13-09-2016, 07:11 PM
Hello All,
I decided to start this. It is not as comprehensive or as good as Marks but I hope it’s of some interest.
“Tube Amp 2“ kit.
This is just a short report on building this kit. I’m not what you would call an audiofool but I did fancy trying one of these. Built ones can be expensive but when I saw the kit I thought I’d have a go at building it.
The kit came from Banggood and cost around £14. It took just short of three weeks to come. Packaging could have been better but was probably OK. Valves were in their boxes and the rest of the component were in plastic bags. This in turn was wrapped in about two turns of polymer based wrapping material.
The kit comes without any instructions at all. Not even in Chinese. However, the components are of good quality like the other Banggood kits I’ve made (see pic 1). The valve bases are ceramic and are offset from the pcb. The preamp chips are provided with sockets. The valves are 6T5 and made by the Peking Tube Co. The preamps are NE5532. There was no anti-static foam on these. The lack of instruction or a circuit diagram is not that big a problem as the resistor values are printed on the pcb (see pic 2). Again the colour codes on these are sometimes difficult but resistors of the same value are on the same strip. As I’m sure most of you do when building kits I tend to test every component I can before I fit them so the colour codes are not really a problem. There are 5x4.7k resistors. Four are marked on the pcb. There is also one marked 5.1k. I assumed the fifth 4.7k went here. Values for the caps are not marked but the polarisation of the electrolytics is so it’s fairly easy to work out where and which way round the they go. For the positions of the lower value caps I used the pictures of the finished kit on the web site (see pic 3).Most of the components fit well but not the two 3.5mm stereo sockets. They sit at a slight angle. This can be reduced but the main problem is that the pins come just about level with the pcb rather than through the holes. They can still be soldered but care must be taken to ensure that a connection is in fact made. The pins on the preamp chips and the valves were bent. Some careful realignment was required before these could be fitted. Three blue LEDs are supplied with the kit. Two go under the valves I assume to “light” them. I did not fit these.
I took some care to make sure that everything on the top of the pcb was neat and tidy as this will be seen. Thats about it. The only other thing I’ve done to mine is to add a knob This however must be Part 1 of this report as I have not worked out how to power it. I did think of using tree PP3s for the “HT”. I have not yet worked out the current it will draw. The heaters are 12V. The web site says the”LT” has to be 12V DC at greater than 2A. I am wondering if its necessary to use DC. I guess its to reduce hum. Part 2 will follow when I build a power supply. I have attached a sort of spec from the website (see pic4). The pictures are not mine. They are courtesy of the site. I hope this is OK.
Regards,
Ken.
I decided to start this. It is not as comprehensive or as good as Marks but I hope it’s of some interest.
“Tube Amp 2“ kit.
This is just a short report on building this kit. I’m not what you would call an audiofool but I did fancy trying one of these. Built ones can be expensive but when I saw the kit I thought I’d have a go at building it.
The kit came from Banggood and cost around £14. It took just short of three weeks to come. Packaging could have been better but was probably OK. Valves were in their boxes and the rest of the component were in plastic bags. This in turn was wrapped in about two turns of polymer based wrapping material.
The kit comes without any instructions at all. Not even in Chinese. However, the components are of good quality like the other Banggood kits I’ve made (see pic 1). The valve bases are ceramic and are offset from the pcb. The preamp chips are provided with sockets. The valves are 6T5 and made by the Peking Tube Co. The preamps are NE5532. There was no anti-static foam on these. The lack of instruction or a circuit diagram is not that big a problem as the resistor values are printed on the pcb (see pic 2). Again the colour codes on these are sometimes difficult but resistors of the same value are on the same strip. As I’m sure most of you do when building kits I tend to test every component I can before I fit them so the colour codes are not really a problem. There are 5x4.7k resistors. Four are marked on the pcb. There is also one marked 5.1k. I assumed the fifth 4.7k went here. Values for the caps are not marked but the polarisation of the electrolytics is so it’s fairly easy to work out where and which way round the they go. For the positions of the lower value caps I used the pictures of the finished kit on the web site (see pic 3).Most of the components fit well but not the two 3.5mm stereo sockets. They sit at a slight angle. This can be reduced but the main problem is that the pins come just about level with the pcb rather than through the holes. They can still be soldered but care must be taken to ensure that a connection is in fact made. The pins on the preamp chips and the valves were bent. Some careful realignment was required before these could be fitted. Three blue LEDs are supplied with the kit. Two go under the valves I assume to “light” them. I did not fit these.
I took some care to make sure that everything on the top of the pcb was neat and tidy as this will be seen. Thats about it. The only other thing I’ve done to mine is to add a knob This however must be Part 1 of this report as I have not worked out how to power it. I did think of using tree PP3s for the “HT”. I have not yet worked out the current it will draw. The heaters are 12V. The web site says the”LT” has to be 12V DC at greater than 2A. I am wondering if its necessary to use DC. I guess its to reduce hum. Part 2 will follow when I build a power supply. I have attached a sort of spec from the website (see pic4). The pictures are not mine. They are courtesy of the site. I hope this is OK.
Regards,
Ken.
