looneytubes
New Member
Does anyone know the difference between a vintage Harman Kardon 330 A and a 330B?
Harman Kardon 330A vs. 330B ?
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The HK 330A and 330B are nearly identical. The B is a mildly updated version with the same circuit topology and just a few improvements. Both feature cap-coupled outputs. The A was also re-badged as a B and sold as a B when the B became so popular they couldn't keep up with demand.
One of the threads describing the differences is here http://www.audiokarma.org/forums/in...on-330-variations.396817/page-2#post-10334200
One of the threads describing the differences is here http://www.audiokarma.org/forums/in...on-330-variations.396817/page-2#post-10334200
looneytubes
New Member
thank you very much.
looneytubes
New Member
Well I picked up a 330A the other day for $40. I thought it was a good deal. The wooden case was in bad shape, so I knocked it off. In general it's okay but too bad for me, one channel sounds crackly. I opened it up and sprayed the controls with Deoxit, worked it around but still the left channel is all crackly, all the time, not just when you touch a knob. So I sent it to my local guy to check it out. Still, here are a couple of photos. One lamp out, new LED's ordered.
Both the A and B are great-sounding units. If you can get it back to working condition for less than $120 all in, I'd say you did great.
The electrolytic caps and small signal transistors should be replaced. I haven't done a BOM or parts list for a 330A yet, but you could get a good start from the 330B list. If you end up going that way, definitely start a "restoring and recapping a HK 330A" thread and we can help with any 330A-specific questions.
The electrolytic caps and small signal transistors should be replaced. I haven't done a BOM or parts list for a 330A yet, but you could get a good start from the 330B list. If you end up going that way, definitely start a "restoring and recapping a HK 330A" thread and we can help with any 330A-specific questions.
The Nocturne is the stand out visually for me. You're one model shy of a full house, or maybe it's a Royal Flush 
or both hehehe
Incidentally the Rotel RX-400A receiver is identical to the HK-330A. With the covers off or by looking at the back you can't tell them apart, and even the controls have the same layout. I'm thinking maybe Rotel built them for H-K as Rotel built a lot of gear for other name brands.
Really?!?!? That's really interesting. Can you post a few photos?
I was looking at one on CL and googled some pics to check out the circuit build. The insides looked exactly like the 330A I was just working on, then I googled a little more and found this AK thread with pics comparing the two. I knew I wasn't seeing things! These are rislin's pics below, not mine. HK is on top, Rotel is on the bottom...one and the same. Pretty cool, eh? 
I did end up buying that Rotel RX-400A and I swear the HK-330b (and probably all of the Japanese HK receivers built before HK got sold off in the early 80's) had to be built by Rotel. Here's the one I picked up, made in 1972, (click on the photo for full size)
Everything about it is similar if not identical to the HK-330B. The only differences are pretty minor, like the addition of the Haffler circuit for "simulated 4 channel sound" (it's just a couple of resistors and a slide switch screwed to the back panel and wired into the remote speaker terminals) and the heat sink (uses the same screw holes, just a different shape and not as nice as the HK's heat sink).
This one had an odd factory defect: the main / remote speaker switches and the headphone jack were never wired in. There was no attempt to wire them in at the factory, no solder on the terminals at all...they just wired the main speaker output terminals directly to the amp board. I went through all the trouble of soldering everything in the way it was supposed to be and then found out why they never bothered to wire them in...the original switches Rotel put in there had the wrong action! They were momentary contact slide switches that only made contact when pushed in or out, not when resting in the "on" position.
At first I thought they were just dirty, but when cleaning didn't work I took them apart and saw that they were never designed to make contact when pushed in, only when traveling from one position to the other. I guess Rotel goofed and figured the best thing to do was to not wire in the headphone jack, bypass the switches, ignore the whole thing and call it a day.
Anyway, I found some exact replacements with the correct action in one of my parts drawer so I replaced them both, rewired the headphone jack and the speaker outputs and it's all good now. Only took 45 years to get it right!
