Mine arrived yesterday and I got as far as the LED. Can't wait to hear it, but I'm having fun with the assembly too. Been a long time since my HS Electricity/Electronics class, but it's all coming back to me. I love the versatility of this little kit. I got a set of KT88s, EL34s and some old GE pre-amp tubes with my first time buyers discount. That should keep me tinkering for a good while.
fadhle matrook not too many like that cat. she is feral and she bites and scratches. only I can pet her. she won't let anyone else touch her. she likes jazz music. I turn on jazz and she makes herself at home on the back of my chair. I turn on rock and she leaves. funny as hell. should film it sometime.
fadhle matrook not too many like that cat. she is feral and she bites and scratches. only I can pet her. she won't let anyone else touch her. she likes jazz music. I turn on jazz and she makes herself at home on the back of my chair. I turn on rock and she leaves. funny as hell. should film it sometime.
It is funny, because if I put on jazz the cat comes, jumps up on the chair. If it is something else she doesn't give me the time of day. It must be the sound of certain instruments, I am thinking saxophone, but certain sounds bring her in the room, and others not so much. I'll film it sometime.
The FET are in the HV soft start circuit. They are there only to provide a delay, and a ramp up of the HV after the heater has warmed the cathodes on the tubes. What they are attempting to do is simulate how a rectifier tube operates. This protects the power tubes. One of the big killers of power tubes once the switch from tube rectifiers to solid state was the smack of full B+, about 400Volts onto the plate when the cathode was stone cold. What happens is with all that power on the plate as the cathode warms is thermal shock to the grids which are not ready to be bombarded with electrons. With tube rectifiers the HV build up is gradual as the rectifier tube has to warm before DV HV is produced. So by delaying the start of HV until the tubes are warm, and then bring it on gradually the life of the tubes is greatly improved. Once the FETs go into full conduction there is no heat produced, and the current flow is very low anyway. Tubes dissipate only a few hundred miliamps of current. It is the output transformer that converts that low current HV swing into low voltage high current to drive the speakers. So no thermal paste or heat sink is required. If you go back and look at the build of the TU8100, it used a DC-DC converter, and the MOSFET switching transistors were handling a fair bit of current, and switching back and forth to generate the 220v for the B+. On that design, the tabs of the MOSFET, were soldered down to the PCB to provide not only an electrical connection, but a thermal connection to drain away heat.Had heat sink or thermal compound been required they would have been provided in the kit, and it would have been in the destruction manual.However this is not the case. If I felt it would benefit from putting thermal paste under the FETS I would have done it, however I agree with the engineer that designed it, there is not enough current passing through these to pose a problem as they are just being used as a switch, so once they are on there won't be any resistance in the junction to produce heat. They are either on or off, not operating as a linear regulator where there would be voltage regulation, and the excess would be dumped as heat.
Vocal little cat, cute too ;-D Ive used the metal nail clippers for component leads, work quite well. The pcb looks very neat, and the led bending jig was a really thoughtfull idea :-D What brand were those electrolitics?, quality i hope.
They are all Nichicon capacitors. All high quality. This is a Japanese kit, so all the parts with the exaction of the tubes are Japanese. The tubes supplied in this kit are from China for the small signal tubes, and the power tubes from Russia.
I bet you haven't seen any CD players with Vacuum tubes in them well I have and they are Kronus Electronics CD players with vacuum tubes in the signal path and they actually look quite nice looking would love one but they give of a lot of heat, but the tubes they are using are Russian vacuum tubes,(Not being rude) I wonder if that guy would like to take a vacation to Northern Ireland and he could get his whole music system with Russian vacuum tubes at KRONUS ELECTRONICS LTD Dungannon Northern Ireland, would save the hassle of having to build it all he needs to do is when returns from vacation is to install the tubes and let them burn in for 8 to 10 hours before he starts listening to his new system.
DAVID GREGORY KERR sure have. yaquin also makes cd players with tube audio output. makes not a lot of sense unless you are driving a ss amp and want the warm sound. all one needs is a tube pa to get the benefits for all inputs.
Something so therapeutic about soldering or watching someone else solder up a kit. Very nice kit that one and nice work building that one up.
Part 3 coming up next.
Mine arrived yesterday and I got as far as the LED. Can't wait to hear it, but I'm having fun with the assembly too. Been a long time since my HS Electricity/Electronics class, but it's all coming back to me.
