diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Solid State (http://www.diyaudio.com/forums/solid-state/)
-   -   Hafler P500, need schematic, manual, and some help (http://www.diyaudio.com/forums/solid-state/54319-hafler-p500-need-schematic-manual-some-help.html)

still4given 27th March 2005 05:15 PM

Hafler P500, need schematic, manual, and some help
 
Hi folks,

I have acquired a Hafler P500 that is not working. Hafler has the DH-500 manual on their website but nothing for the P500. The P500 has a PCB for the gain controls and balanced inputs. I'm hoping someone here has a schematic or manual or even a wiring diagram for this amp.

The bridge had been removed as well as three of the N channel MOSFETs. I am trying to get it hooked back up properly so I can begin testing things to find why they decided to start using it for a parts supply. I would really like to get this beast up and running.

If no one has a manual, perhaps someone owns one of these and would mind opening the top and at least giving me an idea of which wires hook up where.

Thanks Terry

still4given 28th March 2005 12:58 PM

Back to the top in hopes that someone will see this and be able to help.

I mostly need info on the gain circuit board. One of the wires was cut and I have no idea where it originally hooked up. It should only take a few minutes for someone to look as see for me if they own one of these. Of course having the schematics and wire management pics would be ever so helpful as well.

Thanks, Terry

still4given 29th March 2005 07:23 PM

BTTT

AcidJazz 30th March 2005 10:20 PM

I got a P505..
 
and it uses the PC-19c driver board, which is the same as that in the DH500. I would think the circuit is the same, but I will have to check when I get home. The DH500 circuit should be available on the Hafler website, under the Library Archive section.

still4given 31st March 2005 02:22 AM

Re: I got a P505..
 
Quote:

Originally posted by AcidJazz
and it uses the PC-19c driver board, which is the same as that in the DH500. I would think the circuit is the same, but I will have to check when I get home. The DH500 circuit should be available on the Hafler website, under the Library Archive section.


How are you going to check? Could I be so lucky as to have found someone who owns a P500?

Thanks, Terry

AcidJazz 31st March 2005 02:52 PM

I sent you an email with the link to the 500 manual. Did you get it?

still4given 31st March 2005 03:23 PM

Hi AJ,

Yes I got the email, thanks.

I had already D/L'd the DH-500 manual. I wasn't sure if it was the same. Thanks for verifying it.

I was able to do some voltage checking last night. I didn't have a voltage table for the DH-500 so I used the one for the DH-220 which uses the same boards. I used a variac so I could adjust the rails to 64V which is what the DH-220 uses. For some reason I'm reading +3VDC too high on the bases of Q3,Q4,Q5,Q6,Q9,Q12,Q13, Q401, Q402, Q403, Q404, Q405 & Q406. Does anyone have an idea of what componant would cause the voltage to be three volts higher than it should be on these transistors?

If I can scan the schematic I'll try and post it. It can be found here in PDF form.

http://www.hafler.com/techsupport/pd...20_amp_man.pdf

The reason I was hoping for a schematic or wiring diagram for the P500 was so I could tell where the wires for the PC-20D board hook up. I have one W/BRN wire that has been cut and I can't find where it should land.

Thanks, Terry

still4given 14th April 2005 02:22 PM

Hi guys,

Well I just wanted to follow up on my success. First, I emailed Hafler about the manual and they were kind enough to email the P500 manual to me so I now have it. If anyone here needs it, send me an email and I send it to you.

I now have the amp up and running and it sounds very good. I had to replace 6 MOSFETS and the filter caps.

The P500 manual doesn't give the bias setting for this amp so I set it per the instructions for the DH220 which calls for 275mA. When I first hooked up the ammeter it read 350mA on both channels. I have to wonder if this amp should be biased higher than 275mA. If any of you know for sure I would love to have that information.

A special thanks to Dick West for all of his help both here and through email.

Thanks all of you.

Blessings, Terry

mlloyd1 14th April 2005 10:50 PM

zero tempco point for the Hitachi lateral MOSFETs is ~100mA per device. so, a decent rule of thumb is set bais for 100mA per device on each power rail. So, if you have 6 output devices total (3 N channel, 3 P channel), you'd set bais for 3 * 100mA or 300mA total. If you had 12 output devices total (6 N, 6P channel), set the bais for 6*100mA or 600mA per rail.

FYI - many have said the Hafler amps sound better with more bias. Try it and see what you think

mlloyd1

anatech 14th April 2005 11:29 PM

Hi Terry,
Could I trouble you for a copy please? bhome at sympatico dot ca .

Thanks Terry!

-Chris


All times are GMT. The time now is 10:30 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2