jelle wrote:The 220k//250pf on the signall access loop...not unique?
No, it is in a few amps I've seen, although the ones I've seen that have it have all been amps with Music Man Iron EXCEPT #124.
quite honestly I don't care for it too much, but I add it knowing that it can be bypassed with a jumper across the loop, and I like to make them as versatile as possible.
Let me also extend my thanks for posting these pics.
I've got a couple more questions for you... I figured I'd post it here since others may be interested as well.
1) I notice that your HRM board has the mid pot wired as a voltage divider with the mid cap attached to the wiper, rather than the more 'typical?' configuration of connecting the mid pot as a variable resistor. I could easily jumper it but I wanted to ask which is the 'preferred' configuration?
2) I noticed that you've moved the OD/Clean relay board over about 1/2 to 3/4 of an inch.... what for?
Cheers! Brian
"Let's face it, the non HRMs are easier to play, there, I've said it." - Gil Ayan... AND HE"S IN GOOD COMPANY!
1) From what I can tell from the pics I have of the HRM board it is wired as a VD, but you shouldn't let that stop you from trying both ways to find what suits you best. I will be spending some more time inside of an early 90's ODS in the very near future, and I can confirm this 100% I have always wired it fender style with great success.
2) If you have an earlier version of my chassis than you may want to reposition the relay so that the wires going to the tone controls are not under the board, the new chassis from the last batch and upcoming batch have been moved already. This is not at all necessary, just looks neater that way, and i had an amp a while back that the tone control wires somehow coupled to the input and created an oscillation, this gives you enough room so that doesn't happen.
Couple of questions if I may:
What's that...thing (it looks like a smaller, lighter colored Dale) just to the left of the .1uF cap for the second PI grid? (in the first picture)
What did you do to secure the bottom right corner of the preamp board? Is there no nut there because it's too close to the eyelet for that red B+ wire?
Fischerman wrote:Couple of questions if I may:
What's that...thing (it looks like a smaller, lighter colored Dale) just to the left of the .1uF cap for the second PI grid? (in the first picture)
What did you do to secure the bottom right corner of the preamp board? Is there no nut there because it's too close to the eyelet for that red B+ wire?
That is a sweet, sweet looking build.
Editted because I'm lysdexic.
The NFB resistor you mean? it's a 2W Dale Metal film, they are teeny, but they are definitely a 2w. You really can use whatever composition you like there, it makes little to no difference.
There is no nut there because I hadn't put it on when I took the pics, there is 1/4" distance between the nut and the eyelet, that is pretty sufficient. That hole is an extra "Speriment" to make wiring quicker, I have since gone back to the old way. I tend to try a little something new on every amp, but with the heat I was getting I thought I'd better get something up!
OK I see it, it's not a trimmer, just 15Ks before the 220K and from 100K trimmer to gnd.
Funk, I do have a few dumb questions:
How did you arrive at determining a 15K was needed before the 220K and at the gnd side of the trimmer? Is this to unload CL2 a little more and/or the OD entrance or exit? Did you determine this with your ears or waveforms. I stumped.
