Working Crack but some readings are not correct.

[ELBEBE1000]

Happy new year!

I am new in this forum. I just finished my building 2 days ago. So far is working fine. However, I have some questions may some one can help>

>I noticed that resistence reading not much with the manual.
>The metal face is real hot
> The little front tube is no on. Is this normal?

Despite those issues, my Crack is working fantastic! My Senheiser never sounded better.
Any advice will be appreciate.
Thanks,
Yashin

 

[Grainger49]

Yashin,

I'm going to guess at your first question, you didn't get the same readings for resistance as are in the manual, right?

Different meters give different readings.  That is odd, they are supposed to "Measure" either resistance or voltage, right?  Well meters with separate ranges can be fooled if the resistance/voltage is over the range, also these meters will not be accurate at the low end of the range.  Say if you are measuring 220 ohms on a 200,000 ohm range you will get a bad reading.

A search would answer your second question about heat.  The amps do get hot.  Both the tubes and the transformer are designed to work at higher temperatures than any Solid State amp.  The transformer gets hotter than some other tube amps.

Often the tubes don't glow enough to be seen without either getting next to them or turning off lights.  What matters is if it gets warm.  That is easy to check.  If it is warm, it is heating.  Notice I didn't say working, that requires more.

So...

1) if your measurements are not within plus or minus 15% of the manual post only the out of spec measurements, what it should be and where it was measured.

3) that is probably normal

3) check if the tube is warm, if so, you are fine, if not then measure the voltage from tube pins 4 or 5 to pin 9 on the small tube.  It should be about 6.3V AC.  If not post back what you read.

 

[ELBEBE1000]

Thank you Grainger49,

the only different data is resistance terminal 22 should be 0 and my multimetter reads 11.6 . I checked the small tube and its warm! the instrument that I used to read resistance and voltage is a Fluke 87 V. In conclusion the amp:

1. its hot but I can live with it.
2. looks nice ( and I built )
3. My Sennheiser HD800 (around 6-7 times the price of the amp) Never sound better!!!! I read that speadball make improvement, but also changing the tube or atenuator is best choice. what is your imput? Honestly, I doubt that speadball up grade will improve the sound of my Senn (I am walking in heaven with this combination)

4. Thank you Grainger49 for your help and Doc. and Queen for bring us such wonderful product.
Yashin

 

[Doc B]

If the voltage readings are all correct you don't need to worry about any resistance reading that is not correct. Your meter is probably just a little different than ours in the way it reacts to various components in the circuit. I can say from personal experience that the HD800s will sound even better with the Speedball upgrade. Let the amp break in for a month or so before you try it.

 

[ELBEBE1000]

Thank you, Doc B. This summer I will try the speedball. Once more, the Crack is fantastic product.
Yashin