Help with possible broken EHX 12AY7

[trodden]

what happens when you go Mic -> EHXpre -> tascam 1/4 tape deck?

Dont think ive tried it that way yet.

ummm that is the way its SUPPOSED to be used.

a preamp boosts the signal coming from the microphone into the recording device. mic-->preamp-->recording device(tape machine, computer, etc.)

What if you want to use more than one mic?

really?

for every mic you need a mic pre.

[trodden]

Im coming out of the Tascam 1/4 TRS-XLR into the Electro Harmonix out XLR-1/4 TRS into a Spirit Notepad mixer. I dont think I mentioned the mixer last time.

what is a Tascam 1/4? and why are you sending signal from that into the preamp?

1/4 tape deck? so your going mic->spirit mixer->EHX->Tascam 1/4?

why?

Why not? Because I want to use a preamp.

ummm either you're confused, or i'm confused, or we're both confused..

why are you using a preamp on the signal coming OUT of your tape deck?

the only time i really do that is if i want to really push the signal going into a compressor or other device on mix down....

Because I heard the EHX is good on acoustic gutiars.

what does that have to do with using a mic pre coming out of your tape deck.. "out" means, signal that has been recorded and is now being played back...

acoustic guitar played -- sound created OUT of ac guitar-- INTO mic --OUT of mic-- INTO pre---amplified by pre-- OUT of pre--INTO recording device--recorded and stored.

Is this for real?

[rhythm ranch]

Welcome to the jckinnick event horizon.

Sorry jc, but this stuff has been explained to you a dozen times. You don't seem to be able to get your head around signal flow.

[trodden]

Welcome to the jckinnick event horizon.

Sorry jc, but this stuff has been explained to you a dozen times. You don't seem to be able to get your head around signal flow.

I don't think he knows what a preamp is, what it does, or how it works..

or is just really really good an pulling one over on us.. and if that's the case, i raise my glass... cause i usually try to keep it somewhat entertaining around here.. but this is gold!

[jckinnick]

Welcome to the jckinnick event horizon.

Sorry jc, but this stuff has been explained to you a dozen times. You don't seem to be able to get your head around signal flow.

I don't think he knows what a preamp is, what it does, or how it works..

or is just really really good an pulling one over on us.. and if that's the case, i raise my glass... cause i usually try to keep it somewhat entertaining around here.. but this is gold!

So how would you suggest I set it up to use the EHX?

[trodden]

Welcome to the jckinnick event horizon.

Sorry jc, but this stuff has been explained to you a dozen times. You don't seem to be able to get your head around signal flow.

I don't think he knows what a preamp is, what it does, or how it works..

or is just really really good an pulling one over on us.. and if that's the case, i raise my glass... cause i usually try to keep it somewhat entertaining around here.. but this is gold!

So how would you suggest I set it up to use the EHX?

read my previous posts you've already responded to.

[trodden]

what happens when you go Mic -> EHXpre -> tascam 1/4 tape deck?

Dont think ive tried it that way yet.

[jckinnick]

I opened it up and there is a trim knob inside I turned it down but it didnt seem to do anything. Anybody know how to get rid of this hum? ldm311 are you still there?

[nlmd311]

I opened it up and there is a trim knob inside I turned it down but it didnt seem to do anything. Anybody know how to get rid of this hum? ldm311 are you still there?

Hey jckinnick,
My thoughts are along the lines of most of the other comments so far. It really sounds like a problem with your signal flow. Have you tried connecting everything exactly as trodden and I have mentioned in previous posts?
If not, do give it a try, with the most simple signal possible. Microphone to 12AY7 to your recorder. Use and XLR - XLR to connect the microphone to the input on the 12AY7. Next use your XLR - TRS to connect the output of the 12AY7 (using the XLR) to one of the Line Inputs on the DP01 FX (using the 1/4" TRS end of the cable). Make sure you have it selected for a line level signal coming in, this way it knows exactly what to expect seeing.

