Because I need to get the courage 
Right now it looks like a success, and I want to enjoy that for a little while
It is more than 2 years ago that I first assembled this thing.
It were not exactly the pleasent way, but I learned a lot from this build, and I have many of the parts for a F4 lying on the shelf, so maybe I should try to build that too. But that is another thread.
A shame that DIYTech does not want to sell these kits anymore. He delivered good quality.
Right now it looks like a success, and I want to enjoy that for a little while
It is more than 2 years ago that I first assembled this thing.
It were not exactly the pleasent way, but I learned a lot from this build, and I have many of the parts for a F4 lying on the shelf, so maybe I should try to build that too. But that is another thread.
A shame that DIYTech does not want to sell these kits anymore. He delivered good quality.
Today I got the courage to put my F5 to the final test.
I started up with some old car speakers which I have for testing - No sound at all. I didnt want to remove the shorts on the input to prevent oscillation, so I put them on my very effecient OB living room speakers - no sound at all.
Turning up the preamp - the sweetest music comming out - ITs WORKING)
Being used to tube amps it is a new experience that you cant hear any noise at all.
How does it sound then - very musical and relaxed, without beeing too relaxed. I agree with one from another Pass thread, it is hard to focus on the amp, because you just enjoy the music
Next project will have to be a preamp to go with it. I have BA1/BA2 PCBs on the shelf, a very good Aikido tube pre with 6SN7, and some of the parts for a Raven tube pre. Also trying to learn more about CCCS and shunt regulators, which seems to be what is cooking now.
Some time ago I converted 100% to disk based music, with a dedicated PC, an Italien USB to SP/DIF or I2S converter that bypasses the Windows mixer, and a DIY 1794A based DAC going up til 24/192, with discrete analog stage with shunt regulator. I couldnt get the Radio playing working as wanted until now, but I will. Then I only have one source, which makes the preamp easier.
I am also building a power conditioner, that should prevent spikes from the mains and that converts the mains to a balancet power source with a 1000VA toroid.
Then I want to explore PC based spectrum analyzers, sorry if I am going too much off topic.
Thanks again for your patience.
Best regards
Arthur.
I started up with some old car speakers which I have for testing - No sound at all. I didnt want to remove the shorts on the input to prevent oscillation, so I put them on my very effecient OB living room speakers - no sound at all.
Turning up the preamp - the sweetest music comming out - ITs WORKING
)Being used to tube amps it is a new experience that you cant hear any noise at all.
How does it sound then - very musical and relaxed, without beeing too relaxed. I agree with one from another Pass thread, it is hard to focus on the amp, because you just enjoy the music
Next project will have to be a preamp to go with it. I have BA1/BA2 PCBs on the shelf, a very good Aikido tube pre with 6SN7, and some of the parts for a Raven tube pre. Also trying to learn more about CCCS and shunt regulators, which seems to be what is cooking now.
Some time ago I converted 100% to disk based music, with a dedicated PC, an Italien USB to SP/DIF or I2S converter that bypasses the Windows mixer, and a DIY 1794A based DAC going up til 24/192, with discrete analog stage with shunt regulator. I couldnt get the Radio playing working as wanted until now, but I will. Then I only have one source, which makes the preamp easier.
I am also building a power conditioner, that should prevent spikes from the mains and that converts the mains to a balancet power source with a 1000VA toroid.
Then I want to explore PC based spectrum analyzers, sorry if I am going too much off topic.
Thanks again for your patience.
Best regards
Arthur.
"It is just very convinient to be able to buy complete kits."
I'm seeing an increasing number of shared Mouser BOM/carts for popular amps and DACs. They usually appear as a single channel and one need only "click an buy". Not sure of any component changes on the new F5 board, but I suspect one will appear shortly. Even if a builder chooses not to buy from Mouser the cart can be translated to other suppliers easily.
I'm in almost the exact place as you with the F5 and BA-3. I use the options in JRiver Media Studio to bypass the Windows drivers and get a super clean signal with the minimal PC -> DAC -> Power Amp combo. 6L6 suggested the addition of the rather simple O2 head amp might be all that's needed for a bit of clean gain/control. I'll post the results.
