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80's Technics Integrated Amps

Discussion in 'Solid State' started by GreenV, Apr 22, 2012.

  1. GreenV

    GreenV New Member

    Messages:
    12
    Location:
    South-West, Western Australia
    There seems to be heaps of different SU-V... model amps issued by Technics from the start of the 80's. Does anyone know in which way they are generally grouped? Perhaps either by type, high end/low end? Having enjoyed 70's amps, would like to know a little bit more about this era and perhaps pick up some to have a play with!
    Cheers, Chris.
     
  2. SaSi

    SaSi AK Subscriber Subscriber

    Messages:
    4,021
    Location:
    Athens, Greece
    There are two groups I've looked into:
    SU-VnnnX
    and
    SU-V nX

    I own an SU-V620 since new and although it's nothing special, it has served me well. The series is nothing fancy but they are solid - as solid plastic can be...

    The SU-VnX series (like SU-V4, SU-V6, SU-V10X are much more solidly made. I have a couple of SU-V6X and one SU-V10X. Clean sound, well built and appear reliable.

    Then ther's also the SU-Vnn range (SU-V85 comes to mind). Haven't seen one of them up close and personal but I'd rate them above the 3 digit series.
     
  3. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    1978-1987

    The SU-V series was Technics full sized HiFi line that introduced new class A circuitry in 1978. Their other offering was the SU-Z series (Z1 and Z2) which were not quite as wide. The Later Z series also become full width (43cm). The first lineup of the V series consisted of V2 V4 V6 and the flagship V8. The V4 also was known as V4A and V4K. The V2 and V4 were both based on STK80*0 output ICs, the V6 and V8 on transistor outputs. All featured the synchro bias outpit stages. In 79/80 the lineup was the V3 V5 V7 and the flagship V9. All these amplifiers were discrete output, with the V9 using high current outputs. All were new class A with synchro bias. In 82/83 Technics developed computer drive in their amplifiers where a microprocessor could alter ICQ levels in the output stage calculated by signal and thermal sensing, also doubled as a protect circuit for overtemp overcurrent and some cases overinput. These were released as V303 V505 V707 and the flagship V909 again all were discrete output with the V909 having the same high current outputs. In 84/85 Technics had simplified the computer drive circuit with the MN1421STA being retired with a MN1404STE appearing in the new lineup except the SE-A3MK2. Also Heatpipe heatsinks were introduced. The new lineup being V1X V2X V4X V8X. In this lineup the V1X introduced Technics 1st own developed hybrid IC, the SVI2003 which was a 50 watt per channel ic that had synchro bias. The V1X didnt feature computer drive. The V2X featured computer drive, earlier V2X amps were fitted with STK2038IV and others recieved the SVI2003. The V4X was computer drive and all were synchro bias with the SVI2004A power IC, this amp I consider to have the best sound. The V6X and V8X were discrete outputs with synchro bias. In 1986 the V7X and V10X were late additions to the series, both having computer drive discrete outputs with synchro bias. Also in 86 the V40 V50 and V60 were produced. This phased in class AA amps which have a very different setup with a voltage control amp and current drive amp with a wheatstone coupling to the speakers. These amps are not featuring synchro bias. V40/50/60 have discrete voltage control amps with SVI400* current drive IC that has the wheatstone resistor bridge inbuilt. In 1987 the V85A was added class AA discrete output with no synchro bias. The amps from 86 were still in production

    All these amps were very well made, all had metal faces. The BPC had not entered the SU-V series. Though it surfaced in the 1986 with the SU-500 and the SA series recievers
     
    Last edited: May 7, 2012
    24Vboost likes this.
  4. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    Will add more soon
     
  5. nashvillebill

    nashvillebill Super Member

    Messages:
    2,853
    Where does the SU-Z25 fit in there? I've got one sitting downstairs, got it from a thrift and never hooked it up.
     
  6. terra1

    terra1 Addicted Member

    Messages:
    5,336
    Location:
    WA
    Invaluable info.

    I had to break it up to read.

    I love the smooth sound of the SU-V9. Impressions are very robust sound and amazingly heavy like a rock. Amp adjustments are a little more complicated than the usual adjustments found on other amps. Sounds warmer than my SU-7300, 7700, 8600. Sounds closer to my SU-8080.

    Note: The glass door is the V9s only weakness. Make sure the seller packs so no stress is placed on the glass.
     
    Last edited: Apr 22, 2012
  7. Michael Powers

    Michael Powers Well-Known Member

    Messages:
    971
    Thank you for all the information; you are my hero. I have a SU-V6 that is not in service right now.....it needs to have a new power cord soldered in; I might substitute a jack from an old computer power supply so I can use a computer AC cord. Any more comments on this first generation effort from Technics?
     
