Hi Merlin,
Nice to see you again, the RIAA amp is doing very well, the only problem was the temperature of the MOSFET, my fault, I should have used a bigger one like a TO220 using the chassis as a heat-sink ! One question, if I increase the 27k source resistor to 47k to reduce power dissipation, did you think that there will be enough current to drive correctly the output ?
I have continued to work on the power supply with a new version based on the Maida architecture with a MOSFET like in your book, but I have decided to use a more up to date regulator LT3080 recommended by Tom in the 21 century Maida regulator... Don't worry about pin names in the LT3080, I have used an other device library, but the pin number is right (I hope 🙂), this version should have an even better noise floor...
I will test the stabilized version first before to decide if I build the regulated one.
Regarding availability of PCB for the RIAA amplifier, I have not yet finished the Baby Huey GB and that was a very time consuming job 😀 I like to share audio exoerience but I have to find the time, may be later if there is enough interest ? For the power supply, I prefer also to test them before I can offer them, may be I will make a combined offer : 1 RIAA amplifier PCB + 1 power supply PCB...
Cheers,
Marc
Nice to see you again, the RIAA amp is doing very well, the only problem was the temperature of the MOSFET, my fault, I should have used a bigger one like a TO220 using the chassis as a heat-sink ! One question, if I increase the 27k source resistor to 47k to reduce power dissipation, did you think that there will be enough current to drive correctly the output ?
I have continued to work on the power supply with a new version based on the Maida architecture with a MOSFET like in your book, but I have decided to use a more up to date regulator LT3080 recommended by Tom in the 21 century Maida regulator... Don't worry about pin names in the LT3080, I have used an other device library, but the pin number is right (I hope 🙂), this version should have an even better noise floor...
I will test the stabilized version first before to decide if I build the regulated one.
Regarding availability of PCB for the RIAA amplifier, I have not yet finished the Baby Huey GB and that was a very time consuming job 😀 I like to share audio exoerience but I have to find the time, may be later if there is enough interest ? For the power supply, I prefer also to test them before I can offer them, may be I will make a combined offer : 1 RIAA amplifier PCB + 1 power supply PCB...
Cheers,
Marc
Attachments
If the current in the MOSFET is 5mA you can drive anything you're likely to encounter. But even if the current is as low as 2mA I wouldn't wet myself. Tube buffers often run at this level and people don't seem to notice. 😱
"maybe I will make a combined offer : 1 RIAA amplifier PCB + 1 power supply PCB..."
I would be interested
I would be interested
Hi,
I have been quite busy with the Baby Huey EL34 GB and my little back problem didn't allow me to spend as much time in my lab that I wanted, but I am back and I finished the first power supply and made some tests with it.
The result is very good, this power supply is a good complement to the RIAA preampli, at the beginning I tested the power supply with a simple 10 ohms power resistor and later with a 10 H choke, both version are very close, I could not hear a real difference between them, in principle the choke version should be better... The heatsinks are not definitive, I need to make a dedicated one witch will also be used for the fixation of the module.
I still make the test with my old Thorens TD160 with the Shure M95 ED. The power transformer is a toroïdal custom made in Switzerland many years ago with 250 V 300 mA, 9 V 8 A and 50 V 50 mA (total power about 140 W), it is also used for my 6CA7 Baby Huey amplifier, for the RIAA preampli it's an overkill but since I have 5 of these transformers I use them always🙂
I have added some photos and now I need to put everything in a nice box, not the easiest job for me 🙁
Cheers,
Marc
I have been quite busy with the Baby Huey EL34 GB and my little back problem didn't allow me to spend as much time in my lab that I wanted, but I am back and I finished the first power supply and made some tests with it.
The result is very good, this power supply is a good complement to the RIAA preampli, at the beginning I tested the power supply with a simple 10 ohms power resistor and later with a 10 H choke, both version are very close, I could not hear a real difference between them, in principle the choke version should be better... The heatsinks are not definitive, I need to make a dedicated one witch will also be used for the fixation of the module.
I still make the test with my old Thorens TD160 with the Shure M95 ED. The power transformer is a toroïdal custom made in Switzerland many years ago with 250 V 300 mA, 9 V 8 A and 50 V 50 mA (total power about 140 W), it is also used for my 6CA7 Baby Huey amplifier, for the RIAA preampli it's an overkill but since I have 5 of these transformers I use them always🙂
I have added some photos and now I need to put everything in a nice box, not the easiest job for me 🙁
Cheers,
Marc
Attachments
Hi please let me know if you intend to do the boards. If not I was going to make
eyelet boards. I have started on the pre (1 channel) The power supply i will start tonight. Maybe ill build this while Im waiting for your pcb. I like the footprint of yours. I'm going to use the tube follower instead.
