Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Stereomour => Topic started by: jwrossie on February 02, 2015, 09:07:05 AM

Title: Stereomour build question
Post by: jwrossie on February 02, 2015, 09:07:05 AM

I am building my stereomour at this moment. I got a question about the power supply PC board assembly, in the manual they talk about 1N4007 rectifiers and I got two UF4007 in my kit. Is it safe to use these?

Title: Re: Stereomour build question
Post by: Doc B. on February 02, 2015, 09:11:54 AM

Yes, they are fine. In fact they are a little better than a standard 1n4007.

Title: Re: Stereomour build question
Post by: jwrossie on February 02, 2015, 09:14:22 AM

Quote from: Doc B. on February 02, 2015, 09:11:54 AM

Yes, they are fine. In fact they are a little better than a standard 1n4007.

Thanks Doc!

Title: Re: Stereomour build question
Post by: jwrossie on February 07, 2015, 11:19:07 AM

I Finished my build!

I just did resistance check, all ok.

But between A1 en A4 I measure 2V AC instead of 2,5V AC (same for C1 and C4)
That's more than 10-15% , what to do?

All the voltages are all good to.

Title: Re: Stereomour build question
Post by: Paul Joppa on February 07, 2015, 12:36:40 PM

What is your power line voltage? Does your meter measure more accurately than 2 volts AC, such as 2.0 or 2.00 volts?

Title: Re: Stereomour build question
Post by: jwrossie on February 08, 2015, 10:27:48 AM

237 Volts is the measurement out of the powerline voltage.

And my meter gives 2.0 volts AC.

Is this a big problem? What do I need to hear/see/missing out with this 2.0 volts?

I am listening to the amp at the moment but it is playing fine.
The 2A3 tube don't light up, only the 12AT7 is visible lighting up, the 2A3's are getting warm though.

Title: Re: Stereomour build question
Post by: Paul Birkeland on February 08, 2015, 11:23:31 AM

I would imagine it's a meter issue.  At 2V AC, your DC voltages at pins 1 and 4 of the 4 pin sockets would drop noticeably. 

Title: Re: Stereomour build question
Post by: jwrossie on February 08, 2015, 11:31:27 AM

I think it is, my meter isn't a fluke but a cheap-ass one.

Just to be sure, here are my VDC measurements:
A1 58
A2 364
A3 0
A4 58

C1 57
C2 364
C3 0
C4 57

Title: Re: Stereomour build question
Post by: Paul Joppa on February 08, 2015, 11:37:57 AM

Those are just about perfect.

Many meters don't handle low AC voltages very well. Sometimes (not always!) the specifications have a hint buried in them somewhere.

Title: Re: Stereomour build question
Post by: jwrossie on February 08, 2015, 11:47:30 AM

Quote from: Paul Joppa on February 08, 2015, 11:37:57 AM

Those are just about perfect.

Many meters don't handle low AC voltages very well. Sometimes (not always!) the specifications have a hint buried in them somewhere.

So if the VDC are 'just about' perfect it's assumeble the 2.0v AC must be 2.5v AC and the problem is my meter?

Title: Re: Stereomour build question
Post by: Paul Birkeland on February 08, 2015, 12:18:21 PM

Quote from: jwrossie on February 08, 2015, 11:47:30 AM

So if the VDC are 'just about' perfect it's assumeble the 2.0v AC must be 2.5v AC and the problem is my meter?

Yes, at this point, that's a reasonable assumption.

Title: Re: Stereomour build question
Post by: jwrossie on February 09, 2015, 09:17:28 AM

So I borrowed a Fluke multimeter and the results are good  :) .

So my own multimeter has problems with measurements of low AC volts.
Paul you were right!

Thank you.

Title: Re: Stereomour build question
Post by: Paul Joppa on February 09, 2015, 11:32:03 AM

Thanks for posting, that was a valuable confirmation for us!