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harman/kardon "Twin Power" Receivers

There was a problem with the old database, which was corrupted. The attachments seem to have been lost forever.

I'll try to post some pics when I get the time.

Regards,
Joe
 
Hi, I found the problem in my hk670, but the thing named "RV401" going to the terminal on the heatsink came off the terminal. What is it?
 
Check the service manual to discover what the function of the "RV401".
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That's what I did before asking, and I didn't find anything. I looked again but remembering this time that the components don't have the same codes. (RV401 in my amp is D421 in the manual)

I found out it's a MV11Y variable diode and that it's impossible to find some. I think that the component is still good but that the glue holding it dried out. The only thing is that it looks like half a diode.
 
Another thanks for the HK info. I have three models, the 730, 430 and 330A. The 730 gets regular use with a pair of JBL 4313Bs and they are a fantastic match.

I've done a little bit of work on these, I'll touch on it, might be useful for someone. These use the infamous brown circuit boards of the era that tend to lift pads when soldering, so be careful when swapping out components. The controls on these tend to get scratchy, but after DeOxiting, I find that they lose their firm silkiness, end up loose and floppy. If you don't have to clean the controls, don't. Unfortunately, they frequently require cleaning. It would be great to find drop in replacements for the pots, but I have not been able to find any.
 
Same line, differnt model

tomt said:
this might be a '670' -




bigger -

http://img198.imageshack.us/img198/6366/1007999jpgy.jpg
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Hi,

This is not the 670, but it is from the same line up as the 670. I suspect it is the 560 or 450 (there was also a 340). The integrated amps from that line are the 505 and 503. I can't remember the model number of the tuner. I believe that only the 670 and 505 are twin powered.

This was the line after the great 730/430/330c line. I think the styling was just too different, and they didn't sell well. Kick ass units though, very underrated.

Jim
 
This is the 670. (I've got one right next to me, and it's identical, except for the writing that isn't missing on the lower left end.)

It's twin-powered, but both channels use the same transformer. (Separate rectifiers and PSU)
 
I received my 430 (40€ incl shipping =~40$ :) ) yesterday.
Bought the unit because I wanted a decent sounding, great looking vintage receiver for a relatively low amount of money.

I'm still testing it at the moment and it seems to run properly as-is.
The internals need to be cleaned and the VU light does not work.
Can I change that and where to can I get one (preferrably in Europe)?
Or do I need to change the entire VU unit?

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Love the looks & feel of the 430 so far, Need to do some more listening before I can make a statement about its sound. :)
 
voltcontrol said:
I received my 430 (40€ incl shipping =~40$ :) ) yesterday.
Bought the unit because I wanted a decent sounding, great looking vintage receiver for a relatively low amount of money.

I'm still testing it at the moment and it seems to run properly as-is.
The internals need to be cleaned and the VU light does not work.
Can I change that and where to can I get one (preferrably in Europe)?
Or do I need to change the entire VU unit?

picture.php


picture.php


Love the looks & feel of the 430 so far, Need to do some more listening before I can make a statement about its sound. :)
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If it sounds anything like the earlier 630, then it must be great. Nice-looking receiver.
 
Nice price for the 430, $55 at the current exchange rate, delivered.

Looks like you need a few bulbs to make it glow like new. Maybe change all of them and not have to worry about it for a while. Someone will post what bulbs it uses.
 
Listen, I have the 330B which is not even twin powered, but sounds so good, that I can just imagine how amazing the twin powereds sound.

I would expect them to be up there with the best sounding SS receivers ever.

Cheers
 
Voltcontrol, pm AK member dgwojo regarding the bulbs you need. (I think he has a website dgwojo.com) he knows his stuff.

Hope you enjoy your 430, mine was my first vintage receiver. Still in use, still my fav. Sounds good with EVERY speaker I've hooked up to it. My favorite combo to date is the 430 running Klipsch KG4's (great on live recordings) Close second would be Boston A-100's (really nice on vocals.)

Some may scoff, but this was the rig that convinced me that music should be listened to in the format it was intended. I.E. 60's & 70's music (some 80's too) sounds best on vinyl.
 
eThink said:
I personally did not care for the h/k 870 power amp because it did NOT use the dual power supply design that h/k used in mnay 1970s and 1980s receivers and power amps. Note the single power supply in the picture below.

I use (2) h/k 775 mono power amps with an h/k 825 preamp and an h/k 915 tuner.
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The hk870 has a single toroidal tx with dual windings and dual rectifier bridges.

That's a dual supply surely?

P.S. I realise I'm replying to a very old post :D
 

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HK 430 twin powering 6 ohm psb speakers??

Just a quick question. I have a HK 430 twin in mint shape and (currently) I have it playing Norah Jones with some image 2B speakers from PSB (10 to 100 watts) but hey are speced at 6 ohms and the HK was a 8 to 16 ohm spec. Will I wreck anything with this set-up? A very sweet warm sound at moderate volume and I'd like to keep it... Thx.
 

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wyaldbill said:
Just a quick question. I have a HK 430 twin in mint shape and (currently) I have it playing Norah Jones with some image 2B speakers from PSB (10 to 100 watts) but hey are speced at 6 ohms and the HK was a 8 to 16 ohm spec. Will I wreck anything with this set-up? A very sweet warm sound at moderate volume and I'd like to keep it... Thx.
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You should be fine. They handle efficient 4 ohm speakers well, so 6 ohms nominal shouldn't be a problem unless at some point in the frequency spectrum they dip below 4ohms. I'm not familiar with those speakers, so I can't say with absolute certainty.

Ray
 
Thanks Ray. I think these receivers have more constant current as well vs. some newer ones that are peak power ratings. Is that fair to say? I like this receiver and if anyone has a minty 730 twin I would be interested, prefer shipping within Canada. Thanks. Bill.
 
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