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transistor replacement

  1. E

    Superscope R1240 / Marantz 1040 receiver - oscillations

    Hello! I've been working on a Superscope R-1240 which I posted about in another thread: Superscope R-1240 (Expert TA 940) Now I've solved some of the initial issues. But I would like to get some input about another(?) issue which I hope there might be some experience about in the Marantz forum...
    • E029127
    • Thread
    • oscillating oscillations transistor replacement
    • Replies: 0
    • Forum: Marantz Audio
  2. N

    Help! Transistors replacement AudioAnalyse A9 power amplifier

    Hello Experts, I have a question regarding the replacement of transistors in my AudioAnalyse A9 amplifier (Pure Class A, 50WPC). This amp delivers excellent sound quality, which I really enjoy (sweet, calm, with a wide soundstage). Unfortunately, two MJ15015 transistors have shorted, and after...
  3. 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
  4. Gerge_Sletar

    Pioneer A-X5 overheating after replacing transistor

    Hello I’m in need of some advice, I've been working on a pioneer A-X5 that is overheating after replacing a transistor in the left channel. After much probing with a multimeter, the right channel output transistors and other components showed the correct voltage. Moving over to the left...
  5. Carbsandcaps

    What makes a good audio output transistor?

    I’ve been working with a lot of T0-3 based amplifier setups lately and finding an inexpensive replacement for a T-03 output transistor is next to impossible. Going on maximum voltage and amperage alone can bring up some matches that at least won’t blow up and produce sound but at what quality...
  6. 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...
  7. JB8

    HARMAN KARDON 430 - Oscillating DC Voltage At Speaker Terminal

    Hey All, I've read several threads on this issue, feels like I've checked most of the viable culprits but I need some help, please. ISSUE: Wildly fluctuating DC voltage at left speaker terminal, both spkrs 1 & 2 With DMM in 600 range, out of necessity, the voltage is quickly bouncing around...
    • JB8
    • Thread
    • 430 dc voltage dc voltage on output harman kardon harman kardon 430 speaker terminal transistor replacement
    • Replies: 6
    • Forum: Solid State
  8. H

    Replacement output transistors for 2SA747 and 2SC116 - Yamaha A-1

    Need to replace a pair of OT’s on a Yamaha A-1. Have a couple of recommendations but can anyone say which transistor pair is best suited OR has worked well in this particular amp (or both, of course!) Would like to place an order today if possible, so all replies much appreciated. Existing...
    • Hifibythekg
    • Thread
    • 2sa747 2sc1116 a-1 output devices output drivers to 3 transistor replacement transistor substitute yamaha a-1
    • Replies: 3
    • Forum: Solid State
  9. mhz

    Marantz 2238 Transistor Replacement

    Hello! I am new to AK but have been around quite a bit and have to thank everyone for all the great information here which has helped me a ton. I recently picked up a Marantz 2238 (non-B) in need of some care from a local record store. Don't think it has ever been serviced before; lamps were...
    • mhz
    • Thread
    • 2238 marantz restoration help transistor transistor replacement
    • Replies: 5
    • Forum: Marantz Audio
  10. simplyvolkol

    Trouble, big time

    I have always relied on my Kenwood KR 6050 and built my whole setup around it as it was one of the first components I got with my Dual 606 (might tell the short story if y'all are interested). However one day BOOM, the amp blew a fuse and apparently, the power amps left side blew and both of the...
  11. tlite

    Marantz 2235 Headphone Hiss

    Howdy all: This is the same Marantz 2235 receiver I replaced transistors in back on this thread. I'm getting a hiss from all input channels when listening through headphones. Even with nothing playing. Through the speakers all sounds fine. In reading the service manual, I'm having a hard...
    • tlite
    • Thread
    • headphone hiss hum marantz 2235 marantz hiss transistor replacement vintage marantz
    • Replies: 1
    • Forum: Marantz Audio
  12. Mightyhal

    Can't balance DC on SX-880 after repairs

    Following up on https://audiokarma.org/forums/index.php?threads/sx-880-output-transistor-replacements-b705a-2sa1075.961503 -- I've had some ups and downs repairing the SX-880 (I'd shorted part of the power supply with a probe slip, and one of the output chips had shorted--one which had been...
    • Mightyhal
    • Thread
    • 880 bias circuit dc balance dc offest sx-880 transistor equivalent transistor replacement transistor substitute
    • Replies: 6
    • Forum: Pioneer Audio
  13. JB8

    Not another "330c Blowing Fuses" thread! Yes, I'm afraid so...

    I'll do my best to state the facts, just the facts: Came across a decent looking 330c, cleaned the pots and interior dust, had to install new speaker terminals as previous owner had hacked them out of the unit After new terminals installed, tested the unit and found left channel good and...
    • JB8
    • Thread
    • 330c blowing fuses blown fuse transistor replacement
    • Replies: 23
    • Forum: Solid State
  14. Flapper

    Technics SU-V8 Amp - ICQ problem - dead trim pot?

