So, two positive regulators are used instead of the usual negative-positive regulator paring. The odd fact about three-pin IC voltage regulators is that no one makes a great negative voltage regulator or, put differently, no one makes as good a negative regulator as the LD1084 is as a positive regulator. But more importantly, this new PCB can be configured configured as a bipolar power supply for use with solid-state circuits. In fact, it holds two LV-Reg regulated power supplies.
This newly designed 4.5 by 4.4 inch PCB holds two low-voltage bipolar regulated power supplies. The most important change is the return to the option of building an Aikido push-pull headphone amplifier. I made a few changes to the Aikido noval stereo PCB, so it is now in revision F. Friends and readers had been telling me for years that giving each channel its own heater power supply improved the resulting sound. In other words, both channels would share the single high-voltage B+ voltage and ground, but each channel's heater would get its own independent voltage regulator. In post 459, I wrote about my urge to build a truly minimalist line-stage amplifier, which would take advantage of my PS-21 power supply that offers a regulated high-voltage and two entirely separate low-voltage outputs. One PS-8 power supply will easily power two electrostatic amplifier PCBs. Both PCBs are 3.4in by 6.4in large and two are required for stereo listening. The ES HPA-1 uses a noval input tube and an octal output tube, while the ES HPA-2 uses noval tubes I both positions. I have decided to finally release for sale these two PCBs and the PS-8 power supply. How do you get 120Vdc out 12Vac? A voltage octupler circuit, which uses many rectifiers and capacitors to build up the raw DC voltage of about 130Vdc. The heaters get DC voltage and the two SRPP circuits get a high-voltage B+ voltage of about 120Vdc. Why? My existing two other 12Vac designs are big hits, as the 12-volt AC sidesteps the wise fear of high-voltage.The most interesting part of the design is the on-broad power supply. Thus, the name change.Īfter writing about both the new 12Vac SRPP in post 505 and single-ended MOSFET-based power amplifiers in my last post, the itch to actually build hybrid headphone amplifier based on the SRPP and the Zen single-ended power amplifier proved too hard to resist-so I laid out a PCB design and had them made.Ī while ago, I decided to make my next design an SRPP-based one furthermore, it had to be a 12Vac design. In addition, I decided to replace the old pair of voltage regulators, the LM317 & LM337, with newer low-dropout designs, the LT1086 & LT337. Recently, low-voltage bipolar power supply kits are all the rage, so I decided to reintroduce the design.
#T RACKS DELUX SONNOX OXFORD NAMD BLUE TUBE DRIVER#
The PS-11 makes building a tube power amplifier much easier, as it provides three output voltages taps: one for the output tubes, one for the driver stage, and one for the input stage.Īctually, the PS-22 is the old PS-19, which I stopped producing years ago. This change meant that I could not use the half-wave octupler rectifier circuit to create to the high-voltage B+ rail for tube use. So, instead I created a 12Vac power supply that delivers a regulated 12.6Vdc (or 12Vdc) heater voltage. Why not? The 12Vac SRPP's power supply creates a 24Vdc heater voltage, which limits its usefulness for most tube fanciers. I have needed this power supply for a long time now, as I own both an HK Citation II and two Heathkit W-6M tube power amplifiers, all of which use solid-state rectifiers and a voltage doubler rectifier circuit to establish their B+ voltage and both need a refurbishing.ĭue to several requests for a PCB that held the 12Vac power supply from the 12Vac SRPP. The new Attn-2 uses two rotary switches, one 6-position switch (on the left) for fine decrements of 1dB and one 12-positon switch (on the right) for coarse 6dB decrements, which allows for 0dB to -65dB in 1dB steps for two channels.
Thus, the need to be frugal with the number of switches used. Sadly, they are never cheap-well, at least the high-quality ones are never cheap, as the sealed switches with hard-gold contacts are expensive in the extreme. Stepped attenuators deliver decisive clicks and precise attenuation. The wire is easy to work with and quite heat resistant (500 ☏ and 260 ☌) and maintains its twist perfectly. I found the solution: 23-gauge, solid-core, Teflon-FEP coated CAT-6 wire. Why not? The wire is either 24 or 26 gauge and the sheathing is usually PVC, which is not very heat resistant, and the wire easily unwinds. I have been making due with taking apart CAT-5 cable, but the results are not ideal.
I needed hookup wire, as my old stock finally ran out.
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