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Harman Kardon HK 330B recap, restore and upgrade BOM part list (kinda)

Now for the bad news.....the transformer smoked. I had 38.5 vac on the primary and 6 vac on the secondary however after a minute the trans began to smoke. I pulled the wires off of the rectifier board to get it out of the circuit and it still smokes.......and stinks for that matter. Are there any replacements out there for these? Did a quick search and nothing came up but one for a 330B-A which I don't know if that would work for this being a true 330B.
 
sweatyk said:
Now for the bad news.....the transformer smoked. I had 38.5 vac on the primary and 6 vac on the secondary however after a minute the trans began to smoke. I pulled the wires off of the rectifier board to get it out of the circuit and it still smokes.......and stinks for that matter. Are there any replacements out there for these? Did a quick search and nothing came up but one for a 330B-A which I don't know if that would work for this being a true 330B.
Click to expand...

You're sailing the seas of audio repair without a dim bulb tester? If you toasted a transformer keep an eye on eBay or pony up for a subscription and put a wanted ad in bartertown, AKers are good people.

Hey @dlucy , after having big fun rebuilding my brother-in-laws 330B I had to get one for myself as a "keeper", I've got a pile of Yamaha and Pioneer to dig through but I'm retired as of October 2nd so I should have time.
Life is good!
 
CosmoK said:
One more question: What is the best method of setting the center voltages (DC center balance) after replacing transistors and trimpots on the amp board? Since I don't have a signal generator and oscilloscope, I followed the advice here:

https://audiokarma.org/forums/index...ing-speakers-but-not-headphones.785161/page-2

and used VR401/VR402 to set the voltage on the positive side of C419/C420 to 25.2V. After this I had no problem setting the idle current.
Click to expand...

Just wanted to follow up on my question from earlier. I borrowed an oscilloscope and used my phone as a signal generator to check my DC center balance. The method above had it very close to centered, although I made some small adjustments using the scope just because I could.

I also enjoyed tracing the signal through circuit with the scope. I noticed that the left and right channels had slightly different applitudes, except when the bass and treble were turned all the way down. When the knobs are down, the channels are even at all volumes. It just seems that moving these knobs to their center positions created the channel imbalance (at all volumes). Before I disect the schematic, does anyone know off-hand whether this is just a design weakness, or if there is likely a bad part. I replaced all the capacitors, but there could be a bad resistor or two (new) transistors with slightly unmatched hfe. Any thoughts?

If its a tricky problem, I may let it go. I can see it on the scope, but it sounds okay to my ears.
 
Hi,

First - OP, thank you so much for this wonderful work.
Your posts convinced me to buy a HK330B a few years back, so I knew that in case something goes bad, I will have a complete repair tutorial :)

Now, since I've been having intermittent one channel issues, and that was mostly fixed with pots cleaning (from front and behind), the issue comes back. There is also a lot of noise while listening to radio, but only in stereo mode.

So finally, I've decided to look into ordering parts with BOM lists provided here.
Welp, semiconductor shortage, a lot of them are unavailable until mid 2022. Some are not available anymore.

Is there a good alternative BOM or alternative supplier to Mouser/Digi-Key?
I'm not advanced enough to decide what could be a good alternative for a part that is obsolete.

Thanks,
FD
 
bs0 said:
So finally, I've decided to look into ordering parts with BOM lists provided here.
Welp, semiconductor shortage, a lot of them are unavailable until mid 2022. Some are not available anymore.

Is there a good alternative BOM or alternative supplier to Mouser/Digi-Key?
I'm not advanced enough to decide what could be a good alternative for a part that is obsolete.
Click to expand...

which parts are you unable to find at Mouser?
 
I appreciate your response.
Here is the list (may contain some repeats):
512-KSA1220AYS
283-0.47-RC (minimum order of 100)
652-3309W-1-104
652-3309W-1-502
810-FK20C0G2A223J
810-FK28C0G2A101J
810-FK24C0G2A332J
647-UKL1HR47KDDANA (minimum order of 3600)

Not in stock:
647-UKL1V221KPD
647-UPW1V221MPD6
647-UPW1J470MPD
647-UPW1H182MHD
647-UHE1H272MHD
505-MKS02.1/63/10
647-UKL1HR47KDDANA
512-KSC1845FTA
512-KSA1220AYS
283-0.47-RC
652-3309W-1-104
810-FK20C0G2A223J
667-ECW-FD2W224KQ
71-RN60D3301F
71-RN60D-F-330K
810-FK28C0G2A101J
810-FK24C0G2A332J
625-UF5404-E3
 
I have noticed that Mouser can show similar products, so I chose these, but I'm unsure if they are okay to use:

512-KSA1220AYS (TTA004B)

283-0.47-RC (660-MOSX3CT631RR47J)

652-3309W-1-104 (3339S-1-104LF)

652-3309W-1-502 (279-409VA502M)

810-FK20C0G2A223J (FG24C0G2A223JRT06)

810-FK28C0G2A101J (810-FG28C0G2A101JNT6)

810-FK24C0G2A332J (810-FG28C0G2A332JNT6)

647-UKL1HR47KDDANA (647-UKL2AR47KDD with double ripple current?)


