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Tourmaster 4212 combo distorted clean and random loud hum.

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AlienRocker

AlienRocker

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Wonder if anyone here had these situations happen and know what it is ....
I just bought an Egnater 4212 combo about a little over a month and love the sound! After about 4 gigs with no problems, I have encountered 2 things at home when rehearsing.
1: randomly, a hum will come out of nowhere. Sounds like when you unplug your cable from your guitar. Yes that loud "eeeeehhhhhhhhh" noise. sometimes it will stop after about a second and other times it won't stop. I isolated the issue to the amp by unplugging the guitar cable from the amp to fing that the noise would still continue so its the amp. I have had to give the chassis a "love tap" to get it to stop. I'm aware this is NOT the right thing to do but when all other options failed, I tried it. Then I found that does not always work and what did work was flicking the standby switch on and off rapidly until it stops humming. It will go for days without doing it and then all of a sudden you put a pair of pliers down on the amp or a cup or your tuner and you will here a sudden "eeeehhhh" for a fraction of a second like if it was going to do it again or you tap the chassis and you hear it quickly start and stop in a fraction of a second. It eventually starts to do it for a second or longer while you're playing until I eventually flick the standby switch again until it finally stops. I tried to re-seat all the tubes but found that was not the issue when it did it again after about 2 days. I will take it to my amp guy to look at but any intuition to what it may be would be helpful and might get me through the next 2 gigs before I take it in?

problem number 2: It seems that if I strum the guitar a little more aggressive than normal, the amp distorts the sound like if I clipped the signal. I'm in the "high" input and no pedals turned on just clean amp. low to moderate volume. not cranked at all. Rear power grid is set to half power 25 watts. This also happens randomly. Maybe its something I'm doing wrong? Doubt it but I'm open to any possibility. Any suggestions?
Thanks in advance.
 
have you FOR sure isolated the issue to the amp alone? the reason i ask:

aside from me being on high gain settings (like above 3oclock) and standing right in front of the amp with my guitar....my amp's pretty quiet.

-we have a sump pump in our basement. the reason i mention it is, its the ONLY thing that causes my amp to be noisier, unless the furnace kicks on, which is 220 and draws direct from the panel.
-when the sump pump kicked on for that brief 3-5 seconds while my amp was on, i was getting major buzzage. it drove me insane literally for months on end... until....it was a dark and stormy night...i was jamming on low volume and i actually heard the pump kick on and the noise started with it. the lightbulb went off, and i changed what circuit on the house main that the pump was plugged into and it solved the issue (as my amp and the circuit it's plugged into is pretty much isolated from everthing except for the 2 lights in the front of the basement, an outlet which the pump was on, and one line that runs to inside diningroom wall, and of course, the the issue of the furance drawing from the main at 220).
i can still hear a faint power noise when the pump kicks on for a few seconds.

-another thing you may want to check is your input jacks. switch over to the unused input that you arent using currently. does the amp make the noise with that one? maybe you have a loose solder joint or connection to the other jack inside the amp, if the noise stopped?..or maybe your cord is damaged since the noise didnt stop by switching jacks? if you haven't eliminated your issue yet, read on.

-obviously, you tried reseating the tubes. can you replace them? specifically v1/v2/v3/v4 to start...and your power tubes.

my mesa heartbreaker used to make a weird humming noise and i figured out before i traded it that it was a power tube issue, even though it wasnt an issue i could eliminate visually...what i did:

unplug the amp from the wall. open the back panel carefully, pay attention to that fan wire. unplug that fan wire and set the metal panel aside.

now, plug your amp back into the wall, flip it on, keep it in standby. unplug your guitar cord from the input jack from the front. power grid setting doesn't seem to matter for your issue, so just leave it on full out. now, put your od1 or od 2 with about 50% gain on the classic setting. channel volume on 50%. amp master on around 11oclock or so. you want to be able to hear the amp hissing and whatnot, but not totally blow your head off loud if you cranked a chord.

now, take a pencil and tap lightly on each preamp tube. switch the effects loop on and tap that corresponding tube with the levels set to about 50% in serial, switch it off. same with reverb, make sure the reverbs all the way on. also, while you're there, tap on the reverb tank, maybe about as hard as you'd knock on a door..you should hear some clattering when the reverb is on. check the wires going in and out of the reverb while you're back there, just for good measure.. if at any time you can make the hum louder or worse by tapping on any of the tubes or the reverb tank, or the reverb wires, you've found the problem. if you didnt, move on to tapping on the power tubes.

if you can't make the amp do this by tube tapping, and wire wiggling, chances are you've got an issue inside the amp. but, it's pretty easy to at least eliminate the tubes themselves and the reverb by following that method above, or something similiar as a diagnostic tool.

