Question?

77custom · Post by **77custom** » Sat May 13, 2006 2:39 pm

The first picture is of my '82 2204. See the 10K 1 watt, resistor and jumper I have circled? What is this resistor called? Anyhow I noticed on the 50 watt version, there is a jumper in one of the positions. As pictured below.

I also noticed that on the 100 watters they have 2-10K 1 watters there. As pictured below.

On the board I bought from George for my other 50 watter I have a 8.2K/10K thing going on. As pictured below.

Could someone explain to me why this is this way?

Thanks,

Ed

Flames1950 · Post by **Flames1950** » Sat May 13, 2006 3:13 pm

Those resistors "decouple" the B+ line between filter capacitors, and drop the B+ voltage as well.
Early amps with higher voltages used two 10K resistors there to lower the preamp voltages where they wanted them. But by the later 70's and up, the voltages were getting lower and lower until they didn't need two resistors there anymore for the fifty watt amps, so one spot was jumpered.
You can add the resistor there if you like, but FWIW I wasn't thinking and put a resistor there when I first reworked the original PCB in a '78 50-watter I had, and the amp was just compressed and lifeless sounding. Removing the extra resistor put some punch and dynamics back in the amp by bringing the preamp plate voltages back up.

77custom · Post by **77custom** » Sat May 13, 2006 4:37 pm

Flames,

Thank you. To be honest with you my 2205>2204 conversion with that extra resistor in it sounds great. I was debating on whether or not if I should remove the 8.2K but I think I'll leave it. I happy with the sound of it.

Thanks again,

Ed

Flames1950 · Post by **Flames1950** » Sat May 13, 2006 4:56 pm

That's all that matters, a smile on your face when you crank it up......

Dax-The-Ax · Post by **Dax-The-Ax** » Thu May 18, 2006 9:19 pm

Hey, that 100 Watter is my '76 2203, Beautiful!!!

5150loveeddie · Post by **5150loveeddie** » Thu May 18, 2006 11:23 pm

DAX where the hell were you bro

77custom · Post by **77custom** » Sat May 20, 2006 3:27 am

Dax-The-Ax wrote:Hey, that 100 Watter is my '76 2203, Beautiful!!!

I hope you don't mind!!! I can't remember where I found it, but it does look good!!!!