Fredrik 1977
Super Member
Control Amp C501,C502 these doesnt happen to be signal coupling caps? i try to use filmcaps MKT/MKP in such places if possible.
Recap and restore Harman Kardon HK 330B (recap BOM under development)
- Thread starter dlucy
- Start date
Well said....Some people take this so seriously, I have one too and I really like them, it will be fun to see how far can this little unit go.
The control amp circuit board of Harman Kardon HK 330B before, during and after removing all the capacitors and transistors. The last one is really meant to show off the PCB and its silk-screening. All the transistor and electrolytic markings (on this one) are verified and correct.
very nice... funny thing mine doesn't have any silkscreen
very nice... funny thing mine doesn't have any silkscreen
There are at least two versions of the 330B. Mine has "A" at the end of the serial number, but it has the same layout as the "Roland" version. I don't understand the exact details or history here.
Some of the boards, notably the two power supply boards do not have silk-screening on mine, so I had to improvise:
Good thinking, that rectifier board is looking very strong!
Thanks. Many people will call the result overkill, but for something like $2 extra in parts the power supply is beefier, quieter, and ready for another 30 years.
Final assembled recap, restore and upgrade of the main rectifier board:
Holy molly... that's what I call overkill!! Very nice my friend.
I'm glad you're not listening to the naysayers and are enjoying the rebuild. I've acquired a 330 and a 330B but that's as far as I've gotten with them. A high school buddy had a 330B in the pool table room so it has nostalgic value to me. I've rebuilt a 330C and liked the sound very much! Every piece of vintage gear is worth saving and restoring to me.
Tip of the day for you: Use a red felt marker to mark all e-caps before starting a board. That way none get missed!
Tip of the day for you: Use a red felt marker to mark all e-caps before starting a board. That way none get missed!
The 330A and 330B are very similar, circuit-wise, but I think I've read the 330C is somewhat different. I'd be keen to see the schematic. Hmmm, maybe I've got a lunchtime sub-project.
Great! Thanks.
I just read this thread for the first time and thought of this:
Its called an "Outlaw RR2150 Receiver"
And it really is a modern "Vintage" receiver. Well at least the amp parts of it. Pretty nice unit.
Its called an "Outlaw RR2150 Receiver"
And it really is a modern "Vintage" receiver. Well at least the amp parts of it. Pretty nice unit.
Its called an "Outlaw RR2150 Receiver" And it really is a modern "Vintage" receiver. Well at least the amp parts of it. Pretty nice unit.[/QUOTE said:
very nice... funny thing mine doesn't have any silkscreen
So, I've found all mine boards have silkscreen (and correct markings) except the FM MPX and the two rectifier boards. I wonder if some of this was made in one country or production run and the rest was made elsewhere.
All the replacement parts have been soldered in place, the HK330B has been powered back up... and it plays great! Absolutely no noise and plenty loud. Now I need to do the adjustments and try a better, flatter set of speakers to hear if it is working as well as before or even better!
the little fella is looking awesome!! Kudos!
I forgot to ask you, What is the function of those 2200 caps on the amp board.
and curious thing... I replaced the 2sc438 for KSC945C on mine.
From what I understand, the HK 330B is a capacitor-coupled-output design. The final output of the the amp goes through these final capacitors just before going to the speakers. This gives a very distinctive "tone" to the receiver.
The original circuit called for a 1000 uF cap and I increased it to 2000 uF or 2200 uF because: 1) some thread here on AK mentioned any less value than 2000 uF would cause some amount of rolloff (of lower frequencies?) and 2) it was the higher-capacitance value available in the KL series.
Looking at the datasheets for the KSC1845 and the KSC945... and remembering a thread somewhere here on AK, I think those two replacements are good. The 1845 seems, to my untrained eyes, to be a bit beefier than the 945. Both are the same price: $0.21 each, $0.14 in small quantities, and $0.06 each for 100 at a time.
Nice! Thank you for your explanation regarding the cap.
Jeez I think I will have to get another 330b to try the 1845
Cheers!
basil13
Active Member
Nice work! I have one of these and it sounds very nice. I am doing some work on it now and was wondering what you ended up using for the 3k and 100k trimpots on the main board? From the picture above they don't look like the ones in your BOM. I know the originals are two leg and was looking for a replacement since most are three leg.