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Topic: Line Out for a Fender Tube Amp? |
Gary Cosden
From:
Florida, USA
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Posted 13 Jun 2012 11:57 am |
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| I have a Fender Dual Showman head with a 2x12 cabinet as well as a Nashville 400. What I would like to try doing is using a DI box of some kind and somehow get a line out so I can drive the power amp IN on the NV400 and use it as a powered speaker. From what I have read most of the DI boxes out there give you a MIC level output to go to the PA system as opposed to a line level out. Is what I want realistic? Any ideas would be appreciated! |
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Steve Humes
From:
Tampa, Florida, USA
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Gary Cosden
From:
Florida, USA
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Posted 13 Jun 2012 3:10 pm
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| Thanks for the reply Steve but unless I am missing something (entirely possible!) all I am getting here are ways to split an existing line level signal and not a way to get a line level signal from a speaker lever signal. |
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Steve Humes
From:
Tampa, Florida, USA
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Posted 13 Jun 2012 3:37 pm
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| Why would you want to take an amplified signal and send it to another amplifier? If you are trying to use 2 amplifiers, then send them both a line level signal from the source. If you are trying to use the colored signal of one amplifier and send it to another, you would use the line level out, not the speaker out. The DI boxes will take a high impedance line level signal and convert it to a low impedance XLR out, and usually have a throughput high impedance 1/4" to send to an amp, that why I linked the splitter in the previous post. I don't think you are going to find a device to convert a speaker level signal to a line level. Then again, I may be wrong. |
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Gary Cosden
From:
Florida, USA
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Posted 13 Jun 2012 3:53 pm
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There is no line level out on 60's era Fender tube amps
and what I would like to try is using the NV400 as a powered speaker only. I can (and do) play through both amps but I wanted to try only using the Peavey power amp with a line out from the Fender if possible. Maybe its not possible - I don't know. |
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Bob Hoffnar
From:
Austin, Tx
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Gary Cosden
From:
Florida, USA
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Posted 13 Jun 2012 5:51 pm
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| I think the EDI gives you a MIC level out and not a line level. Can you drive the power amp IN with that? Maybe you can but I thought it would need to be line level. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 13 Jun 2012 6:40 pm
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Not a big deal, really. Any good tube amp tech can add a "line out" jack to your old Fender.  |
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Gary Chiappetta
From:
San Bruno, California, USA
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Posted 13 Jun 2012 9:56 pm Line-Out for Fender Tube Amp
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I use a JDI passive direct box by Radial Engineering.
It connects to the speaker output jack of the Fender Amp and gives you the signal you want.
"...allows the engineer to ‘tap’ the sound coming from a guitar amplifier speaker ‘post distortion’ thus adding another creative dimension. This unique function incorporates a speaker emulation filter circuit that rolls off highs and lows to more closely approximate the sound of a 12” driver."
http://www.radialeng.com/di-jdi-features.htm |
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Steve Humes
From:
Tampa, Florida, USA
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Posted 14 Jun 2012 2:19 am
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| I am curious. What is the advantage to doing this over splitting the signal at the source? To re-amplify the colored sound? Wouldn't that be noisier? |
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Rick Abbott
From:
Indiana, USA
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Posted 14 Jun 2012 3:24 am
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I guess the idea is to take a signal off the speaker-out, getting the tone and overall sound of the first amp, then send it to a clean power-amp, bypassing the coloration of the second amp. Gerald Weber, the tube amp guy put a recipe for one of these in his first book. It's two wires, two or three resistors and a 1/4 inch jack. I made one and used it from a brown Princeton into a Fender Pro 185 (solid state). It worked, but I was always scared of it and didn't use it very often. Is this what you are thinking?
_________________
RICK ABBOTT
Sho~Bud D-10 Professional #7962
Remington T-8, Sehy #112
1975 Peavey Pacer |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 14 Jun 2012 6:51 am
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I used an OT from a '94 Twin in my Twin build. Has 4, 8, 16 ohm out, and a line level from the secondary side of the OT. I used a Marshal impedance switch.
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Gary Cosden
From:
Florida, USA
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Posted 14 Jun 2012 6:59 am
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| Thanks guys. I've seen the schematic for the line out box that Rick Abbott was referring to and it kind of scares me as well.I guess I would need to have a line out installed but I did not want to mod a vintage (66') Fender tube amp that way unless there is no other good choice. |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 14 Jun 2012 8:04 am
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It's actually quite easy and often done. You simply tap the signal right at the input side of the 220k mix resistor before the phase inverter. Run that to a jack on back of the amp. Even better is to send it to the input leg of a 100k or 250k pot and let the pot's wiper feed the "preamp output" jack. This is precisely what our SMS Classic Tube preamp is based on. We took the Fender preamp channel and put it in a small package, and of course cleaned things up a bit, upgraded the signal path and power supplies.
Us Jerry Garcia nuts have been all over this method for years since this is exactly what Jerry did since the late '60s till the end. Tap the Twin preamp and feed it out to an external power amp.
Here's a page that has great info on ways to tap and route the preamp out. The only reason I suggest using an output level pot is because this preamp circuit is VERY VERY VERY hot at the output, and also the NV400 power amp input jack has no master control, so you really need a pot in there to tame the signal down and get things under control.
Scroll way down and you'll see a couple of preamp tap options. Sounds like you want the method that keeps your Showman still using its own power section simultaneously.
http://www.wald-electronics.com/preampmods.html |
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Gary Cosden
From:
Florida, USA
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Posted 14 Jun 2012 8:43 am
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| Thanks Brad! Just what the doctor ordered. |
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Rich Hlaves
From:
Wildomar, California, USA
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Posted 14 Jun 2012 8:45 am
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Gary,
The link below is to a "Tap Off Kit" from Vintage Speakeasy that will do what you want. All you will need to do is connect the black and green wires to the leads of one of your speaker. The box comes with some velcro so you can stick it to the inside of your cabinet.
They have a gain control and a second tap for low frequency signals if you wish to use it for a sub.
They work well. I have used several in Hammond organs to tame preamp signals and for speaker level line outs from spinets and A100s. I have one installed on my personal RT3 and use it to drive keyboard amps or for recording when I don't want to mic the Leslie.
http://webstore.speakeasyvintagemusic.com/tap-off-kit-p-50.html
_________________
On man....let the smoke out of another one. |
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Dan Tyack
From:
Olympia, WA USA
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Posted 21 Jun 2012 2:11 pm
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Adding to the great information provided by Brad and others:
There are two basic ways to get a line out signal. One is to do what Brad describes above and get the output from the preamp. The other (and my personal favorite) is to get a line leve signal after the power stage. This is how my Little Walter and THD amps are configured.
Why would you do this? You probably wouldn't if you are talking about a transistor amp. But if you have a tube amp, a lot of the overall sound of the amp comes from the power amp stage. This is especially true if the output stage is being pushed. So if you love the sound of your amp at a particular volume level, but want it louder, then IMHO the way to go is a post power amp line out into a neutral sounding amp, the TC Furlong cabs are ideal. |
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Jim Mathis
From:
Overland Park, Kansas, USA
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