Recent content by john.luckins

All that information appears in safety data sheet .pdf further down the product page. Do you think that helps make it more legal?

Acetone is very effective on flux but can dissolve some plastics so a little risky/aggressive.

Whether grounding one leg of a balanced source works acceptably depends upon the nature of that source. If the source is an output transformer then there is merely a loss of 3dB of signal. Actively balanced sources are not always so forgiving. One example that I have in front of me here, a...

The simplest solution would be a line input transformer such as the Lundahl LL1540, set up for an asymmetric amplifier input as per the Lundahl datasheet with 2 X 12k loading. Will work with both balanced and unbalanced sources and you do get a 70kHz low pass filter thrown in! I used them on my...

Hi Graham, These look like just the ticket. Conversation started... John

It's a bit safer now we're shot of Peter Bone!

Conversation started by me as I'm just round the corner...hopefully I'm quick enough for once! John

I've just spotted something that looks fishy to me. If you take a look at the ALWSR manual, page 26, you will see figures 7 and 8 are the connection diagrams for local and remote sense. I'm pretty sure you are using local sense in which case the two pins below your "out -" sticker are linked...

I can see that the sensitive end of the ALWSR's, i.e. the voltage references and their RC filters are within a couple of cm's of one of the transformer feeds and its respective rectifier. See if moving the ALWSR's further away from the lower transformer helps. Also , if you are using full wave...

Cricklewood Electronics have the ZTX 653 which is near identical just a higher voltage rating still. John

I mended a couple of the Original Obelisk amps about 10 years ago as well as doing re-caps. I am surprised that Heed haven't used the on board PSU and transformer for the output stage and used this separate power supply to feed just the input biasing and voltage gain stages (front end input B)...

Here are some picies and the schematic for my rather rudimentary layout of a Fetlington Cap Multiplier. I use it in front of ALWSR's when currents are high and/or choke regulation is not possible. I have found it to be beneficial but I would wouldn't I!:D Please note the values on the schematic...

I'll share the files for this high current cap multiplier here shortly, probably over this weekend. I did order 10 boards but have used them all now and there are some improvements to be applied before the next batch. The only tricky component to source is a single N channel depletion mode jfet...

I've always aimed to get between one and two milliamps through R4 to give the LED enough juice to offer a steady voltage and low enough noise. For a 10v output ALWSR you are expecting about 12.5 volts across the LED and R4, which means 10.7volts across R4, so a series pair of 5k1's would be the...

Here's a link to a thread which shows the schematic of the regulator. Looks like a shunt reg with a CCS at the input and an AD797 shunting away excess current via a FET. Should be "workoutable" from this...