seams a waste to use the GU46 with such a low voltage and tiny PSU.
GU46 is better over 1500V and 250mA
GU46 is better over 1500V and 250mA
Why would it be better? Sounds better? To USE 1500 Volts and 250 Ma. the Japanese have found many Tubes sound better at lower voltage, like the 833. I run 572B's at 600 volts 70 Mills very Good sound over 100 Watts
Phil
Phil
Up Date, ongoing work on PSU
All transformers and chokes have finally arrived.
Nearly 40kg of custom wound toroid transformers from toroid.pl
Nearly 40kg of output transformers and custom wound chokes from ogonowski.eu
Output Transformer SE 150W 4.5k/8&16Ohm, 13.7kg in EI 150/93 - 16 Ohm tab will be used as 8Ohm tab to get 150W, 2.2k/8Ohm
First level with transformers, safety diodes, rectifiers, "low" voltage chokes (650VDC), russian 4uF caps.
Seconds level with high voltage chokes (1200 VDC) and caps.
Rectifier Tubes: 4x 5C8S per channel
Schematics will be updated
All transformers and chokes have finally arrived.
Nearly 40kg of custom wound toroid transformers from toroid.pl
Nearly 40kg of output transformers and custom wound chokes from ogonowski.eu
Output Transformer SE 150W 4.5k/8&16Ohm, 13.7kg in EI 150/93 - 16 Ohm tab will be used as 8Ohm tab to get 150W, 2.2k/8Ohm
First level with transformers, safety diodes, rectifiers, "low" voltage chokes (650VDC), russian 4uF caps.
Seconds level with high voltage chokes (1200 VDC) and caps.
Rectifier Tubes: 4x 5C8S per channel
Schematics will be updated
Attachments
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Hi jazbo
Wiring is a bit messy on the lower level, but this is on the AC side only, DC is less messy.
The amp is a stereo amp, all parts in one rack, made of industrial aluminium profiles and plates. High voltage areas will be covered with 6mm plexy.
A Siemens Logo 8 will manage the start up and shut down procedure of the amplifier, switching heater transformers, bias transformers, high voltage transformers and the signal relais on and off.
Including a safety loop for closed housing.
Low ampere DC heaters will be regulated with tentlab supplies - why reinvent the weel.
For the GU-46 I am still looking for a good DC regulating solution, 13V unregulated DC in, 8.3V regulated DC Out at 15A.
Does anyone have a simple and effective schematic for these currents?
Wiring is a bit messy on the lower level, but this is on the AC side only, DC is less messy.
The amp is a stereo amp, all parts in one rack, made of industrial aluminium profiles and plates. High voltage areas will be covered with 6mm plexy.
A Siemens Logo 8 will manage the start up and shut down procedure of the amplifier, switching heater transformers, bias transformers, high voltage transformers and the signal relais on and off.
Including a safety loop for closed housing.
Low ampere DC heaters will be regulated with tentlab supplies - why reinvent the weel.
For the GU-46 I am still looking for a good DC regulating solution, 13V unregulated DC in, 8.3V regulated DC Out at 15A.
Does anyone have a simple and effective schematic for these currents?
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You could use one of these but I dunno if you want to go switching...
https://www.ebay.ca/itm/DC-DC-Conve...8fe0965c0:m:mCHY1nLxgu47cYpdyd1LmDA:rk:2:pf:0
https://www.ebay.ca/itm/DC-DC-Conve...8fe0965c0:m:mCHY1nLxgu47cYpdyd1LmDA:rk:2:pf:0
I'd try just plain AC heating to start, hum may not be an issue at all. 🙂
@ kodabmx I would prefer to go the classic way with a voltage regulator
@ jazbo AC heated GU-46, even with a SE output stage? I am a bit afraid to so, I wouldn't want to reopen the box for just having chosen the easiest way in the worst case.
Does anyone else have experience with voltage regulators for low voltages (8.3V DC) in high current environments (15++ A)?
