Looks like the transformer specified (MCI MLP75) is from a US maker, still operating. So you could ask them if their MLP75 can supply 4,2A rms from the ~5V windings.
Contact MCI Transformer Corporation - MCI Transformer Corporation
Contact MCI Transformer Corporation - MCI Transformer Corporation
Hi i have a problem. I have 813 tube amplifier with rod coleman dht modules, and i have humm in my speakers. First i have a litle hum in setup: 200va 2x 19v toroid , raw dc with 10000uf - 40mh inductor coil ,10000uf, 0.33R resistor-0.47R resistor -5x 10000uf and rod coleman module with give me 10v 5A out for one 813tube. Raw dc was near 15v out. Problem was in resistors they was to hot, on resistor i have 5v i give us about 25wat of hot, so i consider to desolder resistor and put 0.1
R and to rebuild my toroid to get lover voltage. \so now i have about 14v AC and 14.4V raw dc out. I was proud for my work, but when i turn on my amplifier i heard more noiser ham that i have last time! damn 🙁 resistor and inductor coil is on +. Please help my, what to do with this hum? i will be problem to add more resistor cuz i dont have more voltage.
R and to rebuild my toroid to get lover voltage. \so now i have about 14v AC and 14.4V raw dc out. I was proud for my work, but when i turn on my amplifier i heard more noiser ham that i have last time! damn 🙁 resistor and inductor coil is on +. Please help my, what to do with this hum? i will be problem to add more resistor cuz i dont have more voltage.
With your raw dc constructed like this, there should be no hum.
I will send some email - for taking measurements.
I will send some email - for taking measurements.
I have bridge recyfilter not mbr diodes, it is problem? And i have just one 0.1 R resistor and one incuctor coil, everythink on +site. Hum is noiser than last two resistor i haved before.
Yes.
"Normal" diode has significantly more (about double) drop voltage than schottky ones, thus dissipation also more.
If you use ONE large capacitor as C1, the charging spikes on C1 would reach 10A current! Fast (schottky, FRED/HEXFRED, SiC) diodes makes "better" transient responses, than "normal" diodes in the bridge.
For now im changeing my bridge for mbr diodes, and i have seen that i have not CLRCCC But i have LCRCCC it is problem? ot is Ease to change to CLRCCC just cut one wire.
After a huge success in using the Rod regulator (V2?) in 300B, 4P1L and GM70, I'm wondering if I could use it for my next project (still in paper and just starting some trials) with a GU46 SE. The filament needs some 8.3V 13.5 to 16 A. As so filament impedance is very low, so not sure the regulator will make a sensible improvement. Also dissipation might be an issue...
Rod, can you give me some insight on the way to go?
Rod, can you give me some insight on the way to go?
I'm pleased to hear that the DHT amps are a success!
The low impedance of the GU46 filament does not diminish the success in using current regulation - the filament impedance can be almost zero - so long as the dynamic impedance looking outward is high.
up to 16A is too much for a single regulator though. But they are able to operate in parallel perfectly (it's been done a number of times). This is because currents always add (as Kirchoff says they do), an the Regulator has no voltage feedback to get in the way.
Maybe if you send me some email, we can check if there's a suitable solution for you.
The low impedance of the GU46 filament does not diminish the success in using current regulation - the filament impedance can be almost zero - so long as the dynamic impedance looking outward is high.
up to 16A is too much for a single regulator though. But they are able to operate in parallel perfectly (it's been done a number of times). This is because currents always add (as Kirchoff says they do), an the Regulator has no voltage feedback to get in the way.
Maybe if you send me some email, we can check if there's a suitable solution for you.
Hi. I would use Duncan Amps PSUD2 simulator. You can get simulator result real close to real result.
PSUD2
Adrien.
From the Hammond transformer catalog:
Attachments
Hi Rod,
Any problem with referencing the regulator to -250VDC?.. that is to say that the design has a fixed biased stage with filament (DH) referenced to -225V.
L.H/S
Any problem with referencing the regulator to -250VDC?.. that is to say that the design has a fixed biased stage with filament (DH) referenced to -225V.
L.H/S
Hi - When the filament is biased away from ground, the voltage applies stress at 2 places:
- from the power transistors to the heatsink;
- across the power transformer.
