If I understand his application correctly, he is trying to heat a 6sn7 filament with a SR. Why?
IMO that type of use would be better served by a simple 7805, with a pair of fwd biased 1n4002s between the 7805 gnd pin and the circuit (-) rail. 5v + 1.2v is almost dead on for a 6v filament tube.
I am using a 36V smps and superreg to replace a 24v smps. I have tried LT1085 LDO based circuit, but it would require a huge filter cap before the ldo to reduce psu hum, and that wasn’t as good as superreg in sound quality.
I don't understand these valve circuits at all, but I'm seeing a lot of valve audio guys talking about very good filament regulators? Tom Christiansen's Maida regulator for instance: 21st Century Maida Regulator: A modern B+ voltage regulator – Neurochrome A friend who built Tom's 300B valve amp was surprised to see three of these regulators required in each stereo amp. That amp has five circuit boards, three of which are the Maida regulators, which really susprised my friend. I think the Maida regulator is mentioned in Morgan Jones' old book too?
Is upgrading from a 78xx to an excellent regulator like the SR useful in improving valve circuit sound quality?
A well implemented 78xx would be good enough.
I was making that statement partially because of my configuration. I used a smps, if you noticed. My specific smps has buzzing noise and LT1085 just pass it through, despite I put a 3900uf in parallel with 0.1uf prior to it. Had to use a 10000uf in pre-regulation to eliminate it. Then I noticed sound was a bit slower and seems smeared in bass (slower, slightly less details) compared with superreg.
So later I changed my wording, specifying that superreg is much more efficient, in case some people have a different preference.
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Is this not for the complete amplifier, a 24V anode voltage very low voltage tube amp?
Jan
Simulation for LT3042, supposedly a bit inferior to LT3045, shows 12uOhm @ 80Hz and 29uOhm @ 700Hz.
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That's because you have a heavy load on the regulator and pass transistor.
The convention is to use a 25mA load ... this keeps everyone on the same page when testing regulators for stability. (If I were to go back and retest all the regulators for the Linear Audio article I would use 25mA and run the Z-test out to a few megaHertz - )
Set I_1 to AC=1, DC=0.025 and eliminate R7, or AC=1, DC=unspecified, R7=600 Ohms.
D45H11 is in the LTSpice library isn't it? BD140 isn't a good choice as hfe is lower and safe operating area smaller.
It is possible, but I will leave it to more experienced members to explain any downsides and limits.
I built the Reliaxed2 pre-amp a decade ago. That design used an opamp at low gain as a buffer for an analog section power supply. Of course, an opamp is limited in current output capacity and most would struggle at the 25 mA test standard. And the opamp needed to be close to the load because of capacitance drive limits. But an opamp running near unity gain can have a low output impedance.
Naturally, this approach could be implemented with discrete components.
In Reliaxed2 passive amp did you noticed any sound improvement of relay based volume control over standart cement or alps pots?
First, the Reliaxed2 isn't completely passive. It has a single opamp with about 6 dB gain in the signal path. That was used to control impedance.
I did compare it with a mid level Alps pot and also to a Lightspeed Attenuator that I borrowed from a friend. The differences weren't big, but I did prefer the Reliaxed2 over the Alps and Lightspeed.
I did compare it with a mid level Alps pot and also to a Lightspeed Attenuator that I borrowed from a friend. The differences weren't big, but I did prefer the Reliaxed2 over the Alps and Lightspeed.
"Jung super regulator "
Hi all.
Surfed a bit around on fleebay and noticed this regulator, it uses lme49710 opamp, and I guess all those led's are current sources.
There's literally no specs on this thing which makes me suspicious.
Has anyone here tried one and maybe measured it? And the topology? I don't recognize any jung here.
Link to product.
HiFi Walt Jung Super Regulator DC Power Supply Board Linear Audio For DAC Preamp | eBay
Hi all.
Surfed a bit around on fleebay and noticed this regulator, it uses lme49710 opamp, and I guess all those led's are current sources.
There's literally no specs on this thing which makes me suspicious.
Has anyone here tried one and maybe measured it? And the topology? I don't recognize any jung here.
Link to product.
HiFi Walt Jung Super Regulator DC Power Supply Board Linear Audio For DAC Preamp | eBay
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