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amplifier

  1. J

    HK770 HOT Left Channel

    Hi team, I have a Harman Kardon HK770 that I'm trying to fix up and put some real usage into. I've recapped the power and driver boards, and re-flowed any suspicious solder already. My issue is that the Left channel runs hot pretty fast, and when I check the output with a multimeter I'm...
    • Jacope
    • Thread
    • amplifier amplifier repair dual mono harman kardon hk770
    • Replies: 7
    • Forum: Solid State
  2. mosfets

    Building the John Linsley Hood JLH 1969 Class A audio amplifier

    There is a channel on YouTube called Steve's Trivia by an interesting old fella named Steve Wagner. He did a video series on the JLH 1969 amplifier. I thought to email him and ask for a trade and see if he was interested in making a few videos on the Mike Bitner amplifier called Symasym. Wagner...
    • mosfets
    • Thread
    • amplifier class a jhl1969 jlh 1969 john linsley hood
    • Replies: 25
    • Forum: Solid State
  3. R

    Scott A437 Strange noise in both speaker

    My Scott A437 amplifier makes a strange noise on both speakers when turning on. After that, it works correctly. Could you also help me with the Bias adjustment? Where should I place the probes and which resistor should I adjust to get 5mV? Thank you very much for your help
    • Radas
    • Thread
    • a437 amplifier fix issue scott
    • Replies: 2
    • Forum: Solid State
  4. K

    Buy NAD or Linn?

    Hi! I can buy: NAD 1020 + 2140, and Linn intek - its in the same price. Which one should sound better?
  5. david winter

    Output stage transistor subs for BD517/518 (=MPSU05/55) and BD597

    Hi, Both output stages (schematic below) have one shorted BD597 output transistor. One channel has both drivers + BC238B shorted (all ok on the other). I'd like to use modern subs instead of those pricey BD5xx. For the BD597 output transistors I still have one or two pairs of MJE3055 (same...
    • david winter
    • Thread
    • amplifier output stage saba transistor replacement
    • Replies: 15
    • Forum: Solid State
  6. D

    Luxman MB3045 biasing guide/help

    Hello all and thanks in advance I recently purchased a beautiful pair of Luxman MB3045 amps. They are running well but given the age and the previous history being unknown I would like to check the bias etc on them. I have done a bit of a search online and thought I would come across a service...
    • DanBun
    • Thread
    • amplifier bias biasing luxman tubes valves
    • Replies: 22
    • Forum: Tube Audio
  7. T

    sony hp-210a repair help.

    I have a sony hp-210a all in one system that has some issues with the power amplifier section. 3 of the 4 power transistors are shorted to ground and the resistors directly in line with the top two got completely toasted. I ordered some replacement d291 transistors from alie and I am checking...
    • TrevorBarten
    • Thread
    • all in one amplifier blown output transistors help repair sony
    • Replies: 5
    • Forum: Solid State
  8. maskof

    JVC JA-S31 and Scott A426. worth to collect?

    Hi everyone, I found these two amps, the JVC JA-S31 and Scott A426. Do you think they are worth collecting? Thanks in advance!
  9. S

    MC152 - Power Guard Light issues and power off Subwoofer pop

    Hello, I have an MC152 that I've owned for over 2 years, it had this problem where the flat ribbon cable that connects to the front display was not seated and my left Meter would randomly stop functioning (this was pointed to me by a Mcintosh dealer tech when I got this checked wiht them). The...
  10. Akur98

    Kenwood KA-3080R going into protect mode?

    Hello! I just got Kenwood KA-3080R amp, it was working fine, except the input buttons didn't work properly i.e. when CD pressed, the TAPE enables, if i press PHONO, then CD turns on, and so on. It's always random. The buttons are microswitches on the PCB. After some time it turned off. Tried to...
  11. sean sweeney

    Question on 1959 Crown SXA tube amp power supply, switching noise from half wave rectifiers?? 120hz hum.

    So I got this amp in a trade deal a few weeks ago, and after one issue of basically building it back from scratch, from a blurry schematic from 1960, I still am getting some 120hz hum when the unit is idling, with the inputs shorted. I just replaced the selenium rectifier, and that seemed to...
    • sean sweeney
    • Thread
    • 1959 amp amplifier control crown gcr monitor studio sxa tube
    • Replies: 175
    • Forum: Tube Audio
  12. M

    Sansui A40 bulb busted; weird power reading from PSU?