Try connecting everything just like this, and making sure your input is set for a line level signal. This *should* set you up for a nice, simple, proper signal flow from mic to device.

Let us know what's up after you do that.

ps - I hate to say, but I'm not sure what the internal trim pot in the 12AY7 is and there is a possibility that all bets are off as that may have been some type of bias, or output/input attenuation and if not set correctly by the factory, may lead to noise issues.

If all else fails, send it back to EHX and start again.
I know this has to be frustrating, but making sure you have the proper signal flow is above and beyond anything else.

-Darrill

[jckinnick]

I opened it up and there is a trim knob inside I turned it down but it didnt seem to do anything. Anybody know how to get rid of this hum? ldm311 are you still there?

Hey jckinnick,
My thoughts are along the lines of most of the other comments so far. It really sounds like a problem with your signal flow. Have you tried connecting everything exactly as trodden and I have mentioned in previous posts?
If not, do give it a try, with the most simple signal possible. Microphone to 12AY7 to your recorder. Use and XLR - XLR to connect the microphone to the input on the 12AY7. Next use your XLR - TRS to connect the output of the 12AY7 (using the XLR) to one of the Line Inputs on the DP01 FX (using the 1/4" TRS end of the cable). Make sure you have it selected for a line level signal coming in, this way it knows exactly what to expect seeing.

Try connecting everything just like this, and making sure your input is set for a line level signal. This *should* set you up for a nice, simple, proper signal flow from mic to device.

Let us know what's up after you do that.

ps - I hate to say, but I'm not sure what the internal trim pot in the 12AY7 is and there is a possibility that all bets are off as that may have been some type of bias, or output/input attenuation and if not set correctly by the factory, may lead to noise issues.

If all else fails, send it back to EHX and start again.
I know this has to be frustrating, but making sure you have the proper signal flow is above and beyond anything else.

-Darrill

Thanks

Yeah Ive hooked it up exactly like you guys have said. And it still has a very loud hum. Do you think EHX would take it back again or maybe exchange it?

[nlmd311]

I opened it up and there is a trim knob inside I turned it down but it didnt seem to do anything. Anybody know how to get rid of this hum? ldm311 are you still there?

Hey jckinnick,
My thoughts are along the lines of most of the other comments so far. It really sounds like a problem with your signal flow. Have you tried connecting everything exactly as trodden and I have mentioned in previous posts?
If not, do give it a try, with the most simple signal possible. Microphone to 12AY7 to your recorder. Use and XLR - XLR to connect the microphone to the input on the 12AY7. Next use your XLR - TRS to connect the output of the 12AY7 (using the XLR) to one of the Line Inputs on the DP01 FX (using the 1/4" TRS end of the cable). Make sure you have it selected for a line level signal coming in, this way it knows exactly what to expect seeing.

Try connecting everything just like this, and making sure your input is set for a line level signal. This *should* set you up for a nice, simple, proper signal flow from mic to device.

Let us know what's up after you do that.

ps - I hate to say, but I'm not sure what the internal trim pot in the 12AY7 is and there is a possibility that all bets are off as that may have been some type of bias, or output/input attenuation and if not set correctly by the factory, may lead to noise issues.

If all else fails, send it back to EHX and start again.
I know this has to be frustrating, but making sure you have the proper signal flow is above and beyond anything else.

-Darrill

Thanks

Yeah Ive hooked it up exactly like you guys have said. And it still has a very loud hum. Do you think EHX would take it back again or maybe exchange it?

Get a hold of them again however you did the first time around and see if they'll take another look at it.
Were you ever able to replicate the set up you had when you first got it back, with the shorter cabling, where it didn't hum, or at least not as noticeably?

-Darrill

[jckinnick]

I opened it up and there is a trim knob inside I turned it down but it didnt seem to do anything. Anybody know how to get rid of this hum? ldm311 are you still there?

