I need some more bass from my c+

[cremona]

Hi

My simual c+ DRG needs to have the bass slider turned all the way up and still it lacks alittel in the bass area, also ,(bass nob is on 2 ) and over thise last days the dynamics and bass have seem to decreasse even further, and it dossent show the same balls as it did 2 week ago

i suspekt it might be a tube problem.

I had the power tubes changed not long ago , 6l6 from tung sol and el34 from mullard,but the preamp tubes could be as old as the amp.

Now the sound , it is not completly bad , but i really think that somthing is not right.


Eny advice on if it could be the preamp tubes ?

 

[Boogiebabies]

Regardless of where the bass knob is set, the 80hZ full up should shake your house.
Try some fresh preamp tubes first and don't forget the phase inverter.

 

[cremona]

Thanks

Il get some new pre tubes, proberly nos.

But what is the phase inverter , and where is it located ?

regards

 

[Shep]

V5. It's the Pre amp tube next to the power transformer on the out side.

 

[Shep]

Also don't forget Power filter cap's!!!! how old are they??

 

[cremona]

Hi

It was converted and serviced in 2006 to c+ status by MB , and as i recall it had the bias caps replaced also.

Now regarding tubes, im a bit on a budget at the moment, but i read through another thread where the EI ecc83 where recormendet for the c+ for there grunty sound.

Here in denmark a shop sells them but the are called Ei elite ecc83 , will the work ?
And would a new EI in V1 and V5 be enourgh to rule out if its a pre tube issue.

I recording some music at the moment and even with the 80hz jamed all up, bass is light, somthings 100% not right.

 

[cremona]

Hi shep

Ok i see it, but whats the deal with the V5 , have is this specific phase inverter tube related to the lack of bass ?.(just curious)

The tube that is in that place is a boogie 12ax7 , if i where to replace that one with a new tube is there eny specialities of tubes i shuld look after ?

 

[cremona]

UPDATE


I had a epiffany , i have a simual sat head here and i looked what kind of 12ax7 it had in it , behold two GE jan 12ax7aw`s

Well i placed on in V1 and one in V5 , good news the grunt came back , i tryed swaping the tubes into different places and the most difference where in the V5 to my ears.

But sadly the bass is still weak only a littel beter thne before , eny idea if i need to change all the pre tubes to rule that out as the culprint , or could it be some caps that needs to be replaced ?

Oh one more thing , when i replaced the preamp tubes i toke out the 2 6lg tubes, when i fired it up it sounded great but a littel different , then i realised i had forgot to put in the 6l6 tubes, i diddent know the c+ could play with out the 2 6l6 tubes.

thanks for you time

 

[Shep]

I don't Really think you should run your amp with only 2 tubes, the A class switches out the the two AB tubes to give a A class tighter sound.

I have a feeling you will burn out your output transformer.


I would replace all of them . then look at another things like Caps.

 

[cremona]

Hi only played for 10 seconds with el34`s only , and quicky after that turned it of and put the 6l6´s in there.


There is diffently somthing going on with the pre amp tubes because it got ALOT better when i put on of those GE tubes in the phase inverter and p1.

I now have the bass slighter 2 mm from the top and it sounds well amazing, its still not all good dow.

Amp sounds creazy brutal but even with the 80 hz slighter maxed out the bass is not to much, and not like i recal with the other mesa mark series i have had..

Since im on a budget i think il buy some sovteks, and a tung sol for p1.

Since the P1(phase inverter ) seem to be the most important for the dynamics and bass , what would be the Bomb tube for that application ?

 

[boatright]

I can't remember if that has the pull deep function or not. I think the IIc+ does, correct? Is it functioning?

 

[cremona]

Jep it has the pull deep , mine is pulled alwayse because its the pull that gives that c+ grunt .

 

[tony777]

Not to offend, but two things have crossed my mind, following your posts.
1. The C+ isn't for you, maybe you should have another amp, like Engl powerball or something.
2. Your amp should be gone over by a tech, and if he says it's ok, go to the line above.

FWIW My 80hz slider at full breaks the house down even with master at 2.

 

[cremona]

Pleas dont get me wrong, i love thise amp to death.

If i have the 80 hz maxed out its the sound of my dreams end of story. but since that setting shuld give a different bass outputs logicaly i want to investegate what is wrong, thats all i want.

If it was just the way it sounded il be fine with it, but since there is clearly somthing not right i wanna fix it.

I proberly shuld have made a different headline, it dossent lack balls , not at all , but the 80 hz sliderdossent do what its suppose to do , and i want tis amp to preform at its best.

I think il take it to a amp tech shop and have them look into it before i throw money out on new tubes.


BTW it would be alot of money time shipping it from denmark to mesa , so is there enything in paticular i shuld ask the tech guy to look after , one mention Power filter cap's, but enything else ?




regards

 

[cremona]

Update

I decided to send it in for the power filter cap job and a service tjek , and 5 new pre tubes, only way to be sure .

Aparently i did have the bias cap job done in 2006 but the power caps are from 83.

Played it again this morning , and besides the 80 hz needing to be maxed or close o maxed out , I love the sound and the amp in general , not figurley speakering I love the amp and its sound, so i wanna make 100% sure it runs at full capacity.

stay tuned il post as soon as i have had it overhauled