• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Need help with Harman/kardon 330B recap/rebuild

OskarBas1

OskarBas1

Member
Ok so I'm going to do a recap/rebuild of my Harman Kardon 330B. I'm not that familiar with doing things like this so I'll need som help.

I'm think I'm gonna order the full parts list that dlucy provided in the thread linked below
https://audiokarma.org/forums/index...store-and-upgrade-bom-part-list-kinda.739572/

Not only the cabs but the rest as well.
Will i be able to complete all the upgrades shown by dlucy in the thread with the parts from the list?
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 are there any possibility that changing these parts will "ruin" the sound of the unit or is it just improvement?
I've never done this before so all tips would be appreciated.
Someone mentioned in the linked thread that you need to tune the unit with a ociloscope and a 1000/4000hz signa after doing the upgrade. How am I suppose to do this? I have a scope and a signalgenerator so i should manage.
In the linked thread some pictures and instructions are provided for some of the upgrades but I'm still kinda confused on what to put were. All help will be needed.
If someone clarifies if there is anything else i need apart from the full partslist and in that case what I'll order the parts and go from there.
I don't know what current dlucy's unit is running on but if it's not 230v i assume I'll need som other parts.
I'm not sure what type of 330B I've got. It has the serial and model numbers of a Roland unit but is made in Japan. I'll provide som pictures.
To begin with i need help modifying the partslist to fit my unit, if its needed.
Thanks in advance for the help.
I'll brovide som pictures.
 
Register to hide this ad
You say you have never done this before? Uh-oh? :yikes: :D

If it works now, I would leave it alone before you end up with a door stop on your hands. You might be able to get away with it, but with no experience, why take a chance? I would probably find a junk amplifier or stereo to practice on before maybe ruining a good stereo that you already have. :thumbsup:

It's not the voltage in that matters, it's the voltage out. In other words, if the power transformers primary windings have factory taps for 100, 117, 120, 220, 240 volts etc., the secondary voltages will still stay the same.

And yes, you might end up changing the sound.......or maybe even something worse. :bye:
 
Last edited:
I have some experience with electronics in general but not this kind of upgrade. If i get a complete partslist that fit my unit I'm sure I'll work it out. Just concerned about my unit being a 230v and that probably changes som of the parts? Or maybe it's just another transformator?
 
Last edited:
If its factory set for 240, the output voltage will stay the same as a unit set for 120 volts used in the U.S.

No offense but I remember saying the same thing when I was 18. :biggrin:

Thought I knew a lot about electronics but actually knew squat. I am in my late 50's and I have learned more in the last 10 years than my entire life. :angel:
 
cademan said:
If it works now, I would leave it alone before you end up with a door stop on your hands
Click to expand...

Yes there is of course the risk of messing it up, but I have to disagree. I mean, you got to start somewhere. And the HK 330 is good candidate. Old enough to need it, nice enough to be worth it, yet not to expansive to risk it. And fairly easy to work on.

The trick of not screwing up it to:
- make good close-up pictures at every step
- be patient and delegant; don't rush and never use force
- work over small parts, and test every time in between
- use a DBT
- keep your AK buddys in the loop

As mentioned: after the transformer it doesn't matter anymore what the input voltage was; it's all the same from there.
 
Ok great, as far as I know there are no components to replace before the transformer. There's always a risk of messing up but you won't learn not to if you don't try. Thanks for the response.
 
OskarBas1 said:
Ok great, as far as I know there are no components to replace before the transformer. There's always a risk of messing up but you won't learn not to if you don't try. Thanks for the response.
Click to expand...

You will, without doubt, get advice of varying value for you. You're doing great, asking questions, and sticking to your plan of learning how to diagnose, repair and restore for your own purposes. Don't give up. We're here to help.
 
Some photos of my unit
 

Attachments

  • DSC_0281.JPG
    DSC_0281.JPG
    87.1 KB · Views: 26
  • DSC_0280.JPG
    DSC_0280.JPG
    152.1 KB · Views: 25
  • DSC_0279.JPG
    DSC_0279.JPG
    163.1 KB · Views: 24
  • DSC_0278.JPG
    DSC_0278.JPG
    124 KB · Views: 26
  • DSC_0277.JPG
    DSC_0277.JPG
    115.5 KB · Views: 26
  • DSC_0276.JPG
    DSC_0276.JPG
    87.7 KB · Views: 26
  • DSC_0275.JPG
    DSC_0275.JPG
    114.3 KB · Views: 26
  • DSC_0274.JPG
    DSC_0274.JPG
    101.6 KB · Views: 25
  • DSC_0273.JPG
    DSC_0273.JPG
    120.9 KB · Views: 25
OskarBas1 said:
Ok so I'm going to do a recap/rebuild of my Harman Kardon 330B. I'm not that familiar with doing things like this so I'll need som help.

I'm think I'm gonna order the full parts list that dlucy provided in the thread linked below
https://audiokarma.org/forums/index...store-and-upgrade-bom-part-list-kinda.739572/

Not only the cabs but the rest as well.
Will i be able to complete all the upgrades shown by dlucy in the thread with the parts from the list?
Click to expand...

