more framus cobra issues, HELP!!

  • Thread starter Thread starter rottingcorpse
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rottingcorpse

rottingcorpse

Well-known member
so i cannibalized the preamp tubes from my diamond nitrox and replaced the preamp tubes on the framus cobra. this got the popping problem to go away, but other problems have raised their heads. (note the cobra had a mixture of E.H., J.J. and a no-name 12ax7. the tubes from the diamond were all J.J's and i know they are good order tubes)

with the channel volume on 5 (noon) and the master at 5 (noon), i would expect it to be loud as hell. but it is really only about max bedroom level (in a well built house) at that point.

and if i put anything in the loop (noise gate....on or off), anything above 5 on the channel volume causes wild breakup noise like i have never heard. same thing happens if i just run a cord from the send to the return. i know that some loops are effected by channel level, but......

those of you that have played with a drummer with one of these, if you could tell me where your volumes are on both your channel and master i would have an idea if i have another issue here.

thanks, martin
 
Well, you are right it would be loud as hell with both at noon. I was playing my framus yesterday, I had the channel master at 3:00, and the overall master at 8:00, it was so loud! But it sounded really good. COuld this be power amp tubes causing the extreme loss in volume?

Regarding the loop problem, where do you have the loop mix knob?

When I play with a drummer with my framus, I usually set the channel master to 3:00, and my overall master to 9:00.
 
just had the channel volume at 6 and the master at 8 (1 oclock and 3 oclock). was just getting loud enough to play with a power drummer.

to use a gate (decimator to quiet the hiss) in the loop, the knob has to be at clockwise. that's for series. the other way it's parallel.

will try a power tube swap later today.
 
I'm pretty sure a power tube swap will help, and an re-bias. If I have my masters up that high That would be way too much to handle in a moderate size room. That would be way too loud for the drummer too.

What power tubes do you have in your amp?
 
Not sure what the problem is...however I will tell you of the 4 Cobras I've owned, 2 had serious serious issues. One was purchased new so sent back on warranty, the other was not :( and as much as I love the Framus (probably my favorite amp of all time) I will never purchase one again.
 
selvanias in the diamond (used to test) and grove tubes in the cobra (pulled out). no difference in volume on the cobra. i could yell and hear myself well with it cranked up.

put the tubes back in the diamond, and fired it up. volume of the nitrox stomped all over the the cobra, even at less than 4 on the master. couldnt hear myself think, much less yell.

to do another test, i fired up the single recto at 5 on the master and it smoked the cobra in volume. had to back up from the cab. the 50 watt pittbull did the same thing, loving that amp more and more.

dimebag11, this is my second cobra too. the first one had issues and sold it at a loss. the craigslist buyer put new power tubes in it and loved it for a year or so before selling it.

this one sounds great. dont wanna send it back for a couple of reasons. really just want it to work.
 
Just a word of caution, as for that EH preamp tube, do not plug it into the V3 position of your Cobra. That is the cathode follower (CF) position. Anything manufactured by New Sensor ie Tungsol and Mullard reissue, EH, Sovtek etc have a lower heater to cathode rating. They will either completely die, go half gain/volume or fluctuate in volume.

JJs, Chinese and NOS preamp tubes will be fine for the CF position. Your Cobra can be easily modified to correct that so you can use New Sensor tubes in the CF positions. It's 2 resistors and a cap if you are handy. Hope that helps.

Cheers,
Mike
 
thanks for the info mike. as always, your willing to share your wealth of information if refreshing in this world of secrets.

it is obvious this amp has issues. tried everything i can. even the 50 watters are stomping a mud hole in it. too bad, as i really like the tone it has, it just doesnt have any volume.
 
Sounds like you dont know how to dial it in and all.........
just saying..... :confused:






























:hys:

You know your my Bro!
Just FN with ya! :lol: :LOL:
Get it fixed so I can snag it from ya! :rock:
 
Martin, just saw this thread and I am incredibly sorry that there are these issues. I can just contact FedEx about a claim since it must have been mishandled/jarred based on that piece of wood loose in the cab you mentioned. I experieced none of this crap or I would never have offered it for sale

If you want to keep the amp, I will pay for the repairs that need to get this right. I just can't understand about the issues you have as this amp shook the house on 3-4. Are you manually selecting the Master or using a footswitch? Can you just drop in other power tubes without rebiasing this? I wish I knew more about the technical aspects of the amp

I will make this right my Brother but if it is a jarring/mishandling issue, FedEx needs to take care of it asap

This is making me sick to my stomach Brother
 
Northwinds":1oy7isoj said:
Martin, just saw this thread and I am incredibly sorry that there are these issues. I can just contact FedEx about a claim since it must have been mishandled/jarred based on that piece of wood loose in the cab you mentioned. I experieced none of this crap or I would never have offered it for sale

If you want to keep the amp, I will pay for the repairs that need to get this right. I just can't understand about the issues you have as this amp shook the house on 3-4. Are you manually selecting the Master or using a footswitch? Can you just drop in other power tubes without rebiasing this? I wish I knew more about the technical aspects of the amp

I will make this right my Brother but if it is a jarring/mishandling issue, FedEx needs to take care of it asap

This is making me sick to my stomach Brother
Click to expand...

This is why I love this place... very good of you to uphold yourself to this deal bud! :thumbsup:
 
make no mistake, northwinds and i go way back. i know he would want to make it right.

just tried to call you again, mang. headed back home tonight, and have a couple of other things to check tomorrow when i get there.

gonna run from another amps send to the cobras return to test the master again. this will tell me if the issue is in the power section.
 
the loop's are designed for use specificaly with rack gear. I don't know if that helps but, food for thought in the future.
 
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