Thanks
eyelet boards. I have started on the pre (1 channel) The power supply i will start tonight. Maybe ill build this while Im waiting for your pcb. I like the footprint of yours. I'm going to use the tube follower instead.
Thanks
Attachments
Last edited:
Bonjour,
Le plus sûr serait de reprendre le schéma original de Merlin Blencowe qui utilise aussi une triode ECC82 comme cathode follower...
Hi,
Sorry, I was switched on French 😀
I said that the safer solution was to use Merlin schematic that was also based on an ECC82 triode as a cathode follower...
Rgds
Marc
Le plus sûr serait de reprendre le schéma original de Merlin Blencowe qui utilise aussi une triode ECC82 comme cathode follower...
Hi,
Sorry, I was switched on French 😀
I said that the safer solution was to use Merlin schematic that was also based on an ECC82 triode as a cathode follower...
Rgds
Marc
Hello,
I have modified the regulated Maida style Power Supply to make it usable as a high voltage variable power supply for my lab, or as a fixed high voltage power supply for tube application by disconnecting the pot and using only R3 for setting output voltage.
I also modified the layout to use heat-sink on the side instead of the bottom, I was also thinking to make the high voltage module only and to design a separate switching regulator module for the 6.3 V heater supply, but finaly I leave it, it is always possible to not populate it ?
If you don't find an error on this last version, I will send it to the PCB manufacturer Monday, if you find an error tell me 🙂
Cheers,
Marc
I have modified the regulated Maida style Power Supply to make it usable as a high voltage variable power supply for my lab, or as a fixed high voltage power supply for tube application by disconnecting the pot and using only R3 for setting output voltage.
I also modified the layout to use heat-sink on the side instead of the bottom, I was also thinking to make the high voltage module only and to design a separate switching regulator module for the 6.3 V heater supply, but finaly I leave it, it is always possible to not populate it ?
If you don't find an error on this last version, I will send it to the PCB manufacturer Monday, if you find an error tell me 🙂
Cheers,
Marc
Attachments
Hello,
I am still working on the second power supply, but I have some troubles 😡
You can find more detail here : http://www.diyaudio.com/forums/powe...voltage-floating-regulator-2.html#post5265314
I appreciate your interest for a GB but I need to make more test and to wait a little after the previous GB because it was very time consuming, it is not a business for me and I don't make money with that, it is only for the fun of building tubes amplifier 🙂
I would like also to have some feedback from those who bought the 40 kits to know if they have build them and if they like their sound ? If everything go well I could make a GB for the RIAA and the power supply in January...
Cheers,
Marc
I am still working on the second power supply, but I have some troubles 😡
You can find more detail here : http://www.diyaudio.com/forums/powe...voltage-floating-regulator-2.html#post5265314
I appreciate your interest for a GB but I need to make more test and to wait a little after the previous GB because it was very time consuming, it is not a business for me and I don't make money with that, it is only for the fun of building tubes amplifier 🙂
I would like also to have some feedback from those who bought the 40 kits to know if they have build them and if they like their sound ? If everything go well I could make a GB for the RIAA and the power supply in January...
Cheers,
Marc
You can use the 2W version : 93R1A-R22-A22L Bourns | Mouser France
This will give an output voltage of 50 to 300 V DC
Rgds,
Marc
This will give an output voltage of 50 to 300 V DC
Rgds,
Marc
Hello,
In the past several members requested a PCB for this RIAA preamplifier and following others PM inquiries, I have redesigned the RIAA PCB with 10 cm size therefor it is now possible to buy 10 pieces for only 5 $ from PCBWay or other Chinese manufacturer 🙂
May be there could be some other cosmetic changes ?
I have also replaced the cinch connector with Molex one...
Best regards,
Marc
In the past several members requested a PCB for this RIAA preamplifier and following others PM inquiries, I have redesigned the RIAA PCB with 10 cm size therefor it is now possible to buy 10 pieces for only 5 $ from PCBWay or other Chinese manufacturer 🙂
May be there could be some other cosmetic changes ?
I have also replaced the cinch connector with Molex one...
Best regards,
Marc
