I've built and sold hundreds of amps, but there come a time to move on sales have dropped off and I need to pursue new things going forward this leave me with a LOT!!! of pcbs 3 Channel amps 12Au7 amps Cmoys 100's RA1 Cmoy boards both rechargeable and normal rechargeable amps bass boost amps...

Hi guys I've been a little absent from the boards life got in the way :-) in summary   My wife passed away after 19 years with cancer I had a scan on my back - results were - your back is stuffed oh and by the way you have cancer had surgery to remove a kidney - hurt like a pig!! then had...

I needed some Starving Student pcbs and the only way to get a decent price was to buy quite a few, I have checked with the moderators and it's ok for me to sell these at cost plus postage There always seems to be someone wanting to try their hand at building the SS this is the 12AU7 version  ...

Neutral and completely transparent, in fact it has no audiable effect on the sound at all !!!!   tested with several dac's and not one of them even noticed the tube     its so good I'm willing to put the design in the public domain, I'm sure there will be lot of group buys  ...

I was asked by a member to build them a K272A, they had the parts but not the time   This is what happened     Loads of very clear instructions infact the board is so simple you really don't need instructions, its like painting by numbers     Filling the board was quick and...

Got these from ebay, something just looks wrong     cheers FRED

********************************ALL GONE************************************************************************   Going through my junk box (making room for more junk) I found these cmoy pcbs, I don't want them and I will post them for free to anyone in Australia   There's only 4, first...

This is based on an idea from Avro_Arrow and he suggested I try it   First take your copper board   Now don't use steel wool or any kind of abrasive, simply put in in the etching solution for 30sec to 1 min until its an even salmon color     then normal ironing on the layout...

I thought I'd have a go at one of these   many thanks to Dsavitsk for the modified circuit       The case is the next problem, but it sounds great so I'll worry about it later :-)   its nice and stable just sitting on the caps   anyhow just sharing  ...

I have just started using a Sansa view and an e260, first thing I'd better get a LOD for them   It arrived today, looks just like an iPod LOD and it works with both the iPods and the Sansa's   NOT with the iPhone 3GS (but its a pig anyway)   so the LOD's are interchangeable between...

I know I'm missing something, but I just don't see how this is working??    http://i460.photobucket.com/albums/qq329/Fred_fred_2004/CIMG8357Small.jpg   Using a tread type powersupply to power both a simple Cmoy and a simple Szekeres amp,   source (sansa) to cmoy input, cmoy output to...

    Start with a very small electret mic insert 3mm is good               Bulk it up with a few layers of good old heat shrink               Put on a final layer this time insulate the mic body                 ...

I have a young friend of the family heading over with his pride and joy a Nintendo DS, this has had milk poured into it by baby brother and has stopped working (surprise). To clean it I plan to open the case rinse it throughly with distilled water to get all the milk particles out, then rinse...

I couldn't find a tool I needed for love nor money so I set out to make one Brass tube 9/32" and brass rod 1/8" Grind and file Bend the rod Go mad with heatshrink Guessed it yet YES its a 3.5mm jack tightener Works a treat, no more slipping and...

Hi, a friend of ours is a medical student and has a slight hearing problem, I'm making an eletronic stethoscope to help them with their studies, the electronics is not a major problem, simple amp - low pass filter etc I'm having trouble mounting the microphone in the stethoscope because of...

I found this and while messing about with a little project thought I'd give it a shot Sponge + Ferric Chloride Method -- Etch PCBs in One Minute! You won't believe how quick and easy it is for a small prototype board or quick experiment, that took about 3 minutes to do Anyway it...

I'm trying to charge 2 x 9volt Nimh batteries, I have the usuall trickle charge circuit (Lm317, 2 diodes, resistor ) I have the current set at about 19mA (1.125/68R) and it works fine with a normal 18volt unregulated plug pack. I thought I'd use a 19volt laptop supply, hooked it up all good...

I was asked a while ago about making a stripboard CMOY, I was bored and hung over (red wine!!) so decided to remake it again, I hope its some use to anyone getting their feet wet. here it is And this is how to make it first a piece of strip board Mark where to cut the tracks Use...

I want to charge 2 X 9volt nimh batteries that are in series from a 12volt supply, I was going to try using a dpdt switch to connect them in parrallel whilst charging and series when in use. any other ideas would be appreciated cheers

Just wondering Does anyone know, would it be feasable to put a bass boost circuit on the output of an amp, so you could make a sort of bass boost dongle that could be transportable and used on different amps??

I'm trying to build a passive preamp using this circuit, but the range of control of the pot is very small it's either off or full on which is still heavily attenuated, just wondering if anyone has experience of this type of circuit

I finally got some 4556's and made an RA1 clone just for the heck of it, I must have made a mistake with the layout and I cannot see it, the problem is when I turn it on there is a fairley loud pop in the headphones, once thats over it actually sound really good but I don't like the pop on start...

I'm charging a nimh battery (3.6v 800mA) from a usb port by simply connecting it direct, current is now 86mA and is very slowly dropping as the battery charges. Is there any danger in doing this it seems to easy cheers

I want to protect a circuit from damage if an incorrect polarity plug pack is used, my first thought is just a nice meaty diode in series with the power to prevent reverse current flow. Any better ideas? or would this be enough? cheers

I have a friend who has one of these little amps, she has lost the plug pack to recharge it, does anyone know the voltage and pin out ,its fairly low and I don't want to fry anything by plugging in the wrong voltage thanks FRED