    Ls, Not long ago I replaced the 8v bulb that sits behind the meters in this Amplifier. It started failing, but would relight on light tapping. Changing a bulb is about as good as I get with electronics, but I thought I'd try some quick metering before I turned to the AudioKarma Oracle. So the...
    • MacShrike
    • Thread
    • amplifier sansui a40 technical help needed
    • Replies: 2
    • Forum: Solid State
  13. K

    JVC AX-435 vs Yamaha AX-470

    I'm trying to decide which among these two amps is better. The JVC is part of the Super-A series, so I know that it's a Class-A amplifier. On the other hand, I cannot find much info regarding the Yamaha. In your opinion which is the better amp?
    • Kuro21
    • Thread
    • amplifier amplifier classes jvc jvc ax-435 solid state amplifiers yamaha yamaha ax-470
    • Replies: 2
    • Forum: Solid State
  14. V

    Recapping and FM tuner station issue on Technics SA-5360

    Hello everyone, I had recently purchased a Technics SA-5360 Stereo amp tuner from eBay. This was after a long break since 2019 I took from my vintage electronics hobby. I used to mainly collect and restore tube based tuners and amps, but recently it has become quite expensive I noticed...
    • VTGCollector
    • Thread
    • amplifier capacitor technics tuner
    • Replies: 5
    • Forum: Tuners
  15. Jeezlouise

    SHARP SM-511H connection type

    Hi, I have a bit of a stupid question: I found a sharp sm-511h amp and i don’t know what kind of cables I need for the connection Please help :)?!
  16. david winter

    Blue "ladder" slide for input selector (PM-65AV, PM-80 etc)

    Hello, I need to replace the blue "ladder" slide which links the front panel rotary input switch to the linear input switch on the input board. The thin flat metal strip has broken and I can't manage to solder something on it. I don't know the right term for this part, and can't find a...
  17. analogwisdom

    A comprehensive list of 100WPC+ @ 8Ω Integrated Amplifiers, 1970-1980

    Hey y'all. I was searching the forums for a list of Integrateds from this era (my favorite) that are 100WPC @ 8ohm or more and noticed the lists I found weren't maintained by the OP so I wanted to make this thread with a more comprehensive list that I will do my best to keep updated. We can't...
  18. kevka

    JVC JR-S400 with a noise problem, any ideas?

    Hello and best regards! I have a JVC JR-S400 “Mark I” that is looking for some use. However, it doesn’t quite work as I had imagined. In and of itself, everything is almost fine, but there is always some sort of noise in the background that can also be influenced by changing the volume control...
    • kevka
    • Thread
    • amplifier jr-s400 jvc noise receiver
    • Replies: 0
    • Forum: Solid State
  19. L

    Repair help: Yamaha AX-540 amp

    Love my old AX but the left channel sounds slightly "dull" compared to right channel. At first I thought it was just a volume difference, but it also lacks some brilliance compared to the other channel. Sitting at ideal listening position, the right channel sounds brighter and louder. I have...
    • Ludd
    • Thread
    • amplifier repair yamaha
    • Replies: 6
    • Forum: DIY
  20. Freestone

    Pioneer SA-6700 Power on, No Sound

    Hi all, I am new to audio equipment, audio karma, and vintage electronics. I purchased my late model SA-6700 in its current condition for $90 because I love the look of it and have experienced the high quality sound from a similar Amp in the past. I have been wanting to get a nice setup for a...
  21. B

    AU-555A adjustment

    Hello, In 2013 I bought a Sansui AU-555A. Since then it had been working fine, at least for my expectations, except for the phono but I did not use it. A few months ago, after reading, I don't remember where, that after 50 years an amplifier with original electrolytic capacitors (EC) should be...
  22. Q

    Intermittent Noise Coming from Left Channel

    Hello! I'm not well-versed in audio matters regarding equipment, hence why I'm here. So heres the issue I've been having for months now: my left channel is making a weird noise, even if no audio is being played or if I set my volume to 0. Whether its my speaker or my open-back headphones, the...
    • quietfactory
    • Thread
    • amplifier audio advice excessive noise/interference integrated interference speaker technical help needed turntable advice
    • Replies: 4
    • Forum: Speakers
  23. Synergy

    EL34/6CA7s + 6GH8A + ECC83/12AX7s ... Superb !

    Sweetest sounding amp with EL34 / 6CA7s + 6GH8A + ECC83 / 12AX7s and all selfmade transformers. Added a stereo bluetooth though, but its switchable. Demo video
    • Synergy
    • Thread
    • 12ax7 6ca7 6gh8a amplifier ecc83 el34 vacuumtube
    • Replies: 15
    • Forum: Tube Audio
  24. Econolett55

    BGW 500D HELP

    I need help identifying the transistors for this power amp. I'm experiencing issues with the left channel in which the volume is either near quiet or fluctuates up and down or pops then goes back quiet. I Isolated the issue to the amp and not the pre-amp. I deoxit the gains but still did...
  25. M

    Cartridge Upgrade - Noob looking for advice

    Hello all! I'm new to this community but by the looks of it you all seem super welcoming, so I thought I'd come here for a bit of advice. I have come into possession of my father's Dual 505-1 and I purchased a humble setup to start playing some records. Everything works great, plays nicely...
    • MrclCrml
    • Thread
    • amplifier cartridge speakers turntable
    • Replies: 26
    • Forum: Turntables
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