Hi all ,
Is there any technical reason I should not use an Transformer volume control ( Sowters 9335 ) in front of my F6
I want to use it as passive pre at the output of my DAC , the DAC has 112 ohm impedance
Thanks for your returns
.
Is there any technical reason I should not use an Transformer volume control ( Sowters 9335 ) in front of my F6
I want to use it as passive pre at the output of my DAC , the DAC has 112 ohm impedance
Thanks for your returns
.
No problem, there is an input buffer stage. Do check for capacitive loading effects.
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Not at all, those values are fine. Make sure the DAC has an output coupling capacitor
large enough (around 10uF) to drive the Sowters without bass loss.
large enough (around 10uF) to drive the Sowters without bass loss.
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Sometimes it's beneficial to add a buffer before the TVC too, like a simple B1 buffer but it's a trial/error 'thing' too.
The F6 needs about 3v signal to produce it's full output - it has a gain of about 5 (if I remember correctly) so will possibly need about a 6dB gain stage for full output of 25W/8R (14V).
The F6 needs about 3v signal to produce it's full output - it has a gain of about 5 (if I remember correctly) so will possibly need about a 6dB gain stage for full output of 25W/8R (14V).
Yes, the F6 has x5 gain (14dB), so the source would need about 3Vrms to drive the F6 to full output.
that's an cool info , I wouldn't have thought it 😉
I have no need of 25 w , at all , half of those is plenty enough for me , I drive 94 db speakers
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DACs often have about 2Vrms output, a loss of 1V below full output drive for the F6.
Then 2Vrms x 5 = 10Vrms, which into 8R would be around 12W output.
Then 2Vrms x 5 = 10Vrms, which into 8R would be around 12W output.
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Fabrice,
Judging by this link, with a source impedance of 1k ohms, the frequency response is excellent all the way out to 100khz. You have a source impedance that is 1/10th that, you should be just fine.
I used a very similar setup for years. I had a fully balanced autoformer based TVC using Intact audio silver autoformers. Excellent sound, excellent measurements and specifications. It worked especially well with sources that had low output impedances like 1K ohms or lower. Since I am purely digital and the output voltages from the dacs I use are 3V RMS or more, I always needed to attenuate and a TVC works well in those types of systems as do amplifiers that are of low gain (as long as your speakers are sensitive like 92dB or more; or you have a small sized room with less sensitive speakers).
Enjoy!
Best,
Anand.
Judging by this link, with a source impedance of 1k ohms, the frequency response is excellent all the way out to 100khz. You have a source impedance that is 1/10th that, you should be just fine.
I used a very similar setup for years. I had a fully balanced autoformer based TVC using Intact audio silver autoformers. Excellent sound, excellent measurements and specifications. It worked especially well with sources that had low output impedances like 1K ohms or lower. Since I am purely digital and the output voltages from the dacs I use are 3V RMS or more, I always needed to attenuate and a TVC works well in those types of systems as do amplifiers that are of low gain (as long as your speakers are sensitive like 92dB or more; or you have a small sized room with less sensitive speakers).
Enjoy!
Best,
Anand.
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