Hello folks,
I want to try running a signal from my interface's DAC through my HiFi integrated valve amplifier and back into my interface to see what, if any pleasant colour this brings to the sound.
It looks like a simple voltage divider is required to convert from speaker level to line level.
My valve amp is an Almaroo A318B, this has no preamp outputs, has only unbalanced inputs and is quoted at 18watts per channel.
What sort of resistor values would be recommended for this and would it be best to use high wattage wire wound types?
The end game is to run mixes or elements from a mix through the amp to see what the transformers, pre and power valves add to the signal.
Many thanks in advance!
I want to try running a signal from my interface's DAC through my HiFi integrated valve amplifier and back into my interface to see what, if any pleasant colour this brings to the sound.
It looks like a simple voltage divider is required to convert from speaker level to line level.
My valve amp is an Almaroo A318B, this has no preamp outputs, has only unbalanced inputs and is quoted at 18watts per channel.
What sort of resistor values would be recommended for this and would it be best to use high wattage wire wound types?
The end game is to run mixes or elements from a mix through the amp to see what the transformers, pre and power valves add to the signal.
Many thanks in advance!
If you employ a 10R 20Watt wire wound resistor as a dummy load, place a 100k 1/2Watt resistor from the hot side of the speaker and terminate it with a 1k2 to ground.
Take the ground and top of 1k2 resistor as your mix out.
You could use a 600R 1:1 transformer if you want isolated balanced out to mixer.
Take the ground and top of 1k2 resistor as your mix out.
You could use a 600R 1:1 transformer if you want isolated balanced out to mixer.
No decent amp will add any "color" nor will the sound be "improved" by this.
If anything is changed it is distortion or part of the spectrum is missing.
If anything is changed it is distortion or part of the spectrum is missing.
You'll just monitor each input A/B with headphones? And of course not send the fedback signal back out.
The biggest “problem” with this idea … is that virtually inevitably, the tapped, attenuated speaker-output taken back in will be at a different level, absolute compared to the signal. Its just the nature of things.
That in turn WILL definitely be perceived as a change. Change for the better, change with 'color', change with bigger bass, more treble (or less of them all), but change will be had. And its darn difficult for people without oscilloscopes and a good sense of metrology to ferret out and counteract.
For instance, just passing a signal into your amp, then to a 10 Ω, 20 watt resistor as a load, having that in parallel with a 100:1 much larger ohmage volt-divider chain (to provide the 'tap and return') is going to have the integrated amplifier's VOLUME CONTROLS between source and that tap. Will the volume control always be exactly set the same?
Its like in the old days when 'fancy' amplifiers used to have bass, midrange and treble 'tone controls'. How many of my friends turned all three knobs up, citing that it made the sound much more live sounding. Well engineered, all three controls "at 10" just counteracted each other, resulting in louder, but flat spectrum-change output. Couldn't convince them. Had to laugh.
I wish the OP luck, and to have a ton of fun. Try the 10 Ω in parallel with 100 kΩ + 1 kΩ string, tapping the 100 - 1 junction for the tube-processed input signal. Can't hurt. If the 100:1 attenuation is too much, then try a 47 kΩ top resistor. Or a 33 kΩ. Or a 22 kΩ. Respectively they are:
100 kΩ : 1 kΩ = ¹/₁₀₁ = –40 dB
47 kΩ : 1 kΩ = ¹/₄₈ = –33 dB
33 kΩ : 1 kΩ = ¹/₃₄ = –30 dB
22 kΩ : 1 kΩ = ¹/₂₃ = –27 dB
15 kΩ : 1 kΩ = ¹/₁₆ = –24 dB
10 kΩ : 1 kΩ = ¹/₁₁ = –21 dB
if the OP is interested, the relationship is
dB = 20 log10( RBOT / ( RTOP + RBOT ) )
For any RTOP and RBOT.
Alternately, and deeply ironically, one could just use a audio-taper stereo volume control as the "parallel to load" resistor. Mount in a box (along with the load resistor!, and lots and lots of heat-escape holes), and a couple of jacks. The experimenter's tap then becomes portable and easily inserted. One can easily just "turn the knob" to adjust attention to your heart's content. And then my whole objection about 'matching' goes to the curb.
LOL
GoatGuy
That in turn WILL definitely be perceived as a change. Change for the better, change with 'color', change with bigger bass, more treble (or less of them all), but change will be had. And its darn difficult for people without oscilloscopes and a good sense of metrology to ferret out and counteract.
For instance, just passing a signal into your amp, then to a 10 Ω, 20 watt resistor as a load, having that in parallel with a 100:1 much larger ohmage volt-divider chain (to provide the 'tap and return') is going to have the integrated amplifier's VOLUME CONTROLS between source and that tap. Will the volume control always be exactly set the same?
