Hafler dh-200 switch

[jakelm3075]

Well the new switch came in. Soldered all the wires in place......Plugged it in.....Flipped the switch...SPARKS flew everywhere!!....Plug caught on fire and fire was spreading....


Just kidding... switch worked perfectly. Plugged it in, flipped the switch on and the little red light in the switch lit up. Just like brand new.

I unhooked the plate amp in both the MTX and the Polk. Ran the sub pre out from the reciever and used the "Y" connection to go left and right on Hafler. Hooked left and right to both subs, set the gain on the Onkyo to "0" and popped in Animusic. I believe running a raw amp is a great improvement from the plate amps. The subs disapeared in my living room.

Being I have my beautiful vintage Polk 7's as front main, I set my reciever to 60hz. Now I know some of you might think that alittle low, but the Polks handle the rest beautifuly and blend everything in very well.

I just want to thank all of you for giving me such great help. And if there is anything I can help with , let me know.


I cant wait to dismantle those terrible manufacture sub boxes and use Win Isd to create bigger, better and lower tuned boxes for my 10" Polk and 12" MTX.


Jake

[6BG6GA]

Glad to hear that it worked.

[jakelm3075]

It works great, burnedfingers. But I didnt realize how warm that amp ran. Is it safe to just leave it on? Or should I turn it off and on everytime I use it. The rest of my electronics stay on allways. I believe that leaving them on reduces moister that can currode connection. Am I right in leaving this particular amp on?

[6BG6GA]

The purests would say to let all your gear run. In todays world with the increasing cost of electricity I would suggest turning on the equipment about 1/2 hour before listening to it. To answer your question I would not let it run. I would also check the bias to make sure it is tracking correctly and is set per factory specifications. As you know the sign of heat can sometimes mean the bias is a little heavy.

Actually I would turn off your gear. Turn it on 1/2 prior to using. I wouldn't worry about a moisture problem or corrosion.

[jakelm3075]

The heat is not unusual heat (if that makes any since). As a matter of fact on my Onkyo reciever I can cook an egg (figuratively speaking), the Hafler isnt as warm as the Onkyo.

[slowhands]

Originally posted by jakelm3075
It works great, burnedfingers. But I didnt realize how warm that amp ran. Is it safe to just leave it on? Or should I turn it off and on everytime I use it. The rest of my electronics stay on allways. I believe that leaving them on reduces moister that can currode connection. Am I right in leaving this particular amp on?

The bias might be set too high. It should run a little warm, but not extremely hot. Factory standard bias current is 200ma, which you measure by replacing one of the DC power fuses with an ammeter. Turn the P2 pot (in the center of the board) a little counter clockwise to turn it down a bit. The DC fuses are the pairs of fuses, two on each side of the transformer.

I'd leave the amp on all the time, because you don't want to burn out the switch again. It's days are numbered.

[anatech]

Hi Jake,
I am solidly on the turn your gear off side. Many reasons to do so and very few weak arguments to leave it on.

Turn it all off and follow Joe's (burnedfingers) sage advice. You can easily add a soft start, or just replace the switch when needed.

-Chris

[fab]

I have already asked Hafler tech support and it says 260 ma for DC bias.

[anatech]

To measure bias in fuse clips, use a 1 ohm resistor, I also have 0R1 ohm resistors for this purpose.

Remember to remove them before packing it up or running it hard. You will learn the hard way like I have a few times.

-Chris