The Fuxtor
Addicted Member
Ahhh! another AB International fan! I have a AB precedent 1100A i picked up to power a set of SMGA's . Good stuff!
" And now back to your regular program"
Speaker level to line level converter; how bad the distortion is? (plus crazy idea)
- Thread starter Kreshna
- Start date
Ahhh! another AB International fan! I have a AB precedent 1100A i picked up to power a set of SMGA's . Good stuff!
" And now back to your regular program"
JayBlok
Super Member
Yeah,that is my first ever power amp ever! Fell in love with it immediately
Kreshna
...but I have to know.
Unfortunately, Sanyo 3300KA is pretty hard to find on ebay.
How about DCA 1500X instead?
I need to buy three for 5.1 AV receiver. For that amount of money, what do you think about Behringer Ultra DI Pro 1800 instead?
You can build a speaker level to line level converter for a lot less than $40. Build one per channel.
Last edited:
I need to buy three for 5.1 AV receiver. For that amount of money, what do you think about Behringer Ultra DI Pro 1800 instead?
I am unfamiliar with that piece of audio equipment.
I am unfamiliar with that piece of audio equipment.
Thanks for the diagram. I don't understand all of it though. I'm very much a paint by numbers guy. If you've got paint by numbers instructions for this device, let me know!!
It's been over a year since the last post on this topic so I am guessing nobody will read it but anyway. I need line outputs from my AVR also but for a different purpose. I have a pair of really old but I think great DBX Soundfield 10 speakers. The problem is they need active equalisation else they sound very poor. In the old days I could take either the pre-amp out of the AVR or the tape record out into the equalizer. These days only high-end AVR's have pre-out and mine isn't one. So I need to take the speaker outs from the front channel, attenuate the signal and feed it into the equalizer. I can then take the output from the equalizer and feed it into another power amp to drive my front channels in my Atmos seutp. The circuits don't look too hard to build so I might give it a go.
Schurkey
Well-Known Member
Given a choice, I'd use a transformer coupler rather than a resistor network.
In fact, "I" would be looking for one of the Carver or Soundcraftsman impedance-matchers as described previously in this thread.
I didn't watch this video with the sound turned on. Therefore, I'm only suggesting it as a reference for how the Carver Z-1 looks.
[EDIT]
http://www.hifi-manuals.com/Carver/Z-1/downloads
Ooops. I guess there's no transformer in there after all. [/EDIT]
Nice schematic, though.
Last edited:
Yes, not too hard to build and it will give you the signal you want.
Just thinking, rather than build the part myself, wouldn't a couple of these do the job?
https://www.parts-express.com/boss-...-output-converter--265-4040#lblProductDetails
Designed for a car head unit so it might be set for something less than 4 ohms but the brief comments on the listing indicate folks have been using it fine for home audio
https://www.parts-express.com/boss-...-output-converter--265-4040#lblProductDetails
Designed for a car head unit so it might be set for something less than 4 ohms but the brief comments on the listing indicate folks have been using it fine for home audio
WaynerN
Addicted Member
My Marantz 3300 preamp, (1974) has provisions for returned speaker signal from an amplifier. This is how the preamp can control 2 sets of speakers (system 1, system 2, both or none). The "none" position is then routed to the phono jack for headphone use.
The 3300 also has a center channel tap that is powered by the stereo power amplifier, that thru resistors and a volume control, create a summed mono channel (L + R) and outputs that thru a rear RCA jack. I use this system in my 3 channel stereo system using a Marantz MA-500 mono block power amp to drive the 3rd speaker.
There is no detectable distortion. BTW, 3 channel is really fun, mains on the side walls, center channel on the front wall. I use this system to listen to classical music or pipe organ music.
The 3300 also has a center channel tap that is powered by the stereo power amplifier, that thru resistors and a volume control, create a summed mono channel (L + R) and outputs that thru a rear RCA jack. I use this system in my 3 channel stereo system using a Marantz MA-500 mono block power amp to drive the 3rd speaker.
