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transistor

  1. A

    Need help diagnosing G-4500

    I recently picked up a G-4500 in "I swear it was working fine!" condition. Opened it up and there were no obvious issues (swollen or burnt up bits) beyond bulbs and popped fuses (using random size 12 volt fuses). Replaced fuses and bulbs, cleaned all the knobs with contact cleaner and fired it...
  2. Isaac C.

    Hitachi SR 603 Transistor Question

    Hello everyone, I have a Hitachi SR 603 that I purchased a few months ago that has a hissing noise that gets louder as the volume is increased. For the longest time I thought it was noise from my turntable, but it is there regardless of what input is selected. It wasn't until today that I...
    • Isaac C.
    • Thread
    • 2sc1815 2sc2240 2sc458 hitachi hitachi sr 603 ksc1845 transistor
    • Replies: 25
    • Forum: Solid State
  3. O

    Kenwood KR-3130 Replacement Transistor

    I'm in the process of my first vintage audio restoration - a Kenwood KR-3130 that was given to me by my dad. The right channel didn't have any sound initially which I traced down to a bad Q16 transistor (2SA565). I switched this one with the left channel (Q15) and now the right channel works...
  4. david winter

    Harman Kardon HK 450 transistor subs

    Hi, I wondered what typical subs should be used in place of those old transistors with roten legs of the same family as the well known 2SC458 (well known for causing problems). Phono section: Q701, Q702: 2SC1775(F) Q703, Q704: 2SA872(E) Q706, Q707: 2SC1775(F) Eq sections: Q501-Q504...
  5. T

    Technics SU-7100 Project - Need your help!

    Hello everyone, First off, I'd like to say that I love this forum. You seem to make everyone feel welcome, and the information on here is priceless. In a few days, I will be buying a Technics SU-7100 amplifier. According to the seller, it works great, except for the fact that one channel has...
    • twilliams
    • Thread
    • no sound solid state technics technics su-7100 transistor
    • Replies: 26
    • Forum: Solid State
  6. Mike Sweeney

    2245 etc bias transistor upgrade

    Here is the final outcome of my own version of the round to TO transformation. All I did was reverse the bend for the diode, get a longer screw and put the new transistor on some lead extensions. And yes, there is a mica insulator between the heatsink and the body of the transistor with a dab...
  7. Krosya

    Need advice - Optonica SA - 5605 left channel distortion

    Hi, I'm hoping someone can point me in a right direction here. My Optonica SA - 2605 developed a distortion in a left channel. I almost cant hear at lower volumes, but starting about 1/3 up the volume dial and higher it becomes pretty obvious. Right channel is clean and clear. It's there with...
    • Krosya
    • Thread
    • distortion optonica optonica sa-5605 transistor
    • Replies: 59
    • Forum: Solid State
  8. Mike Sweeney

    Bias transistor revisited

    I read with interest this thread - http://audiokarma.org/forums/index.php?threads/solution-for-2270-high-bias-early-serial-number.770102/page-2#post-10572328 And I liked it well enough to go back to my two boards and redo the two transistors I had just soldered in last night :) But I made a...
  9. Racingh11

    T03 vs standard 3 lead transistors

    Does anyone have any information on the differences of using metal case mount transistors such as the T0-3 style; compared to the popular current three leg transistors such as the T0-264? Is it just a cost decision the T0-3 aren't used as much now, or is there a difference in performance?
    • Racingh11
    • Thread
    • engineering information technical transistor
    • Replies: 32
    • Forum: Solid State
  10. david winter

    2SD360 + misc questions on motor / relay bord of Akai GX-600D

    Hi, I'm posting the question here as it's prurely related to solid state circuitry and not tape itself. I'm repairing an old Akai GX-600D PRO (2 track) recorder. The schematic below shows a 2SD360 NPN transistor right after the diode bridge. This transistor was replaced by a TIP42B (same...
  11. Vlad_9_

    Replacing Transistors in AKAI PS-200M

    Hello, My father has an Akai PS-200M amplifier that was broken for a long time. Manual...
    • Vlad_9_
    • Thread
    • akai replacement transistor
    • Replies: 8
    • Forum: DIY
  12. MusicRobb

    SX-737 Not working after recap

    So I recently got a non-working SX-737 from a friend. When he had it it was working okay but, when warmed up, it would occasionally pop and the audio would and cut out for a bit. I guess he figured a recap was in order so he went ahead and did some work on AWH-033, AWR-057, and AWF-011...
  13. Mike Sweeney

    New transistor smell :)

    So after recapping, potting and cleaning the main amp, I could not get the left channel dialed to 0 mv DC Offset .. it kept swinging about +- 1mv which is not much but it was bugging me. So I ordered up a whole set of transistors ( 4 PNP, 4 NPN) for the 2285B. Swapped them with new mica and...
  14. Mike Sweeney

    This weeks task :)