I love the versatility of this little kit. I got a set of KT88s, EL34s and some old GE pre-amp tubes with my first time buyers discount. That should keep me tinkering for a good while.
I have yet to roll in some vintage glass. It sounds fantastic with the stock Electroharmonix 6L6EH
It looks like you used small conical tip on all of the solder joints. What solder and temp did you use?
I generally solder with the iron at 700F or 375C
Which soldering station are you using?
I like your Mascot !
i like your cat!!! i mean your job
fadhle matrook
not too many like that cat. she is feral and she bites and scratches. only I can pet her. she won't let anyone else touch her. she likes jazz music. I turn on jazz and she makes herself at home on the back of my chair. I turn on rock and she leaves. funny as hell. should film it sometime.
fadhle matrook
not too many like that cat. she is feral and she bites and scratches. only I can pet her. she won't let anyone else touch her. she likes jazz music. I turn on jazz and she makes herself at home on the back of my chair. I turn on rock and she leaves. funny as hell. should film it sometime.
so your cat can separate music performance and come from jazz !! cool ... turn on music to see that.
It is funny, because if I put on jazz the cat comes, jumps up on the chair. If it is something else she doesn't give me the time of day. It must be the sound of certain instruments, I am thinking saxophone, but certain sounds bring her in the room, and others not so much. I'll film it sometime.
Thumbs up for short video with cat,22:20 no thermal paste ?.
The FET are in the HV soft start circuit. They are there only to provide a delay, and a ramp up of the HV after the heater has warmed the cathodes on the tubes. What they are attempting to do is simulate how a rectifier tube operates. This protects the power tubes. One of the big killers of power tubes once the switch from tube rectifiers to solid state was the smack of full B+, about 400Volts onto the plate when the cathode was stone cold. What happens is with all that power on the plate as the cathode warms is thermal shock to the grids which are not ready to be bombarded with electrons. With tube rectifiers the HV build up is gradual as the rectifier tube has to warm before DV HV is produced. So by delaying the start of HV until the tubes are warm, and then bring it on gradually the life of the tubes is greatly improved. Once the FETs go into full conduction there is no heat produced, and the current flow is very low anyway. Tubes dissipate only a few hundred miliamps of current. It is the output transformer that converts that low current HV swing into low voltage high current to drive the speakers. So no thermal paste or heat sink is required. If you go back and look at the build of the TU8100, it used a DC-DC converter, and the MOSFET switching transistors were handling a fair bit of current, and switching back and forth to generate the 220v for the B+. On that design, the tabs of the MOSFET, were soldered down to the PCB to provide not only an electrical connection, but a thermal connection to drain away heat.Had heat sink or thermal compound been required they would have been provided in the kit, and it would have been in the destruction manual.However this is not the case. If I felt it would benefit from putting thermal paste under the FETS I would have done it, however I agree with the engineer that designed it, there is not enough current passing through these to pose a problem as they are just being used as a switch, so once they are on there won't be any resistance in the junction to produce heat. They are either on or off, not operating as a linear regulator where there would be voltage regulation, and the excess would be dumped as heat.
Nice.
Vocal little cat, cute too ;-D
Ive used the metal nail clippers for component leads, work quite well.
The pcb looks very neat, and the led bending jig was a really thoughtfull idea :-D
What brand were those electrolitics?, quality i hope.
They are all Nichicon capacitors. All high quality. This is a Japanese kit, so all the parts with the exaction of the tubes are Japanese. The tubes supplied in this kit are from China for the small signal tubes, and the power tubes from Russia.
mio..mio miaw it mean jazz!!
meow... PENTRODE! I mean PENTODE!
I have the same cat.
I bet you haven't seen any CD players with Vacuum tubes in them well I have and they are Kronus Electronics CD players with vacuum tubes in the signal path and they actually look quite nice looking would love one but they give of a lot of heat, but the tubes they are using are Russian vacuum tubes,(Not being rude) I wonder if that guy would like to take a vacation to Northern Ireland and he could get his whole music system with Russian vacuum tubes at KRONUS ELECTRONICS LTD Dungannon Northern Ireland, would save the hassle of having to build it all he needs to do is when returns from vacation is to install the tubes and let them burn in for 8 to 10 hours before he starts listening to his new system.
DAVID GREGORY KERR
sure have. yaquin also makes cd players with tube audio output. makes not a lot of sense unless you are driving a ss amp and want the warm sound. all one needs is a tube pa to get the benefits for all inputs.
if you have time for hummer to destroy bad think