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Just a quick pic of the soft start board I have made and fitted to my 1KW Heathkit SB-200 RF amplifier. Tested and working well. 2 x 5172B valves.

A few weeks ago I won a very scruffy, ancient Mullard 5-10 in a raffle. I decided to clean it up a bit and see if I could get it to play, after finding most of the right valves in my second-hand spares box. I tested the power transformer and got 320-0-320, 3.15-3.15 and 2.5-2.5. I then changed...

I am trying to fix a broken 13.8V 10A DC Regulated Power Supply. It is a Spectrum PS4140M Model DF1763SCT. The PCB is marked AQF7820.7409. I cannot fine the schematic, after a lot of searching, so I thought I would ask our resident gurus for help. I have AC coming in to the transformer, being...

Please help! I've managed to get my mind in a knot regarding this, and need some pointers. The valves are 12AX7, so triodes. There are 4 of them in my phono pre-amp. I know one can supply the heaters either in series (12.6v) or in parallel (6.3v). AFAIK the 12.6v series feed goes to pins 4 and...

I need to buy a 100% legal, 100% not-a-scam and very, very cheap copy of Windows 11 for my HP microserver. Where do I go? Thanks, Johan

I have decide to build one. Any ideas / thoughts / pointers / do's and dont's? Or any designs that work well, and I should consider? At this stage very simple - no transformer volume control - but things may change in future... Please let me have your thoughts. Thanks!  :thumbs:

I need 1 x4uF 600~1000VDC cap and 2 x 8uF 600~1000uF caps to replace leaky, out-of-spec paper in oil caps in an old valve amp. (Power supply filter and smoothing caps.) Preferably I would like to cut open and re-stuff the big black square capacitor can, and re-fit. So size /may/ matter :-)...

Does anyone know anything about the Hammerstein brand of valve radio grams made in SA in probably the 60's? I am busy converting this one into a small audio amp. I have removed all the "radio" bits, and replaced most of the caps (most of them wildly out of spec!) as well as some other parts...

I am looking to start building a push-pull Class AB EL84 stereo valve amp soon. I have the input transformer(s) and two EL84 output transformers. I have come across the Il Terzo by Giuseppe Amato, and I like his approach and design. It all seems clear and simple (well thought out, and well...

A few months ago I bought a non-working little old suitcase turntable with built-in amp. The thing - probably from the late 1950's or early 1960's - had a wobbly thin pressed-tin 7-inch platter, a plastic arm with no head shell and moths had eaten every non-metal bit of the single speaker, and...

I am really curious as to why so many people find (what they consider) a "low ball offer" so insulting and/or offensive? (Unless, of course, someone said: "Hey you, with the big ears, and the beer boep, and the tiny penis, I will give you R1 for your R65,000 amplifier". Then I would be offended...

I have seen, in the past some thoughts on how to "restore" / "rejuvenate" / "refurbish" an old turntable idler wheel. In this case there is no cracking, no flat spot and no excessive hardening, but I still want to treat the dull grey-ish rubber to ensure this wheel works as best as possible...

I am looking for five, preferably six, 5751 valves for my Conrad Johnson Premier Three pre-amp. Used, new or NOS - I will consider them all. If anyone can be of assistance, please pm me with details and price. Thank you!  :groovy:

I have started looking at this little valve amp, the Leslie Model 125. I have replaced all the caps and resistors, except the 2 "cement" (wire wound) resistors that stick out the top. They measure fine. The 4-1 metal cap was way, way out on almost all readings. Replaced with separate caps...

My Retina Display MBP 13" mid-2014 now has a tired battery (down to max 2 hours). I am considering having a new battery put in. Any recommendations in Cape Town? And an idea of price? (It seems that MacWave in the city can replace for R2084 and no labour cost - is this a good deal, or can I do...

I am the very lucky new owner of an almost-40-year-old CJ P3 valve pre-amp. I really like the look and feel of it, and I love the sound! It honestly is everything I have always wanted from a pre-amp to drive my various valve power amps. I do, however, have 3 questions about this pre-amp. (I do...

Pic 1 shows what a parcel looks like when it has spent 10 days travelling down from the far North East of SA down to Cape Town, and then back up to the far North West of SA (West Coast) transported by the "trusty" Stofpad Koeriers :-)(name made up, as I am not sure where the blame should go)...

I have obtained a scruffy-looking pair of QUAD II amps, S/N 30773 and 30679. They are going to need a lot of cosmetic work, but all the resistors and capacitors have been replaced in 2014, (for a total component cost of R82 from Communica in Cape Town!) :-) I will check all the values, and make...

This morning, while carrying an Irish load, I dropped my trusty Fluke from a height of about 1m onto the tiled kitchen floor. When I switched it on, the display comes on for about 1 second, then goes blank. Every time. :sd: :sd: :sd: I opened it up, checked and cleaned the rotary selection...

My partner (a lecturer at UCT) is looking to buy a new MacBook Pro 13". This one: 13-inch MacBook Pro 1.4GHz quad-core 8th‑gen i5 processor 256GB - Silver from R28 999 now R27 999. iStore and Digicape are "out of stock", even though iStore advertised a R27K special (less a 5% teachers'...