NAD: Tech21 TM60, but no sound on Ch1

jbratter

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Sep 16, 2012
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14
Location
charlotte, nc
Hi! I picked up a TM60 over the weekend from someone a few hours away. I didn't have good chance to check it out thoroughly. Dude send me a video showing that the amp worked as he twisted some knobs and pushed some buttons and I heard sound, so i thought it was good enough to buy without further checking.

Turns out there's basically no volume on channel 1. if i hit the channel switch to ch2, the amp works fine. but when i switch back to Ch1, no sound. well, basically no sound. if i turn all 3 knobs up to 10, i hear a faint sound.

So i did my research, and figured I needed to Deoxy it from head to toe, especially the loop jacks. I took out the chassis, sprayed everything down, and did all the jacks directly and plugged it in/out many times.
I put the chassis back in, and VOILA, Ch1 works perfectly! Sounded great and I couldn't be happier.

Then i turned the amp on again today, and the same situation. ugh. pulled the chassis again, sprayed everything down again, and Ch1 came back! but then I took the cord out of the amp, plugged it into another amp to compare tone, and when i plugged it back in, Ch1 didn't have any sound.

Yes, i can pull the chassis again, or just try spraying the loop jacks again, but this doesn't sound like the typical issue. I even left the loop jacks connected by a 6" cord, but still no sound on Ch1.

Any ideas or suggestions? I don't think i'm going to be able to return it, so i want to see what y'all think the issue could be and hopefully something i can fix.
thx!
 

Chupacabra

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Oct 18, 2016
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massachusetts
You got it to work once. It could be a loose connection. Maybe something with those effects loop jacks. Those amps seem notorious for that. Never seems to be a big issue with owners of those amps.
 

ale.istotle

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Mar 22, 2016
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I have to clean the pots about annually on mine. Involves pulling the chassis. I guess i could pull the knobs but 10 knobs vs 4 chassis screws... I'd focus on the three for channel 1.
You will also want to look into the channel switch.
Did you get the footswitch with it? May want to check with the footswitch vs the panel switch for swapping channels. May help to troubleshoot the problem item.
 

jbratter

TDPRI Member
Joined
Sep 16, 2012
Posts
14
Location
charlotte, nc
checked what i could. its small and tight in there ;) didn't see anything glaring. sprayed everything down again (3rd time) and the sound has come back on channel 1. pretty buzzy, though, and with bite off, drive at noon and punch at 0. trying to get BFDR tone out of my strat at home office (ie: low) volume. level on ~3.5 and its barely above conversation level. that doesn't bother me too much, as I just noodle around in my home office. just not sure if this is typical. i'll just leave it on with guitar vol at 0 while i'm away for an hour. hopefully still good then. and the buzz is coming from the reverb. its set ~4, but that's pretty buzzy.
thx!!
 

lupowitz

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Jan 31, 2007
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1,784
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Hungary
Hi! I picked up a TM60 over the weekend from someone a few hours away. I didn't have good chance to check it out thoroughly. Dude send me a video showing that the amp worked as he twisted some knobs and pushed some buttons and I heard sound, so i thought it was good enough to buy without further checking.

Turns out there's basically no volume on channel 1. if i hit the channel switch to ch2, the amp works fine. but when i switch back to Ch1, no sound. well, basically no sound. if i turn all 3 knobs up to 10, i hear a faint sound.

So i did my research, and figured I needed to Deoxy it from head to toe, especially the loop jacks. I took out the chassis, sprayed everything down, and did all the jacks directly and plugged it in/out many times.
I put the chassis back in, and VOILA, Ch1 works perfectly! Sounded great and I couldn't be happier.

Then i turned the amp on again today, and the same situation. ugh. pulled the chassis again, sprayed everything down again, and Ch1 came back! but then I took the cord out of the amp, plugged it into another amp to compare tone, and when i plugged it back in, Ch1 didn't have any sound.