also, just curiously, have you checked your bias lately? my bias floats from time to time...i check it weekly. when i first got the amp, it was the first thing i noticed, i'd set the bias and it would float up or down, about every 10 or so hours of use. even after i replaced the power tubes as per Bruce last summer. i run mine between 128 and 132ish. i've found that it's SO touchy of a knob, and so loose (i suspect that the looseness/non waxing of that knob pot is what lead to it floating up or down while im playing from vibration) that is quite tedious to get it right to 132, so, i just try best as i can to get it to 130 and usually end +/- 4 which i can live with. reason i say check it is, if you're set too high, that might explain the mushiness to your hard chord hits, and it might also explain the other problems.

other than the bias, the tubes, the verb circuit, the jack, i'd say something internal.

i dont recommend love tapping due to having my amp open, i saw that there were a lot of wires that were "clipped" onto the lugs, not soldered. my reverb quit working, and i found that one of the clips came off the lug from the reverb transformer, which, i was able to fix. you dont wanna knock something loose that you're already previously skating on thin ice with connection wise. granted, those clips are pretty tight, and i did get this amp on a trade and it was gigged pretty well by the previous owner, so i attribute it to the unknown variables that he may have subject it to.

yes, i type really fast.
 
AlienRocker":2ksq6c5v said:
Wonder if anyone here had these situations happen and know what it is ....
I just bought an Egnater 4212 combo about a little over a month and love the sound! After about 4 gigs with no problems, I have encountered 2 things at home when rehearsing.
1: randomly, a hum will come out of nowhere. Sounds like when you unplug your cable from your guitar. Yes that loud "eeeeehhhhhhhhh" noise. sometimes it will stop after about a second and other times it won't stop. I isolated the issue to the amp by unplugging the guitar cable from the amp to fing that the noise would still continue so its the amp. I have had to give the chassis a "love tap" to get it to stop. I'm aware this is NOT the right thing to do but when all other options failed, I tried it. Then I found that does not always work and what did work was flicking the standby switch on and off rapidly until it stops humming. It will go for days without doing it and then all of a sudden you put a pair of pliers down on the amp or a cup or your tuner and you will here a sudden "eeeehhhh" for a fraction of a second like if it was going to do it again or you tap the chassis and you hear it quickly start and stop in a fraction of a second. It eventually starts to do it for a second or longer while you're playing until I eventually flick the standby switch again until it finally stops. I tried to re-seat all the tubes but found that was not the issue when it did it again after about 2 days. I will take it to my amp guy to look at but any intuition to what it may be would be helpful and might get me through the next 2 gigs before I take it in?

problem number 2: It seems that if I strum the guitar a little more aggressive than normal, the amp distorts the sound like if I clipped the signal. I'm in the "high" input and no pedals turned on just clean amp. low to moderate volume. not cranked at all. Rear power grid is set to half power 25 watts. This also happens randomly. Maybe its something I'm doing wrong? Doubt it but I'm open to any possibility. Any suggestions?
Thanks in advance.
Click to expand...

Intermittent things like this can drive you crazy. If you have a friend's house you can take the amp to, I would give that a shot. Plug it in somewhere other than your house to see if the noise still happens. If you have dimmer switches on the same circuit that your amp is plugged into, they can cause buzz. Like Yeti suggested, you may also have something like a sump pump that you wouldn't think could cause that, but it's something to watch for. Alternatively, you could just have a bad tube. My first suggestion is to take it somewhere else and play for a while to see if the buzzing returns. If the buzzing only happens at your house randomly, and nowhere else, then my guess would be that there is something on the same circuit that you plug the amp into that is causing your grief. Let me know if you've got any questions about it though.
 
Yeti and Ian ....
Both of you thanks for your suggestions. For some reason, I didn't get notified of your replies and just saw this today. I had opened up the amp previously, checked for any loose connections and re-seated the tubes. After about 5 minutes of playing, the loud humm raised its ugly head. It did it a couple days prior at a show so that eliminates the theory of just my home. I get it to go away by flicking the standby and on/off switch up and down until it goes away. I'm going to next try Yeti's troubleshooting suggestions. You know my guess is that its a bad power tube. Well for certain its not the smaller ones since those tubes are grouped 2 per channel which means that when I switch from one channel to another, the noise should go away if it was one of the smaller tubes dedicated to the channel that caused the noise but no .... The noise continues no matter what channel I switch to. I think I'm going to change out the power tubes first since I should have done that after I bought it anyway.
I'll let you know what happens next. Thanks a bunch for your time!
Cheers!
 
if it is a power tube, we can further narrow the power tubes down to one of the outside ones, since you said it's in half power/25 and the hum occurrs in all channels.

