Purchased this Hafler 945 series preamp recently. Determined it's locked in Mute mode which is only accessible through the remote control system; and I don't have the factory remote. Programmed my Harmony 300 with the Hafler codes, but that doesn't trigger the Mute circuit. Heard from someone with a Hafler Iris that he was able to remove the remote pcb which made the preamp controllable through the knobs, without remote control of course, which would be fine for me.
The user manual, which is a little more extensive than most, is easily available; but cannot locate a service manual or schematics anywhere. Inspecting the unit I notice that the two large power circuit electrolytics have leaked, but doubt those would cause the Mute situation. The pcb containing the remote control "eye" is fairly extensive and contains lots of stuff other than the remote receiver.
Anyway, best thing would be to get the schematics so I could see what it's all about; I just don't have the skill or experience to tackle this thing without documentation. Checked all the usual sources including fee-services, but no luck. If anyone has a service manual, or knows of a source, or would be willing to send copies of key pages, or has any other ideas, I would be eternally grateful.
Thanks,
Warren
The user manual, which is a little more extensive than most, is easily available; but cannot locate a service manual or schematics anywhere. Inspecting the unit I notice that the two large power circuit electrolytics have leaked, but doubt those would cause the Mute situation. The pcb containing the remote control "eye" is fairly extensive and contains lots of stuff other than the remote receiver.
Anyway, best thing would be to get the schematics so I could see what it's all about; I just don't have the skill or experience to tackle this thing without documentation. Checked all the usual sources including fee-services, but no luck. If anyone has a service manual, or knows of a source, or would be willing to send copies of key pages, or has any other ideas, I would be eternally grateful.
Thanks,
Warren
I have a pdf of the schematic. It's too large to upload. Send me a private message and I'll send it to you by email.
ok since here not much info around them here is a few tips
mine had a blown trafo actually called the guys in Hafler ( US) before i hung up a cool guy named Forrest dropped me a mail with a generic but workable schematic
Seen that for audio anything between 18+18 till 23+23 will do ( it will be regulated to 15+15 ) but you will also need another winding for 5 volts to light up the fluorescent display .
beyond that there is a 78L05 regulator that is powered from the +rail line of unregulated 24 volt and fails quiet often ( resulting no 5 volts no display and a few other things that don't work ) and also next to the IC that is the display driver there is a crappy capacitor of 1000/10 that might fail badly enough to take down the all 5V line ...
So ...schematic is now available
kind regards
sakis
mine had a blown trafo actually called the guys in Hafler ( US) before i hung up a cool guy named Forrest dropped me a mail with a generic but workable schematic
Seen that for audio anything between 18+18 till 23+23 will do ( it will be regulated to 15+15 ) but you will also need another winding for 5 volts to light up the fluorescent display .
beyond that there is a 78L05 regulator that is powered from the +rail line of unregulated 24 volt and fails quiet often ( resulting no 5 volts no display and a few other things that don't work ) and also next to the IC that is the display driver there is a crappy capacitor of 1000/10 that might fail badly enough to take down the all 5V line ...
So ...schematic is now available
kind regards
sakis
Not any more ..I am done
But thank you though !
On the other hand you may sent it to me to see if the one you have is better than mine
service@eastelectronics.gr
Nice diyaudio people !!!!
But thank you though !
On the other hand you may sent it to me to see if the one you have is better than mine
service@eastelectronics.gr
Nice diyaudio people !!!!
I realize some of the posts on here are a little dated, but if any of you are still offering schematics for the Hafler JFET Series 945 pre-amp........I'm a taker. Just happen to have one here in need of service, but no luck on finding schematic. [ slybyrd@sprynet.com ]
Also looking for schematics for Hafler 945
If some schematics of are still available, i would be very interested also
Best regards
Guenther
If some schematics of are still available, i would be very interested also
Best regards
Guenther
To all 945 owners . In case you ever need a replacement remote or a backup remote. Logitech Harmony line of universal remote has the Hafler 945 (because of it's Av capability in their database. I have 3 945s but only 2 remotes. SO i decided to try it out and yes I could program the Logitech Harmony 700 which is what I have. Tested it out and it works. Further I got a Pioneer PDF-17 multi cd changer ( 100 CDs) to be exact and I did not have remote with it programmed it also and work fine.
Now all I have to do is fix the one unit that won't come out of Mute mode so it is unusable and another that doesn't respond to any remote commands at all but can be used manually. I am in the process of documenting parts list and locations as well as connectors and transistors for the 945.
Now all I have to do is fix the one unit that won't come out of Mute mode so it is unusable and another that doesn't respond to any remote commands at all but can be used manually. I am in the process of documenting parts list and locations as well as connectors and transistors for the 945.
Fix for 945 that is ON constant mute and Remote or Vol ctrl will not fix.
The 945 that I have that was not responding to remote commands. I put a scope on the IR rxer line it didn't move so I took the front panel apart to see if I could check out the IR RXER. Turned out some one had placed electrical tape over the IR window because he found out like I did that some function on the remote for my STB would respond to some of the STB remote function like AV being selected on the 945. So now I have 2 out of 3 fully functional now. I also bought one that is in solid mute mode. I shot the bug down with some help from the people at MUSICAL CONCEPTS. They told me they had an identical bug ( D701 had pulsing both end of this diode When the mute relay works properly after the time out for RY4 ( mute relay) the pulsing stops. ). The good news is I have a bad ry4. The bad news is I haven't been able to find a PCB 12v gold plated contacts relay along with the proper coil resistance . One of the units I have some one else has shot the same bug and replaced the relay with a larger plug in unit hard soldered to the PCB. The gold plating on the N/c contacts are required because the normal pre amp signal goes thru these contact so gold will have lower resistance than
any other metal except for platinum.
The 945 that I have that was not responding to remote commands. I put a scope on the IR rxer line it didn't move so I took the front panel apart to see if I could check out the IR RXER. Turned out some one had placed electrical tape over the IR window because he found out like I did that some function on the remote for my STB would respond to some of the STB remote function like AV being selected on the 945. So now I have 2 out of 3 fully functional now. I also bought one that is in solid mute mode. I shot the bug down with some help from the people at MUSICAL CONCEPTS. They told me they had an identical bug ( D701 had pulsing both end of this diode When the mute relay works properly after the time out for RY4 ( mute relay) the pulsing stops. ). The good news is I have a bad ry4. The bad news is I haven't been able to find a PCB 12v gold plated contacts relay along with the proper coil resistance . One of the units I have some one else has shot the same bug and replaced the relay with a larger plug in unit hard soldered to the PCB. The gold plating on the N/c contacts are required because the normal pre amp signal goes thru these contact so gold will have lower resistance than
any other metal except for platinum.
Hafler 945 schematic
If anyone can send the pdf on the 945 that would be great. Thanks.
Rickclk1@gmail.com
If anyone can send the pdf on the 945 that would be great. Thanks.
Rickclk1@gmail.com
The thread that would not die... 🙂
Does anyone out there have a good Hafler 945 schematic to share? Or a link to a decent PDF/image?
Thanks!
Does anyone out there have a good Hafler 945 schematic to share? Or a link to a decent PDF/image?
Thanks!
I also need the schematic for the 945
What is the difference between the 945 and 915 preamp besides the tuner section and remote control ?
What is the difference between the 945 and 915 preamp besides the tuner section and remote control ?