Yes, i can pull the chassis again, or just try spraying the loop jacks again, but this doesn't sound like the typical issue. I even left the loop jacks connected by a 6" cord, but still no sound on Ch1.

Any ideas or suggestions? I don't think i'm going to be able to return it, so i want to see what y'all think the issue could be and hopefully something i can fix.
thx!


I have one too, my favorite amp, and I faced the same problem as you.
The effects loop jacks is where your problems lay most probably. The cleaning process you do is good, and can serve as a temporary sollution, but there is a time when replacing them is the only option.
I first was advised to plug in and out as many times as my hands can handle, and it helped, but the same problem reoccured, just as in your case. Since a tech replaced the loop jacks, it works like a charm. It was seven years ago.
I was told to leave a dummy plug in the loop jacks to avoid bumping into the same problem again.
 

jrblue

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Nov 14, 2010
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Location
Santa Barbara
On some amps, you can leave a cord plugged in to one/both? of the loop jacks and this probloem goes away. It happened to me all the time on a crap Vox Valvetronix (cheapo jacks) that I leave in our summer home, and it was cleaning and "exercising" the loop jacks, and keeping a cord in one, that worked for me. Ridiculous but true.
 

jbratter

TDPRI Member
Joined
Sep 16, 2012
Posts
14
Location
charlotte, nc
quick update - i left it on for about 4 hours last night, not playing it really, but checking it every hour (geez, it sounds like I have a sick kid!!). worked fine and then i turned it off when i went to bed. just turned it on now and ch1 is still working!! hopefully it lasts, but wow, it must've really been badly oxidized for it to take 3 deep cleans.
And to be honest, i'm still a little concerned that it only affected ch1 and not ch2. odd..
thanks for all the help and suggestions!
 

Jim622

Friend of Leo's
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Apr 1, 2011
Posts
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Location
Philly
TM60s been my main amp for an easy 20 years. I (knock on wood) haven’t had any issues. I been paying close attention here. I’m glad to hear all is well for you. I don’t know what I’d be looking for if mine went. I think they are great amps, 60s don’t just turn up. Best of luck with it.
 

Walker

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Jan 18, 2007
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1,145
Location
CT
I had the same problem with mine years ago when I first got it. At the time you could send it back to Tech 21 and they'd fix it for free, I don't know if they still do. After the repair I never had any problems, but I eventually sold it, just never bonded with it, seemed too sterile.
 

jbratter

TDPRI Member
Joined
Sep 16, 2012
Posts
14
Location
charlotte, nc
Just an update. I've been playing the amp in my home office for the last week, and it sounds great with my strat! I even love the bridge pup now on ch2 with the knobs at mid (no weep) and treble at 4pm. sounds killer!
BUT.... the problem returned today. I hadn't touched the plug and had the same cord attached all week. when i went to change cords to a little wireless thing i have, ch1 cut out again. exact same symptom. ch1 didn't work but ch2 did. ugh.
I plugged the input into the return jack of the loop, and ch1 worked! no reverb, of course, but that makes me think that the problem is with the input jack. The channel switch button seems to work fine. not sure why the input jack would cause this problem, but not sure what else it could be.
Also, I plugged headphones in and ch1 worked fine.
So i'll pull the chasis again and spray everything down again. I hope it works again until i figure out my next steps.
But the amp does sound damn good!!
 

sluglas

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Jul 26, 2013
Posts
122
Location
mattituck
If you plan on keeping the amp and not using the effects loop.
You can remove the effects loop jacks and add jumpers .
I have a Vox VT50 that cut in and out. The culprit was a faulty headphone jack. Both the input jack and headphone jack are directly soldered to a small circuit board and are a common problem on those amps. So I got the schematic online, removed the headphone jack (never use them) and added a jumper. I removed the plastic input jack added a switchcraft metal input jack , moved the little circuit board to another spot inside chassis and ran wires to the input jack.
Works beautiful.
 




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