This one CineMate(R) GS Series II digital home theater speaker system - Bose Product Support
With the input i mean the rca input. I like to make more warm sound but i dont want remplace the original preamp with a tube preamp.
With the input i mean the rca input. I like to make more warm sound but i dont want remplace the original preamp with a tube preamp.
A genuine buffer only changes the sound if there was something unusual in the original setup, such as very long cables or a significantly non-linear input impedance in the amplifier.
A 'buffer' can, if sufficiently badly designed, add some low order distortion, a little noise and some frequency rolloffs. Some may like this 'warm' sound.
A 'buffer' can, if sufficiently badly designed, add some low order distortion, a little noise and some frequency rolloffs. Some may like this 'warm' sound.
There are designs for amp stages that add second harmonics (more distortion) which makes a "warmer" sound, but as DF96 said, a buffer circuit should be completely transparent if properly designed.
Perhaps a grounded cathode triode stage with a voltage divider on the output to lower the gain to unity?
Perhaps a grounded cathode triode stage with a voltage divider on the output to lower the gain to unity?
Or a low voltage build, intentionally running the tube in the "bent" area of the curves. Finally a use for all those clear-top 12AU7s in my stash!
So how can i use a 6ns7 at low voltage? One triode for L channel and the another triode for the R channel
Cardio75
Look here:
https://www.diyaudio.com/forums/the-lounge/328632-distortion-bad-2.html#post5585400
And here
H2
Look here:
https://www.diyaudio.com/forums/the-lounge/328632-distortion-bad-2.html#post5585400
And here
H2
OT posts removed, do try to stay on topic.
Thank you, Jazbo.
Here's a design I kanged together this morning... I don't have SPICE, but my experience tells me this will work fine for the OP. If it doesn't, change 10k to 4k7.
Attachments
Check Pass Lab's H2 thread. Mr. Nelson Pass recently released the H2 buffer board, which should be very good too.
Hi Cardio75
Not sure where in the chain you'll insert the circuit. If you go for between pre and power amp you would have something like 0.775 Vrms = 1.1Vpk and should design for your max desirable THD at this point. Alle these circuits will produce higher THD as the input is increased, therefore knowing what your max is is important.
Very good and impressive circuit you just draw up kodabmx 😉 ... but the THD is quite lower than for the Pass H2 (which is just a normal single ended jFet design). (have tried to sim with a lot of different jFet's and the J112 is really a gem in this ... so use that ..... Mr. Pass really know what he is doing 😉 )
I have made my version and produced a protoype in 10 min, and it is just running on a 9V battery.
I have attached a LTSpice file for you own simulation and tweeking, including both jFet and Valve option. You can probably find a valve which will produce more THD but others will know more about that. But it is much more expensive and combersome to go the valve way I think.
Go for it, Baldin
The prototype....
Forgot to say, I have targeted ca. 1% THD (-40 dB at 1.1Vpk)
Another guy who have worked on something similar is the one doing the Lampizator and the FETishizator ....... Fet-ishizator
Not sure where in the chain you'll insert the circuit. If you go for between pre and power amp you would have something like 0.775 Vrms = 1.1Vpk and should design for your max desirable THD at this point. Alle these circuits will produce higher THD as the input is increased, therefore knowing what your max is is important.
Very good and impressive circuit you just draw up kodabmx 😉 ... but the THD is quite lower than for the Pass H2 (which is just a normal single ended jFet design). (have tried to sim with a lot of different jFet's and the J112 is really a gem in this ... so use that ..... Mr. Pass really know what he is doing 😉 )
I have made my version and produced a protoype in 10 min, and it is just running on a 9V battery.
I have attached a LTSpice file for you own simulation and tweeking, including both jFet and Valve option. You can probably find a valve which will produce more THD but others will know more about that. But it is much more expensive and combersome to go the valve way I think.
Go for it, Baldin
The prototype....
Forgot to say, I have targeted ca. 1% THD (-40 dB at 1.1Vpk)
Another guy who have worked on something similar is the one doing the Lampizator and the FETishizator ....... Fet-ishizator
Attachments
I've got one of those H2 generator boards sitting in my parts bin, it was one of the giveaways at Burning Amp 2018. Not sure if I'll be using it anytime soon, if at all.
To do similar with tubes, I wouldn't look at nicer more linear tubes like the 6SN7, I would look at something like the 12AU7, or even 6BQ7, maybe even the subminiature 6111. Run them at lower voltage (a 19~21 volt laptop power brick and a 7806 voltage regulator for the filament) and i bet it would do the trick. You want to run the tubes in the "bent" part of the curves to really get it to do what the OP wants.
To do similar with tubes, I wouldn't look at nicer more linear tubes like the 6SN7, I would look at something like the 12AU7, or even 6BQ7, maybe even the subminiature 6111. Run them at lower voltage (a 19~21 volt laptop power brick and a 7806 voltage regulator for the filament) and i bet it would do the trick. You want to run the tubes in the "bent" part of the curves to really get it to do what the OP wants.
Hi! Thanks for the info.
My idea is put in first place of the chain. Before the preamp. The same place were i connect my music sourse.
My idea is put in first place of the chain. Before the preamp. The same place were i connect my music sourse.
kodabmx's kang, used between line-amp and power amp, can work "OK" at 12V. With obvious simplicity.
Since Cardio75 is looking for "change", I would target well over 1% THD.
Supply voltage to signal voltage ratio has much more effect than tube type. Lo-Mu triodes are much easier than Hi-Mu triodes to get working well at low plate voltage. I'm well aware that 6SN7 and 12AU7 are different at the <1%THD level; but for "change" (from clean sound) we probably want to spank the tube so much that the SN/AU differences don't matter.
Since Cardio75 is looking for "change", I would target well over 1% THD.
Supply voltage to signal voltage ratio has much more effect than tube type. Lo-Mu triodes are much easier than Hi-Mu triodes to get working well at low plate voltage. I'm well aware that 6SN7 and 12AU7 are different at the <1%THD level; but for "change" (from clean sound) we probably want to spank the tube so much that the SN/AU differences don't matter.
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