You're welcome.
@ abraxalito
Done the filter yesterday and enjoyed all the evening & night listening music, a big thanks again.
About step up transformers I guess I need 1:1.27 my calculations:
0.56Vrms = 1.58Vpp
0.71Vrms = 2Vpp
So I need to increase 0.15Vrms to reach the 2Vpp, it's OK.
Also I need an OPT with primary impedance of 50 Ohm & a secondary of 63.5 Ohm
Are my calculations OK?
@ abraxalito
Done the filter yesterday and enjoyed all the evening & night listening music, a big thanks again.
About step up transformers I guess I need 1:1.27 my calculations:
0.56Vrms = 1.58Vpp
0.71Vrms = 2Vpp
So I need to increase 0.15Vrms to reach the 2Vpp, it's OK.
Also I need an OPT with primary impedance of 50 Ohm & a secondary of 63.5 Ohm
Are my calculations OK?
Are you sure you want 2vpp? Most digital signal sources are 2v RMS.
I would just go with a plain old 1:2 step up transformer. That would give you 1v rms out.
I'm sorry yes for 2Vrms, so I will need 1:4 ratio, primary 50 ohms & secondary 200 ohms, that's?
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The impedance ratio is the square of the transformer's winding ratio . Most ready made transformers for audio are 600 ohms . What you need is 600:10k . See on Aliexpress .
Yes I forgot thanks, I need a primary impedance of 50 ohms because is the output impedance of Amanero and the input/output impedance of the 4th order low pass filter so I need a custom made OPT 50:833 ohms 1:16 ratio?
What have I to look for: Line input transformer or Step-up MC transformer?
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Still looking for DHT analog stage advice, after looking for I saw 3A5 that Ale Moglia praised for "small signal amplification"
"A very nice result I think. THD of 0.03% is outstanding for small signal indeed. Look at how close H3 is to H2, interesting to see that."
Ale Moglia schematic:
Now I'm using 5687 triode SE with hybrid mu-follower from Ale Moglia and it have more gain than the phono preamp MM Valve Itch, so a little less gain than 5687 fit perfect the gain.
Can you suggest other possibilities?
"A very nice result I think. THD of 0.03% is outstanding for small signal indeed. Look at how close H3 is to H2, interesting to see that."
Ale Moglia schematic:
Now I'm using 5687 triode SE with hybrid mu-follower from Ale Moglia and it have more gain than the phono preamp MM Valve Itch, so a little less gain than 5687 fit perfect the gain.
Can you suggest other possibilities?
I have started down the same path as you @merlin el mago
3a5 output stage advice
I have been testing out various supplies - and have been listening for a bit trying to decide whether to continue or go down a different route. 3a5 are certainly microphonic, and I think a regulated B+ and coleman type heaters will be needed. I hope to get looking at it again this week.
I'd be interested to hear your thoughts.
3a5 output stage advice
I have been testing out various supplies - and have been listening for a bit trying to decide whether to continue or go down a different route. 3a5 are certainly microphonic, and I think a regulated B+ and coleman type heaters will be needed. I hope to get looking at it again this week.
I'd be interested to hear your thoughts.
merlin....I give you one cheap solution. You can have 3a5 in parafeed config-resistor loaded 3a5 output via 10k:600ohms line transformer. Gain should be 3x. Coupling cap should be 4.7uf. For filament you can use 317 voltage regulator followed by 317 CCS for 220ma. I use it (with 15k:600 for about 2.5x gain) as my preamp with wonderful sound.
Regards
Regards
minhaj that's a great idea to try before to buy Rod Coleman regs. once I tried 317 CCS as anode load and didn't liked.
Cheers
Cheers
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Hi Merlin, Others,
I'm trying to learn about the no DAC solution and have seen some threads here. My current DAC, ADI-2 Pro, also outputs a DSD direct stream that I believe bypasses the DAC. However, I want to explore other solutions. I am trying to understand how other solutions work. Looking at post 9, it seems an Amanero USB transport can be used with the filter shown to get the output. Am I understanding that correctly? Is anything else needed?
Thanks for the help!
I'm trying to learn about the no DAC solution and have seen some threads here. My current DAC, ADI-2 Pro, also outputs a DSD direct stream that I believe bypasses the DAC. However, I want to explore other solutions. I am trying to understand how other solutions work. Looking at post 9, it seems an Amanero USB transport can be used with the filter shown to get the output. Am I understanding that correctly? Is anything else needed?
Thanks for the help!
It all depends the filter order?
The filter at post 9 it's a 4th LPF with a characteristic impedance of 1.5K not ideal for Amanero with a output impedance of 50R.
The filter at post 9 it's a 4th LPF with a characteristic impedance of 1.5K not ideal for Amanero with a output impedance of 50R.
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Okay, but apart from the filter order, is anything else needed? What other solutions exist? Thanks!
The characteristic impedance of filter must match the output impedance of the filter, the LPF order & cutoff it's up to you. BTW I use 4th order LPF with characteristic impedance of 50 ohms.