Marshall Amp Forum - View Single Post - Preamp Tubes?

ts31966 · 05-02-2009, 08:21 PM

Hi all!

Well, I have been trying a million different combinations. A few tubes I have are microphonic. I am not going to throw them away though. They sound to good for that. I am going to experiment with the rubber bands that I saw on fleabay.

Some of the NOS tubes make some strange noises sometimes. I am hoping that with a burn in period they will burn in and quiet down.

I saw a device on EAT's website to quiet microphonic tubes but they are very expensive. I am hoping to get them for cheaper.

Has anyone here experimented with the rubber bands? If so will the metal sleeves fit over the top of your 12ax7 with the rubber bands on?

My 5150 III takes 8 12ax7's so it is taking me alot of time to get into different combinations. I am going to see if I can find some books with some useful information on tube positioning. Sometimes my high gain channel gets quiet with different tube combinations. But only the high gain channel. I have a theory on this but I have to go over the schematics to figure it out.

05-02-2009, 08:21 PM	#221 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Hi all! Well, I have been trying a million different combinations. A few tubes I have are microphonic. I am not going to throw them away though. They sound to good for that. I am going to experiment with the rubber bands that I saw on fleabay. Some of the NOS tubes make some strange noises sometimes. I am hoping that with a burn in period they will burn in and quiet down. I saw a device on EAT's website to quiet microphonic tubes but they are very expensive. I am hoping to get them for cheaper. Has anyone here experimented with the rubber bands? If so will the metal sleeves fit over the top of your 12ax7 with the rubber bands on? My 5150 III takes 8 12ax7's so it is taking me alot of time to get into different combinations. I am going to see if I can find some books with some useful information on tube positioning. Sometimes my high gain channel gets quiet with different tube combinations. But only the high gain channel. I have a theory on this but I have to go over the schematics to figure it out.