I've built and am quite happy with my tubelab sse, audio nirvana full range open baffle with plate amps driving H frame woofers.
The sse amp has a cap at the input eliminating the bass going to the amp driving the A.N. full rangers (6dB/ octave at ~250 Hz).
Because of this crossover, the amp will get far less than the full 2 volts that the cd player should be sending.
I don't think that my ipod sends even 2 volts, so it doesn't play as loud with it.
If I used a preamp (other than unity gain types) I could just crank the vol on it.
But I wanted a laptop based music system, and I was thinking of purchasing a dac or making one of the diy dac's from ebay.
I would like to get the one with the highest output possible.
Or is there a way to increase the output voltage of a dac? (using atransformer?)
I'm thinking dac's less than a couple hundred bucks (not firm)
Thanks,
Paul
The sse amp has a cap at the input eliminating the bass going to the amp driving the A.N. full rangers (6dB/ octave at ~250 Hz).
Because of this crossover, the amp will get far less than the full 2 volts that the cd player should be sending.
I don't think that my ipod sends even 2 volts, so it doesn't play as loud with it.
If I used a preamp (other than unity gain types) I could just crank the vol on it.
But I wanted a laptop based music system, and I was thinking of purchasing a dac or making one of the diy dac's from ebay.
I would like to get the one with the highest output possible.
Or is there a way to increase the output voltage of a dac? (using atransformer?)
I'm thinking dac's less than a couple hundred bucks (not firm)
Thanks,
Paul
Firstly, the difference in output voltage between DAC's will have minimal impact on level simply because of the way we hear. 1.7v output or 2.3 v output as examples, both will sound surprisingly similar.
Best approach is to either use an opamp gain stage at the DAC output or (if you have the circuit details) reconfigure the DAC output stage to provide gain. In the latter case you may be limited by the supply rails used in the DAC.
Best approach is to either use an opamp gain stage at the DAC output or (if you have the circuit details) reconfigure the DAC output stage to provide gain. In the latter case you may be limited by the supply rails used in the DAC.
pforeman,
I'm not exactly certain about what you are looking to achieve in this. I read you are saying that the D.C. blocking capacitor at the input to your tube amp is sized to act as a 250Hz high-pass half of your speaker crossover. If I correctly understand, then you would want the input voltage driving that amp to drop by 6dB/Oct. below 250Hz.
If, instead, you are saying that you do not want that 250Hz high-pass effect, then you would need to increase the size of that input capacitor by a factor of at least ten.
I suppose, that a third possibility is that the input impedance to your tube amp is loading down the output of your digital source. It's conceivable that the 250Hz high-pass filter has been implemented with an unusually low value input resistor rather than with a low value input capacitor. The input resistor might be loading down the signal source voltage. Determine the value of the input resistor which sets the input impedance of your tube amp. (I would expect it to measure anywhere from about 50k to 100k ohms.) If it measures quite lower, then you may have a loading problem. To resolve, you will need to both increase the input resistor value and proportinately decrease the input capacitor value, in order to manitain the 250Hz high-pass point.
Or, perhaps, I simply misunderstand the problem you are communicating.
I'm not exactly certain about what you are looking to achieve in this. I read you are saying that the D.C. blocking capacitor at the input to your tube amp is sized to act as a 250Hz high-pass half of your speaker crossover. If I correctly understand, then you would want the input voltage driving that amp to drop by 6dB/Oct. below 250Hz.
If, instead, you are saying that you do not want that 250Hz high-pass effect, then you would need to increase the size of that input capacitor by a factor of at least ten.
I suppose, that a third possibility is that the input impedance to your tube amp is loading down the output of your digital source. It's conceivable that the 250Hz high-pass filter has been implemented with an unusually low value input resistor rather than with a low value input capacitor. The input resistor might be loading down the signal source voltage. Determine the value of the input resistor which sets the input impedance of your tube amp. (I would expect it to measure anywhere from about 50k to 100k ohms.) If it measures quite lower, then you may have a loading problem. To resolve, you will need to both increase the input resistor value and proportinately decrease the input capacitor value, in order to manitain the 250Hz high-pass point.
Or, perhaps, I simply misunderstand the problem you are communicating.
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Yes,Ken.
The input cap on the simple se is doing just what i want it to do. It's blocking the lows below ~250 Hz from reaching the amp from the cd or ipod. But, I was assuming (perhaps incorrectly) that the amp is now only receiving a "drive" voltage of ~1 volt, when the cd player actually sent out ~2 volts, and that therefore my amp is not capable of playing at full volume.
Thanks again,
Paul
The input cap on the simple se is doing just what i want it to do. It's blocking the lows below ~250 Hz from reaching the amp from the cd or ipod. But, I was assuming (perhaps incorrectly) that the amp is now only receiving a "drive" voltage of ~1 volt, when the cd player actually sent out ~2 volts, and that therefore my amp is not capable of playing at full volume.
Thanks again,
Paul
Highest output DAC is Benchmark USB DAC1, up to 23Vrms (balanced) output.
http://www.stereophile.com/content/...-processor-headphone-amplifier-specifications
http://www.stereophile.com/content/...-processor-headphone-amplifier-specifications
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