New member with tube question

[BlueTele]

Hey everyone- new to the forum. Been playing off and on for 32 years and had a question regarding microphonic tubes.

I have a Victory preamp pedal (The Jack V4). I found the valve in position V2 is pretty microphonic to my ears, ringing a bit when I switch channels to channel 1. I opened up the chassis and tapped on the tubes with a wooden stick and there’s a mild ringing when tapping any of the tubes, but it really sings on the V2 tube. Victory said it’s normal, but it seems pretty excessive to me. Wondering how hard to fight for new tubes, as they are supposed to have a 2 year tube warranty on the CV4014 tubes.

Posting a pic of my main pedalboard, too.

Thanks.

 

[Music&Chaos]

Hey everyone- new to the forum. Been playing off and on for 32 years and had a question regarding microphonic tubes.

I have a Victory preamp pedal (The Jack V4). I found the valve in position V2 is pretty microphonic to my ears, ringing a bit when I switch channels to channel 1. I opened up the chassis and tapped on the tubes with a wooden stick and there’s a mild ringing when tapping any of the tubes, but it really sings on the V2 tube. Victory said it’s normal, but it seems pretty excessive to me. Wondering how hard to fight for new tubes, as they are supposed to have a 2 year tube warranty on the CV4014 tubes.

Posting a pic of my main pedalboard, too.

Thanks.

Send them a video of it. They may think you are complaining about hearing the taps, which is normal. You are hearing ringing though, which sounds like a microphonic tube to me. Just record a clip of it 'singing' and they will probably ship a replacement.

 

[311boogieman]

Hey everyone- new to the forum. Been playing off and on for 32 years and had a question regarding microphonic tubes.

I have a Victory preamp pedal (The Jack V4). I found the valve in position V2 is pretty microphonic to my ears, ringing a bit when I switch channels to channel 1. I opened up the chassis and tapped on the tubes with a wooden stick and there’s a mild ringing when tapping any of the tubes, but it really sings on the V2 tube. Victory said it’s normal, but it seems pretty excessive to me. Wondering how hard to fight for new tubes, as they are supposed to have a 2 year tube warranty on the CV4014 tubes.

Posting a pic of my main pedalboard, too.

Thanks.

Welcome to Rig-Talk and enjoy your stay
I'm not the brightest bulb here but...
You should always have at least 1 known good tube back up (pre and power)
I've never even heard of this tube (CV4014) but I see it is real on google
So buy one, so you can prove it to yourself and them that the tube went microphonic
If you can afford it, get a NOS version so there is really no question
Also rotate that known good one around until you get the best tone
Use Dioxit or similar to spray and lube the pins before insertion (like once a year)

Edit: I mostly agree with @Music&Chaos except if you hear tapping coming through the speaker - that 'can' also indicate microphonics. In other words, I do not consider that normal.

 

[BeZo]

Tubes are a good thing to have laying around anyways. Sounds like you might need some. I can see Victory not doing a warranty on michrophonic tubes considering it's a pedal. Technically the tubes still work. It sucks, but you won't regret having preamp tubes on hand for it.

 

[70 Mach 1]

welcome aboard RT

having a extra tubes around is like the spare tire in your trunk. you'll never need it until you do

not sure what tube you have but of they're all the same family 12AX7 12AT7, 6L6 5881, El34 6CA7, etc you can roll them around to isolate the bad one

 

[Music&Chaos]

Welcome to Rig-Talk and enjoy your stay
I'm not the brightest bulb here but...
You should always have at least 1 known good tube back up (pre and power)
I've never even heard of this tube (CV4014) but I see it is real on google
So buy one, so you can prove it to yourself and them that the tube went microphonic
If you can afford it, get a NOS version so there is really no question
Also rotate that known good one around until you get the best tone
Use Dioxit or similar to spray and lube the pins before insertion (like once a year)

Edit: I mostly agree with @Music&Chaos except if you hear tapping coming through the speaker - that 'can' also indicate microphonics. In other words, I do not consider that normal.

Depends on the amp design - tapping near a tube near the input and hearing the tap through the amp can be completely normal.

 

[CDawg]

All tubes are microphonic due to their design. Manufacturers of tubes such as New Sensor or RCA who invented the 12AX7 will tell that to you.

https://www.tungsol.com/html/faqs18.html

It becomes a matter of preference and tolerance where it might be too microphonic for you but maybe to someone else its perfectly acceptable. Maybe that tube performs too microphonic in that piece of gear for you in that position but in another piece of gear or another position it could be fine. Try not to think of microphony as black and white but shades of grey.

If you'd like to see variations in tube measurements go on ebay and type 12ax7 maxi for example. People will post the measurements of tubes and you can see the variations for gain, transconductance and noise. There's no measurements for microphonics but it'll give you ideas that tubes are in ranges and not just a static number ie 12ax7 = 100 gain.

 

[ChurchHill]

I'd never heard of that tube, either, so I looked it up. The CV4014 is not related to any of the common 12A*7 types. Not sure they even make them anymore, so they all may be NOS. As a military tube type, they were designed to be used in environments of high vibration, so I would think that being overly microphonic is out of the norm for these. The good bit is that they seem to be cheap, if you can find them, like in the $5-10 range. Looks like that pedal uses 3 of these.

The other tube in that pedal is an EC900, another I'm not familiar with and another uncommon type. Likely would have to be NOS, too, but again, cheap in the same $5-10 range.

 

[Alpha Stryke]

The tap method may have worked in the 60's but in my experience is not a very good indicator.