Resistance Test
- Thread starter gnnett
- Start date
Okay the black and drain wires were reversed on input to filament regulator board, so now only problem is if 1.4ohm to 50kohm range is acceptable for A6 and C6. Will take safety warning seriously and hold off plugging it in until I get clearance on these readings.
Thanks in advance.
Grant
Thanks in advance.
Grant
Hi Guys
So have a pair of readings that conflict with the manual commands of DO NOT PASS GO DO NOT COLLECT $200.
Don't mind being told my question is stupid but 1.4ohm (A6) and 1.7ohm (C6) are both Greater than 1ohm and 50kohm is greater than 40kohm by 25%.
Desperate to plug the valves (sorry tubes) in and measure voltages but have heeded the safety warning. Would love to be told these are near enough, or that this is not normal and has everyone stumped.
Anyone able to advise?
Running out of nails. :-[
Cheers
Grantn
So have a pair of readings that conflict with the manual commands of DO NOT PASS GO DO NOT COLLECT $200.
Don't mind being told my question is stupid but 1.4ohm (A6) and 1.7ohm (C6) are both Greater than 1ohm and 50kohm is greater than 40kohm by 25%.
Desperate to plug the valves (sorry tubes) in and measure voltages but have heeded the safety warning. Would love to be told these are near enough, or that this is not normal and has everyone stumped.
Anyone able to advise?
Running out of nails. :-[
Cheers
Grantn
My hunch is your OK, but I'm at home at the moment without an amp in front of me to look at. When I get in to the office I'll have a look at a Smash for you. With all the kits we have these days (combined with the memories of all the kits we have done in the past) I just can't carry in my head what all those terminal designations are connected to like I used to.
PB is way more hands on the kits these days and he may be able to answer off the top of his head before I can get hands on.
PB is way more hands on the kits these days and he may be able to answer off the top of his head before I can get hands on.
Grant,
I can't answer your question about resistance tests, but I noticed something in your pictures you should fix before doing the voltage tests. The drain wire of the STP cable going from the power switch to the power supply does not appear to be connected. You should either connect it wherever it goes or trim it.
By the way, from what I can see in the pictures you have done a great job on the solder connections! Very neat.
I can't answer your question about resistance tests, but I noticed something in your pictures you should fix before doing the voltage tests. The drain wire of the STP cable going from the power switch to the power supply does not appear to be connected. You should either connect it wherever it goes or trim it.
By the way, from what I can see in the pictures you have done a great job on the solder connections! Very neat.
A6/C6 connect to the output of the level pot. With the volume all the way down, the readings will be quite low. As long as you don't get some insanely high resistance, there's nothing to worry about.
-PB
-PB
Hi Guys
Voltage test completed.
Different results left and right so repeated test after swapping 4P1L's. Problem stayed on same side.
All 0V were correct so not included below.
Terminal Voltage
4 -1.1V
9 142V
15 -1.1V
16 -1.1V
17 190V
20 142V
21 45.9V
22 45.9V
29 190V
35 203V
A2 / C2 -1.1V / 43.2V
A3 / C3 -1.1V / 45.7V
A4 / C4 1.47V / 1.48V
A8 / C8 1.47V / 1.48V
B3 190V
B5 142.3V (Note manual asks to measure B4, which has no connection and measures 0V)
B7 190V
Will now repeat inspection to see if there is something wired differently on each side and proceed from there.
Did check mains voltage and it measures 215V AC. The main voltage standard here is supposed to be 230V so either I have low voltage or meter is reading low. Will run with the latter so will assume good side (volume control side) is about right.
Will update tomorrow once I have completed the inspection again.
Cheers
Grant
Voltage test completed.
Different results left and right so repeated test after swapping 4P1L's. Problem stayed on same side.
All 0V were correct so not included below.
Terminal Voltage
4 -1.1V
9 142V
15 -1.1V
16 -1.1V
17 190V
20 142V
21 45.9V
22 45.9V
29 190V
35 203V
A2 / C2 -1.1V / 43.2V
A3 / C3 -1.1V / 45.7V
A4 / C4 1.47V / 1.48V
A8 / C8 1.47V / 1.48V
B3 190V
B5 142.3V (Note manual asks to measure B4, which has no connection and measures 0V)
B7 190V
Will now repeat inspection to see if there is something wired differently on each side and proceed from there.
Did check mains voltage and it measures 215V AC. The main voltage standard here is supposed to be 230V so either I have low voltage or meter is reading low. Will run with the latter so will assume good side (volume control side) is about right.
Will update tomorrow once I have completed the inspection again.
Cheers
Grant
Okay my bad found wire from B5 to T5 instead of T4.
Corrected and voltages now:
Terminal Voltage
4 139V
9 139V
15 43.3V
16 43.3V
17 190V
20 139V
21 45.6V
22 45.6V
29 190V
35 204V
A2 / C2 40.8V / 42.9V
A3 / C3 43.3V / 45.5V
A4 / C4 1.5V / 1.5V
A8 / C8 1.5V / 1.5V
B3 190V
B5 139.2 (Note manual asks to measure B4, which has no connection and measures 0V)
B7 190V
So guessing these are okay, if a bit low.
Will connect it up tomorrow evening and give it a spin.
Cheers
Grant
Corrected and voltages now:
Terminal Voltage
4 139V
9 139V
15 43.3V
16 43.3V
17 190V
20 139V
21 45.6V
22 45.6V
29 190V
35 204V
A2 / C2 40.8V / 42.9V
A3 / C3 43.3V / 45.5V
A4 / C4 1.5V / 1.5V
A8 / C8 1.5V / 1.5V
B3 190V
B5 139.2 (Note manual asks to measure B4, which has no connection and measures 0V)
B7 190V
So guessing these are okay, if a bit low.
Will connect it up tomorrow evening and give it a spin.
Cheers
Grant
Grainger49
New member
The manual says if the voltages are within +/- 15% go to listening. Are they? It seems nobody else is up right now.
It looks like you should be good for a listen.
On the 120V PT-7 transformer, I found that the circuit would operate with as little as 100V AC, so you should be OK with your line voltage.
-PB
On the 120V PT-7 transformer, I found that the circuit would operate with as little as 100V AC, so you should be OK with your line voltage.
-PB
Hi guys
Well hooking up and listening has been interesting but I am a long way from being able to give the Smash a fair go.
In the meantime I have it hooked up to provide sound for the lounge system and no problems with this other than a hf ringing when switching between sources.
The TT in this system has a hum that I have not been able to banish without resorting to a separate preamp with phono built in.
None of the stand alone options work and not in a position to do the forensics to isolate the problem.
TV sounds okay though.
Will update when I have done the required system sorting, maybe the Quicksand needs to be built and then I have full control of earthing.
Cheers
Gn
Well hooking up and listening has been interesting but I am a long way from being able to give the Smash a fair go.
In the meantime I have it hooked up to provide sound for the lounge system and no problems with this other than a hf ringing when switching between sources.
The TT in this system has a hum that I have not been able to banish without resorting to a separate preamp with phono built in.
None of the stand alone options work and not in a position to do the forensics to isolate the problem.
TV sounds okay though.
Will update when I have done the required system sorting, maybe the Quicksand needs to be built and then I have full control of earthing.
Cheers
Gn