There is no detectable distortion. BTW, 3 channel is really fun, mains on the side walls, center channel on the front wall. I use this system to listen to classical music or pipe organ music.
Schurkey
Well-Known Member
Why more than one?
Obtaining line-level outputs, typically < 1 V PP, from speaker outputs requires an attenuator (voltage divider).
A single-attenuation L-pad (two resistors) provides constant impedance for the amplifier, but not the driven device, whereas a single-attenuation T-pad (three resistors) provides constant impedance for both sides.
This is a trivial build. Search for L-pad or T-pad calculators which will provide you with resistor values. Some tinkering may be required to map those ideal values onto actual resistor values available in the marketplace.
Another approach is using an L-pad for variable attenuation for a fixed-load resistor, which has the advantage of being able to reduce the driving voltage to avoid overloading the input.. Plus it's already built!
A single-attenuation L-pad (two resistors) provides constant impedance for the amplifier, but not the driven device, whereas a single-attenuation T-pad (three resistors) provides constant impedance for both sides.
This is a trivial build. Search for L-pad or T-pad calculators which will provide you with resistor values. Some tinkering may be required to map those ideal values onto actual resistor values available in the marketplace.
Another approach is using an L-pad for variable attenuation for a fixed-load resistor, which has the advantage of being able to reduce the driving voltage to avoid overloading the input.. Plus it's already built!
Bill Ferris
Lunatic Member
Why not just tap off the volume control to a unused disconnected input/output RCA jacks with 2 shielded cables ?
Over the past years, I`ve done this successfully, usually, if easily determined visually, especially if the frontend(preamp section is circuit board is separated, breaking into the receiver/integrated amps preamp to the internal amp section input feed ..
Always thought it would be cleaner, & easier then padding down the amplifiers higher voltage swing output stage, with it`s often higher distortion voltage to feed external amplifiers..
Has worked for me in the past with very good results..
I did it with to a Radio Shack ST-2700 receiver to drive 2 mono configured Crown DC 300`s, driving my Mac XRT-18 speakers, until I could afford a Mac preamp, 3 years later in my bedroom audio system.
Life can be a modification, and when done well, can be undone, with none the wiser, outside the "perp".
Just some noise from me, after doing it out in the field a 1/2 dozen or so times, and here on occasion with my own equipment when pressed for time and money..
Go with whatever works with your situation, and skills, folks.
Over the past years, I`ve done this successfully, usually, if easily determined visually, especially if the frontend(preamp section is circuit board is separated, breaking into the receiver/integrated amps preamp to the internal amp section input feed ..
Always thought it would be cleaner, & easier then padding down the amplifiers higher voltage swing output stage, with it`s often higher distortion voltage to feed external amplifiers..
Has worked for me in the past with very good results..
I did it with to a Radio Shack ST-2700 receiver to drive 2 mono configured Crown DC 300`s, driving my Mac XRT-18 speakers, until I could afford a Mac preamp, 3 years later in my bedroom audio system.
Life can be a modification, and when done well, can be undone, with none the wiser, outside the "perp".
Just some noise from me, after doing it out in the field a 1/2 dozen or so times, and here on occasion with my own equipment when pressed for time and money..
Go with whatever works with your situation, and skills, folks.
One for each channel? This is not to drive a sub but to drive an external equalizer for my speakers that need equalisation. Modern AVR's don't have line outputs since the signal appears to stay in the digital domain until it hits the power amp stage and onl higher-end amps provide an analogue pre-amp out signal.
just dave
vintage rules!
Here's a guy who had a similar idea.https://www.audiokarma.org/forums/index.php?threads/the-shock-and-awe-system-phaze-2.306078/
Schurkey
Well-Known Member
I actually found one of the Carver units for sale online in a forum and bought it. I probably could have built the circuit myself but at least I know the Carver was designed for this purpose and will work.
Similar threads
