Dear all,
I've an old (2006) Philips DFR9000 and want to "open" it and tweak it, trying to separate the ClassD amplification from the pre.
I want to "convert it" to a 6 channel power amp without the pre function, connecting directly the RCA inputs to the power section.
Do you think is it possible?
Do you know where can i find the DFR9000 service manual?
Thank you very much!
I've an old (2006) Philips DFR9000 and want to "open" it and tweak it, trying to separate the ClassD amplification from the pre.
I want to "convert it" to a 6 channel power amp without the pre function, connecting directly the RCA inputs to the power section.
Do you think is it possible?
Do you know where can i find the DFR9000 service manual?
Thank you very much!
This is not difficult to do, but you really need the schematic.
I ordered it here in PDF CD format:
http://www.doknet.nl/service_manuals/
But you can look for any other source.
Strange that you want to use the UcD's "as is".
The main culpritt with the DFR9000 is the lack of power (caused by the powersupply).
The frontend is excellent!
With an external powersupply for the UcD's you can crank up the output per channel to a satisfying 180 Watts per channel. If you want to sustain that you have to modify the cooling however.
Or just takeout the UcD's and mount them with a big powersupply in another box.
I ordered it here in PDF CD format:
http://www.doknet.nl/service_manuals/
But you can look for any other source.
Strange that you want to use the UcD's "as is".
The main culpritt with the DFR9000 is the lack of power (caused by the powersupply).
The frontend is excellent!
With an external powersupply for the UcD's you can crank up the output per channel to a satisfying 180 Watts per channel. If you want to sustain that you have to modify the cooling however.
Or just takeout the UcD's and mount them with a big powersupply in another box.
Thank you very much marconist, if I'll not find a "free" one I'll order it from the site you suggested.
My goal is to re-assemble only the power section to a new box (like one of these http://www.modushop.biz/ecommerce/cat069.php?n=1)
About the "power"... which unit do you suggest me to buy to "pump up the volume"? But what about distortion after this upgrade? Philips says that DFR9000 is rated to have THD of 0,065%...
Excuse me for all these questions (and for my non perfect englilsh ) but I'm a newbie od "DIYing"
My goal is to re-assemble only the power section to a new box (like one of these http://www.modushop.biz/ecommerce/cat069.php?n=1)
About the "power"... which unit do you suggest me to buy to "pump up the volume"? But what about distortion after this upgrade? Philips says that DFR9000 is rated to have THD of 0,065%...
Excuse me for all these questions (and for my non perfect englilsh )
but I'm a newbie od "DIYing"I pumped up only two channels, L and R, using the Hypex powersupply using the SMPS180 from Hypex https://www.hypexshop.com/
The Philips uses 2 x 38 Volts, but I adjusted the Hypex to 2 x 40 Volts. You can go higher, but I did not test that out, as I have enough punch now.
I see no reason why distortion should increase ....... the only thing I request from the amplifier is "more punch". The main reason for it is that I modified my T+A speakers for a flatter response, however that caused quite a wild impedance curve, which required more peak current from the amplifier and the build-in Philips powersupply cannot deliver that. It switches off at some 2,2 Amps.
Instead of the Hypex power supply you can choose any other one as long as you make sure it is able to supply some 6 Amps or more in peaks. You have to make sure that the external powersupply switches on and off the right way. You will see in the Philips schematic how to do that.
I still did not finish that so I control by hand till this project is finished.
The Philips uses 2 x 38 Volts, but I adjusted the Hypex to 2 x 40 Volts. You can go higher, but I did not test that out, as I have enough punch now.
I see no reason why distortion should increase ....... the only thing I request from the amplifier is "more punch". The main reason for it is that I modified my T+A speakers for a flatter response, however that caused quite a wild impedance curve, which required more peak current from the amplifier and the build-in Philips powersupply cannot deliver that. It switches off at some 2,2 Amps.
Instead of the Hypex power supply you can choose any other one as long as you make sure it is able to supply some 6 Amps or more in peaks. You have to make sure that the external powersupply switches on and off the right way. You will see in the Philips schematic how to do that.
I still did not finish that so I control by hand till this project is finished.
I've downloaded the DFR9000 service manual for free from www.eserviceinfo.com and I started do disassemble the receiver. I've located the 3 UCD amplifiers and the Power Supply and I've re-assembled them in a new box.
Now I want to send audio signal (from a cd-player for test) to the input of 1 of the 3 UCD amplifiers but from the DFR9000 schematics I did not understand which wires to connect. Do you have any photos that can explain me your work?
