (ground) of each PC-28. You could also run that extra twisted pair from eyelets 21, 23 (signal) and 22 (ground) of PC-29 to the corresponding eyelets on each PC-28. Much shorter wiring and easier to do. This change duplicates the operation of the bypass switch on the Stereo 416, in its bypass position. It leaves Dynaguard in operation; since Dynaguard is out of circuit until actually triggered, disconnecting Dynaguard is not worth the effort if it's working properly. Leaving the inputs connected at PC-29 will provide Dynaguard with a signal to work with. You still need to fix the protection and relay driver circuits on PC-29, so this is not an easy way around diagnosing and fixing the Q105, Q106 problem.. unless you want to bypass the relay and depend on fuses to protect your speakers (Dynaco did that on the Stereo 410). I don't recommend it because fuses depend on excess current to blow, and by then your speakers could be fried. GP49 Joined: April 19, 2006 Of course, all of the original transistors have been replaced, presumably with better parts. With the one I built in 1975, aside from the original power switch having developed a short in it, one of my bigger concerns was the 10-watt resistors on PC-30 getting too hot. That question was addressed on this forum earlier, so I might have a good solution for that problem. Back to original point, I have no intention of bypassing anything in any of the ST-400's that I have, although on one I picked up on e-bay last year, I noticed that input volume controls had been bypassed, and also noticed some film caps on the back of the PC-28 boards, I just haven't gotten into any of them yet. MarkDynaco acknowledged that a whole batch of them were bad! GP49 Joined: April 19, 2006 I'm also considering redrilling the heat sink to double the number of output transistors, as the 416 (and some 400's were done, even though I know this could be a problem. Mark I know of one Stereo 400 that was drilled in our shop for the additional TO-3 devices. Frank could be a curmudgeon; he even said that Dynaco stole his Double 400 design for the Stereo 416.right down to an error he made. But he has never, to my knowledge, ever said what that error was. GP49 Joined: April 19, 2006 Original D3, a BZ102, no longer available, now use 2 1N4148's. Older version replaces D8 and D10 with 1N5231B, newer version lists replacing D7,D8, D9, D10,D11,D13 and D14 with 1N4148's. More? OK, how about replacing the DB301 with a GBPC 35 A 800V. By the way, the BC550B's are cheap at Mouser. Mark One problem with working on Dynaco equipment is the transistors that are marked only with Dynaco part numbers. They can make it tricky for a technician in some cases. An early example: in the Dynaco Stereo 120, the output devices were originally identified in the early-production construction manuals as 2N3055, a very widely available TO-3 power transistor. However, a transistor could meet the minimum specifications for a 2N3055 and yet be inadequately rated for operation in the Stereo 120. I don't know how many of those Stereo 120s are still functioning and still capable of being operated today, but I still have two that were used for years as loaners for customers, because they cost me next to nothing and I wouldn't cry if one blew up. Later, Dynaco finally updated the construction manual with 2N transistor numbers for devices that did meet the requirements for safe, stable operation in the Stereo 120. GP49 Joined: April 19, 2006 What surprised me was his comments about the PC-28 driver boards occasionally overheating (which I can't comment on, as I never remember feeling any heat rising off of them). What he did say about the ST-120's 2N3055's was that these parts were run almost constantly just under their maximum voltage rating, which was why these parts blew so frequently. You did mention that you had access to a jig for redrilling the heat sink on an ST-400. Any chance you could make a paper pattern of it and send it to me? MarkIt stayed with the shop when I moved away. That was when my hair was 0 grey instead of 90. GP49 Joined: April 19, 2006 I'm almost 57 years old, and hair has gone from almost entirely black to largely white. Mark. Read 1347 times.These are FREE for downloading. Even though you may not own any Dynaco solid state gear, some of these manuals make interesting reading. Check the link below. I have here the following Dynaco solid state manuals. 