A friend asked for the Sprint file for the Self Pre PSU. Here it is. You can change the output voltage just by changing the regulators. I have one that has LM7815/7915 and puts out +-16V.
PS If you look closely you will see that I have pads on the foil side to use 100n SMD across the 2200uF caps.
PS If you look closely you will see that I have pads on the foil side to use 100n SMD across the 2200uF caps.
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Is this a design by Douglas Self? It's interesting how clean it is vs much more complicated designs.
Will fitting the usual 100nF 100v MKT film cap to bypass be as effective as the SMT x7r variety?
The DAC I just built has on board, a very similar implementation (sans transistor to control feedback), 2200uF cap, 78xx or 79xx regulator followed by 220uF and 100nF bypass caps at each larger cap. It has three of these for 7812, 7912, and 7809. I guess that transistor makes a big difference - so maybe I should look at making this PSU board.
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I don't think Doug Self designed this circuit. I belive Carl Huff posted the schematic in the thread for the Doug Self preamp and I worked out the layout so I could etch one. I actually think I may have combined some of the ESP P05 into it. I would have to read back and see exactly how I came up with it. I'm not claiming it is better, only that I see less noise in this particular test. I only threw it in the mix because it was in the pile with the other PSUs so I hooked it up. I should probably run the test again with a load on them. If I get time this weekend I will.
I'm sure you can use film caps rather than SMD. I just used them to make my layout easier and I have a lot of them. The layout should probably be changed to accommodate them.
Depends on what you are comparing. IC 78xx is a very complicated design. The ripple is so low but unfortunately the sound is not good.
I actually have a bunch of the 100nF SMT caps on hand but was wondering if there were performance advantages of the MLCC vs polyfilm caps.
If you ca post Gerbers that would be great. Can you please explain how the transistor works to provide the correct reference voltage for the ground pin given that it's the same resistor divider network despite the voltage setting?
If you ca post Gerbers that would be great. Can you please explain how the transistor works to provide the correct reference voltage for the ground pin given that it's the same resistor divider network despite the voltage setting?
Looking at the specs - for the FH9, I think you can simply substitute the IRF540 whenever I used IRFP240 and IRF9540 wherever I used IRFP9420. The current handling on the smaller TO220 package actually appears to be higher and dissipation is he same. The Vds is only 100v but that's plenty. I believe it will work just fine. You may need to spread the pin spacing on the TO220 package a bit to fit the spacing on TO264 format holes.
Go for it! Maybe others with experience interachanging these can chime in.
http://www.vishay.com/docs/91210/91210.pdf
http://www.vishay.com/docs/91021/91021.pdf
Pdf files for Apex A9.
Sorry I deleted last post.
I made revisions to layout only three jumpers now.
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Order some FH9 PCBs from your favorite online store. Shouldn't cost more than $25 for 10. I use Seeedstudio.com
The FH9 HV can be built (not including heatsink and psu) for about $5 to $6ea with parts from Aliexpress. I use Dell GX260 SFF PC Pentium CPU heatsinks ($4 on eBay). Use with a 12vdc fan. The PSU's will cost real money. No way getting around that unless you make your own SMPS or happen to be able to get the $25 Abletec 53v dual rail 450w SMPS with free shipping. For a 5.1 system you need three of these power supplies.
But you would have a 6 channel x 120w/ch system that really can sound good. At these powers you might want speaker protection as it can send 35vdc to your driver.
However, if 60w amp is enough for you then base FH9 can be used with 35v power supplies. You can get 35v SMPS or 250va 27vac trafo can make 35v supplies.
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Ta Da..... mine FX8 is singing!
Hallo Friends.
El Stupido has corrected his failure with success.
I have looked again Datasheet BC546B- very good parts- so desoldering MPSA
and go to BC in LTP and CCS.
Both channels are biased now to 100mA 35VDC and the heat sink for drivers is bigger- because the bias was wanking by blowing air or touching by fingers.
I now can listen the potential of LatFet in this simple Amplifier.
The sound is very clear and transparent- light to follow, non fatigue.
It has a good jumping dynamic and bass if given from source.
My wirekraut is working on capmultiplier without hum with input 50k pot.
I have also registered that the spectrum in sound is nowhere harsh- you can
also listen to bad digital sources.
Could be like Terry predicated to Baby Slew: LatMos is more forgiving.
xrk i see your FH9 HV with interess- very nice finding. And your Aliexpress bought parts also working fine here in FX8.
sownel see my pics: FX8 100-110mA on 50mm high heat sink works with
comfortable heat- so you can build a compact case 5.1 Amp.
I now go looking pedal artists on Tour de France with FX8.
Much movement here last days- i follow.
Bangla 
Hallo Friends.
El Stupido has corrected his failure with success.
I have looked again Datasheet BC546B- very good parts- so desoldering MPSA
and go to BC in LTP and CCS.
Both channels are biased now to 100mA 35VDC and the heat sink for drivers is bigger- because the bias was wanking by blowing air or touching by fingers.
I now can listen the potential of LatFet in this simple Amplifier.
The sound is very clear and transparent- light to follow, non fatigue.
It has a good jumping dynamic and bass if given from source.
My wirekraut is working on capmultiplier without hum with input 50k pot.
I have also registered that the spectrum in sound is nowhere harsh- you can
also listen to bad digital sources.
Could be like Terry predicated to Baby Slew: LatMos is more forgiving.
xrk i see your FH9 HV with interess- very nice finding. And your Aliexpress bought parts also working fine here in FX8.
sownel see my pics: FX8 100-110mA on 50mm high heat sink works with
comfortable heat- so you can build a compact case 5.1 Amp.
I now go looking pedal artists on Tour de France with FX8.
Much movement here last days- i follow.
Bangla Attachments
Nice work BanglaH. Glad you found the problem - I also had problems when trying to use 2n5551 in place of bc546b. Switched back and works fine.
Those are excellent heatsinks - you can probably bias at 175mA which is where I like to run mine.
The sound is indeed excellent. I just put together a great CS4398 DAC from Ali for $23. Sounds very nice compared to built in DAC in laptop. Has socket for output opamp, currently fitted with NE5532, maybe will try Burr Brown OPA2604 next...
Here is is working with the FX8 Bimo very nicely.
Those are excellent heatsinks - you can probably bias at 175mA which is where I like to run mine.
The sound is indeed excellent. I just put together a great CS4398 DAC from Ali for $23. Sounds very nice compared to built in DAC in laptop. Has socket for output opamp, currently fitted with NE5532, maybe will try Burr Brown OPA2604 next...
Here is is working with the FX8 Bimo very nicely.
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Nice cleen setup.Nice work BanglaH. Glad you found the problem - I also had problems when trying to use 2n5551 in place of bc546b. Switched back and works fine.
Those are excellent heatsinks - you can probably bias at 175mA which is where I like to run mine.
The sound is indeed excellent. I just put together a great CS4398 DAC from Ali for $23. Sounds very nice compared to built in DAC in laptop. Has socket for output opamp, currently fitted with NE5532, maybe will try Burr Brown OPA2604 next...
Here is is working with the FX8 Bimo very nicely.