First build, resistance issue

[tonyalves88]

Hey guys so I finishsd my crack last night, it was my first ever experience with soldering so naturally I'm a bit pessimistic about the results, even though I took my time and went through the steps carefully. Also, I assembled and installed the speedball along with the crack initial build, so I'm not sure if that will change the resistance results. So far I have only checked the Resistance's and not the voltage. All of the resistance checks were good except for the ones that were supposed to be 2.9k. So in other words terminals 7, 9, b3, and b6 are not giving me any readings.  It is also my first time using a multi-meter so maybe I'm doing something wrong here but all the terminals that were sup posed to be 0 are, as well as the rca center pins are right around 90 and all the terminals that are supposed to read 2.4k are correct as well. Does the speedball effect these readings? Should I go onto the voltage check? Thanks ahead for any help. I can take pictures when I get home later on.

 

[Strikkflypilot]

First of all, welcome fellow Bottlehead.
Now some very friendly advice.

To avoid blowing up components and what not
Start with removing the speedball upgrade and returning to stock.
Then do the resistance checks, voltage and eventually listening.
So You know that all Youve done so far checks out before the variables
get too numerous.
The manuals and all advice here point in that direction.

It is easy to get impatient but it pays off to follow those pieces of advice.
Much more frustrating to sit waiting for the mailman to deliver
replacement parts.

 

[Paul Birkeland]

^^ What he said. ^^

 

[tonyalves88]

Hey thanks for the advise and welcoming. Yea in retrospect building the crack then speedball separate would have made troubleshooting easier,  I figured I was going to do the speedball eventually, might as well do it all at once. If need be then I can remove the speedball but it seems like quite a hassle to remove it just to install it again, if you guys insist "suggest"  though, I will.

Edit: ok guys, I'll get working on removing the speedball, and get back to you with results/ issues, thanks again!

 

[Doc B]

We don't insist. We just suggest doing it the way we, well, the way we suggest doing it. Yup it's a bit of a hassle to remove it. That's why we say build it stock first, make sure it works, then add the Speedball after it is up and running.

 

[Paul Joppa]

One aspect here that can be clarified:

Experience makes debugging go a lot faster, with more reliable results. We, and the community here, have a lot of experience debugging a stock build. We also have quite a bit of experience debugging upgrade kit installations. We have relatively little experience debugging builds that combine the upgrade initially. So it takes many more posts and much more time, both yours and ours, with less reliable results and more blind alleys. We, both Bottlehead and the community, simply have less to offer when it's an untested combined build.

 

[tonyalves88]

Ok guys, so I detached the speedball, and concluded the original build. The resistances all check out, now as far as the voltage readings, they seem to be off. The amp powered on correctly, tubes glowed and fuse didn't blow. When measuring these were my results :
1 2.26
2 2.95
3
4 2.95
5 2.21
6 0
7 1.94
8 0
9 1.81
10 0
11 0
12 0
13 2.95
14 0
15 3.3
20 0
21 3.64
A1 2.21
A2 0
A3 1.06
A4 0
A5 0
A6 2.25
A7 0
A8 1.02
A9 0
B1 2.26
B2 2.95
B3 1.94
B4 2.21
B5 2.95
B6 1.82
B7 0
B8 0

 

[tonyalves88]

Here's a quick picture, thanks for the any help.

 

[Paul Birkeland]

Check your UF-4007 diode orientation, as well as the trail of black wires back between the two terminal strips.

You should get significant DC voltage between 20 and 21.  If you get close to 0 Ohm resistance between terminal 20 and the chassis plate, and no voltage at 21, you either have a nasty short in the power supply (the 270 Ohm resistors would fail immediately based on how low your voltages are, and the power transformer would be buzzing).  Since these conditions aren't happening, then it is most likely that the diode bridge is improperly wired.

There is also a suspicious looking connection at terminal 19. If the red wire is making contact with the two diodes that come from terminal 18, then you have shorted out the high voltage windings on the power transformer, which will leave you with low power supply voltages.