but, i would again, check your preamp tubes for microphonics as i suggested above, as V1 is the input gain stage and could be suspect...check them all to be sure..you're already back there, no harm in it. it could also be your v8 PI tube. Regardless of what that manual says, i've found that v3 tube is ALSO part of the clean channel section...again, even though the manual only assigns v3 to overdrive channels. even though i dont use the contours on my cleans, v5 also pertains to the clean contours, but is only listed in the manual for the OD channels, or so seemed to be by my ears when i changed that tube out and checked each channels response

again though, i would follow the loose flow chart i posted above, just to eliminate things as you go along.

check the bias also, if you have a multimeter and make sure it's within range of 120 - 130. make sure you're on full power 100 watts on all channels when biasing...read your manual on that.

my first guess would be a preamp tube, or a power tube, more so one of your outside power tubes, but it could also be something internal non tube related.

you can always watch some quickies on youtube and learn some stuff too while you're at it.

https://www.youtube.com/watch?v=wSl-l9aWDHw

good luck

Geo
 
Hi again Geo and Ian.....
I followed as Yeti instructed. I set up the volumes on 50% but the Master I set to 2 0-clock instead. This amp is still rather quiet even on OD 1 and 2 at these settings. Tapped the power tubes and no noise. I began from right to left tapping the preamp tubes. Everything cool until I got to V8, then all hell broke loose! I replicated the problem by tapping on that one. Sometimes it takes just a light tap and sometimes a little more but surely that preamp tube is causing it. However when the sound is produced some of the other preamp tubes seem to get sensitive and then tapping those either starts or stops "the noise", V7 in particular. So that throws me off the scent a little. I'm going to move the "bad tube" to another preamp section like V3 and see if the issue follows the tube because it may be the circuitry in V8 and not the tube. This next test will determine if it is the tube or the V8 circuitry. I wish I could afford to buy all the preamp tubes but I can't right now but hopefully if it is the tubes, I can buy the 2 or 3 that seem to be "sensitive" and change those and take it from there! Thanks! You got me closer to solving this problem!!!
 
Update: The noise follows that one tube! There is also another tube that makes noise when tapped. So I'll replace those 2 tubes for now. Would like to replace all of them and then the power tubes. Thinking of using Tung - Sol all around. Preamp and Power. Any suggestions? Or should I keep with the groove tubes?
Thanks! You guys saved my A - -!!!! :-)
 
good to hear you solved it. the preamp tube chase is on for you it seems! it too me FOREVER to find the preamp tubes i LOVED in this amp.

the FIRST advice i would give you is.....play the amp stock for a while, and get to know it well enough...that way, when or if you do choose to switch out a preamp tube or two, you'll hear the result differently as you're used to your amp sounding one way.

i would recommend initially, a sovtek LPS for that v8 position (some people say matched, others say it makes no difference). and a JJecc83s in V5. if you only end up changing 2 or 3, these two will get you the most benefit sonically (not so much amounts of gain or distortion wise, but color and tone), along with V1.

i play mostly hard rock and metal, but i can get ANY sound i want out of this amp when i need to, from jazz and blues to full blown heavy as hell modern metal and tuned down "Djent" (*blech, i HATe that term!).. i've tried a TON of tubes in this amp, i actually pulled the chassis, ran a few licks on a loop into the amp input and just pulled, rolled and listened to tubes...for about 60 hours...if not more. my wife was threatening divorce. after about 3 weeks straight of me coming home from work and rolling tubes for 4-5 hours on end and just listening, and taking notes...i ended up settling on the following tube cocktail:

V2 RFT 12ax7.

v1 v3 and v4 are all Chinese 12ax7b that i got off ebay..they sound VERY close to the stock groove tubes to me. Of the 8 groove stock groove tubes and the 6 or 7 chinese 12ax7b that i bought, these three "silver dragons" tested highest and sound like they have the most gain/distortion to me. you certainly can't lose by leaving the groove tubes in these 3 slots...Bruce knew for sure what he was doing when he matched the tubes to these amps, or, if he didnt do it on purpose, it was an awesome lucky choice IMHO using the chinese groove tubes.

v5-like i said, is one of THE TWO tubes i recommend replacing ...and i highly recommend the JJ12ax7/ecc83s...for some reason, of ALL the tubes i tried in this spot, i kept coming back to the JJ..it seems to add a deeper,


if you start switching preamp the stock tubes around, i suggest numbering them so you can always return to stock if you need to. you can also write down different cocktails by numbering duplicate preamp tubes. it's a lot of fun. i'd also suggest that you switch tubes out on a carpeted floor, if you drop them, they'll have a good chance of surviving on carpet...i broke 2 or 3 in the past year, cause my cellar floor is cement with no carpet.

heres a few links about tubes that i posted last summer when i first got my amp, before i did my extensive preamp tube experiment, and the documented journey..and some other fun stuff and tips!