    Hi all, A few years back I bought a second hand Technics SU V8 amp which quickly became my favoured amp (slightly, over a Sansui AU-317 that I also like). Every so often I have set the DC balance, Clamp Voltage and ICQ without problem using a multimeter and the instructions in the service...
    • Flapper
    • Thread
    • bias adjustment icq technics su-v8 transistor replacement
    • Replies: 55
    • Forum: Solid State
  15. zeferinoj

    Sansui 210, board F-1301-2, transistor replacement and other pointers

    Hello! I'm in the process of fixing a Sansui 210, looking at the transistors now. This excellent thread already covers the process but I believed it's based on a later board, an F-1301-4. The one on my set is an F-1301-2, and most noticeably the original transistors are different. I'm looking...
  16. J

    Sanyo DCX6000K restore - Transistor replacements needed!

    Hello everyone! I currently own a Sanyo DCX6000K with a problem in the main power amplifier section. This stereo receiver has two amplifiers (one per channel), one of which is giving random high volume noise spikes on the correspondent speaker while the other channel works perfectly. Some...
    • joocfpinto
    • Thread
    • sanyo transistor equivalent transistor replacement
    • Replies: 3
    • Forum: Solid State
  17. jd-audio

    Sansui AU-222 smaller transistor replacements

    Hi Guys, I have an nice little AU-222 amp. It is working fine and is used as a daily driver. But I am wondering about the replacement transistors that are present on the amp board. I have got this amp recapped in the past and also had it serviced/repaired once or twice over the years (due to...
  18. tusntuk2

    How do you tell what is most important when substituting transistors?

    A constant topic - transistor substitution. I needed a sub for a 2sc1222, and as the dates on the threads change, so do the answers. Some is due to obsolescence, of course, but it is changes due to the understanding of how the transistor is applied in the circuit that seem the most important -...
    • tusntuk2
    • Thread
    • 2sc1222 compare transistors equivalent ka-3500 muting circuit transistor replacement transistor substitute transistors specifications
    • Replies: 6
    • Forum: Solid State
  19. Chris Dykes

    Transistor Replacements for Darlington/BJTs & Outputs Kenwood KA3700

    Hi All, I've done as much legwork as I can to identify good replacement options for the driver and output transistors in the nice little Kenwood KA3700 amp. I would love opinions on selecting the best replacement options. I see that NTE - while convenient - is often maligned as being low or...
    • Chris Dykes
    • Thread
    • darlington kenwood ka transistor equivalent transistor replacement vintage 70's kenwood
    • Replies: 17
    • Forum: Solid State
  20. T

    SAE 2200 transistor replacement

    Hello from Oregon coast. I am replacing some transistors in my SAE 2200. The same ones that always blow. The drivers and emitter resistor between them. Last time I did this was a long time ago. I used 2sa1011 for (sae# 11-0150) and 2sc2238 (Y)for (sae# 11-0151). That channel is still good. But I...
    • Trebolo
    • Thread
    • 11-0068 11-0074 11-0150 11-0151 equivalent sae 2200 sae amplifier repair transistor replacement
    • Replies: 4
    • Forum: Solid State
  21. F

    Sansui AU-5900 hissing (background noise)

    Hi everyone, I found a Sansui AU-5900 in an estate sale for 75$ CAN. The receiver wasn't plugged for the last 4 or 5 years and was really dirty (smoker house). I cleaned it good, used Deoxit in all switches, pots and selectors (more then once). After a few minutes of working, the right channel...
    • franclou
    • Thread
    • background noise hiss noise sansui sansui au sansui au-5900 transistor replacement
    • Replies: 14
    • Forum: Exclusively Sansui
  22. BHaines

    Kenwood KR-9400 LOUD poping noise left channel

    Would appreciate some help on this one... Just moved to my new house, setting up my stereo room, turn on my KR-9400 and BOOM! Massive pops/cracks coming only from the left channel. Took it about 15 seconds to start after I first turned the receiver on. Happens with volume all the way down...
    • BHaines
    • Thread
    • capacitor kenwood kenwood kr-9400 pops and cracks power amp transistor replacement
    • Replies: 3
    • Forum: Solid State
  23. Keith Baran

    2SD315de transistor for Marantz

    Hello all, I'm new here and beginning my first restoration project. I'm trying to find the output transistor for a Marantz 1030. The transistors are labeled "Sanyo 2SD315DE". I've been searching the web for hours and all I come up with are some Chinese generic. I can't even find a cross...
    • Keith Baran
    • Thread
    • marantz transistor replacement
    • Replies: 20
    • Forum: DIY
  24. A

    CR-420 Transistor Replacemnts

    Hi this is a call for help for all good hearted geniuses out there. I got a non-working CR 420 a couple of years ago and I have got it to work a couple of times but for very short time. I decided to replace the transistors and it is being hell. I was wondering if anyone out there has a list of...
    • adolfo
    • Thread
    • cr-420 transistor replacement transistor substitution
    • Replies: 5
    • Forum: Yamaha
  25. Fonzombie

    PIONEER SX-3900 - Cracked Output transistor sockets

    I have a pioneer sx-3900 and it seems to be working great - i opened it up to give it a look through and found on the bottom side connected to the heat sink most, if not all, of the white silicon output transistor heads were cracking. Is there a way to fix this??? The rest of the unit is in...
    • Fonzombie
    • Thread
    • output pioneer silicon sx-3900 transistor replacement
    • Replies: 20
    • Forum: Pioneer Audio
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