Tubelab SPP first timer build

[jcalvarez]

Bad news!
B+ when measured was too high

How much too high? Are you using a choke or a resistor for R1?

 

[jcalvarez]

... I assume you measured after the output tube heaters got hot, right?

 

[stonegreen]

What input voltage did you choose?
240VAC or 250VAC

 

[Steve Morley]

What is it? Were all of the tubes installed?

 

[OldHector]

There wil be a collective sigh of relief around the DiyAudio world when that switch is flicked and whatever tickles your fancy bursts from the speakers
What is first up? 1000Hz?

 

[calpe]

Well there is no sign of relief in any shape or form from where i'm standing, basically i'm fed up to the back teeth after so many issues.
Mains input was wired back to 240VAC.

The current limiter that i decided to include, blew along with the mains fuse.

 

[OldHector]

Maye a short somewhere ... what is the resistance between the live and neutral connections to your amplifier? What rating fuse? Can be worth having slow blow. Maybe a picture of the wring around the IEC and switch?

 

[stonegreen]

The current limiter that i decided to include, blew along with the mains fuse.

How long did it take (after switching it on) for the problems to appear?

 

[Francois G]

I can hardly stand the suspense!

 

[calpe]

Problem happen immediately & Current limiter removed.

Of course this should be gospel http://tubelab.com/designs/tubelab-spp/parts-list/

C1 47uF 450v
C2 150uF 450v

R2 150K 3W
R3 10K 1W
R4 150K 2W

 

[stonegreen]

For R3 30K should be used instead of 10K.
This picture also seems to have 30K installed.

How was the CL installed? Photos?

 

[OldHector]

I'm thinking the CL was wired across the supply and not in series with live.

 

[Francois G]

OldHector,

Good guess! If we could get calpe back on the job we may be able to fix things.

 

[Francois G]

We stood by @calpe through almost 400 posts and now he disappeared!

calpe, can we send the rescue crew? What can we do to help you finish this?

You are so close! Don’t give up now.

 

[calpe]

Yes, I shut down after the in series CL blew & mains fuse. Then i switched on & the H.T. supply was too high.
I'm extremely disappointed after so much effort, time & £££
I hope to have a fresh look this week as I have time off from work.
I'll make note of tests done.

 

[Francois G]

Good to have you back. Tracking down a bug and tweaking PS voltages are all parts of the fun. Let us know how the tests are going and take good photos if necessary. Good luck!

 

[calpe]

Good afternoon all. After the CL blowing, I just decided to switch off for a while (with other issues not helping) give it a rest and come back to the build. Spare time is very scarce at the moment, so that didn't help.
Post #391/392 - Yes the CL was wired in series with the Live mains and i'm not replacing it, don't have anymore.
R3 has a 30K fitted.

Post #393/394/395 - Thank you.

I needed for self satisfaction to double check components just to reassure myself that the power supply components were all correct.
These included: -
R1 (actually now a choke), R2 - 150K, R3 - 30K, R4 - 150K
C1 - 47uF 450v, C2 - 150uF 450v, C3 - 0.47uF 100v

Tests done will be included a little later.
Thank you to you all.

 

[calpe]

My Mains Transformer, if wired for 240v, is shown below.
But as the 240 is never that, but closer to 250 (actually measured yesterday with a Fluke), the measurement i got was 248V.
I assumed pushing 248 into a 240 winding would give me slightly higher secondary voltages, something i didn't need.

So i wanted to play safe and wire it for 250v.
What connections should be used?
Clearly somewhere out there will know.
Anyway i contacted Primary Windings U.K. and it appears that they have had numerous people asking about the wiring for either 220, 240 or 250.
I leave this open for the clever people..........
I now know.......

 

[stonegreen]

Power Transformer Primary

220V - Blue   / Orange
230V - Purple / Orange
240V - Blue   / Brown
250V - Purple / Brown

 

[calpe]

Clever clogs Stonegreen!