Hi,
I am upgrading my Anzai SRPP preamplifier starting from the PSU. As I intend to do an all valve PSU I intend to use the attached schematic with EZ80 rectifier and ECL82 regulater. My dilema is:
EZ80 has limit Vac 350-0-350 so I think after clc filtering the Vdc has to be no more than 400-410v. As I need 350Vdc regulated to supply the Anzai, some 60v drop on the serial element of the ECL82 shall be enough? Perhaps some one more practic with spice programe can simulate and give me some real help.
Thanks in advance.
Victor
I am upgrading my Anzai SRPP preamplifier starting from the PSU. As I intend to do an all valve PSU I intend to use the attached schematic with EZ80 rectifier and ECL82 regulater. My dilema is:
EZ80 has limit Vac 350-0-350 so I think after clc filtering the Vdc has to be no more than 400-410v. As I need 350Vdc regulated to supply the Anzai, some 60v drop on the serial element of the ECL82 shall be enough? Perhaps some one more practic with spice programe can simulate and give me some real help.
Thanks in advance.
Victor
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Power supply design must include the *current* needed. Not everybody has all details of all preamps in their head, so a link or some data is needed here. I've seen preamps from 1mA to 120mA.
Tube data is needed. If you have it, share a link. EZ80 data At a glance, there is "no" problem getting quite high voltages out of EZ80, unless current is large.
And the ECL82 data. At a glance the 100V H-K rating limits how we can safely use it as a regulator. The fat-side is a pentode, but small regulators really do not want a floating screen supply, and I wish there was data on the pentode in triode mode.
Why even have a regulator? Most tube circuits are fine as long as the voltage is "steady".
Tube data is needed. If you have it, share a link. EZ80 data At a glance, there is "no" problem getting quite high voltages out of EZ80, unless current is large.
And the ECL82 data. At a glance the 100V H-K rating limits how we can safely use it as a regulator. The fat-side is a pentode, but small regulators really do not want a floating screen supply, and I wish there was data on the pentode in triode mode.
Why even have a regulator? Most tube circuits are fine as long as the voltage is "steady".
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today when ecaps are much improved and can be had in large values and small sizes, tube regulation is really not mandatory...
class A circuits are a fixed voltage/current load, so all you need to look at is your ripple voltage targets....
a CRCRC is usually sufficient...
start with a higher voltage than you need, it is easier to lose voltage than when you do not even have enough...
class A circuits are a fixed voltage/current load, so all you need to look at is your ripple voltage targets....
a CRCRC is usually sufficient...
start with a higher voltage than you need, it is easier to lose voltage than when you do not even have enough...
Hi,
Sorry I did not start with the beginning. My SRPP as attached was a late 70' project nice sounding especialy the RIAA section so I decieded to upgrade it.
The point I consider to make some improovments is the psu which at the verry beginnings was a simple ss bridge followed by an clc filter, then some french guys proposed a valve rectifier and then a ss serial regulater. Now I think is time to make an all valve psu and I allready make some prove using a el36 and half of an ecc83. The difference in sound is astonishing so I'd like to go further using the same diagram original from the AN 2 but shaped for my necesityes 350V 18mA.
TDSL Tube data [EZ80]
You are right in theoty but, as I have less expertise in electonics but a lott of live music listening, I can asure you the difference is astonishing, I mean previeus psu (bridge+clc) against valve rectifier+serial regulater.
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The answer why:
"Why tube regulators?" you're asking yourself. Well, there are good reasons for and against. Some people like the sound of unregulated supplies because "raw" supplies sound more warm and tubey. Others like the sound of regulated supplies because they feel that regulation gives the sound more impact and focus. Some prefer the sound of tube regulators because they find that tube based regulators sound more natural than the solid state variety. All elements in a design affect the sound of that design. The power supply is a major element in any design. The decision to regulate or not to regulate will ultimately be decided on the basis of the resulting sonic qualities -- hopefully
the problem here is that your ear is not my ear and not his ear, as each one of us are unique individuals....
so i would rather go with known science any time...
Ive been using tube based regulated power supplies for a long time, I decided to move to hybrid variations to hopefully bridge the gap, and get the best of both worlds.
I’ve found that Mike Maida’s use of the LM317 regulator to produce HV power supplies useful particularly in tube circuits. It will give you the best S/N ratios and ripple rejection of any topology hands down.
And lastly ,very minimal parts count, another positive!
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Sure, I’ve havent worked any with shunt regulated supplies But I’m curious about this one, I have several 6GV8’s that would work with This arrangement, the ECL82(6BM8)is a little better tube though. I will Post here when I’ve had time to look it over.
Thanks
Ran the schematic you posted through B2 Spice, really nice power supply very low ripple voltage less than 1mV, this was at 30mA rms, 1~20,000Hz. I would make a couple of changes, change the screen resistor from 1K to 100, switch resistors in the voltage divider, so that the trim pot will end up at 350VDC at mid-point!
I would go with it!
I would go with it!
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Thaks, The SRPP Anzai needs no more than 18 mA so I suppose ripple shall be less. In anny case the CLC input filter do a nice job too. Did you mean 100R in stad of 1k? Also have a look at the zenner polarising resistors(R9 R10)...are they right values? I am asking that because in the original schematics of the AN M2 psu they where missing...on purpose by mistake or right?..so the zenner is not polarised at all.
By the way, some time ago I tried the shunt regulated psu at a friend AN RIAA preamplifier but the sonic result was not convincing.
Regards,
Victor
By the way, some time ago I tried the shunt regulated psu at a friend AN RIAA preamplifier but the sonic result was not convincing.
Regards,
Victor
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