    I'm restoring a battered 2285B and it's coming along. I have it working again and the recap is done except for the main amp and the AM/FM board. In the process I had to remove the power amp transistors to re-goop them :D I decided to order up a full set of modern replacements and swap the OEM...
  15. Mike Sweeney

    Why pull and redo power transistors on the heatsink

    I'm working on my 2285B getting through various bits and now it's the main amp. The transistors all work but the mounting was pretty sloppy. I pulled two (PNP and NPN) and saw that the silly putty was starting to dry out and get cake-like. So scrub and cleaning I go. I also put cleaner into the...
  16. Johnny_Law

    Yamaha YP-D6 Pulsing Speed - Rebuilt - Parts List - SOLVED YAAAAYYY

    EDIT NOT QUITE SOLVED: Issue with all three pots & pot adjustments but came back aaaagggghhhh :no: EDIT2: Was the diodes!!! This wasn't holding speed so I cleaned the pots and put in all new electrolytic caps & transistors, and it still won't hold speed. But now, it pulses fairly aggressively...
    • Johnny_Law
    • Thread
    • parts list rebuild recap transistor yamaha yp-d6
    • Replies: 68
    • Forum: Turntables
  17. artsybob

    Fisher TFM-300- Replacing Selenium Rectifier

    I have already posted this in the General Audio thread, but I figured I'd repost it here as well. I'm in the process of restoring a Fisher TFM-300 tuner. It's been advised that I replace the selenium rectifier in the unit but I've never replaced one before. I bought this full-wave bridge...
    • artsybob
    • Thread
    • fisher hybrid tfm-300 transistor tube tuner
    • Replies: 3
    • Forum: Fisher
  18. PTL-Pioneer

    1060 - Purchased, now restoration

    Hi all I have purchased what i think to be a virgin 1060 - Gonna see what all this fuss is about! Can someone point me in the direction of a new replacement power switch, and multi turn pots for these preferably from mouser? Are there other bits that require attention in these? Resistors etc...
  19. J

    Help with Pioneer SX-850 w/two HPM-100 speakers

    Hello to all, My name is John and to start, I'll throw in a bit of background of the receiver. The radio used to be my grandfather's, and when I received it, it wasn't working (one didn't hear the "Clic" of the relay when you turned it on). All the lights turned on, it was receiving FM and AM...
    • jumoe
    • Thread
    • hpm 100 pioneer relay sx850 transistor
    • Replies: 2
    • Forum: DIY
  20. B

    Upgrading Vintage Marantz 1030 Power Supply to Zener Transistor

    Hi, First time poster. I've started cleaning up and recapping a Marantz 1030 as a summer project. It's going well. However, one of the things I'd like to do - due to its relative ease - is upgrade the power supply to a better level of regulation. To do this I'm going to replace the resistor to...
    • benhodgson
    • Thread
    • calculate marantz modification modifications power power supply transistor upgrade upgrades improvements zener diode
    • Replies: 23
    • Forum: DIY
  21. Kecap Manis

    Parts Supplier

    Hi. I need to buy some Toshiba transistor parts for an amplifier made in 90s. Some of the parts are found at B+D Enterprises in Florida. Can anybody give feedback regarding their product reputation? Thanks.
    • Kecap Manis
    • Thread
    • parts toshiba transistor
    • Replies: 2
    • Forum: DIY
  22. B

    Bose 1800 series 1 restoration - help appreciated!

    Hi, It's the second bose 1800 series 1 in my family. My other one I also took completely apart, added a loudspreaker protection board and replaced the 2 resistors needed to avoid the board from blowing. Did the most necessary stuff on it and plays fine (except for the silent buz it makes, but...
    • belgiansound
    • Thread
    • bose bose 1800 series 1 bose amplifier capacitor recap transistor
    • Replies: 50
    • Forum: Solid State
  23. kjello

    Transistor replacement soldering question

    Hi all gurus or other helpful souls of this beloved forum I have a question regarding pcb mounted transistors without heatsink. As you can see in this picture there are some heat damage on the board, (amplifier probably took some abuse) my questions are; would it be better to leave the "legs" a...
    • kjello
    • Thread
    • 4r7f carbon film flame fusible inflammable proof resistor soldering transistor
    • Replies: 45
    • Forum: DIY
  24. W

    What else to do when output transistors go bad?

    I have replaced output transistors in many different receivers and usually they function just fine afterward. Some continue to repeatedly blow the transistors. Besides merely replacing the transistors, what other steps and measures should be taken to ensure an amplifier is running properly and...
    • W.T. Holt
    • Thread
    • amp bias bjt output output transistor transistor
    • Replies: 13
    • Forum: Solid State
  25. B

    Kenwood KR-6340 Right Channel Issue

    Hi all, I've acquired a 6340 quad to build my first vintage audio system. I've found invaluable information on AK's forums already, however I'm having an issue with the right channel on this receiver and I'm hoping someone is able to point me in the right direction and offer guidance. I've...
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