Horrible Crackling from 2230

[birchoak]

The 2230 is a favorite of mine. There is a lot of info on AK that will help you get it going.
http://audiokarma.org/forums/showthread.php?t=207005
http://audiokarma.org/forums/showthread.php?t=167010
There is a cap list in this thread:
http://audiokarma.org/forums/showthread.php?p=4233367

Good luck!

Tom

Tom, just got the parts in the mail; noticed that the replacement for the giant 4700/80 cap is a 2200/200v. Is this right? Shouldn't the replacement cap be more like, oh, 4700uF/80V? I do hereby confess that I don't know tons about electronics; I just want to make sure I didn't somehow misconstrue the cap list! And thank you again, very much, for the info.

 

[wlhd1610]

For what it's worth I had this same exact problem on the left channel of my 4270.

It turned out to be a bad(noisey)transistor on the preamp board.

Everything was ok for awhile ,but as it was on for a bit, major crackling/static regardless of where the volume pot or selector was.

As time went on it would do it immediately when turning it on.

Per catrafter's,echowars and avionic's posts I changed that transistor out with a 2sc1815 and all is well.

 

[petehall347]

i have a huge bag of them 2sc1815 think 500 of them i got from ebay £1.20 i paid ,good for testing with and if they work i leave em in my prob was they are npn and i needed pnp but that's another story .. a heat gun or and freeze spray could find the problem pretty quickly

 

[birchoak]

i have a huge bag of them 2sc1815 think 500 of them i got from ebay £1.20 i paid ,good for testing with and if they work i leave em in my prob was they are npn and i needed pnp but that's another story .. a heat gun or and freeze spray could find the problem pretty quickly

Lemme guess--spray freezing stuff on suspect part while noise ocurring; if noise subsides, that's your problem part?

 

[birchoak]

Which leads + under big filter cap?

Yep, I snipped before I snapped (a pic, that is) and am not completely sure whether the bundled white leads under the big filter cap (4300uF/83V) are negative or the bundled red ones. I'm pretty sure the whites are negative, based on some deductive reasoning, but if anyone, ah, knows for sure a shout out would be just grand before I smoke a 2230.

 

[catrafter]

Tom, just got the parts in the mail; noticed that the replacement for the giant 4700/80 cap is a 2200/200v. Is this right? Shouldn't the replacement cap be more like, oh, 4700uF/80V? I do hereby confess that I don't know tons about electronics; I just want to make sure I didn't somehow misconstrue the cap list! And thank you again, very much, for the info.

Oops! This is why I recommend that you check the list against what is actually in your receiver. The part number is wrong, you could use a Panasonic ECE-T2DA472FA. P10659-ND at Digikey will work.

You need a 40MM diameter cap to fit the bracket. It should be 4700uF, but you could go up to around twice that value. You will need at least an 80V part.
Digikey has a 8200uf/80V 105° part but it's only 50MM tall, P10644-ND.

Tom

 

[catrafter]

Yep, I snipped before I snapped (a pic, that is) and am not completely sure whether the bundled white leads under the big filter cap (4300uF/83V) are negative or the bundled red ones. I'm pretty sure the whites are negative, based on some deductive reasoning, but if anyone, ah, knows for sure a shout out would be just grand before I smoke a 2230.

You are correct, the white wires go to the negative terminal.

Tom

 

[birchoak]

You are correct, the white wires go to the negative terminal.

Tom

Thanks, Tom! That is how I connected them.

Well, I finished installing the power supply caps & the 4300uF cap replacement (I couldn't wait; I went ahead and installed the wrong one). Outcome: 2230 has much more power than before; it's "right there," no need to turn volume up past 12. But the crackling is there and it is as bad as ever. Hmmm. Can some kindly person point out this mysterious transistor that could be the problem? Is it that silver thing that looks a little like a Mexican hat? Or is it that teeny black thing w/ 3 legs?

I only had the 2230 on for about ten seconds; do ya think I did any damage with that wrong value cap?

 

[birchoak]

Before all that work, although it's probably worth doing anyway,
have you used the amp section of the 2230 with another pre amp?