  8. mbartosi

    mbartosi New Member

    Messages:
    30
    Location:
    Poland
    In the low end of the lineup :)

    http://wegavision.pytalhost.com/technics82/
     
  9. GreenV

    GreenV New Member

    Messages:
    12
    Location:
    South-West, Western Australia
    Wow that was a detailed history SVI2004A! I imagine during this period there was an explosion of ideas with the dawn of digitally encoded music and accelerated adoption of integrated circuit technologies. No doubt there were some duds left in the wake, and also assume that mainstream amplification gear that exists today relied on what was successful in this period?
     
  10. ajpanic

    ajpanic New Member

    Messages:
    48
    Location:
    Denver, NC (Charlotte area)
    This is great info! SVI2004A, please do add more. I have an SU-V10x that I would love to learn more about. Many of these integrated amps by Technics from the 80's look to be well built with great specs, but not much info or reviews out there.

    Personally, I find the SU-v10x to be a solid performer. It generates good clean sound backed by a lot of power. Very true to the music without coloring or being too sterile. It looks good, too.
     
    24Vboost likes this.
  11. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    1988 on

    In 1987 the V45A V55A and V65A were introduced ( these all SVI400* current drive setup same as the V40/50/60) power output was up over the predecessors as minor refinements were done and larger power transformers were used.

    The V85A carried over unchanged

    1988 saw radical revision of the V series amp. The SVI4003 and SVI4004 power ic was retrenched in favour of a discrete wheatstone setup, which saw in the SVI320* series power IC rolled out. The all new lineup was the V450 V550 and V650.

    Of interest here is where cutting costs on heatsinks become a fork in the road.
    The V660 running a SVI3205 could happily supply 2x 140W into 4 ohm, where in the later V78/V98(Z780/Z980 all used the same SVI3205 which was rated to 110W into 8 ohms only ( one only has to see the heatsink difference in the V660 and a V98 to get this)

    Also the V85A was retired and replaced with the again discrete output V90D. The big difference here was Digital Inputs ( fiber optic and coaxial) with an onboard 18 bit D/A converter. Power out was on par with the V85A

    The cheaper V78/V98(Z780/Z980 came out mainly bought as part of a system)

    1989 saw in revised models V460 V560 and V660 with the V90D unchanged.

    1990/91 again small changes with V470 V570 and V670 revision and power supplies being the main changes. (G50 and G70 amps took over from the V78/98)

    1992 this daw in the VX series VX500 600 700 and the monster VX820. At this point the SVI series were replaced with those awful BC power modules.

    From hereon in it simply got cheaper as the march of the BPC invaded the once serene offerings. Later models like the VX920 and their pre and power combos still carried on till the mid 90s.
     
  12. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    The V10X was a very well made amp. Underrated a tad, moreso rarer and often fly under the radar. A solid 120W into 8 ohms 20-20k @ 0.003%thd and was rated 140W/ch at 1khz 8 ohm. These 13.5kg beasties suckle 670W from the socket when provoked.

    Other than the V7X the V10X was Technics 1st integrated that had any kind of Video jack for AV in on the front.
     
  13. ajpanic

    ajpanic New Member

    Messages:
    48
    Location:
    Denver, NC (Charlotte area)
    Really neat info, thanks SVI2004A. I always wondered exactly where Technics wandered off into BPC. My personal opinion is that many of these 80's units fly under the radar as they are considered BPC.

    the RCA inputs on the front are a real nice feature. It's great for plugging in an iPod or giving another component a quick listen.
     
  14. coonmanx

    coonmanx Super Member

    Messages:
    2,202
    Location:
    Colorado Springs
    It does seem that the SU-V series and the SU-Z series were the same at some point with the only difference being that the SU-V series has the New Class A badge on it.

    I have an SU-V75 amplifier that I would guess is the same as the SU-Z750 (internally). I believe that it has an SVI 3205B chip in it. Right now it has an issue with the left channel being weaker than the right although it still sounds good. I am having it looked at right now.
     
  15. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    Technics ventured into BPC round 83/84 the SU-V series were not affected at this time. The poverty pack SU-Z100 Z200 were frontrunners here.


    Plastic fronts also were standard on the hi density SU-X series in the earlier models , then in the base models. The mid level and top were still fabricated with metal.
     
