Need Help with a Harman Kardon PA-4000

 

New member
Username: Original_shakes

Post Number: 1
Registered: Mar-05
I'm a knucklehead! About a year ago I purchased a Harman Kardon power amplifier. I have a Bose lifestyle 28 system. I planned on using the amp to power multi-room, stereo only configurations controlled by zone 2 of the Bose system. When I received the amp and the expansion kit for the Bose, I discoved that I had no way of controlling volume (with the exception of the push button switches on the back of the amp). I gave up trying to resolve the problem and have since been controlling the volume the hard way.

Now, I am trying to solve the problem once again.
I first figured that I would purchase a low end receiver and connect the amp to the pre-amp output. I learned that most (if not all) pre-amp outputs (if there is one) are not variable. As I understand this, I would be right back where I started, without a way to control volume.

I am aware of the KP-1 in-wall controllers, but I have found only limited information about them. Furthermore, they appear to be discontinued, or at least unavailable at this time.

I have concluded that a pre-amp is likely my best solution. Any recommendations for a pre-amp or any other possible solutions will be greatly appreciated!

Thanks in advance
Bennett
 

J. Vigne
Unregistered guest

Pre amp out is after the volume control, so it is definitely a variable output level. Tape out, on the other hand, is a fixed level.

How many speaker locations aer you trying to control? How many of these need independent volume control? In dependent volume control means are there any pairs that will be running at the same volume all the time or are you looking for the ability to control each pair of speakers separately.

Does the Bose provide an overall volume control for zone two operation, or is it a fixed level output?


 

New member
Username: Original_shakes

Post Number: 2
Registered: Mar-05
I had identified a few receivers that had pre-amp outputs, but when I called to get more information I was told it would not work and that I was only creating more problems. Perhaps that sales rep is a bigger knucklehead!

So, let me get this straight. Any receiver or integrated amp that has a pre-amp output will give me volume control to my power amp? This is what I understood initially. So are both amps then controlled by the volume (controller) of the receiver or integrated amp? Or, is the first amp in line merely bypassed?

The PA-4000 has up to 4 channels. I presently have 2 pairs bridged. I have two pairs of Bose in-ceiling speakers, each pair powered by a bridged channel. I have no need for independent volume control in this configuration. However, in the future I may use one channel independently for my patio. So independent volume control is a consideration.

Furthermore, I am not happy with the base provided by the Bose speakers. I am considering two options. I (we) have an old pair of Klipsch (sp) Speakers with 8" or 10" woofers. I don't know much about them as my wife bought them in '93 or '94, years before we got married. But I suspect that will contribute significant base.

Or, if I purchased a receiver with sub-woofer pre-amp output...I could add a powered sub-woofer.

As for the Bose system. It has independent volume control between zones 1 and 2. But the connections are unique. The output jack on the unit (for zone 2) is similar to the connection for a mouse or keyboard. On the other end are two standard RCA jacks (audio L & R I presume) and a third jack that I am unfamliar with (I suspect this is power control & volume). According to Bose Support personnel, it is "proprietary" and will only work with other Bose products. There doesn't seemed to be a proper place for such an input on the PA-4000 anyhow. Obviously, I made an uniformed purchase when I bought this amp.
 

New member
Username: Original_shakes

Post Number: 3
Registered: Mar-05
Perhaps, a speaker selector with volume control is my best solution.
 

J. Vigne
Unregistered guest

"Any receiver or integrated amp that has a pre-amp output will give me volume control to my power amp?"

Yes.

"So are both amps then controlled by the volume (controller) of the receiver or integrated amp? Or, is the first amp in line merely bypassed?"

That would depend on how you make the hook ups. In your situation, I would asssume you want the pre amp outs to control only the HK amp. You do not need an entire receiver, just a used pre amp will suffice.

"The PA-4000 has up to 4 channels. I presently have 2 pairs bridged"

"Bridged" operation implies you have connected the left and right channels together to make a single mono speaker output. Is this what you've done? You can only bridge an entire amp into mono, you cannot selectively create a mono channel and still have two stereo channels.

" I am not happy with the base provided by the Bose speakers ...Klipsch Speakers ...will contribute significant base."

More bass? Maybe. Better bass? Maybe. I don't understand what your plan is or what you want to achieve.

"Or, if I purchased a receiver with sub-woofer pre-amp output...I could add a powered sub-woofer."

You could, but at that point why keep the Bose unit. Get rid of it and buy a receiver that does what you want in the first place. Otherwise you will have a jumbled system that no one can operate properly.

"As for the Bose system. It has independent volume control between zones 1 and 2. But the connections are unique."

You can use the independent volume control from the zone two of the Bose as is it were a pre amp out, which basically it is. At that point the need for a separate receiver will only complicate the hook up again. Or you can see my comment above about discarding the Bose entirely. Either way you have a pre amp output going to the HK. The additional plug is most likely a trigger for powering another Bose product.

At this point, the least expensive route would be to use a selector with vc's. You will have to buy a controller that can withstand the power of the HK at full gain since the best you can do is lower the overall gain to the PA4000 from the pre amp out of the Bose or new receiver. If you go this route, I would use the zone two volume at less than full power unless required for a short term listening session. Hook up the system with the volume controls at their max position. Adjust the output of the Bose (or receiver) to obtain a comfortable level from the amp and remote speakers. Let the zone two level remain there unless a temporary change is desired. This will work and will have the least amount of possibility of damage (overheating) to the vc's and ultimately to the amplifier.

There are two other options that you can consider. I don't know of anyone making a unit of line level volume controls prepackaged, but what you need are independent volume controls in casework to make the level set between channels on the HK amp easily accomplished. If you can solder well, you can construct a box of vc's from inexpensive parts found at Radio Shack. You need as many vc's as you want to control channels. This whole arrangement of vc's and connectors should run less than $30 and an afternoon's work. The hook up is from pre amp out to vc to power amp input. If you don't know how to accomplish this, possibly someone you know can do the wiring.

Or, you can just admit your mistake and stop trying to jerryrig a situation that shouldn't have been put together in the first place. Sell the HK, or the Bose, and put together a system that works properly with the least amount of confusion.





 

Bronze Member
Username: Harrypalmer

Bellevue, WA

Post Number: 14
Registered: Feb-06
Good choice of words.
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