1. Dynaco AF-6 stereo tuner manual 2. Dynaco FM-5 stereo tuner manual 3. Dynaco PAT-4 preamp manual 4. Dynaco PAT-5 preamp manual 5. Dynaco SCA-50 integrated amplifier manual 6. Dynaco SCA-80Q integrated amp manual 7. Dynaco SE-10 equalizer manual 8. Dynaco ST-80 power amplifier manual 9. Dynaco ST-120 power amplifier manual 10. Dynaco ST-150 power amplifier manual 11. Dynaco ST-400 power amplifier manual 12. Dynaco ST-410 power amplifier manual 13. Dynaco ST-416 power amplifier manual 14. Dynaco DSC-1 stereo control unit 15. Dynaco QD-1 Quadaptor manual 16.I've purchased copies for most of my solid-state equipment, but the ST-120 manual is a little harder to come by. The scans are outstanding. Harry Maryville, Tennessee Happy owner of both tube and solid state Dynaco gear. It's been awhile since I encountered any SS Dyna, but this resource may see me snagging the best I see if and when it crosses my path.My sincerest thanks! Bill Given the great service you are providing, please let me know and if I have paper copies in my archives I will snail mail them to you for your scanning and posting. Either tube or solid state Dyna units. Best regards, Frank Van Alstine The only two manuals that I know I DIDN'T have were two solid state manuals. 1. The SCA-50 solid state integrated amp 2. The QSA-300 which is a 2 or 4 channel solid state power amp I have recently located these two manuals but I have not had the chance to scan them. I will scan them within a couple of weeks and have Roy Mottram post them with the others. Frank - If you check the manuals listed on both the tube and solid state pages and you notice one that you have that is not listed there send me a PM and I will send you my address. Thanks again, Bob Latino By using our site, you consent to the use of cookies by us. If you are looking for something specific, please check the list below. This list comprises everything we have available at this time. If you do not find what you are looking for, please note that Radial purchased the Hafler brand and was not involved in any of the manufacturing. Thus, we do not have source information. We are however working hard at increasing the data on the web site and are encouraging folks to provide data that we can share. So if you have schematics, manuals or anything else that you believe would be of value to fellow Hafler and Dynaco enthusiasts, please send them our way. Hafler (division of Radial engineering Ltd.) has no way to assure that the information provided is accurate or represents the latest revision of a given product. Any use of the schematics presented herein is your sole responsibility and is done so under the understanding that you are taking the full and entire risk for their accuracy and that you shall hold Radial (Hafler) harmless under any and all conditions. We kindly ask that you get in touch with your local repair center to see if they can assist by downloading one of the many documents made available on this site. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd.Introduced in 1959, the ST 70 was available as a kit ( Dynakit ) intended for assembly by the purchaser or as a complete factory-wired unit. It produced 35 watts per channel. The output transformers are an ultralinear design, whereby part of the primary winding is fed back to the output tube's screen grid. This design reduced distortion and improved audio quality. The popularity of the ST 70 contributed more than any other single product to continuing consumer interest in tube-based stereo amplifiers at a time of increasing market dominance by solid state audio products. In 1992, an updated version of the Stereo 70, the Stereo 70 II, was produced by Sound Valves for Panor Corporation. Even today, upgraded components, rebuilding kits, and complete tube amplifiers using the basic Stereo 70 design are still in production, and the ST 70 has inspired numerous other amplifier designs, such as Ars-Sonum's Filarmonia SE. Dynaco continued to build both mono and stereo amplifiers until 1977.VI mono power amplifier of 1976, which produced 120 watts (continuous). Because of early problems involving circuit, power supply, and transistor failures, the ST 120 was not as popular as earlier Dynaco tube amplifiers. Numerous small circuit changes were introduced by Dynaco over the years in an attempt to improve the stability and reliability of the ST 120, without much success. With the PAT-4 preamplifier in 1967, the company affirmed its ability to design reliable solid state equipment at an affordable price. In 1969 the Dynaquad 4-channel matrix decoder system was introduced, helping to start the quadrophonic sound craze. In the 1970s, the Stereo 400 was developed and marketed. This was a high power amplifier at 200 watts per channel that offered automatic protection circuitry to prevent electrical destruction of the loudspeaker. The FM-5 tuner was offered as was the SCA-80 integrated amplifier