zero loss FX loop sounding very thin

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norburybrook
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zero loss FX loop sounding very thin

Post by norburybrook » Sat Aug 02, 2014 2:37 pm

Just installed the zero loss FX loop in my newly built JTM45.

I presume I've installed it correctly, the voltage from the board is showing 290v DC . When I engage the loop however , the sound is very thin, all there body disappears, all most sounds like it's out of phase.


Any ideas?

Don't know if it's relevant but I did notice on my amp before I installed the loop that the treble control didn't seem to do much , it sounded like it rolled off the bottom end as I turn it up. Is this how JTM45's sound?


I'll enclose a photo.

Cheers

Marcus
fx loop.jpg
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JimiJames
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Re: zero loss FX loop sounding very thin

Post by JimiJames » Sat Aug 02, 2014 11:31 pm

I am uncertain on your board. Possibly SDM can stop in & post.
My decoupling resistor is connected to Red and you have yours connected to (mid) Yellow.

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norburybrook
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Re: zero loss FX loop sounding very thin

Post by norburybrook » Sun Aug 03, 2014 10:03 am

Thanks Jim,

I don't think the issue is where the power comes from. I tapped the power at that spot on my JTM45 as that's where the voltage was in range, on the point where it's circled red my voltage was around 460vDC which is too much.

Hope SDM can drop by and help.

Cheers
Marcus

RACKSYSTEMS
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Re: zero loss FX loop sounding very thin

Post by RACKSYSTEMS » Sun Aug 03, 2014 1:19 pm

If you look the output of the bypass switch is going to the mid cap and not the phase inverter cap.
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RACKSYSTEMS
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Re: zero loss FX loop sounding very thin

Post by RACKSYSTEMS » Sun Aug 03, 2014 1:22 pm

As best I can tell from the picture. The blue wire that goes to the phase inverter cap has to move to the mid cap of the eq. Then the shielded wire to the phase inverter. The wires need to be swapped.
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norburybrook
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Re: zero loss FX loop sounding very thin

Post by norburybrook » Sun Aug 03, 2014 2:36 pm

RACKSYSTEMS wrote:As best I can tell from the picture. The blue wire that goes to the phase inverter cap has to move to the mid cap of the eq. Then the shielded wire to the phase inverter. The wires need to be swapped.

Well done :) I've just reached the same conclusion after staring at the amp now for a day :D



:oops:


As always....user error..

I'll post back when I've sorted this out.

cheers guys.

MArcus

norburybrook
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Re: zero loss FX loop sounding very thin

Post by norburybrook » Sun Aug 03, 2014 5:14 pm

Ok, swapped the offending wires and as expected it's now working.

Only issue I seem to still have is a quite severe interference/Hum/Noise issue when using my reverb and delay pedals from my pedal board. I've a feeling it's something to do with the power supply, however it's all fine when I plug it in in line with the guitar.


Any thoughts?


Marcus

JoseSiar
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Re: zero loss FX loop sounding very thin

Post by JoseSiar » Fri Dec 05, 2014 4:38 am

I ever meet such problem before, after the high recommendation of one of my good friends, I got a mobile phone signal booster, everything is OK now. You can have a try!

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Re: zero loss FX loop sounding very thin

Post by neikeel » Fri Dec 12, 2014 10:08 am

SPAM!!!!
Neil

norburybrook
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Re: zero loss FX loop sounding very thin

Post by norburybrook » Mon Jan 12, 2015 5:07 am

Update :)


The amp is sounding better than ever after I swapped out the 3 pre amp valves with a balanced PI and a Harman vintage and standard JJ .


I've now got a Voodoo labs power supply so thought I'd give the loop another go. Still get massive earthling buzz when putting my TC HOF on the loop.


Any ideas?


Marcus

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