It is likely that blindly following a BOM or Bill Of Materials from someone else's thread here on AK will not perfectly match your unit or not be able to find the exact same components from the exact same vendors. That's just something to know as you get into this. For me, that's a good part of the learning you're getting.

OskarBas1 said:
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.
Click to expand...

The parts lists might be a tiny bit different in the early stages of the power supply and in the FM MPX board. The schematic in the service manual will help there.

OskarBas1 said:
But are there any possibility that changing these parts will "ruin" the sound of the unit or is it just improvement?
Click to expand...

The only way to "ruin" the sound of the 330B would be to increase the capacitance value of the two output caps. They are 1000 uF from the factory, they form a filter of the audio signal going to the speakers, and increasing the amount of capacitance would effect an emphasis on the lower frequencies... or, more simple, would sound like the bass had been turned up.

Other than that, it is a quasi-complementary, single voltage rail, cap-coupled output audio amp design. Choice of the quality of replacement parts, choice of like-functioning semiconductors, and choice of same-value resistors and capacitors may alter the sound character a little, here and there, but certainly won't ruin it.

OskarBas1 said:
Someone mentioned in the linked thread that you need to tune the unit with a ociloscope and a 1000/4000hz signa after doing the upgrade. How am I suppose to do this? I have a scope and a signalgenerator so i should manage.
Click to expand...

We can explain when you're ready to do so, but it isn't 100% necessary.

OskarBas1 said:
In the linked thread some pictures and instructions are provided for some of the upgrades but I'm still kinda confused on what to put were. All help will be needed.
Click to expand...

You should print out the schematics and the board layouts from the service manual, look at each component number in the parts list, and look to see where on the board layout (from the service manual, that component is physically located.

OskarBas1 said:
I'm not sure what type of 330B I've got. It has the serial and model numbers of a Roland unit but is made in Japan. I'll provide som pictures.
Click to expand...

Good job on the photos. On the rear panel of your unit there is printed "Series B-" something. What is the "something" on your unit? B-1? or B-2?
 
Thanks for the response. Great tips on how to do things. i will defenatly print out the manual. Ok, so finding a substitute to a component already listed in the partslist won't be a problem, just find one with similar specifications and a good brand.
At first I thought of only replacing caps and did a list of the caps in my unit and measured the voltage over the caps to chose new ones that will be running at 60-70% of max voltage. Then i found the linked thread with lots of fun stuff to do. So finding new caps ain't that hard.
The thing that i find hard is finding good replacements for diodes and transistors etc, for example how the two bords for power underneath the unit were rebuilt.
Is it a good idea to have the bom from the mentioned thread as starting point and start with finding alternatives for parts in the list isn't avalible. And then try to change list for the power supply and FM mpx bords to fit my unit.
Some help to get all the components right would be appreciated but it's good if i learn how to do it myself along the way.
My unit is a series B-1
Thanks again
 
I've found the service manual with schematics, about 22 pages. Is the manual the same for all kinds of 330b.s?
If i use the partslist from the other thread as a starting point, how do I know what components that's different in my unit?
 
I always go about it the other way around. Just opening up the unit and reading the values on the components themselves. Electrolytic capacitors are often not even mentioned in the parts-list anyway. If for some reason a component can't be read (say it is melted) then I use the schematic. Reading those values off the components can be a bit of a pain. Just use a handheld light and push'm around if you need to.

The found components go in to a sheet like the example below. I have standardized the format for myself, but you can find your own perfect fit of course.
Screenshot_20211217-130919~2.png

Then I take one little plastic zip-bag for each PCB, and collect the required components from what I have in stock. Note for each component which is his replacement, because it might not have the exact same values. Then the list is used for ordering the components for which I did not find a suitable replacement in my own stock. These are noted in the list in red, until the order comes in and the components are delt into their respective baggies. There is also a baggie for screws and washers and all that, plus one bag for the components that so far came out of the unit. Then all these baggies go in to a slightly bigger bag that stays with the unit.

That might seem over organized but it saves out a lot of "oepses". Especially if you have to wait on parts, and end up with several units opened up, each requiring a whole bunch of components. Just mentioning all this for you to consider;)
 
Thanks for the info. Over organization is good. I think i would manage to just find a straight up replacement for the parts that's in te unit, but when it comes to doing "inprovement" On the unit, bumping up parts, and rebuilding things with other components than original I'm i little confused. Thats why I thought it was a good idea to use the partslist in the mentioned thread.
 
One of the issues you’ll run into on the 330A and 330B is the variations on which boards were used in any one production unit. One 330B series B-1 unit may leave the factory with FM MPX board variant 1 while another 330B series B-1 unit leaves the factory with a different FM MPX board variant. You really have to compare the photos of each board (in restoration threads here on AK) and the BOM parts list with what _your_ 330B unit has in that spot. It can be frustrating at times, but the results are rewarding.
 
You must log in or register to reply here.
Back
Top Bottom