Very nice sounding receiver but it has a nasty CRACK! sound when powered up in the right channel (left channel has the usual gentle "Thump" that HK's are known for) so I'm going to replace the caps on the main amp board (probably do the PS too) and put stacked films in the coupling positions between pre and power boards while I'm in there.
The electrolytic capacitors in your 330A have very likely started to fail due to age. That isn't the only possible cause, but it is where I would start.
@Spenser did a really nice writeup on the 330A he repaired/recapped. Read through this thread for some direction: http://www.audiokarma.org/forums/index.php?threads/hk-330a-repair-and-restore.823100/
The right next step for you would be to post a new thread in the Solid State forum, title it something including "330A" and "distortion in one channel", describe your problem there and ask for help. AK'ers will get right on helping you.
Good luck!
Thanks
I saw something about monitor switches, that they commonly get dirty or something and that could be the problem. Are those just the switches on the front panel and how to best clean them. Thanks
Old HiFi Guy
Well-Known Member
I did end up buying that Rotel RX-400A and I swear the HK-330b (and probably all of the Japanese HK receivers built before HK got sold off in the early 80's) had to be built by Rotel. Here's the one I picked up, made in 1972, (click on the photo for full size)
View attachment 941064 View attachment 941068
View attachment 941070 View attachment 941071 View attachment 941072
Everything about it is similar if not identical to the HK-330B. The only differences are pretty minor, like the addition of the Haffler circuit for "simulated 4 channel sound" (it's just a couple of resistors and a slide switch screwed to the back panel and wired into the remote speaker terminals) and the heat sink (uses the same screw holes, just a different shape and not as nice as the HK's heat sink).
This one had an odd factory defect: the main / remote speaker switches and the headphone jack were never wired in. There was no attempt to wire them in at the factory, no solder on the terminals at all...they just wired the main speaker output terminals directly to the amp board. I went through all the trouble of soldering everything in the way it was supposed to be and then found out why they never bothered to wire them in...the original switches Rotel put in there had the wrong action! They were momentary contact slide switches that only made contact when pushed in or out, not when resting in the "on" position.
At first I thought they were just dirty, but when cleaning didn't work I took them apart and saw that they were never designed to make contact when pushed in, only when traveling from one position to the other. I guess Rotel goofed and figured the best thing to do was to not wire in the headphone jack, bypass the switches, ignore the whole thing and call it a day.
Anyway, I found some exact replacements with the correct action in one of my parts drawer so I replaced them both, rewired the headphone jack and the speaker outputs and it's all good now. Only took 45 years to get it right!
Very nice sounding receiver but it has a nasty CRACK! sound when powered up in the right channel (left channel has the usual gentle "Thump" that HK's are known for) so I'm going to replace the caps on the main amp board (probably do the PS too) and put stacked films in the coupling positions between pre and power boards while I'm in there.
Although this is an old thread I just had to reply. I recently bought a made in Japan Soundcraftman 1000A receiver and it is almost identical as my HK 330B. Same front panel layout with buttons like the 330C instead of the B's rocker switches and split bass and treble controls. Even the real wood case as opposed to the HK's vinyl covered "wood case" fits the HK. Some factory was busy building receivers to be sold by three different companies. Like to figure out who it really was. Odd the knobs are plastic on the Soundcraftsman as opposed to the HK's metal ones but the case is real wood veneer as opposed to the KK;s vinyl one.
Neat! I’m betting that the third party builder is Roland Electronics (Rotel) since they’ve been known to spec build equipment for other brand names. Somewhere on AK I remember reading a thread that featured yet another brand of receiver with the Roland / Rotel build, can’t remember what the brand stamp was though.
that’s really interesting. I’ve looked around and I can find a Soundcradtsmen 2000A and 3000A which look a lot like the 330B, but I can’t find an example of the 1000A.
will you please post a photo of the front and the rear?
Old HiFi Guy
Well-Known Member
Sorry, my bad typing, it is a 2000A. I currently use it as a preamp for 5 100WPC and up power amps.
Spe@kerBox
Addicted Member
From being inside the As and Bs, I have found that the latter versions of the 330B had improved heat sinks (more surface area).
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