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That was for the the output jacks, not the input jacks!

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

The shielding should be grounded to the ground ("ring") lugs of the respective input jacks. The jacks themselves should be insulated from the chassis. The ground lugs of the input jacks should be connected to the preamp ground, which should be connected to the chassis at only a single point, close to the input jacks.

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Great tones come in small glass jars!

I think I can manage it as soon as I get a new iron, I use one of these parts express types and i need some new tips, they just won't heat up anymore, I prolly broke down the tip cleaning the thing so much.I'll do the inputs based on stephens diagram, it should be fine, I'll let ya guys know, I think it will be a very descent sounding amp in the end !!

Well, I rewired the heaters w/ solidcore nicely twisted, I removed all powdercoating around the 3-different
star grounds, I re-did the inputs based on the tutorial in the resources section w/ a single ground (pre-amp star ground) to no avail, still humming like a mother.I also notice a very faint crackling type sound through the speaker, very faint.

If I pull either V1 OR V2 the noise goes away, also leaves with the power tubes pulled.
When I turn the stanby to OFF, the noise vanishes immediately as opposed to fading.
I get a strong pop when turning the standby to off.

I guess the next thing would be too check all the board connections, particularly the grounds near the pre-amp, underboard wires,etc.

I wonder if reversing the P.T. anode wires would help?

I'm open to suggestion for sure!

Ground connections are very important. Make sure the same heater wires got to all the same pins on the 12AX7s. i.e. red to pins 4-5 for all 12AX7s and black to pins 9 for all.

You have a problem in the preamp stages if it goes away when you pull tubes. Does it go away when #1 is pulled, then the problem is around #1, if not, pull #2, same logic.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

If I pull either V1 or V2, no noise. I think the heater wiring is fine, I did it twice.Moss doesn't show 2 wires

on the layout going to the phase inverter and on to V2 but common sense dictates that. I'm thinking it must be one of the underboard ground wires, there's 2 in the vicinity of the preamp.Am I correct in assuming the terminal strip at V1 is just a holder, not needing chassis ground ?............Thanks

Well, I re-flowed all the underboard solder joints, still noisy.When the volume is on zero the amp plays at a medium TV volume w/ no noise at all, I still have to install the power scaling so being a low volume player and always scaling these amps at least 3/4 maybe the noise floor will be tolerable.Looking at the layout the only thing I did differently was to run the ground fron the trim pot above the board, he shows as an underboard wire, I don't know if ground wires near signal wires could induce hum in the amp.I'm out of ideas, I did read somewhere that its not a good idea to ground the heater center-tap to the PT but thats what the layout shows.How about checking continuity on all the grounds?, don't know if that works at all.........Peace and Happy Holidays !!

Coco, I read a post by a guy named Deric over at 18 watt who built the amp, he says he grounded the shielding of the input wires at the terminal strip at V1, I only connected the shielding at the input jacks the to chassis ground, could this be the problem ??

If removing V1 stops the hum, then the problem is associated with V1. Also, to answer your question, shielded cable must have the shielding only grounded at one end. In the case of the connections from the input jack to V1, the shields would be grounded to the ground lusg of their respective input jacks. The input jacks must all be isolated from the chassis - preferably Cliff jacks. The preamp bus wire should be connected to chassis right close by the input jacks, and the input jacks' ground lugs should be grounded to that same point.

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Great tones come in small glass jars!

ok, as a first step, if I de-solder the input lines at the terminal strip and the hum ceases then I know the problem is in the input jack circuit ??

This should be easy enough to troubleshoot using a process of elimination approach.......I think.

ok,I notice when I look at Moss' gut shots there are 2-poly caps on both sides of V1, are these grid stoppers, I don't see them on the layout 3.1, could this be the issue causing the noise? Here's the pics

http://brownnote.net/dirty18/D18GUTS-2.jpg