    Last edited: May 8, 2012
  16. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    The V75 is not the same as a Z750. These are USA models. Though I cant pinpoint their exact year Id say 1988 SVI3205B? Id say someone changed the output ic 3205B is one of those BC modules post 1992 originally it would have had SVI3205
     
  17. coonmanx

    coonmanx Super Member

    Messages:
    2,202
    Location:
    Colorado Springs
    Guess I put down the wrong info. I just popped the top on it and it indeed has a 3105B chip in there. It does say "Made in Japan" on the back so I would think that by USA model you mean sold in the US market. I'm pretty sure that this was part of a rack system as it has the special ribbon connector for the matching tuner (ST-S74).
     
  18. proimage1

    proimage1 Well-Known Member

    Messages:
    526
    Location:
    Florida Panhandle
    I can honestly say that my Technics SU-V909 Integrated Amp has become my go to unit for everyday listening. The more I listen the better it sounds compared to everything else I own. I really didn't know much about it until I inquired here a while back - seems this one was never sold here and according to the post here is quite rare. I do know I love it !!!
     
  19. SVI2004A

    SVI2004A Synchro Bias

    Messages:
    1,391
    Location:
    Albany Western Australia
    SVI Chip overview.... What do those numbers and suffixes mean?

    Matsushita are a well known manufacturer of amplifiers that are based from a hybrid power ic.
    In the earlier years it was common to see STK chips utilized. Matsushita started with the mono chips like STK0039 darlington packs in their base models, which served well.

    Sanyo had since developed their 2 channel DPP (Darlington Power Pack) with varying features.

    In the mid 70s to late 70s utilized this exact series STK00XX mono DPP then STK20*8 stereo darlington packs which almost certainly quasi complimentry config.

    Whilst i do not consider this optimal, it certainly resulting in marantz beating capabilities

    Matsushita soon had Sanyo producing dedicated output ICs For their New class A series amps.

    This saw Sanyo dedicated chips starting with STK8040 complimentry symmetry that has pinout to integrate the synchro bias circuit to the power amplifier circuit.

    Matsushita then had STK20*8IV chips made that were 16 pin complimentry symmetry.

    Not only was this chip complimentry symmetry, the pinout was mirror image. (one can Install this ic in reverse to see if fault changes channel ( note heatsinking)

    Matsushita basically copied the STK layout but improved it. Gone were the carbon film tracks in favour of SMD resistors. Transistors too were all SMD other than drive and output.

    83/84
    The 1st in the lineup was the SVI1001 and 1002 30 and 40W Which shortly predecessed the SVI2003 and SVI2004A the 50 and 80W output ICs that featured synchronous bias and overcurrent detect.

    84/5
    SVI2100 series (2104 2105 At 80 and 100W) based from the 20 series but with inbuilt overcurrent detect, thump-dethump and relay drive circuit.

    86
    SVI3000 3001 3002 3003 3004 3005 same pinout as STK41*2 series, though internally complimentry symmetry as opposed to the quasi complimentry STK

    SVI3100 series 3100~5 3100 3101 and 3102 becoming the foundry of the later SVI3 series. These were 14 pin total enclosed voltage amp power amp and respective protect circuit.

    3103 3104 and 3105 being the 18 Pin config, centre 14 pins same in function as the 14 pin chip. This IC has relay drive output at pin 1.

    SVI400 series 4003 and 4004 mirror image pinout, similar in layout like the SVI1 and 2 series this lineup went back to mirror pinout it had the resistor bridge inbuilt for classAA which in fail, rendered the whole current drive pack useless unless you knew where to put resistors externally ( and you had continuity to both cannels emitters of the outputs)

    87
    SVI3200 series. Based from 3100 series but all were 18 pin. Like the 3100 series effectively all centre 14 pins having same function, though relay drive pin now being pin 18. 3203 60W 3204 80W 3205 110W and not long following SVI3206 130W.

    Throughout the lineup 3102 and 3205 were most prevailent. 3206 effectively a 3205 with larger outputs.
    These chips saw Matsushita through to 1992.

    In late 91 / early 92 the plant was changed and BC power modules came out. Carrying over the SVI**** series mostly suffixed with C or D variants, and occasionally A or B variants if not already done so in the original SVI lineup.

    Copper tracks become alloy composite in the BC modules

    Mid 90s RSN became the prefix. Though some pinouts were the same (ie SVI3102 - RSN3502.

    At this point synchro bias had become non existant. Mid-later 90s saw class H+ come into the scene, which we all know is AB with switched supply rails.
     
  20. Synchro-bias

    Synchro-bias New ClassA

    Messages:
    536
    Location:
    Australia
    Awesome infomation there Baily :D had a great read of the info, so the little SVI3102 in the SU-500 is synchro bias also
     

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