Hey jckinnick,
My thoughts are along the lines of most of the other comments so far. It really sounds like a problem with your signal flow. Have you tried connecting everything exactly as trodden and I have mentioned in previous posts?
If not, do give it a try, with the most simple signal possible. Microphone to 12AY7 to your recorder. Use and XLR - XLR to connect the microphone to the input on the 12AY7. Next use your XLR - TRS to connect the output of the 12AY7 (using the XLR) to one of the Line Inputs on the DP01 FX (using the 1/4" TRS end of the cable). Make sure you have it selected for a line level signal coming in, this way it knows exactly what to expect seeing.

Try connecting everything just like this, and making sure your input is set for a line level signal. This *should* set you up for a nice, simple, proper signal flow from mic to device.

Let us know what's up after you do that.

ps - I hate to say, but I'm not sure what the internal trim pot in the 12AY7 is and there is a possibility that all bets are off as that may have been some type of bias, or output/input attenuation and if not set correctly by the factory, may lead to noise issues.

If all else fails, send it back to EHX and start again.
I know this has to be frustrating, but making sure you have the proper signal flow is above and beyond anything else.

-Darrill

Thanks

Yeah Ive hooked it up exactly like you guys have said. And it still has a very loud hum. Do you think EHX would take it back again or maybe exchange it?

Get a hold of them again however you did the first time around and see if they'll take another look at it.
Were you ever able to replicate the set up you had when you first got it back, with the shorter cabling, where it didn't hum, or at least not as noticeably?

-Darrill

In the other thread analoghacker the guy that supposedly designed the unit said "some converter boards are not really balanced in, or are but only with certain settings (delta 1010 comes to mind..., it must be on the +4dB and NOT the -10dB in). nearly all of these complaints come from converters using TRS and not XLR inputs (other converters)". Does you know what he meant by converters? Is he talking about the inputs or cable or what? Maybe my Tascam is not really balanced.

[nlmd311]

When he is referring to converters in that reply, he is referring to the physical piece of equipment, in that case, the Delta 1010. The converter is what is *converting the current from your microphone, or signal from your preamp into a digital signal. In your case, your converter would be the DP01-FX.

The +4/-10 refers to the level the device is expecting to see coming in.
For example, I use the MOTU 828mkII which allows me to change the inputs from balanced to unbalanced by switching a knob from +4 to -10 and the other way around. What he is saying when he says "or are but only with certain settings (delta 1010 comes to mind..., it must be on the +4dB and NOT the -10dB in)" is that it is required that you make sure the input is set to +4 and not -10 if it (the input) is variable.

I can't look into it right now, but try researching the DP01 through your manual, or online and see if you have to set the inputs to balanced. Read up on it and see what you can find out. If anything, give the people at TASCAM a call or email and see if they can help you out if you are thinking this might be the issue before you get back in touch with EHX.

-Darrill

*Sorry to define the term using itself in the definition.

[jckinnick]

When he is referring to converters in that reply, he is referring to the physical piece of equipment, in that case, the Delta 1010. The converter is what is *converting the current from your microphone, or signal from your preamp into a digital signal. In your case, your converter would be the DP01-FX.

The +4/-10 refers to the level the device is expecting to see coming in.
For example, I use the MOTU 828mkII which allows me to change the inputs from balanced to unbalanced by switching a knob from +4 to -10 and the other way around. What he is saying when he says "or are but only with certain settings (delta 1010 comes to mind..., it must be on the +4dB and NOT the -10dB in)" is that it is required that you make sure the input is set to +4 and not -10 if it (the input) is variable.

I can't look into it right now, but try researching the DP01 through your manual, or online and see if you have to set the inputs to balanced. Read up on it and see what you can find out. If anything, give the people at TASCAM a call or email and see if they can help you out if you are thinking this might be the issue before you get back in touch with EHX.

-Darrill

*Sorry to define the term using itself in the definition.

I looked in the Tascam manual and the XLR input has a nominal input value of -8dbu. Could this be what is causing all the hum?

[vier-personen]

http://messageboard.tapeop.com/viewtopi ... light=hiss