Leestereo's Restoration and Upgrade Of A Marantz 2325

Discussion in 'Marantz Audio' started by Leestereo, Nov 18, 2015.

  1. Rasputin47

    Rasputin47 Woad

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    Leestereo, I'm curious what you did with the tuner boards, Dolby boards, and buffer amp on this rebuild.
    Did you do anything special to them, or recap them with the same values?
     
    Last edited: Dec 5, 2015

     

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  2. Leestereo

    Leestereo Super Member

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    Yes, there is a Marantz service bulletin regarding H718 and H719 for the replacement of VD1221M diodes to 1S1555a diodes (or 1N4148), but this is late production 2325 already had the 1S1555a diodes installed.

    Replacement of the 2SA722 was performed as a proactive measure (same as the differential pair replacement).
     
  3. Leestereo

    Leestereo Super Member

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    For this particular 2325, the owner only requested that the power supply, power amplifier, preamplifier and the phono stages be restored/upgraded. Although not the same model, this restoration of the tuner boards in a 2235B should provide some useful information: Restoration and Upgrade of a Marantz 2235B Receiver
     
  4. hirscwi

    hirscwi AK Subscriber Subscriber

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    Thanks, Ben. Another thread showed the CE07 and CE08 ceramics replaced with C0G/NP0. Are they in the signal path/worth replacing?
     
  5. KutzlerTrans

    KutzlerTrans Jennie & I with Buddy and Barney. Subscriber

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    I actually had a similar question about the signal path. In the amp board we have the 8pf C711 ceramic. Is this the feedback return and would it help to put a cog there.??
    Thanks!, John
     
  6. Leestereo

    Leestereo Super Member

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    CE07 and CE08 are Miller capacitors: they are connected between the collector and base of the input transistor in the equivalent circuit of the BA312 IC. They are there to prevent oscillation and are not directly in the signal path.
     

     

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  7. Leestereo

    Leestereo Super Member

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    Yes, C711 is in the feedback circuit and should be replaced with a C0G type; note that, as mentioned in post #32, in this 2325 the stock ceramic capacitor was already a C0G/NPO and hence was not replaced.
     
  8. KutzlerTrans

    KutzlerTrans Jennie & I with Buddy and Barney. Subscriber

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    Yep, I read it and brain farted. I wrote down the upgrades on another note and forgot to put the 8pf down. Thanks Ben.
     
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  9. 0070julie

    0070julie I'm working on it!

    Messages:
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    Location:
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    Hi Leestereo!
    I started a thread about my Marantz 2325 that has an issue with the protection relay that engages as the amp warms up(about 30 minutes)
    With some help from fellow members I isolated the issue to the right power amp
    With all the infos from members (that also recommended this thread)I have managed to:

    - Recap electrolytics (P700 and P800 boards) + relay
    - Change the H701-702 transistors I did HFE match them as recommended by you guys I also changed the H703 as I saw it on this thread since I had some spears from the hfe matching ))
    - Apply new paste and Mica were needed
    - Apply new solder where needed on old solder
    - I change also the big resitors next to the h718-719 as one of them had brownish spots on the board as if it was too hot at some point
    ** As for the - Change the diodes H718-719 (VD1122) failure prone blob diodes I read on your thread that :
    there is a Marantz service bulletin regarding H718 and H719 for the replacement of VD1221M diodes to 1S1555a diodes (or 1N4148), but this is late production 2325 already had the 1S1555a diodes installed.
    Now the diodes I have on mine do not look blob, they look like small normal glass diodes. Does this mean that I too have the 1S1555a type ones and that I do not need to change them? I tested both they they seem fine
    ** Also, I had a kit that has 3 electrolytic caps of the same value per power amp board..I only see 2 elec caps (C706-C707). Is there one to convert to an electro.cap? and would you happen to have the board number?
    I am new at this so I do not want to change something that I do not need to, I wanted to repair / change electrolytic caps to enjoy my 2325 for many more years :)
    Thank you in advance for your help!!
    Julie
     
  10. hirscwi

    hirscwi AK Subscriber Subscriber

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    If the 1S1555 diodes have been installed there's probably no reason to replace them but if you received new 1N4148 in your kit it wouldn't hurt to replace.
    Relative the amp board, I assume you received 2) 10/25 caps for C706, 707. The 3rd is likely a 33/25 to replace C703, which is probably a tantalum (33/6.3). Many people replace the tantalums because they are a bit failure prone.

    I can't quite tell from your post if you're still having problems with the right amp board. If so, what's the nature of the problem?
     
  11. 0070julie

    0070julie I'm working on it!

    Messages:
    38
    Location:
    Canada
    Hi hirscwi!
    And you are right :D I just checked and I have 4x10/25 and 2x33/25. C703 is a blue and round as a bubble that seems to need replacement as it looks blooby :D Thanks so much you saved me from a mistake!! :)
    The title of my thread is : Marantz 2325 protection relay engages after 30 minutes of play.
    I can resume it for you:


    My Marantz 2325 stops +/- 30 minutes after being turned on, the protection circuit's Relay triggers.
    With the help of a friend, via emails, I have managed to isolate the issue to the Right power amp
    - unplugged each one while using main amp input. Both amps it stops, left amp it does not stop. right amp was on alone, it stopped
    The protection relay triggers after about 30 minutes of playing
    I have tested all the big transistors on the heat sinks, all fine
    voltage changes drastically as it is warming up, in the right output (left one stayed at +/- 280mv) By the time I joined the pic and writing this, the right channel is already over 1.000 mv and still going up... I swapped the 2 DMM and still got same readings, right output way up, left output stable at 280mv...
    I have measured DC, Adjust with No Volume/load for 0vDC @ Pot #R713. I did adjust to zero but started to go up after a few minutes, like before. So the pot works but the issue still persist.
    - So with all advices from members here I :
    - Recap electrolytics (P700 and P800 boards) + relay
    - Change the H701-702 transistors I did HFE match them as recommended by you guys I also changed the H703 as I saw it on this thread since I had some spears from the hfe matching ))
    - Apply new paste and Mica were needed
    - Apply new solder where needed on old solder
    - I change also the big resitors next to the h718-719 as one of them had brownish spots on the board as if it was too hot at some point
    ** I will now change C703 as well with the 33/25 thanks again :D
    And I just finished the dim bulb tester before I try to turn it on after all the work done above ^

    So this is where I am at... If you have any advices they are welcome. I have had awesome help from this site and I am glad I subscribed..saved me from a lot of trouble
    I have not tried to turn on the receiver yet as I wanted to have answers to my insecurity first, and I am glad I did.. :)
     
    Last edited: Jan 3, 2016

     

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  12. hirscwi

    hirscwi AK Subscriber Subscriber

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    Since you already have a thread open about the problem, it's best to get answers there, so as not to confuse things. It seems like I've read a thread with a similar problem. There are many people on this forum who are more knowledgeable than I am so let's direct them to your original thread. I'll give it some thought.
     
  13. 0070julie

    0070julie I'm working on it!

    Messages:
    38
    Location:
    Canada
    for C401 and C402 as well as C414 and C415 digikey linked these PCF1617-ND when I asked for 1.0µF Panasonic polypropylene film capacitors. Are these ok?
     
  14. Rasputin47

    Rasputin47 Woad

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    Those caps are rated 450V, I use these rated at 250V:
    MFG# ECQ-E2105KF
    Digikey# EF2105-ND
     
  15. Leestereo

    Leestereo Super Member

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    Location:
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    I used Panasonic ECW-FD2W105J, this is the 5% tolerance variant, and is "PCF1616-ND" from Digi-Key. Note that the "1617" is the 10% tolerance part, same for the EF2105-ND part.
     
  16. 0070julie

    0070julie I'm working on it!

    Messages:
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    Location:
    Canada
    e
    Ok these are 450V as well. The gap between 25v from the original tantalum one and these 450V scared me a bit so I wanted to make sure with you guys first.
    I did my search with digikey based on your thread Leestereo, The P400 rebuilt- but when more than one piece weas available from the same number I did not know what to take exactly :)
    Here is my cart , if you see something weird let me know ok? Many thanks guys!!

    1 10 PCF1617-ND ECW-FD2W105K CAP FILM 1UF 10% 450VDC RADIAL 10
    Immediate 0 0.47700 $4.77 ***** THIS ONE i WILL CHANGE TO PCF1616-ND or EF2105-ND (WHICH ONE IS BETTER? )
    2 10 493-1611-ND UHE1H271MHD6 CAP ALUM 270UF 20% 50V RADIAL 10
    Immediate 0 0.46900 $4.69
    3 10 493-10822-1-ND UES1C470MPM1TD CAP ALUM 47UF 20% 16V RADIAL 10
    Immediate 0 0.51700 $5.17
    4 20 KSC1845FTACT-ND KSC1845FTA TRANS NPN 120V 0.05A TO-92 20
    Immediate 0 0.18100 $3.62
    5 10 P12398-ND EEU-FM1H271 CAP ALUM 270UF 20% 50V RADIAL 10
    Immediate 0 0.67000 $6.70
    6 20 1N4148FS-ND 1N4148 DIODE GEN PURP 100V 200MA DO35 20
    Immediate 0 0.05400 $1.08
     

     

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  17. KutzlerTrans

    KutzlerTrans Jennie & I with Buddy and Barney. Subscriber

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  18. Leestereo

    Leestereo Super Member

    Messages:
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    Location:
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    There is no problem using high voltage film capacitors when replacing electrolytic types, since film types do not have an oxide layer that has to be "formed" under a voltage. In this case, it was the tighter 5% tolerance which dictated the choice.

    Note that there are 2 listings for the 270µF/50V capacitor in your order, with the Panasonic FM maybe being too tall, otherwise everything else is fine.
     
  19. Leestereo

    Leestereo Super Member

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  20. KutzlerTrans

    KutzlerTrans Jennie & I with Buddy and Barney. Subscriber

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    So the FD Is smaller...:idea: Thats good to know, Thanks!
    That is the reason i posted it. Crap now i have to use up the 25 i have:biggrin:
    on the amp boards on my 2325 and the pre amp i put the vishay1822 and vishay1840 1uf 250v .
    i put the 1822 in one amp and the 1840 in the other amp in the C701 spot, just to see if i could hear a difference.
    The jury is out until they form, but i also put COG'S Everywhere i could,among a lot of other changes but i think i may have scooped out the soundstage.
    Its noticeably more powerfull in the deep bass,but the midrange does not sound as warm.
    I pulled the elna silmics out and put PW's in the P/S to see what happens.
    I just went through another elna silmic power supply and i am going to put a double pole ,double throw switch and hook both power supplies into it.
    Its hard to believe, being the main amps are powered by the filters and have nothing to do with the power supply.
    The changes must have had an effect on the pre amp. I'll let you know if i'm nuts or hearing things.
    This is a receiver i listen to every day and i know its sound very well. Its different now.
     

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