Its like in the old days when 'fancy' amplifiers used to have bass, midrange and treble 'tone controls'. How many of my friends turned all three knobs up, citing that it made the sound much more live sounding. Well engineered, all three controls "at 10" just counteracted each other, resulting in louder, but flat spectrum-change output. Couldn't convince them. Had to laugh.
I wish the OP luck, and to have a ton of fun. Try the 10 Ω in parallel with 100 kΩ + 1 kΩ string, tapping the 100 - 1 junction for the tube-processed input signal. Can't hurt. If the 100:1 attenuation is too much, then try a 47 kΩ top resistor. Or a 33 kΩ. Or a 22 kΩ. Respectively they are:
100 kΩ : 1 kΩ = ¹/₁₀₁ = –40 dB
47 kΩ : 1 kΩ = ¹/₄₈ = –33 dB
33 kΩ : 1 kΩ = ¹/₃₄ = –30 dB
22 kΩ : 1 kΩ = ¹/₂₃ = –27 dB
15 kΩ : 1 kΩ = ¹/₁₆ = –24 dB
10 kΩ : 1 kΩ = ¹/₁₁ = –21 dB
if the OP is interested, the relationship is
dB = 20 log10( RBOT / ( RTOP + RBOT ) )
For any RTOP and RBOT.
Alternately, and deeply ironically, one could just use a audio-taper stereo volume control as the "parallel to load" resistor. Mount in a box (along with the load resistor!, and lots and lots of heat-escape holes), and a couple of jacks. The experimenter's tap then becomes portable and easily inserted. One can easily just "turn the knob" to adjust attention to your heart's content. And then my whole objection about 'matching' goes to the curb.
LOL
GoatGuy
Not all distortion is bad.
Valve type distortion is pleasant to the ear.
Thats why Marshall sell so many guitar amps.
For all systems that seeks "natural sound" aka HIFI any distortion is bad.
This includes amps used for music reproduction at home or in public.
Don't confuse this with guitar amps where distortion is deliberately made.
A natural sound isn't all its cracked up to be.
Many singers in bands use distortion pedals to add harmonics and character to their sound.
Many singers in bands use distortion pedals to add harmonics and character to their sound.
Hi, yes I totally understand where you are coming from here. My mention of it being a Hi-Fi amp was more to state that it isn't designed for interfacing with studio equipment having unbalanced connections. Perhaps the experiment won't bring anything, I half expect it to fail to be honest but I'm intrigued by the possibility either way.
As for how transparent it is, I love the sound of it and I think that the reason I like it is the feel of a euphoric quality to it. It is really very striking when comparing it with what I consider to be a tonally neutral amp such as my Hypex NCore module which I use for mixing. By comparison I find the NCore a little boring to listen to, it just doesn't grab me in the same way.
All highly subjective of course but it leads me to want to attempt to run a mix or elements of a mix through the valve amp to see if it gains any colour that might sound nice.
You would need something like a Marshall valve amp to add enough colour.
A lot of voices on recordings are highly coloured to sound good.
My mate is a roadie and says the signers sometimes have more pedals than the guitarist.
A lot of voices on recordings are highly coloured to sound good.
My mate is a roadie and says the signers sometimes have more pedals than the guitarist.
I guess the term colour itself has no meaning really its simply a subjective term that I chose to use to describe a tonal change that may or may not occur from running the signal through my valve amp. A tonal change that could occur from distortion or any other change to the original signal.
I guess to even say what is or isn't an improvement is also entirely subjective.
There may or may not be a change as a result of the experiment. If there is a change then its subjective as to whether or not it is an improvement with a view to how it changes the mix or the track within a mix.
I guess to even say what is or isn't an improvement is also entirely subjective.
There may or may not be a change as a result of the experiment. If there is a change then its subjective as to whether or not it is an improvement with a view to how it changes the mix or the track within a mix.
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Most of the added colour would probably be second harmonic distortion, you might find this interesting How do i create second harmonic distortion?
A lot of people over the years have gone to great lengths to get distortion to make sound more interesting.
Slashing speaker cones with razor blades so they distort.
Putting rivets through speaker cones to vibrate.
Valve PA systems.
Here is a solid state valve emulator circuit. I used one for 30 years with my guitar.
Slashing speaker cones with razor blades so they distort.
Putting rivets through speaker cones to vibrate.
Valve PA systems.
Here is a solid state valve emulator circuit. I used one for 30 years with my guitar.
An externally hosted image should be here but it was not working when we last tested it.
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I have an RME Fireface 400 interface that I would use for this, its got quite a lot of routing options. I should be able to run the signal out to the amp and back into the interface.
I would then have to compare the captured mix with the original
Hey thanks for the advice!
I have not really though any further ahead than seeing if I can get a signal back to my interface.
I certainly haven't yet considered how I can make it a fair test of which I prefer, level matching etc.
Thank you, yes I have been considering some emulation circuits, there are some interesting kits on diyrecordingequipment.com specifically for the purposes that I am considering.
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