I have always been a tube amp and microphone guy for recording, but I recently built a box to tap the speaker output of my Twin Reverb, used this schematic
http://www.jensen-transformers.com/as/as061.pdf
I have never liked direct recording from any sort of preamp, I find those to be harsh and “plinky”, but by tapping the amp speaker you still get the amp flavor (since the power amp is still seeing the flyback energy from the speaker) but you remove the distortion, phase anomalies, and frequency response peaks of the speaker.
This signal can be mixed with a mic’d signal from the amp also, just have to line up the waveforms in your DAW, then you can adjust how much speaker flavor you are getting.
Not sure if there is a commercial transformer isolated box to do this. I have a THD Hotplate with a line out and it works (that is how I decided to build this), but using a transformer isolated circuit was much quieter in my case.
Direct Recording By Tapping The Amp Speaker
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Scott Swartz
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Bryan Daste
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Gary Cosden
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Is this similar to what you are doing?
http://www.radialeng.com/re-jdx.htm
http://www.radialeng.com/re-jdx.htm
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Scott Swartz
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Gary,
That Radial box is a similar idea, except they are adding filter circuits to simulate the speaker response.
For a pure recording application I would prefer that to not be hard wired into the box so I have more control, you can EQ at the DAW channel.
Additionally they are transforming down to mic level voltage, for recording better to transform to line level.
Bryan,
I do have sound files, will have to export them
That Radial box is a similar idea, except they are adding filter circuits to simulate the speaker response.
For a pure recording application I would prefer that to not be hard wired into the box so I have more control, you can EQ at the DAW channel.
Additionally they are transforming down to mic level voltage, for recording better to transform to line level.
Bryan,
I do have sound files, will have to export them
Last edited by Scott Swartz on 24 May 2010 8:34 pm, edited 1 time in total.
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mtulbert
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Hi Scott,
I have one of these which I think does the same thing that you have built.
http://www.bhphotovideo.com/c/product/2 ... l#features
Can you let me know if it is similar??? I have used it but not in speaker mode for a long time.
Regards,
Mark T.
I have one of these which I think does the same thing that you have built.
http://www.bhphotovideo.com/c/product/2 ... l#features
Can you let me know if it is similar??? I have used it but not in speaker mode for a long time.
Regards,
Mark T.
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Scott Swartz
- Posts: 1080
- Joined: 23 Jan 2001 1:01 am
- Location: St. Louis, MO
Sound files - the solo from the song Ernest Tubb here
www.myspace.com/prairierehab
The mic'd and direct sound files were recorded simultaneously, full chain is a Williams D10 to HSC preamp to passive VP to Twin Reverb to a 1-12 cab with a Celestion Classic Lead 80 to an AEA R84 ribbon mic, and the direct box tapping the speaker also of course.
These are the raw wave files, prior to any plugins, sends, etc from the DAW channel.
www.linemenmusic.com/Mic.wav
www.linemenmusic.com/Direct.wav
Mark,
That ProCo box on speaker is the same thing conceptually, not sure what the winding ratio is on the tranformer they are using which will affect the ouput signal level. The Jensen schematic uses a 1:1 transformer and the output is about the "-10 line level" with no downstream preamp when the steel amp is at a reasonable volume.
One other thing - One of the main reasons this sounds different than a preamp direct out is the speaker interacting with the relatively poor damping factor of a tube amp. If you do this with a solid state amp, all of which have better damping factor than tube amps, I am fairly sure there will be less difference comparing the SS amp output to a preamp direct output.
www.myspace.com/prairierehab
The mic'd and direct sound files were recorded simultaneously, full chain is a Williams D10 to HSC preamp to passive VP to Twin Reverb to a 1-12 cab with a Celestion Classic Lead 80 to an AEA R84 ribbon mic, and the direct box tapping the speaker also of course.
These are the raw wave files, prior to any plugins, sends, etc from the DAW channel.
www.linemenmusic.com/Mic.wav
www.linemenmusic.com/Direct.wav
Mark,
That ProCo box on speaker is the same thing conceptually, not sure what the winding ratio is on the tranformer they are using which will affect the ouput signal level. The Jensen schematic uses a 1:1 transformer and the output is about the "-10 line level" with no downstream preamp when the steel amp is at a reasonable volume.
One other thing - One of the main reasons this sounds different than a preamp direct out is the speaker interacting with the relatively poor damping factor of a tube amp. If you do this with a solid state amp, all of which have better damping factor than tube amps, I am fairly sure there will be less difference comparing the SS amp output to a preamp direct output.