symptoms of bad preamp tubes?

[metallicat]

ok so i'm having some problemd with my 3ch dual recto. it's sounding weak on ch 2 and 3 and there is like a extra fuzzy sound. also i cant get a good clean with my fx loop on. do you this it's a tube issue?

 

[Leng]

Give this a try.

Turn your amp on at a fairly high volume, with your guitar's volume off. Watch your tubes closely, see if the power tubes get hot in about the same time and the rectifier tubes should look similar.

Then tap your preamp tubes, one at a time, with a pencil. If one is microphonic or failing in some way, it should make itself known.

Let me know if this helps.

Also, I've had almost exactly what you describe happen to me from a damaged instrument cable somewhere in my loop.

 

[metallicat]

Give this a try.

Turn your amp on at a fairly high volume, with your guitar's volume off. Watch your tubes closely, see if the power tubes get hot in about the same time and the rectifier tubes should look similar.

Then tap your preamp tubes, one at a time, with a pencil. If one is microphonic or failing in some way, it should make itself known.

Let me know if this helps.

Also, I've had almost exactly what you describe happen to me from a damaged instrument cable somewhere in my loop.

i don't even use my rectifer tubes. also do i need the take the metal covers off the preamp tubes? if so how?

 

[NDRU]

Give this a try.

Turn your amp on at a fairly high volume, with your guitar's volume off. Watch your tubes closely, see if the power tubes get hot in about the same time and the rectifier tubes should look similar.

Then tap your preamp tubes, one at a time, with a pencil. If one is microphonic or failing in some way, it should make itself known.

Let me know if this helps.

Also, I've had almost exactly what you describe happen to me from a damaged instrument cable somewhere in my loop.

i don't even use my rectifer tubes. also do i need the take the metal covers off the preamp tubes? if so how?

Push up on the metal cover (they're held tight with a spring) and twist them. They'll pop out when they hit the right place. Or, in other words, unscrew them and the spring will push it out.

My preamp tubes have made ringing, feedback-ish type sounds. My power tubes have made the whole amp fizzy & quieter.

 

[clutch71]

What your describing sounds like your having an issue with a preamp tube. If memory serves you bought the amp used. I always totally retube used amps when I get them. It makes it much easier trouble shooting issues.

In another post I see you mentioned getting a retube kit from Eurotubes. Bob is a great guy and very fast to respond. I would just get a standard kit for your DR and if Bob's advised he'll make sure the power tubes are in the correct range for your DR.

I would not get a "hi gain" set. You really have to be cranking the amp to get into them from what I've heard and Bob himself did not recommend them for mine. I do like a balanced PI as I feel it smooths out the overall tone.

Dougtoubes.com has some great prices (certainly cheaper than Mesa) so don't hesitate to send him an e-mail. Let him know the gear that you use and the tone your going for.

Tubes become a matter of preference just like speakers, pick ups, strings, or cables. It's all about what your ears hear. Sometimes it takes a little trial and error to find what you like.

 

[Leng]

*Gasp*

Dave, your recto's gone? :shock:

It's dougstubes.com, btw... Do you recommend rubies for 6L6's or was there another brand you liked?

 

[metallicat]

What your describing sounds like your having an issue with a preamp tube. If memory serves you bought the amp used. I always totally retube used amps when I get them. It makes it much easier trouble shooting issues.

In another post I see you mentioned getting a retube kit from Eurotubes. Bob is a great guy and very fast to respond. I would just get a standard kit for your DR and if Bob's advised he'll make sure the power tubes are in the correct range for your DR.

I would not get a "hi gain" set. You really have to be cranking the amp to get into them from what I've heard and Bob himself did not recommend them for mine. I do like a balanced PI as I feel it smooths out the overall tone.

Dougtoubes.com has some great prices (certainly cheaper than Mesa) so don't hesitate to send him an e-mail. Let him know the gear that you use and the tone your going for.

Tubes become a matter of preference just like speakers, pick ups, strings, or cables. It's all about what your ears hear. Sometimes it takes a little trial and error to find what you like.

i orderd the standard retube kit from eurotube about and hour ago after chating with eddie via e-mail for most of the day.

 

[stompboxfreak72]

Im torn on the Eurotube kits. I personally like mesa tubes better. I like Tungsol in V1 though.

I am sure you issue is preamp tubes. The amps tone becomes dull and lifeless. You don't realize how bad it is because it is a slow degradation that you get used to. When you change those you will be much happier with teh tonz !

 

[cabowabo5150]

Give this a try.

Turn your amp on at a fairly high volume, with your guitar's volume off. Watch your tubes closely, see if the power tubes get hot in about the same time and the rectifier tubes should look similar.

Then tap your preamp tubes, one at a time, with a pencil. If one is microphonic or failing in some way, it should make itself known.

Let me know if this helps.

Also, I've had almost exactly what you describe happen to me from a damaged instrument cable somewhere in my loop.

OK I'll bite. what does microphonic mean? I have a tube that rattles when you tap on it or play at volume. Is that microphonic?

 

[Gtr_Pkr]

Give this a try.

Turn your amp on at a fairly high volume, with your guitar's volume off. Watch your tubes closely, see if the power tubes get hot in about the same time and the rectifier tubes should look similar.

Then tap your preamp tubes, one at a time, with a pencil. If one is microphonic or failing in some way, it should make itself known.

Let me know if this helps.

Also, I've had almost exactly what you describe happen to me from a damaged instrument cable somewhere in my loop.

OK I'll bite. what does microphonic mean? I have a tube that rattles when you tap on it or play at volume. Is that microphonic?

Sure is. Needs to be replaced.