Hafler DH 500 v Pro 500 what is the difference??

What is the difference between a Hafler DH 500 and a Pro 500. When I worked in the biz I sold the DH 500 but we never stocked or sold the Pro. Is the pro later?? Thanks

check the search function, above.
I think the "pro" has 8 mosfets vs 7 in the other.

Hi 7? Not sure about that. I could not find a lot in the search but then again i might not have put it in right.

think the count I gave was too high. The P500 has 7, and the DH500 has 6.

Has to be an even number 6 or 8 output devices.

I think that is true if the mosfet needs one P and one N to make a set (sure there is a technical name for this as I am only parroting here); however, I have seen it written a DH 500 can run with three Mosfets if there is a P/N set on one side and two sets on the other.
I will find the reference.

That was my point in questioning the 7. There has to be other differneces. Thanks

google "hafler dh-500 mosfets" and you will find a diyaudio thred from March 2005.

I was under the impression that it was the same as the DH-500, but it had a different faceplate, gain controls, and balanced input connectors. Maybe a change to the Fan speed circuit too?

The DH-500 came before the Pro incarnation.

I have a P-500, the pro model of the DH-500. Here are the differences:

Connections:

- XLR inputs
- Barrier strip inputs
- No RCA inputs.

Display:

- Clipping LEDs - one per channel
- Activity LED - one per channel
- Volume controls - one per channel
- Much heavier duty AC on/off switch

Internal circuits/boards:

- Additional board for the clipping, input controls, and balanced-to-unbalanced signal conversion. Mounted behind the front panel.

- Differences in fan resistor values. This changed the speed at which the cooling fan ran.

- Air filters installed on both of the air inputs. Mounted in the same place as the DH-500, there were 'pouches' where mesh filters could be installed for long-term operation and keeping the interior cleaner of dust.

Otherwise, the chassis, driver boards, heatsink, speaker relay, and power supply components were exactly the same as the DH-500. I suspect that the power supply's ground rails were a bit heavier between the capacitors.

There is some additional wiring in the harnesses to accommodate the additional board and rear connections.

Hope that helps.

Cheers,

David

No RCA inputs on the PRO ? That is a problem

geph0007 said:

No RCA inputs on the PRO ? That is a problem

Click to expand...

Not really a problem. The P-500 used 1/4" inputs as well. All you have to do is get an RCA-to-1/4" adapter for those inputs and you're there.

Cheers,

David

Why does a p 500 have 2 1/4 inch inputs per channel

I just bought one at a hawk shop for $150

Powers up and comes out of protection

About 10 mv offset per channel

I do not have input adaptors yet