@ jazbo AC heated GU-46, even with a SE output stage? I am a bit afraid to so, I wouldn't want to reopen the box for just having chosen the easiest way in the worst case.
Does anyone else have experience with voltage regulators for low voltages (8.3V DC) in high current environments (15++ A)?
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I have just finished my high current regulator for the GU-46
It works pretty well, set up as follows
- bridge rectifier 60A/40V
- SL32-2R005
- Common mode choke 1.3mH/20A
- 300000uF Sprague Powerlytic 36DX
- Elvees's regulator (see link below, Post #5)
delivering 8.3V DC with not measurable AC
Unfortunately my GU-46 tube seems to have lost vacuum, it develops smoke inside when heated, something I have never seen in any other tube. Tube will be replaced.
Low voltage regulator for high current consumer
It works pretty well, set up as follows
- bridge rectifier 60A/40V
- SL32-2R005
- Common mode choke 1.3mH/20A
- 300000uF Sprague Powerlytic 36DX
- Elvees's regulator (see link below, Post #5)
delivering 8.3V DC with not measurable AC
Unfortunately my GU-46 tube seems to have lost vacuum, it develops smoke inside when heated, something I have never seen in any other tube. Tube will be replaced.
Low voltage regulator for high current consumer
Attachments
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Tested with a new tube, very stable at 8.3V DC, 10mV of AC measurable.
The set up needs 20s to power up completely.
Schematics will follow when the amp is finished.
The set up needs 20s to power up completely.
Schematics will follow when the amp is finished.
Have always used L-C filters for heating supplies. In this case, where it is the ripple and not absolute voltage that counts, the capacitance you already have, in combination with some fraction of a Hy should get quite quiet. In any case, I do not worry about SE implementations, and in PP even the 10V of an 813 is quiet.
cheers,
Douglas
cheers,
Douglas
I opted for Rod Coleman regulators. They work quite well (used 3 in paralell for the GU46) and I've seen their effect on sound in other SE's.
Up date
PSU is nearly finished, 8.3V voltage regulator for GU-46 filament, tentlabs regulators for 6.3V heaters, voltage regulators for GU-46 grid and bias regulator.
Additional voltage regulators available in case of need.
PSU is nearly finished, 8.3V voltage regulator for GU-46 filament, tentlabs regulators for 6.3V heaters, voltage regulators for GU-46 grid and bias regulator.
Additional voltage regulators available in case of need.
Attachments
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It will work fine, just would add one resistor and two caps, to reduce zenner noise in the mosfet gate.
up date
small update
new pictures from the amp, Pete Millets 12hg7 driver is installed to drive the GU-46 - maybe i will change this later to an other tube type
the bridge rectifiers of the filament supplies for the GU-46 need to be replaced since they got so hot that they de-soldered themselfes
The HV is rectified with 4 5C8S tubes per channel, visible in the lower tube compartment. all tubes are shielded with Lexan / Plexy
A schematic of the latest set up will be postet as soon as the amp runs properly
the adjustable negative feedback is not yet tested
and yes... the white silicone does not look too sexy but i was too lazy to fix the wiring with screws (an wanted to avoid metal debris in the lower compartments)
small update
new pictures from the amp, Pete Millets 12hg7 driver is installed to drive the GU-46 - maybe i will change this later to an other tube type
the bridge rectifiers of the filament supplies for the GU-46 need to be replaced since they got so hot that they de-soldered themselfes
The HV is rectified with 4 5C8S tubes per channel, visible in the lower tube compartment. all tubes are shielded with Lexan / Plexy
A schematic of the latest set up will be postet as soon as the amp runs properly
the adjustable negative feedback is not yet tested
and yes... the white silicone does not look too sexy but i was too lazy to fix the wiring with screws (an wanted to avoid metal debris in the lower compartments)
Attachments
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It's certainly the largest DIY build I have seen in a long time!