Tech: Tourmaster w/Weak Output on Both Clean Channels

M

marl3y

Member
Local shop has a used TM, but both clean channels are very weak. The OD channels are fine though. Doesn't seem to be the output section as all power grid settings do the same thing. Any idea what this could be and a possible fix? Thanks.

-Scott
 
V1 tube or v8 (phase inverter tube).

is it weak using both the low and high inputs for the guitar cable?
 
Thanks for the reply. I only tested the high input so I can't comment on the low. Wouldn't V8, the phase inverter, effect all channels, not just the clean? I was wondering about V3. According to the manual that's the 2nd and 3rd gain stages for the clean channels.
 
My manual:



my experience with this amp is that the PI tube can cause some weird shit to happen..
 

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now THAT is a quandry!!!

Bruce? Nate? Ian?

mine is a first run, non-mod...

are yours stock tubes? the egnater groove tube ones?
 
Sorry, not sure about the tubes. The amp is at a store and I didn't have a chance to poke around much. It would be nice to hear from the Egnater clan on the manual discrepancy and thoughts on root cause. Thanks again.
 
Marl3y diagram is correct. V3 are for the clean channels and is "likely" the cause of the problem in this amp. There was a misprint in the early diagram that says V3 is in the overdrive channels. V1 is also a possible culprit but V3 first. If the amp has JJ preamp tubes in it, consider replacing them all. We had terrible reliability issues with those.
 
Yes, thanks a lot Bruce. The one Yeti had seemed redundant in the OD channels. I'll see if I can grab the amp for a test and make a few tube swaps. Once more I appreciate the insight.

-Scott
 
Happy to report is was a bad tube. Thanks Yeti. V1 was the culprit. All in all a smokin' deal on a great amp. Only problem was this came in w/o the footswitch. Are these things available? Thanks again to Yeti. Also to Bruce for his assistance and making the greatest amps on any shore.
 
good to hear it was a quick simple fix.

not a bad idea to keep a few spare pre tubes around if you dont already.

how about that channel 3 dude...!!!!!!!!!!!!!!
 
Yeah, I could live in channel 3 almost exclusively. You can cover a lot of territory there with just your volume knob. I also noticed that in all four channels when the channel masters sweep between 1-2 o'clock you get a pretty jump in volume and tone. I've got a MOD50 and although it's a different beast altogether the TM is great in it's own right.
 
yes, for sure. the TM dirty channels especially have a sweet spot it seems between that on the channel masters.

have you tried any different cabinets with it yet? those elite 80s can really push that harsh and ice picky sound in that amp when you run the presence high (unmodded), especially until they break in. if you can get the mod done it will tame that hi end.

i've learned too, the less the gain (around 12 or so) the tone controls react SO much better.....definitely not an amp you want to dime everything out and turn up loud....it needs some dialing.

have you tried any other pretubes?
 
I haven't messed with other cabs yet. I've got a Bogner 4x12 (V30s), VHT Fatbottom 4x12 and Fatbottom 2x12 (both P50Es), a USA Eggie 2x12 (V30s) and two USA Eggie 1x12s (Lead 80). All that is downstairs and right now the combo is upstairs, with me pondering how to get it down there in one piece and with what's left of my spine intact. Seriously, just need to get time. Those cabs are quite different, and I expect the flexibility of the TM will provide a ton of nice combinations.

I'll check for, and do the mod if it hasn't been done. Sounds like everybody prefers post-mod TMs.

I read someplace that the uneven volume transition between 2-3 o'clock with the channel masters is also probably a bad tube. Maybe the PI as you had suggested earlier. I've got a bunch of 12AX7s rolling around here that I could try swapping. I might spring for a full re-tube. Are there brands/ratings that you or others prefer in each position? This one has Egnater labeled Groove Tubes in all positions, which I believe was stock. Not having a serial number anyplace I can't tell if it was one of the early ones plagued with tube issues, but based on what I've seen/heard today it might very well be. In my MOD50 modules I like a 9th gen chinese in V1, but that might not be the input stage in the MOD series. Anyway, there are enough TMs out there that I'm sure folks have their preferences by now. I'm happy to replace them, but I'm generally not the type that wants to try every permutation possible. I'd prefer to go with the consensus and spend more time in front of the amp.

Agreed, less is more (to a point) in the gain dept. Maybe I'm just getting old, well that's for sure, but I hear more with a tad less gain.
 
My TM4212 has the same jump in volume that you are describing. I think it is normal. I have played mine through my Marshall 1960 with greenbacks, it sounded excellent. Although in my case, the stock speakers in the combo do well with the highs because it usually fires at my ankles, sounds pretty balanced when I am standing. I pity anyone in the front row though, ouch.
 
The channel volumes are rather non-linear in the TM. I think you will find the thing really opens up and can become rather beastly when you get them around 1-2 o'clock.

I've had the 4100 for a couple of years now and that was one of my first questions to Bruce on this forum.

Duff
 
the stock speakers take a long time to break in and get some of that icy top end off of....100+ hours playing mine around 1-2 ch vol / 1-230 mast vol.

unless i just got deafer!
 
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