emergency help (att loudthud, edbass)

[Ryanx]

i have a first gen model t that's been giving me some issues.  since i've gotten it, i've noticed that it didnt quite meet the tonal descriptions of being "clean and loud" and whatnot since i can't get a clean tone out of it unless i turn my channel volumes down toward 3 and roll back my guitar volume, it's typically always a rather dirty sound, almost cloudy at times.  i play in a gloomy sludge band so it's not that huge a deal, but when i hear other T's sounding different than mine, even other amps somewhat putting mine down, it bothers me.  now i'm faced with going in studio on the 19th and at rehearsal yesterday i noticed some issues.

i've had my amp recapped with top of the line caps, etc as i got my parts list from members of this board about a year ago.  i've recently retubed with a total set of JJ KT88's and JJ preamp tubes.  In fact, i even use a 12at7 in my phase inverter to try and clean my sound up even more, yet still it remains dirty. 

My issues are that my amp started blowing fuses.  Recently it's been doing it more, i'd say it's blown upward of 5 fuses in the past 6 or so months, playing once a week for about 4 hours of having the amp on each rehearsal, not going crazy with gigs either.  I typically run 2 8ohm cabs and use the 4ohm position on my dial as normal.  Lately we've noticed that my amp runs really hot, and yesterday i noticed that i just wasn't getting the normal volume that i'd gotten even last weekend out of it.  I had just sold some 412sr's i was using to get a 412L and a Roland RE-150 Space Echo (which by the way has a switch that manages power, say -15,-25,-35 which originally made a big difference, but now it's minimal)  Yesterday upon noticing these issues, i decided i'd check my fuse, just to see what it looks like, i've noticed that when my fuse starts to go, ill experience a bit of a volume drop, then the fuse will just pop.  when i did this i noticed that brand new fuses seem to start turning brownish in colour almost immediately, yet they hold up, you can tell that they're burning up.  i've never noticed if this happens all of the time and is just normal, but it seems odd to me that ill put them in brand new, and play a tune, pull it out and they look like old fuses.  My amp is still loud, but i'm getting beat out by a beta bass combo with a 4x10 extension cab on it, it sounds as if my treble frequencies are taking the biggest hit as my leads really don't cut through.  My drummer says i sound very muddy lately, possibly that my mid range is cutting through even though i usually use it at about 4 on the dial.

typically my normal settings would have to be to get my "normal" sound

7 on bright volume
7 on normal volume
7 on bass
3 on mid
7 on treble
7 on presence
7 on master volume

weird, i know but it's worked for me because i've never been able to get a cleaner sound out of the amp no matter the settings, so i just use it for brute strength behind a russian muff which cleans up my sound a bit artifically yet leaving it heavily distorted.  i can't even honestly say that the muff does more for me than to add a bit of treble to my sound, the distortion is there, but not overpowering, as you'd see on a cleaner amp, it's only a bit of a distortion "boost" really. 

I've read that this may be a result of me needing to replace my transformers.  That breaks my heart, and puts me in a rough spot where i may need to determine the exact transformer i need to replace first and blow money i don't exactly have to spend on getting a mercury tranny installed before the 18th, which of course makes my stress levels go sky high.  i ask the sunn pro's to shine some light on me as you have before in my time of need.


THANK YOU!



www.myspace.com/monument610

[django7866]

Hi, I have a 74 Model T that was doing some what the same thing, Except my amp didn't blow fuses and it would not get louder after I turn the volume passed 3. It to was distored and seemed to break up a little to early.  Two of the tubes were running real hot, so I thought maybe the tubes were biased too hot. I had a tech check it out, he cleaned, tightened the tube sockets and re-biased the tubes which I use tung sol 6550's. got the amp back, took it to jam and still had the same problem.
 A friend of mine has a tube tester so I asked him if he could take a look at it let me know what his thoughts were. After a couple of hours trying to pin point the problem, he said he thought it might be the out put transformer. So I took the Model T to a different amp tech and he went through amp and concluded that it was in fact the O.T. I would take it in and see if that is were your problem may be. or If you know that how to check that kind of thing, I would start there.
Hope that helps.

[Ryanx]

thank you for your input! 

i will replace both tranny's if that's what needs to be done, it may come hard though because my tech is a gigging musician.  looking for all the input i can get before i pass on a sentura II to get my hands on some new transformers.

[HRobert]

QUOTE:

Roland RE-150 Space Echo (which by the way has a switch that manages power, say -15,-25,-35 which originally made a big difference, but now it's minimal)

Rynax.  The three position switch that you speak of on the Roland Echo is an input pad switch.  It's used to dampen the sensitivity of the input signal so it doesn't overdrive the sensitivity of the input circuitry of the echo.  It has nothing directly to do with the output signal of the unit.

Rob

[loudthud]

The only way to tell for sure that a Model T is firing on all cylinders is a power output test with a dummy load. This should be done anytime the output tubes are changed and the bias adjusted. It will tell you if there is some preamp problem that needs to be addressed. If the tech you're taking the amp to doesn't do this, get a new tech.

The next thing is you have to use speaker cabs with no issues. That means all the drivers are good and there are no open voice coils. It's very hard to tell at a gig or any time there is a drummer in the room. In a quiet room, put your ear against the grill cloth and verify that you can hear the hiss coming from each speaker cone. If the hiss is faint or muffled, that speaker could be dead and you are just hearing the hiss from the other speakers bouncing around inside the cabinet.

Lastly, you have to know how to use the standby switch. If you don't, your amp could die anytime you turn it on or possibly suffer a loss of headroom. If it's too much trouble to do this, get a transistor amp.

[pickinatit]

typically my normal settings would have to be to get my "normal" sound

7 on bright volume
7 on normal volume
7 on bass
3 on mid
7 on treble
7 on presence
7 on master volume

OFF TOPIC COMMENT:  7  on "bright & normal volume"  and 7 on "master volume"    DANG!!  I can't even imagine how that's possible inside a rehearsal space with a Sunn tube amp. And you know what the really, really scary part is to me?  That you can't cut through the mix with that!!!  LOL.   Something MUST be seriously wrong with your amp!!  (I know none of that is helpful where your problems are concerned,  but ...just sayin' )
Have a nice day,
Michael

[Ryanx]

@ loudthud

why do you assume that i don't know how to use a tube amp?  i mean forget that i've had tube amps and been gigging for 10 years, i think i know how to use a standby!!!

so you're telling me to investigate the speakers in my 412L and that it's probably not a technical issue with the amp itself.  what's with the burning of the fuses?  i ask all of this out of desperation, as i'm going into studio to do a major project and don't want to be faced with issues that will waste my time/hinder my cost.  i'm either buying a new amp, or repairing my T in a pinch!