viewtopic.php?f=26&t=74042&p=859823&hilit=tubes#p859823

viewtopic.php?f=26&t=74239&p=864835&hilit=tubes#p864835

viewtopic.php?f=26&t=74498&hilit=tubes

viewtopic.php?f=26&t=75155&hilit=tubes

viewtopic.php?f=26&t=75822&p=881105&hilit=tubes#p881105

viewtopic.php?f=26&t=74527



theres some info there on what some current production tubes sound like in this amp, at least to my ears. i couldnt decide if i liked the tung sol or not...and eventually found that i didn't love it as much as the other tubes so now it's sitting idle.

another HUGE tip i'd like to pass along about the reverb tube..it makes a TREMENDOUS difference on your reverb sound what tube you put in there...and you honestly, just have to experiment to find one that you love. right now, i have what appears to be a sovtek labled by real tube (from my real tube overdrive) that i like the sound of. i ALMOST kept an electro harmonix in there, it was really bright and watery sounding, but just a lil too much.

a good way to test the reverb tube is to crank the reverb all the way up, put your effects loop on (in series mode, and turn the send way down. basically when you footswitch the effects loop on, you mute the amp this way) and listen to the reverb on each channel with the effects loop "mute" on. you'll hear big differences between tubes, i can promise you that. finding THE ONE, well, it's SO FUN!!!hahah and can get quite tedious..but i love stuff like that!!
 
also, i wanted to mention to you, that i notice my channels sound different in full power 50watt, and half power 50 watt. i like the half power 50 watt better..it feels like it's more rearing to go or something....more responsive and "ready"...

i made some clips of a lot of amp sounds i like that i recorded off you tube...and i have them in my ipod, played through my stereo next to my amp...and i try to set the tourmaster up to sound like them...it's a lot of fun...the TM can do A LOT of sounds...
 
Mine also sounds different set down at half power. I think I like half power better then full power. That ten watt level is great for any kind of breakup or overdrive! I am going to guess that it is noisier though since it pushes the tubes harder.
 
Yeti, your enthusiasm almost makes me want to trade my MOD50 for a Tourmaster… almost.
 
it's funny too, i kinda grew into it....and almost didn't like it, til i figured out how to get it to sound right to me (i think my ears adjusted to tubes finally too..after years of using solid state and buying tube amps and hating them and then having to flip them...). and now, i just run straight into the amp, no wah, no pedals. dont trade, if you can find one at GC, go grab it for a while and try it out!!!

Len Rabinowitz":4fq42aun said:
Mine also sounds different set down at half power. I think I like half power better then full power. That ten watt level is great for any kind of breakup or overdrive! I am going to guess that it is noisier though since it pushes the tubes harder.
Click to expand...

you know, i never really thought of that..probably at higher gain, it would eliminate some buzz by running her full out?!?!?
 
I also found the amp has a defferent sound when set on 25 as to 50 and full out. I also like it at half power 50 watts and at 25. This is probably because for the places I play, this is where I dig in to the tubes a little but still have head room. My ears also hear less noise and the feedback is more of a controlled feedback I can use for enhancing certain parts instead of the squealing I got at a lower power rating when I cranked the amp a little harder for my gigs.
Still having a little problem with the preamp section. Now channel 2 and 4 is loud and strong while channels 1 and 3 sound much weaker, lower in volume gain. I temporarily replaced only 2 tubes in the amp for now so that I can gig with it so I switched the tubes to where I thought they would be best needed and this is when I noticed this change so obviously the other old preamp tubes are weak and causing extreme volume differences. I realize after my noise problem, I need to buy all new tubes before I try to isolate this new situation any further since the answer may just be in getting all the tubes replaced.

My gig went very well last night .... I'm only going through one channel for now (Channel 2) and using all analog pedals for effects and overdrive till I get my amp switcher working in my other pedal board and the tubes replaced. No unexpected loud humming ground noise throughout the whole gig! :-)
 
" i've tried a TON of tubes in this amp, i actually pulled the chassis, ran a few licks on a loop into the amp input and just pulled, rolled and listened to tubes...for about 60 hours...if not more. my wife was threatening divorce. after about 3 weeks straight of me coming home from work and rolling tubes for 4-5 hours on end and just listening, and taking notes...i ended up settling on the following tube cocktail:"

@Yeti....
Wow man! That was alot of work and probably extremely insightful for you as well as for us reading about it! Thanks for sharing your hard work and findings here with us!
 
I had some volume issues with this amp until I got a grip on it. The power level settings can make a difference in that regard. It takes a while to get used to this thing.
 
did i mention HOW MUCH i love this amp. again!

also, when i was messing with my reverb "issues" earlier this year...i found out a neat way to boost the high end (by accident!)

unplug the reverb wires from the amp chassis.
put the reverb full on, turn it on with the footswitch and enjoy the upper highs....can be adjusted with the reverb knob. strange, but true.

it's almost like a built in extra presence knob.
 
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