Another question, does the SMPS180 deliver enought current to the 3 UCD amplifiers (6 channels) or I need to buy 3 pieces?
Now I want to send audio signal (from a cd-player for test) to the input of 1 of the 3 UCD amplifiers but from the DFR9000 schematics I did not understand which wires to connect. Do you have any photos that can explain me your work?
Another question, does the SMPS180 deliver enought current to the 3 UCD amplifiers (6 channels) or I need to buy 3 pieces?
Hi MachZ08.
Sorry for late response.
Photo's will not work. You go a different path than I do. I only added an outboard powersupply to increase audio output punch.
If you take the UcD amplifier schematic (second part) you will find connector 1201. Pin 1 and 3 are normal L+R audio inputs. Pin 2 and 4 should be grounded.
Pin 5 probably needs a pulldown to ground. Use 10 - 100 Ω.
Pin 6 is a loudspeaker protection signal, switches off the powersupply in case of faillure. Can be left open.
Pin 7 is the amplifier switching freq. guardian. It probably can be left open. Just try in case it does not work to pull it down or up.
If you pull up, use a 5 V powersupply or battery. Don NOT pull up with Vb (your some 40V main power supply as the logic is 5V!).
Hope this helps.
Use the block schematic to find out how the boards/signals are interconnected.
Yes, I know, its quite complicated.
Sorry for late response.
Photo's will not work. You go a different path than I do. I only added an outboard powersupply to increase audio output punch.
If you take the UcD amplifier schematic (second part) you will find connector 1201. Pin 1 and 3 are normal L+R audio inputs. Pin 2 and 4 should be grounded.
Pin 5 probably needs a pulldown to ground. Use 10 - 100 Ω.
Pin 6 is a loudspeaker protection signal, switches off the powersupply in case of faillure. Can be left open.
Pin 7 is the amplifier switching freq. guardian. It probably can be left open. Just try in case it does not work to pull it down or up.
If you pull up, use a 5 V powersupply or battery. Don NOT pull up with Vb (your some 40V main power supply as the logic is 5V!).
Hope this helps.
Use the block schematic to find out how the boards/signals are interconnected.
Yes, I know, its quite complicated.
MachZ08 said:
It is just what you want.
The SMPS can deliver a max. peakpower of some 400W for a very short time. That may be enough fo your purpose.
If you really want to blow the neighbours out of their garden, you better take a second SMPS to feed the surround channels.
Much is depending upon the speakers you use. The power supply does not NEED to be a SMPS. I like these, but you can use any other one that delivers between 38 and some 45 Volts, plus and minus, of course.
Very very thank you marconist,
I'm very busy now but the next week-end maybe I'll work on it.
I located the right connector 1201, but I did not know the meaning of the pin n.5-6-7 so I was confused... I'll try as you suggested.
Now my goal is to make the 3 UCD working in congiunction with the original power supply, then I'll think about the "pumped" one ;-).
Read you soon!!!
I'm very busy now but the next week-end maybe I'll work on it.
I located the right connector 1201, but I did not know the meaning of the pin n.5-6-7 so I was confused... I'll try as you suggested.
Now my goal is to make the 3 UCD working in congiunction with the original power supply, then I'll think about the "pumped" one ;-).
Read you soon!!!
Just bought one of these last week. They are very cheap at the moment (100euro).
Replaced the elcos in the signal path: at the CD input, just after the volume controll IC, and after the opamp. The first two with WIMA MKS 4.7uf, and the last with WIMA MKS 22uf. I changed the front channel opamp to National LME4720.
The sound has become much smoother, not harsh any more. But the bass is also attenuated. Will give it some days, to see if the MKSs need "burn-in" time.
Next I'll try to increase the buffer capacity on the UCD modules. Maybe also on the switched supply.
Last I'll try to run the UCD module "hotter" by decreasing the dead time (see 6.3 in UCD application note UM10155).
Replaced the elcos in the signal path: at the CD input, just after the volume controll IC, and after the opamp. The first two with WIMA MKS 4.7uf, and the last with WIMA MKS 22uf. I changed the front channel opamp to National LME4720.
The sound has become much smoother, not harsh any more. But the bass is also attenuated. Will give it some days, to see if the MKSs need "burn-in" time.
Next I'll try to increase the buffer capacity on the UCD modules. Maybe also on the switched supply.
Last I'll try to run the UCD module "hotter" by decreasing the dead time (see 6.3 in UCD application note UM10155).
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