recording problem - signal just dies

[dayexday]

I’m having a problem recording and am not sure which of my components is the faulty one.

I have a studio projects C1 by XLR cable to a studio projects VTB-1 by ¼ TRS cable to RCA to an m-audio audiophile soundcard

My terminology might be wrong but what ends up happening is that while I’m recording my signal (I think it's called signal, the green rectangle in the first picture that disappears in the second one) just dies. Then I have to clap or make a similarly loud sound to get the signal to clip and then it’s back.

Any suggestions on where the problem is? I don’t have another microphone or pre-amp to troubleshoot with.

 

[witzendoz]

You need to actually track down where the issue is so starting with the mixc and pre,

When the signal is lost in the computer, is there still a signal showing on the input meter of the VTB1?

If so is there still a signal showing on the output meter of the VTB1?

Alan.

 

[ecc83]

Whenever valved equipment slowly falls silent you always have to suspect that the heater supply is failing in some way.

If what the other guys say does not help and you can pin the problem down to the pre amp* take the cover off ,(banish kids and pets!) this is quite safe so long as you touch nothing and do it with the power unplugged. Plug up, You should then be able to see if the valve is alight and then if it dims out as the signal fades.

If this is the case there will be a fault in the heater supply circuitry, most likely a dry joint but you will need the services of a technician. But look at the valve VERY carefully. On rare occasions just ONE of the double triode's heaters goes out and that is obviously a duff bottle.

*Even a very modest $20-30 digital multimeter will read the output signal. Anyone who wants to do home recording or even just play electric instruments should have a DMM and learn the basics of its operation.

Err? Which AP soundcard do you have?
Dave

 

[ecc83]

Dave, How are the kids to learn about electronics if not allowed to get their fingers into the gear ? Drool from Fido on the circuit board however probably wouldn't be good .

Don't pop the cover until you've tried some other things first.

The VTB-1 uses a 12vac wall wart and has a reported plate voltage of about 60vdc (semi-starved plate?), so it should be "relatively" safe poking around under the hood with the unit powered using some care.

If you look at the tube in a darkened room while the unit is powered, the filaments/heaters in the tube will have a reddish glow as shown in the image below. The 12AX7 (AKA ecc83 ) is a twin triode and will have two heaters. Dave also has a glowing personality like the tube.

View attachment 83406

Flattery, will get you nowhere A! (bribery might!) Thanks for the great picture.

60volts is oddly enough the EC limit for an exposed DC supply (or 34V peak AC) maybe why they cnose it? I have not investigated very low HT circuits but might have a dabble sometime. Don't by the way, go poking in one of "our" pedals blindly. 300 of the mothers in there and tho' unlikely to kill it bloody hurts!

The one heater out fault has only happened to me maybe 4 times in 3 years (and a LOT of pedal repairs!) and is weird! The heater reads exactly the same DC resistance when cold as any other ECC83 so there must be short occurring when things warm up.

Dave.

 

[dayexday]

thanks so much for the help guys. I really appreciate it. I'll use your guidance to troubleshoot when i get home tonight. Thanks again so much.

 

[DSPDiva]

The problem is probly your interface. Those audiophile sound cards are terrible for recording. Spend $100 on an external interface. The fast track solo's are about $100 and it will do the job better than an internal sound card. They're definitely more reliable.

 

[ecc83]

Gee... I've had an MAudio Audiophile 2496 PCI card in my PC for ages and it's been trouble free, easy to configure, and excellent for recording. S/PDIF has been useful as well.

Completely agree Arc'. To state otherwise, especially on a newbie forum is misleading tosh.

I have had 2 cards that have done over 5 years now with nary a blink.
They have run in an XP Home P4. an XP Pro 3.2G P4, a W7/64 dual core HP and even a P4 running WMCEdition which is not supposed to work!

In conjunction with Cubase LE6 they give super fast latency for MIDI work and the only time I ever had a problem was when fitting one into the 64 bit PC. Turned out I had downloaded the drivers on a 32bit machine and they were corrupted. A dld of the drivers on the W7/64 PC fixed the problem.

The AP 2496 was THE mainstay, semi-pro soundcard. It has probably outsold every other soundcard put together bar the bloody awful SB's!...IF! There was a problem with the 2496 it would have been "all over the papers" years ago!

I have to say I am no longer a fan of M-Audio/Avid (or whatever!) due to the breakup and I shall not forgive them for not implementing a few PCIe cards but the 2496 is a LEGEND in stability!

Dave.