Not in stock:

647-UKL1V221KPD (647-UKL1H221KHD)

647-UPW1V221MPD6 (647-UPM1V221MPD1TA)

647-UPW1J470MPD (647-UPS1J470MPD1TA)

647-UPW1H182MHD (661-EGPA500ELL182MM3)

647-UHE1H272MHD (661-EKY500ELL272MM4)

505-MKS02.1/63/10 (505-MKS0C031000CKI00)

512-KSC1845FTA ?????

512-KSA1220AYS TTA004B

283-0.47-RC (660-MOSX3CT631RR47J)

667-ECW-FD2W224KQ (647-QXP2E224JRPT only 250V instead of 450V)

71-RN60D-F-330K (603-MFR-25FRF52-3K3)

625-UF5404-E3 (625-UF5404-E3/73)

As you can see, I don't know a good replacement for KSC1845FTA which is sold out also on DigiKey and Arrow. Edit: seems like they are available on ebay.
 
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bs0 said:
I don't know a good replacement for KSC1845FTA
Click to expand...
KSC945C works great on this unit.

Regarding capacitors, just look a similar voltage, same capacitance value and size, from good brands (Panasonic, Nichicon, CDE, United-Chemicon, Kemet),.
 
Last edited:
Hipocrates said:
KSC945C works great on this unit.
Click to expand...

I am trying to find replacements for the 2SC458 transistors. There are no KSC1845's left at Mouser or Digikey, my usual suppliers, and none expected for a long time. Does anyone know of suitable replacements for these? Something that is likely or known to be in stock during these lean times? Looking for quietness and quality in my transistors. Thanks for any advice.
 
davstev said:
I am trying to find replacements for the 2SC458 transistors. There are no KSC1845's or KSC945C left at Mouser or Digikey, my usual suppliers, and none expected for a long time. Does anyone know of suitable replacements for these? Something that is likely or known to be in stock during these lean times? Looking for quietness and quality in my transistors. Thanks for any advice.
Click to expand...
 
davstev said:
I am trying to find replacements for the 2SC458 transistors. There are no KSC1845's left at Mouser or Digikey, my usual suppliers, and none expected for a long time. Does anyone know of suitable replacements for these? Something that is likely or known to be in stock during these lean times? Looking for quietness and quality in my transistors. Thanks for any advice.
Click to expand...

Members have access to Bartertown, you can buy some there.
 
davstev said:
I am trying to find replacements for the 2SC458 transistors. There are no KSC1845's left at Mouser or Digikey, my usual suppliers, and none expected for a long time. Does anyone know of suitable replacements for these? Something that is likely or known to be in stock during these lean times? Looking for quietness and quality in my transistors. Thanks for any advice.
Click to expand...
There are center BASE transistors available, but you have to twist the leads to use them. Triangle patterns are easy, but straight line are a little tougher to keep the leads from shorting. I use a piece of insulating tubing for the center (BASE) just to be sure.
 
Poke around the worse transistor thread. The spreadsheet may have alternate parts.

Toshiba has a few that might work.
 
Hello everyone! First post on the forum and I'm kinda new to electronics overall, I've done some small repairs before but nothing fancy. I recently got my hands on a Harman Kardon 630 so my 330b is now siting in a corner ready to be upgraded.
I think I'll order the full parts list that dlucy provided. Not only the cabs but the rest as well. If i order that will i be able to tho the same upgrades you have shown i this thread?
I live in Europe so my unit is running on 230v does that make a difference to the partslist? I understand that all those upgrades ain't completely necessary but it's fun so I'll do it but is there any possibility that changing these parts will "ruin" the sound of unit or is it just improvement.
I've never done this before so all tips would be appreciated. How are you suppose to tune it with a ociloskope when I'm done? I have a scope but i don know how to do it.
Great thread but i can't say that i know exactly how to do this. Where am I suppose to put the new components, etc. A guide on where to put everything would be great or some pictures. That's kind of what you've already done but I'm still kinda konfused. Anything helping me to pull this of wuld be deeply appreciated. Thanks
 
I'm also a little confused about what model I've got, it has product code and serial no like the Roland version but it said made in japan on the back. Another weird thing is that the main fuse is bypassed and instead it's two fuses inside the unit.
 
OskarBas1 said:
Hello everyone! First post on the forum and I'm kinda new to electronics overall, I've done some small repairs before but nothing fancy. I recently got my hands on a Harman Kardon 630 so my 330b is now siting in a corner ready to be upgraded.
I think I'll order the full parts list that dlucy provided. Not only the cabs but the rest as well. If i order that will i be able to tho the same upgrades you have shown i this thread?
I live in Europe so my unit is running on 230v does that make a difference to the partslist? I understand that all those upgrades ain't completely necessary but it's fun so I'll do it but is there any possibility that changing these parts will "ruin" the sound of unit or is it just improvement.
I've never done this before so all tips would be appreciated. How are you suppose to tune it with a ociloskope when I'm done? I have a scope but i don know how to do it.
Great thread but i can't say that i know exactly how to do this. Where am I suppose to put the new components, etc. A guide on where to put everything would be great or some pictures. That's kind of what you've already done but I'm still kinda konfused. Anything helping me to pull this of wuld be deeply appreciated. Thanks
Click to expand...
Start your own thread so everyone can help concentrate on your particular unit without confusion. :thumbsup:
And pictures will go a long way too.
 
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