For Receiving-Tube versions of the Regulator, the all-plastic power transistors can withstand up to 2.5kV.
Correctly-made modern power transformers can also withstand kV levels of stress.
No problems.
For Transmitter versions, the transistor Q5 should be attached to the heatsink with a clip, rather than a screw, for better isolation, when high voltages are present on the "cathode".
Heatsinks with clips are made by companies like Aavid-Thermalloy, ABL Heatsinks, etc., and Laird make good clips for mounting the transistor directly to a chassis.
TSC607-ZP - LAIRD TECHNOLOGIES - CLIP, 2 X, TO-220 | Farnell element14
- from the power transistors to the heatsink;
- across the power transformer.
For Receiving-Tube versions of the Regulator, the all-plastic power transistors can withstand up to 2.5kV.
Correctly-made modern power transformers can also withstand kV levels of stress.
No problems.
For Transmitter versions, the transistor Q5 should be attached to the heatsink with a clip, rather than a screw, for better isolation, when high voltages are present on the "cathode".
Heatsinks with clips are made by companies like Aavid-Thermalloy, ABL Heatsinks, etc., and Laird make good clips for mounting the transistor directly to a chassis.
TSC607-ZP - LAIRD TECHNOLOGIES - CLIP, 2 X, TO-220 | Farnell element14
http://www.diyaudio.com/forums/tubes-valves/38248-new-dht-heater-34.html#post2667405
Hi. I am upgrading from v4 to v7. I was wondering if for the v7, is it also best to have positive return? Currently my v4 is wired for positive return on both 3C24 (filamentary bias) and GM70 (fixed bias).
Thanks,
Adrien.
Hi Adrien,
Yes, Connect the positive side of the filament to system ground, for best results. The regulator version makes no difference to this. You can try it with negative to ground, if you like, since the sound quality is the chief concern. BUT, the bias (anode current) is affected by the choice of +/- to ground, so please make adjustment of bias voltage, to compensate for this effect, before listening, and comparing.
Yes, Connect the positive side of the filament to system ground, for best results. The regulator version makes no difference to this. You can try it with negative to ground, if you like, since the sound quality is the chief concern. BUT, the bias (anode current) is affected by the choice of +/- to ground, so please make adjustment of bias voltage, to compensate for this effect, before listening, and comparing.
You have posted a schematic that shows 2ST1480FP as an alternative to MJE15032 I was going to build your circuit, should I not try to use 2ST1480FP?
The project has moved on a lot since this old version of the circuit - along with the performance. The regulators are now available as my DIY self-assembly kit. The 2ST1480FP was OK for the old circuit, but it is obsolete, and has not been available for years.
I have read through most of this thread should I be using 2SC3852 and ztx489's at this time.
I'd like to use this thread to ask a question about optimising the filament supply before the filament regulator, by which I mean Rod's regs in my case and most others.
How many of you use choke input supplies, or a CLC supply? And have you heard a difference in sound quality? If so, what's the difference - is it smoother or what exactly?
I did some tests with my 4P1L amps, and to my ears it was a little smoother, and I'd like some input from others to see if there's any general agreement!
How many of you use choke input supplies, or a CLC supply? And have you heard a difference in sound quality? If so, what's the difference - is it smoother or what exactly?
I did some tests with my 4P1L amps, and to my ears it was a little smoother, and I'd like some input from others to see if there's any general agreement!
I use LCLC before Rod's regs in both my preamp/DAC and 833C amps. I also use it for the input/driver and output stages of my amps. I prefer choke input, as to my ears it sounds, as you say, smoother.
I just installed Guido Tent's Directly Heated Tubes Supplyboards and I am swiped away with the quality and results. Great build, easy to use.
I use it SE. I have the plus on pin 1 of my 300BC (carbon plate, like a 211) and also I have the cathode resistor there.
So Guido, kudo's
I use it SE. I have the plus on pin 1 of my 300BC (carbon plate, like a 211) and also I have the cathode resistor there.
My Chinese 300BC have a slight imbalace in the winding; in pushpull and AC it can be balanced quite well, but not on a SE application. And then: even a normal DC feed, CCS, shunt still gave some mains lines disturbances.
Now it is quiet as night.
Great depth of sound. Now it is quiet as night.
So Guido, kudo's