I'm seeing an increasing number of shared Mouser BOM/carts for popular amps and DACs. They usually appear as a single channel and one need only "click an buy". Not sure of any component changes on the new F5 board, but I suspect one will appear shortly. Even if a builder chooses not to buy from Mouser the cart can be translated to other suppliers easily.
I'm in almost the exact place as you with the F5 and BA-3. I use the options in JRiver Media Studio to bypass the Windows drivers and get a super clean signal with the minimal PC -> DAC -> Power Amp combo. 6L6 suggested the addition of the rather simple O2 head amp might be all that's needed for a bit of clean gain/control. I'll post the results.
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One of my winter projects is to resurrect my turntable. Still think I'll need a little pre and phono stage help, maybe a little 12AU7 special, and then I can be pure - source to tweeter - regain my self respect and hold my head high.
ps - humor aside, that is an actual goal of mine for the snow season.
ps - humor aside, that is an actual goal of mine for the snow season.
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I bought one of those cheap IR thermometers today, and tested it on my refrigerator, just to see if it would react on low temperatures, and it did 5,1 deg. C.
It is not easy precisely to see exactely what I am measuring, because it has no pilot light, but I couldn´t measure more than 39 deg. C anywhere in my F5 on the inside or outside, with 0.65 mV across the resistors. Ambient temp. is 20.5 deg C.
I am running 3U high heat sinks in one piece with air flow both on the front and on the back side, maybe that is a good idea. Transistors are mounted 2/3 down evenly spaced across the sink.
Somehow I think it runs cool I thought Class A amps were hot, in more than one sense.
Regarding drifting it were turned on all day yesterday and it has been on all day today, and it has drifted from around 1,5mV on the outputs to around 60 mV, but it was easy to adjust it back to around 1,5 mV. I will just monitor and adjust accordingly.
It still plays like a dream, so I think everything is fine, I am happy. Do I have to build a F4 now
Just read yesterday that the inventor of the Raven preamp wouldnt build a Raven today, so I may change strategy and start at thread on a transformer coupled 6SN7 preamp. Why - because I happen to have 2 Sowther 8650A 9:1 transformers on the shelf - for more than 6 years! Even with 6SL7s it will probably not be able to run a F4. For HiFi 6SN7 tubes are the best I have tried so far.
It is not easy precisely to see exactely what I am measuring, because it has no pilot light, but I couldn´t measure more than 39 deg. C anywhere in my F5 on the inside or outside, with 0.65 mV across the resistors. Ambient temp. is 20.5 deg C.
I am running 3U high heat sinks in one piece with air flow both on the front and on the back side, maybe that is a good idea. Transistors are mounted 2/3 down evenly spaced across the sink.
Somehow I think it runs cool
I thought Class A amps were hot, in more than one sense.Regarding drifting it were turned on all day yesterday and it has been on all day today, and it has drifted from around 1,5mV on the outputs to around 60 mV, but it was easy to adjust it back to around 1,5 mV. I will just monitor and adjust accordingly.
It still plays like a dream, so I think everything is fine, I am happy. Do I have to build a F4 now
Just read yesterday that the inventor of the Raven preamp wouldnt build a Raven today, so I may change strategy and start at thread on a transformer coupled 6SN7 preamp. Why - because I happen to have 2 Sowther 8650A 9:1 transformers on the shelf - for more than 6 years! Even with 6SL7s it will probably not be able to run a F4. For HiFi 6SN7 tubes are the best I have tried so far.
.
It is not easy precisely to see exactely what I am measuring, because it has no pilot light, but I couldn´t measure more than 39 deg. C anywhere in my F5 on the inside or outside, with 0.65 mV across the resistors. Ambient temp. is 20.5 deg C.
Somehow I think it runs cool
Great! that means you can turn up the bias! I have found that the higher the bias the better it sounds.
Since you're running 0.66V across the resistor, try it now at 0.75 or even 0.8V.
I run mine at 0.7V but I don't have forced cooling and my sinks are at 55C.
From what you said, you can probably run it even higher