what kind of preamp tubes to put in my IIC+

[kirk19]

hi I want to replace the preamp tubes because my tech said that my hum on high volume came from the preamp tubes. What kind of preamp tubes are the best choice for fitting the IIC+ well?

 

[Russ]

I would go with a quality tube that is low noise and maybe even lower gain than what you have in there. Gain can be a noise culprit. If you use good tubes then you should have no problem getting rid of the hum. There is a small amount of hum that is present using any tube amp. Hopefully your tech has taken this into account before suggesting replacing your tubes. Usually if you select a really good tube as your V1 (primary tone shaping tube) then you can get slightly lesser grade though still high quality tubes to follow in the rest of the positions.

I would seriously suggest uprgrading your cables if you are not using premium cables though because you can get a lot of noise there too. Also check your guitar itself. If you have a grounding issue you will get hum too. Also if your pickups suck you will get all kinds of problems. Something to further consider is how you setup your amp. Amps can create noise just by where you position them and what is nearby. Power source is another source for hum. You may need a power conditioner. There are many variables out there that can create problems for you. If you like your tone then I would look elsewhere as a starting point. I once thought that everything else was the problem then had to concede that it was actually my guitar that had problems. It was a long journey to rid myself of hum, unwanted feedback, interference and whitenoise. I think I have pretty much gotten things dialed in now so that if something makes noise then it is the newest addition to my rig.

Playing at different levels will make certain defficiencies more obvious. It is always a good idea to slowly rid yourself of your problems as you play louder and louder. I would say to get to whatever level you plan on playing at volumewise as soon as possible so that you will know that there are no problems when you need to turn up, ie. shows or rehearsals.

 

[kdove]

My Mark I liked the Groove Tube ECC883 best in both V1 & V2 slots. Got them from Groove Tubes

 

[Dasein]

What's everyone's opinion on the mesa sp12ax7's?

 

[kirk19]

russ

my tech assured me it came from my 12AX7 tubes. They were no proper match for the amp. He said something about -9mv matching I cant remember. He also said that is was harmless but he could fix it by matching preamp tubes to the amp...

 

[dmt]

I just finished putting 'new' tubes in my Boogie Simul Satellite and regarding what kind of tubes to use I will echo what advice I havee been given. They type of tube does not matter in terms of type. A 12AX7 or a 12AT7 or 12AU7 will all sound different, but the important thing is what YOU like, what sounds best to YOU. I would recomend trying a whole bunch of tubes in there and switching them out to hear the difference in tone.

My friend gave me several older tubes he recovered from various tube based equipment, 2x 12AX7A 2x 12AU7 and 2x 12AT7's. The 12AX7A's(labeled Lowery Organs) are made by GE or RCA back in the 60's and sound killer, the 12AU7's one is a British Dynascan (made in Japan) that was used in testing equipment, the other is a Sylvania MAde in USA and it is burnt as hell and breaks up very fast. The 12AT7's, one is marked CHY Hytron, and the other is another Dynascan. The tubes my tech placed in there are new Sovtek 12AX7WB tubes, which have a shorter plate and are larger diameter tubes, these sound very different as well.

I tried differnt cominations of these tubes in quick succession to determine which i liked best and in what position. I highly recomend that you take the time to do the same. The same 5 tubes may sound different in different positions. Try having your tech switch them out if you're not comfortable and crank the amp up on the spot. Look for at what point do the tubes break up, how much head room you have, the tone, if the tubes sound brittle or full, etc. You will hear a difference. Choose whichever ones sound best to you.

I settled on a 12AX7A in the first position which I assume is the signal preamp, and the Hytron 12AT7 in other position (tone?) and it sounds killer.