You have seperated the pre section and it's noisy but you need to see if there is also noise coming from the amp.

If from both it probably is a power supply problem.
But check the amp first so we'll know exactly where to proceed.

Sounds like weak caps or transistors in the pre board.

Detailman,
found another thread on this issue; the problem does appear to be in the pre board (did Catrafter's trick of jumping left pre into right main, etc.) so time to order all those damned teeny little caps and transistors. Why I haven't simply bid on a working 2230 I do not know--guess I want to learn something and need to fight to the bloody end with this specimen. I guess it's been a mini-odyssey of sorts! LOL:yes:

 

[petehall347]

Lemme guess--spray freezing stuff on suspect part while noise ocurring; if noise subsides, that's your problem part?

a bit crude i know but sometimes i put my soldering iron tip on suspect transistors to see what happens but not the metal case ones ..i once fixed a colour issue for 6 months on a tv before it failed again it wasn't a real fix i know but it served its purpose ...back to job in hand....the one i had go bad in preamp was just after vol pot ..it checked good on diode test and in transistor tester .. but in circuit it only behaved when bent over in a certain way suspect it had bad connection just inside it .. these things can be hard to find but its down to logic really ...just ask scotty

 

[birchoak]

a bit crude i know but sometimes i put my soldering iron tip on suspect transistors to see what happens but not the metal case ones ..i once fixed a colour issue for 6 months on a tv before it failed again it wasn't a real fix i know but it served its purpose ...back to job in hand....the one i had go bad in preamp was just after vol pot ..it checked good on diode test and in transistor tester .. but in circuit it only behaved when bent over in a certain way suspect it had bad connection just inside it .. these things can be hard to find but its down to logic really ...just ask scotty

Pete,

I will try that--if I'm going to replace all of them anyway, why not find the suspect? I damned curious what the hell is making that noise!

Cheers

 

[Detailman]

Detailman,
found another thread on this issue; the problem does appear to be in the pre board (did Catrafter's trick of jumping left pre into right main, etc.) so time to order all those damned teeny little caps and transistors. Why I haven't simply bid on a working 2230 I do not know--guess I want to learn something and need to fight to the bloody end with this specimen. I guess it's been a mini-odyssey of sorts! LOL:yes:

The little black transistors are the culprits. If you can replace caps you can easily do the transistors.
2sa and 2sbxxxx are pnp's, 2sc and 2sdxxxx are npn.

If you order from Mouser use parts ksa992 and ksc1845 for replacements.
Just need to be sure the legs are the same pinouts as originals. You can check this with a diode check setting on you meter.(use search in diy forum for explanations on how to do this if you don't know).

Three legged transistors have e=emitter c=collector and b=base. Make sure you take pics before you remove the old ones. Boards are usually marked but not always accurate.

Parts are super cheap so order extras for future projects or mishaps.

 

[birchoak]

The little black transistors are the culprits. If you can replace caps you can easily do the transistors.
2sa and 2sbxxxx are pnp's, 2sc and 2sdxxxx are npn.

If you order from Mouser use parts ksa992 and ksc1845 for replacements.
Just need to be sure the legs are the same pinouts as originals. You can check this with a diode check setting on you meter.(use search in diy forum for explanations on how to do this if you don't know).

Three legged transistors have e=emitter c=collector and b=base. Make sure you take pics before you remove the old ones. Boards are usually marked but not always accurate.

Parts are super cheap so order extras for future projects or mishaps.

Detail, thank you very much for the, uh, detailed info. The transistors on the preamp board on my 2230 are of two varieties: one type has a capital Y printed on its head, with T 4J A493 on the side of the head. The other, BL with T 41 C1000 on its side. Which ones are PNPs? Will the parts you mentioned work? I can take a photo of the board if it helps.

Cheers,
B

 

[catrafter]

A493=2SA493, Y is the current gain (hfe) code indicating 120-240
C1000=2SC1000, BL is the current gain (hfe) code indicating 350-700
EIAJ 2SA, 2SB, Fairchild KSA, KSB =PNP
EIAJ 2SC, 2SD, Fairchild KSC, KSD=NPN
So, the KSA992 would be the sub for the 2SA493
and the KSC1845 would be the sub for the 2SC1000

The Datasheet Archive is your new best friend.

