Metropoulos Forum

Hi all

I was looking for some advice. I built a JTM 45 kit amp for a guy and it sounds fantastic. I did it on the cost effective side and used the classic tone transformers from amp parts direct. They are great. The amp truly sounds fantastic.

The build I am building is identical to another build I did and I am reading the zero loss effect loop kit. The guy wants one in the amp

My question is the decoupling resistor. My B+ is high in this amp as it is the other I built. I have 445 VDC plate and at the 8.2 k resistor and at the b+ on the PI filter cap my fluke reads 447 VDC

now when I read the resistor selections I see it goes 400-386 is 56k and as the VDC drops the resistance drops as well

My question is running 447 at the measures point do I use a 56k or another value.

The instructions do not give a resistor value for my Voltage present

According to the instructions it says the loop board likes to run at 300 VDC so I take 147/.0017= 87k

This would be a 82k 2 watt resistor. Is this the correct value to use? I am shooting for 300 VDC range.

Is that correct?

Question two. This is a JTM 44 so in regards to the 8.2k PI resistor, it says I can swap out the 8.2 for a 7.5k if desired though nothing really need be done. Do I stay with the 8.2 or switch it out to a 7.5k....

Thanks in advance

Dan

I don't have alot of experience with the loop kit so I don't want to give any wrong answers. Here are a couple of recent threads that may offer a little info...http://forum.metroamp.com/viewtopic.php?f=28&t=45390 and http://forum.metroamp.com/viewtopic.php?f=45&t=45326 Hope they help.

Thanks for the help, I got it and its FANTASTIC

I took power off the split turret at the top of the PI and ran it exactly as shown, It is without a doubt THE BEST LOOP I have ever heard

Thanks Guys!!!