As a plain inductor then. That's loading it no doubt. How much bias current your preamps run on 26 tubes? 6+6mA or 10+10mA?
Salas, George,
OK 40mA for the reg.
Yes my power amp with 100k input and I'd like to try anything recommended for I want to pull the best from both opt and the reg. I'd firstly try using the primary as choke with Murdorf silver/gold 0.47 then go on with resistive load so to compare.
Will report asap.
Albert
OK 40mA for the reg.
Yes my power amp with 100k input and I'd like to try anything recommended for I want to pull the best from both opt and the reg. I'd firstly try using the primary as choke with Murdorf silver/gold 0.47 then go on with resistive load so to compare.
Will report asap.
Albert
Salas & George,
Has done the compare with the RC & LC. I still like the LC, only 100H with 1660 10mA, it sounds a bit smoother to me. I need more higher B+ for the RC 22k load. RC measured a bit better with square wave up to 7K, 10k still acceptable and turned really ugly above 12k. LC is good up to 5.5k, sounds more open and not that congest/compress as 4.5:1. It also looks good down to 50 Hz. I'd like to try the LC route further with higher inductance choke, 200-300H. Will the reg handle the total of 600H, or I'll need another reg for the other channel ??
Albert
Has done the compare with the RC & LC. I still like the LC, only 100H with 1660 10mA, it sounds a bit smoother to me. I need more higher B+ for the RC 22k load. RC measured a bit better with square wave up to 7K, 10k still acceptable and turned really ugly above 12k. LC is good up to 5.5k, sounds more open and not that congest/compress as 4.5:1. It also looks good down to 50 Hz. I'd like to try the LC route further with higher inductance choke, 200-300H. Will the reg handle the total of 600H, or I'll need another reg for the other channel ??
Albert
100H is a bit low for the #26. I use the 1660pp which is more than 200H.
You can always put two chokes in series.
The reg can handle the total current for two channels, even if you use more induction, but two is better than one.
You can always put two chokes in series.
The reg can handle the total current for two channels, even if you use more induction, but two is better than one.
Thanks George,
I have couple 0.22 FT-3 teflon on hand, would compare with the Murdorf silver gold. I already put the order for 4 156c chokes, and would try to follow Andy's route with 2 156c in series. Will let you know asap.
Albert
I have couple 0.22 FT-3 teflon on hand, would compare with the Murdorf silver gold. I already put the order for 4 156c chokes, and would try to follow Andy's route with 2 156c in series. Will let you know asap.
Albert
Ok guys, help me in my thinking:
I have just designed, etched and soldered my first Salas HV shunt reg (SSHV2). I would like to use it in a line stage, which will be a ~12mA load @ 200V. Hence I use a 15K dummy load (200/0.012=16.6K).
My raw supply is as follows (dual mono):
Transformer -> EZ80 -> CLCLC (-> SSHV2)
On the 100K bleeder resistor I am using, the PSU gives 220V.
When I attach the SSHV2 with a 15K load, I observe the following:
- SSHV2 led goes on (that's a good sign!)
- Input voltage is 125V... that's less that without load, but so much??
- Output voltage is 125V
- Across R5 (T.P.) I measure 95mV (so 9.5mA CCS)
- Turning any of the pots does not change output voltage/current
Am I missing something? The transformer has 100mA windings so should not be sagging so much....
I have just designed, etched and soldered my first Salas HV shunt reg (SSHV2). I would like to use it in a line stage, which will be a ~12mA load @ 200V. Hence I use a 15K dummy load (200/0.012=16.6K).
My raw supply is as follows (dual mono):
Transformer -> EZ80 -> CLCLC (-> SSHV2)
On the 100K bleeder resistor I am using, the PSU gives 220V.
When I attach the SSHV2 with a 15K load, I observe the following:
- SSHV2 led goes on (that's a good sign!)
- Input voltage is 125V... that's less that without load, but so much??
- Output voltage is 125V
- Across R5 (T.P.) I measure 95mV (so 9.5mA CCS)
- Turning any of the pots does not change output voltage/current
Am I missing something? The transformer has 100mA windings so should not be sagging so much....
I would have been pretty proud if it had worked...
The whole reg is mounted on a huge heatsink
The whole reg is mounted on a huge heatsink
An externally hosted image should be here but it was not working when we last tested it.
DC input must be 20VDC higher than Vout target
CCS target must be 20mA more spare for proper regs power consumption to good output impedance spec so setup your CCS current accordingly 12mA target + 20mA shunt needs you must set your CCS to 32mA
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aarghhh.... I don't have a suitable load resistor so can't test this Sunday. It'll have to wait until tomorrow.
Btw, PSUD2 tests it at 178V (which is too low for me, but still higher than I see when I hooked up the SSHV2)
Btw, PSUD2 tests it at 178V (which is too low for me, but still higher than I see when I hooked up the SSHV2)
Stick a capacitor across the input connector to decouple. Twist the wires if feasible. Also are your 100 Ohm gate resistors really near to the Supertex Mosfets gates and with short pin in your layout?
Unfortunately didn't help.
I noticed, though, that I am able to trim both the CCS and the voltage between
-CCS: 95ma to 130ma
-Voltage: 127V to 111V
So I think the reg is working properly....
the gate resistors are within 1cm (or less)
I noticed, though, that I am able to trim both the CCS and the voltage between
-CCS: 95ma to 130ma
-Voltage: 127V to 111V
So I think the reg is working properly....
the gate resistors are within 1cm (or less)
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It helped, because you couldn't trim anything before. Your low input voltage thing is you need a different transformer. This one sags a lot and/or your coils are too resistive for 30mA CCS not to drop much voltage.
You are probably right, but usually PSUD2 is quite spot-on:
I am using a transformer from a reputable source in Germany, multiple members have used it before without problems.
The chokes are specified by the same source as 330Ohm. I have modeled this correctly in PSUD2.
I did some further calculation, and think I could live with 170V input voltage (then I could have 150V output voltage which would work in my application). However I still don't understand this extreme sagging...
I am using a transformer from a reputable source in Germany, multiple members have used it before without problems.
The chokes are specified by the same source as 330Ohm. I have modeled this correctly in PSUD2.
I did some further calculation, and think I could live with 170V input voltage (then I could have 150V output voltage which would work in my application). However I still don't understand this extreme sagging...
Salas, would there be any trouble using ~5-10cm wires from the Q3-spot on the PCB to mount the FET a little to the side?
Quite possibly, can't predict because it was never designed or tested like that. In any such a test I would move the gate resistor from PCB right at the pin (restore continuity at PCB also), hook scope on rail for oscillation stake out, and start at lower voltage if possible.