-PB

 

[tonyalves88]

Hey Paul thanks for all the help, your the best! So diode orientation seems to be right, I'm sorry I don't follow when you say the trail of black wires back between the two terminal strips. The connection at 19 was suspicious, it turns out the red wire was making contact with the diodes from terminal 18 as you suggested. I moved it all around to insure none of them touch anymore, I also found an extra lead there I had not seen before, so I removed that. I plugged the amp back in and I noticed when putting my ear to the transformer I can get a slight buzz noise as well as occasionally what sounds like a clock's tick. They did glow again and fuse is ok. Voltages were still way off so I re-soldered just about every joint I could. I powered it back on and the buzzing noise is gone. My voltages are still off but getting closer I guess hah... Let me know where to go from here, can't thank you enough for your help I'm itching to hear this baby in action!
1 75.8
2 24.2
3 0
4 24.2
5 61
6 0
7 99.6
8 0
9 33.2
10 0
11 0
12 0
13 24
14 0
15 12
20 0
21 0
A1 60
A2 0
A3 1
A4 0
A5 0
A6 72
A7 0
A8 1
A9 0
B1 72.5
B2 24
B3 97
B4 61
B5 24
B6 33.4
B7 0
B8 0

 

[Paul Birkeland]

I would suggest remeasuring.  Having 75V at T1 and 24V at T2 is really quite impossible in this circuit, you may need to adjust the range on your meter. (Be sure you're on DC volts, etc)

Generally, terminals 1, 5, 7, and 9 tell the story of how the tubes are operating in the circuit, and these voltages look good.  Still, I'd take the time to get the measurements better sorted.

Additionally, I would reduce the amount of exposed bare red wire that you have at A4/A5.  If that wire bends down and touches the plate, more anomalous issues will occur.

-PB

 

[tonyalves88]

Hey guys, sorry I was away for a little while. So I tried remeasuring again, I came up with generally the same results except slightly higher voltages. I'm measuring it on DC with my multimeter set to 200m, I'm not sure what I'm doing wrong if you say that it is not possible to be getting those particular results on terminals 1 and 2. When rechecking the resistance my terminal 13 does not slowly climb to 270k as it should, it stays put at around .5k  I decided to plug in a cheap set of ear buds to see what would happen but I got no volume output at all. Any Ideas where to go from here?

 

[Paul Birkeland]

I'm measuring it on DC with my multimeter set to 200m

200m is 0.2V, which isn't enough.  Do you have a 200V setting?

 

[tonyalves88]

At 200v range I get no reading, at 20v I get a .08 for T1 and .02 for T2 and etc. So I'm assuming when I thought I was getting 80 and 20 volts at the first two terminals with the range set to 200m I was really getting a lower reading, like I said I'm new to DMMs as well, sorry. Obviously I'm going to have to start re-soldering, should I start in a particular area? Thanks for the help.
EDIT: OK, so I re-soldered almost the entire kit, remeasured and came up again with the same results... some things to note, the resistance on T13 is set to .5, it doesn't rise to 270k as it should, also T21 is coming up as 0 for me when it should be around 200 so I'm thinking somethings up there. Both tubes light up on both sides when the unit is powered on but no sound comes out at all.

 

[Paul Birkeland]

Buy a 9V battery, then try measuring it with your meter, just to be sure the meter is working.

 

[tonyalves88]

Good idea Paul, I tested a 9V battery I've had in it's package for a while but haven't used, it measured at 8.12volts so looks like the meter works. EDIT: checked another battery I had and it registered at 9.1 volts, so I definitely don't think it's the meter. I think I'm just getting very low voltages from my kit? I honestly have no idea hah, any help is always appreciated, thanks.

 

[tonyalves88]

You mentioned how I might have a nasty short in the power supply, I remember when I first turned it on the transformer was buzzing, after re-soldering some sketchy looking joints it didn't buzz again. Maybe that was what happened initially? I remember T13 climbing to 270k as it was supposed to before I turned it on a first time, now after checking T13's resistance it doesn't climb, it stays put at .5, did I mess up the 270ohm resistor?

 

[Paul Birkeland]

You may have a blown fuse.

You'll know when a resistor is bad, as it will generally no longer be in one piece.

 

[tonyalves88]

I should have mentioned I already suspected a blown fuse, I checked the fuse but it was still intact, I replaced it with another 1 amp 250v slo-blo fuse just in case, but nope, same results. Sorry, Any other ideas?

 

[Grainger49]

I'm not sure if Bottlehead has changed the IEC connector.  It has a place for the fuse that will be inline with the power and a place for a spare.  Sometimes builders put it in the wrong part.  It should go in the crook that is the farthest from the back that says "fuse."

Just checking.