in the early 1970s time line. Dynaco's solid-state kits were different from the popular Heathkit products (and Dynaco's own vacuum tube kits) because of their preassembled circuit boards. These boards were wired at the factory, tested and packaged with the unassembled chassis. It remained only for the consumer to attach the switches and controls to the chassis pieces, assemble the chassis and power supply, and solder connecting wires to the circuit boards. This saved considerable time and reduced error in assembly.The A-Series were marketed between from 1970 until Dynaco's demise in the 1980s. The patented aperiodic (essentially non-resonant) woofer design utilized a highly damped vent instead of a reflex port, whose acoustic resistance is very carefully controlled. Dynaco followed the A-25 with the slightly larger A-35, which featured a dual-chambered, non-vented design in a walnut-veneered cabinet with even greater transparency and fidelity. Over time, Dynaco marketed a wide range of loudspeakers, ranging from the small A-10 model to the floor standing A-50 series. After some 30 years, these loudspeakers still command good prices in markets such as eBay, and are a testimonial to their quality. The system worked best when the stereo sound had been recorded via two bidirectional microphones on the same spot. When microphone set-up changed to the use of multiple directional microphones and multitrack tape recording and postprocessing (i.c. in the CD era), the QD-1 was less effective.In 1977, Hafler founded the Hafler Company, continuing the tradition of high quality but inexpensive kits and assembled hi-fi gear. The speakers were well regarded by the audiophile community, but their introduction was apparently too late to make any strong impression in the marketplace, and Ed Laurent left shortly afterward to join SEAS Corporation.Panor introduced some new products, such as the Stereo 70 II.By using this site, you agree to the Terms of Use and Privacy Policy. Discover everything Scribd has to offer, including books and audiobooks from major publishers. Start Free Trial Cancel anytime. Report this Document Download Now Save Save Dynaco ST400 Amplifier For Later 0 ratings 0 found this document useful (0 votes) 592 views 38 pages Dynaco ST400 Amplifier Uploaded by plasmapete Description: Full description Save Save Dynaco ST400 Amplifier For Later 0 0 found this document useful, Mark this document as useful 0 0 found this document not useful, Mark this document as not useful Embed Share Print Download Now Jump to Page You are on page 1 of 38 Search inside document Browse Books Site Directory Site Language: English Change Language English Change Language. Got the preamp together OK and used both the amp and the preamp until 1976 when I sold both units to a student at WPI (Worcester Polytechnic Institute) to buy a Pioneer solid state receiver. I mean who knew that tube gear would still be alive and kicking in 2016. The first thing I did was to look for a suitable replacement driver board. I tried a few different driver boards and my ears told me that using the Tubes4hifi VTA driver board (designed by Roy Mottram) made a big difference in sound quality over what I could get out of these older original Dynaco ST-70’s. Bob liked the VTA70 board so much that he later joined forces with Roy Mottram, and became Vacuum Tube Audio’s east coast representative. Then, according to Bob, “In late 2006 a customer lamented that he wished that you could still buy new Dynaco ST-70’s in KIT form. Efforts were also made to make the amp more reliable than the original amp. Some things were not changed like the chassis layout. The size and shape of the chassis and the parts layout of the VTA ST-70 is identical to that of the original Dynaco ST-70. An original or aftermarket Dynaco tube cage will fit this chassis perfectly. The silk screening of the Dynaco markings on the front and rear face of the amp are also the same as on the original amp. Eventually most of these chassis will develop rust spots. The chassis on the VTA ST-70 is made of 16 gauge (.015 inch thicker metal) polished stainless steel and will never rust. All the screws on the VTA amp are also made of stainless steel. Sometimes a “brown goo” would melt out of the choke and deposit like candle wax on the bottom cover below. The C-24X choke in the VTA ST-70 is rated at 240 milliamps and runs cooler. The total capacitance on the original amp was 90 uF. On the VTA ST-70 the total capacitance is 464 uF. The output binding posts on the original amp were simple screw terminals. The VTA ST-70 has modern gold plated binding posts which may be set up for 4, 8 or 16 ohm speakers.