Tom

 

[quadtech]

A transistor tester is a great tool to have. See this thread
for more details -

http://audiokarma.org/forums/showthread.php?t=383449

I have a DIY transistor tester (AVR tester) which link I posted in
the thread above. I can recommend it with no hesitation for
anyone interested in a DIY solution. It cost me like $20ish in parts.
and I built it on a piece of perf board.

 

[birchoak]

A493=2SA493, Y is the current gain (hfe) code indicating 120-240
C1000=2SC1000, BL is the current gain (hfe) code indicating 350-700
EIAJ 2SA, 2SB, Fairchild KSA, KSB =PNP
EIAJ 2SC, 2SD, Fairchild KSC, KSD=NPN
So, the KSA992 would be the sub for the 2SA493
and the KSC1845 would be the sub for the 2SC1000

The Datasheet Archive is your new best friend.

Tom

Thank you very much, Tom--I will order those parts and I'll be damned if I don't get this 2230 sounding perfect again. When I was in high school, my best friend's father had one of these and I remember hearing Pete Townsend's Empty Glass on it for the first time. I had no idea what Marantz was at the time and didn't until about 30 years later.

Cheers,
B

 

[birchoak]

Problem solved!

I did as all you kind folk suggested--replaced all the transistors on the pre-amp board--and that damned crackling is gone!

Unfortunately, now there's no sound in the right channel. Damn!:sigh:

I'm finally going to give up, largely because despite multiple cleaning attempts this 2230 still smells like a rancid air freshener. I guess I can keep it for spare parts or something, although every time I see it it's going to be mocking me. Silently mocking me, because I am loathe to ever turn it on again.

Much thanks to all who assisted me--Detailman, Catrafter, etc.--you were spot on with problem/parts; I may not be as handy as I think I am.

 

[birchoak]

It lives!

Went down to the bench one last time before I turned in. I thought, "Ah, c'mon, don't give up now..." Unscrewed preamp board, checked wires, ran temp ground to chassis ground at back of unit and...beautiful sound in both channels without the cracklin', damnit.

I feel like the little engine that could.

I might have to have a cold one to celebrate this dubious and, perhaps, fleeting victory. :beer: I couldn't have done it without AK, that's for sure.

 

[ssouci]

I HAVE A SIMILAR PROBLEM!

to summarize... when I turn on my 2230, sometimes there is a very loud, sharp crackling/static sound coming from one channel... quite scary and very irritating

the sound is loudest at first, then reduces a bit, then goes into low volume state and finally goes away... the whole thing last about 10-20 secs(?)... does not seem to occur after that while I'm playing music (sounds like someone grinding a turntable stylus into a vinyl record at high volume)

happens with volume at zero, and does not seem to be vol. dependant

happens about half the time I turn it on and is fairly unpredictable

I have tried swapping the pre-in/main-out jumpers (crossing them), and the sound *moved* over to the other channel

note: I just 100% recapped this entire receiver, plus on the pre/tone board, replaced the four 2SC1000 transistors with new 2SC1815 parts... however, I did NOT replace the other four transistors (2SA493)

any ideas? is it likely a transistor, and if so, most likely one of my newly-installed 2SC1815's, or, one of the old 2SA493's I left untouched?

Q1: is there anything I should try next to best diagnose?

also, I've begun searching for new transistors to replace the old 2SA493 on the pre/tone board, which is a likely culprit... I am looking to buy locally here in Vancouver, Canada

my research shows people recommending either 2SA1015 -or- KSA992 as a good equivalent replacement part (for 2SA493)

Q2: which of these two is the better one in this application?

Q3: let's say it is one (or more) bad transistors on the pre/tone board... would this negatively affect the ongoing sound quality, or, is it a case of loud noise at startup, then all reverts to normal and the transistor is then fine?

thx!

 

[geode]

I bet you will have much better luck if you start a new thread. This thread is over a year old. Good luck.