I have obtained a wonderful Harman Kardon 330B. It plays perfect, but there is one thing that makes me a little unsure. Here is the thing. When I power it up, I get a big "thump" sound through my speakers, you can see the woofers move. Is this normal for older gear, or do I have a problem? Any suggestions/thoughts from 330B owners?
Harman Kardon 330B.
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petehall347
the brandy coffee man
try turning vol right down and no signal into inputs
I love the HK330B platform. It sounds great and it is pretty easy to work on.
There are three HK330B's stacked around my bench today. Give me a few hours to test and I'll post with the behavior of an original unit and a recently-recapped one.
In the meantime, do you know which variant of the HK330B you have? There are three main ones and there is a thread to help you determine which one you have:
http://www.audiokarma.org/forums/index.php?posts/10334200/
I have a HK 330C...it does the same thing .So I first turn on the amp and later the speakers, so no pop. My problem is that my turntable is an old Elac idler with auto return and one hears a loud pop when the player shuts on and off. I tried it with a surge protector to no avail...I changed the caps of the record player....it still pops. Still haven´t found a solution...
There are a ton of speaker delay kits on the big auction site that you could easily add to a unit, if yours didn't come with one from the factory. And they are cheap. I did a simple search for "speaker delay" and came up with many like this one:
Ok, the test results:
Your mileage may vary, but those are the results with my two readily-available-for-test units.
- My HK330B all-original Series B1 made in Taiwan does not thump the speakers on start up with volume at 50% and function set to FM Stereo and tuned to a good station (from a dead, cold stop for days)
- My HK330B mostly-refurbed (all new caps, diodes, transistors in all but the FM IF, FM MPX and AM boards) Series B1 made in Taiwan does not thump the speakers on start up with volume at 50% and function set to FM Stereo and tuned to a good station (from a dead, cold stop for days)
Your mileage may vary, but those are the results with my two readily-available-for-test units.
There are some threads here on AK that talk about testing the capacitor or capacitor+resistor "snubber" that many units have across the power switch.
Here is a typical (I guess) snubber cap across a Pioneer SX-something power switch:
The schematic for the HK330B B1 series shows no such cap:
So, if you wanted to experiment, you could add a simple cap across the power switch contacts. I'd use a X2-rated 0.1 uF 250 VAC cap to be safe.
I've never added that kind of cap to my HK330B's before, but it certainly would be interesting to know the results.
There is also a way to reduce the load on the power switch (some vintage receivers have a devil of a time with arcing in the power switch) by putting the pwoer switch on a triac and letting the triac do the "big switching work" with lots of current and pass only a tiny current through the actual switch. That avoids the arc and, in your case, perhaps the thump. http://www.audiokarma.org/forums/in...or-so-of-your-time.504673/page-2#post-6897970
Here is a typical (I guess) snubber cap across a Pioneer SX-something power switch:
The schematic for the HK330B B1 series shows no such cap:
So, if you wanted to experiment, you could add a simple cap across the power switch contacts. I'd use a X2-rated 0.1 uF 250 VAC cap to be safe.
I've never added that kind of cap to my HK330B's before, but it certainly would be interesting to know the results.
There is also a way to reduce the load on the power switch (some vintage receivers have a devil of a time with arcing in the power switch) by putting the pwoer switch on a triac and letting the triac do the "big switching work" with lots of current and pass only a tiny current through the actual switch. That avoids the arc and, in your case, perhaps the thump. http://www.audiokarma.org/forums/in...or-so-of-your-time.504673/page-2#post-6897970
Thanx for all the replies sofar. That speaker delay kit might just do the trick. Thanx for letting me know, dlucy.
Today, I replaced all the 1000uf caps. It sounds even sweeter than it already did. God, I love these series. Going to grab that speaker delay kit and hope that solves my problem.
Today, I replaced all the 1000uf caps. It sounds even sweeter than it already did. God, I love these series. Going to grab that speaker delay kit and hope that solves my problem.
Be sure to let us know how it goes!
The HK330B sounds great already and even better with a recap. Congrats!
Nope, just the B units. I've thought about buying one of each of the A and C, to compare them all firsthand, but broken B units keep showing up and I gotta maintain... control... maintain... control....
Yep! You've got a Harman Kardon B-2 series which is actually a Harman Kardon 330A that has been re-badged as a 330B
The 330B was so popular that HK decided to take the remaining 330A's they had and re-badge them as 330B's. The 330A still has the popular qualities of the 330B, just a little different circuitry here and there.
You can follow the 330B B-2 series schematic and service manual, though.
There is more about these differences in the thread http://www.audiokarma.org/forums/in...on-330-variations.396817/page-2#post-10334200
To my untrained eye there are no significant differences between the preamp/amp sections of the 330A and 330B. The transistors are different, but the topology is the same and they are both cap-coupled output designs. The 330B is "just an upgrade" over the 330A.
http://audiokarma.org/forums/index.php?threads/harman-kardon-330-variations.396817/#post-5110206
Both the 330A and 330B have fuses in line with the speaker output, but no speaker protection or delayed turn on. The 330 was a simple clean design without bells and whistles. I think the delay kit is a good approach, if not recapping the unit first.
Ok, I have ordered three different speaker delay + protection kits, I will install one or more of them, and then report back here with the results and a "how to".
Until then, here is a photo of the next HK330B replacement cabinet I'm making (solid walnut):
Until then, here is a photo of the next HK330B replacement cabinet I'm making (solid walnut):
I´m looking forward to this....especially the ´how to´