it will be witty - tossing out one series 470R , and connecting one adequate shunt R on output
it will relax 6L6/TL combo operation
it will relax 6L6/TL combo operation
I have FT-3 0.22uF, will try later.
Regarding the shunt reg sim, I would like to know, thanks.
The heater reg is a simple 7812 reg, current source worth to try?
I have a Matisse Fantasy clone, difference is thicker mid but a bit rough sounding comparatively to the 6V6 line amp.
Power amp is Aragon Palladium, and speaker is ATC SCM 50P.
Let us know what happened with those FT-3.
It got a bit more flowing with the 317 as Isource like in page 81 schematic, 2x. Will take about a minute to come up. Slow heat up. Can be good for NOS 6V6 long life though. Talking about tubes those are distinguishable in such a circuit. What make are those smoked glass ones in your photo? Exchange some brands if you have around or can lend from friends to taste.
It got a bit more flowing with the 317 as Isource like in page 81 schematic, 2x. Will take about a minute to come up. Slow heat up. Can be good for NOS 6V6 long life though. Talking about tubes those are distinguishable in such a circuit. What make are those smoked glass ones in your photo? Exchange some brands if you have around or can lend from friends to taste.
Hi Salas, a good recommendation to parallel with FT-3, the mid came through with the smooth delicate high, overall a more balance presentation, I love it.
Will change to current when I have time.
Those smoke bottles are Sylvania, have another 2 pairs, Hytrel & GM Genuine Parts, the GM sound quite similar to Sylvania, rebrand maybe?
Just for the record, I used 2 point grounding like Sakuma. Absolutely no audible hum, at least in my system.
Will change to current when I have time.
Those smoke bottles are Sylvania, have another 2 pairs, Hytrel & GM Genuine Parts, the GM sound quite similar to Sylvania, rebrand maybe?
Just for the record, I used 2 point grounding like Sakuma. Absolutely no audible hum, at least in my system.
Possibly rebranding yes. Sylvania is good, I liked a bit more the Miniwatt. RCA should be the best, haven't got any, many others say so. The Tungsol reissue new one is very good.
Quick question -
I have a transformer that has a 6.3v 2A filament winding, and it also has a 5v 2A filament winding.
The B+ winding is only 540v CT so there isn't enough extra to use a tube rectifier.
My question is this - is there any problem making both of the fil windings go into a voltage doubler and then their own regulator, each lighting one 6V6? I.E., using the two windings to heat two tubes? (because one winding by itself cant do both...)
It seems like an efficient use of the transformer.
I have a transformer that has a 6.3v 2A filament winding, and it also has a 5v 2A filament winding.
The B+ winding is only 540v CT so there isn't enough extra to use a tube rectifier.
My question is this - is there any problem making both of the fil windings go into a voltage doubler and then their own regulator, each lighting one 6V6? I.E., using the two windings to heat two tubes? (because one winding by itself cant do both...)
It seems like an efficient use of the transformer.
Not too sure, but what I did was tie all signal ground + heater ground together, connect to chassis near input point, psu ground to chassis at one of the transformer mounting screw. It's quiet.
What is your B+ PSU DC right after the rectifier diodes across the first smoothing capacitor? Also using a 7812 for heaters means you strung them in series?
395VDC,
Yes, 7812 series reg, heater of 6V6 in series, about 5.8-5.9 across each tube heater.
Based on your schematic and data I constructed a sim. Things of notice are:
1. Substantial voltage has to be be dropped across some series ballast to protect the tube cascoded chip for max current. As you did with your RC cells.
2. Ripple eating is so so but it works. Fed 2Vpp 100Hz dc source ripple and 10mApp 1kHz load play in the sim. 140-180mVpp on output. 12.5 times rejection on average (22dB).
3. The output capacitor looks better placed across the high value resistor and trimmer leg for filtering the TL431 ref node. Its a noisy enough chip by itself and that resistor combo is big for Johnson noise. Don't know about stability in that case, it takes much more elaborate modeling and feedback nodes breakage of some full TL431 sub circuit. A practical test would tell much faster. Zo goes higher the opposite way for cap full output shunt or resistor leg shunt, has to do with its bootstrapping the ref or not also. Thus it eats 100Hz ripple stronger due to AC feedback (pic3).
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Good, I didn't think there would be an issue, but it's always good to ask.
Yes, the heaters are only .45A, but the voltage doubler is a current thief, according to Broskie, you only get a bit more than 25% of the winding's AC current rating. (AC current/3.8 = DC current)
True you win some you lose some when transforming tension and current abilities, still 1.5A would cater if you had to.
Hi Salas,
Thanks for the update, as it is, didn't hear any instability. Have been using for a week now, seems ok, did change the 10uF across to the resistor and TL431 ref point this morning though, still run as good.
Thanks again.
Keep it coming if there is any more recommendations.
Thanks for the update, as it is, didn't hear any instability. Have been using for a week now, seems ok, did change the 10uF across to the resistor and TL431 ref point this morning though, still run as good.
Thanks again.
Keep it coming if there is any more recommendations.
Was talking about the change mainly, so it proved stable too. Did it make any subjective change?
Didn't notice any changes.
I am now looking at the Tungsol cryo, what is the difference in soundwise?
I am now looking at the Tungsol cryo, what is the difference in soundwise?
Don't know, I only have the regular set. Not so expensive though. I hope they do not compromise them mechanically during the freeze and thaw cycle at least.
