I am building a power supply for a monster quadrophonic sub amp that has 60mF of rail capacitance a 640VA toroidal transformer. Can I get away with just using an NTC current limiter to limit the inrush and use a slow blow fuse or would something more elaborate be recomended?

Hi I am having trouble understanding what kind of hole I need for these capacitors: http://www.rapidonline.com/netalogue/specs/11-3123e.pdf The datsheet seens to suggest a simple 2mm diameter hole, however whats with the strange shape of the pins? I have some of these capacitors and apart from...

I am wondering if anyone knows where to get rear panel conectors capable of 20A per pin for connection of power supply to amplifier. Low cost is primary concern here as the amplifiers will be moved at most once or twice a year. My basic problem is I want to build a 50W class A speaker...

Over the past few months I have been building a OTL tube amp based on the headwise project using ECC83 and EL84 tubes. Today it produced its first sounds and also made some smoke due to the "5W" resistors getting rather hot and burning some insulation. It also has some severe mains hum problems...

Hello I'm currently fixing a rotell RA-311 Stereo Preamp+Power amp. It has channel imbalance and hum on the attenuated channel. I have narrowed down the problem to the treble control section of the preamp and have in fact found the exact trace where the signal goes in and comes out attenuated...

Hello I have a freind who has recently become interested in headphones and we are building a pretty high end tube amp together. I have HD650's and he is a big fan of the sound and can get a pair for £160 new. However It would be kind of boring not to use this as an opertunity to try some...

where do I get a transformer with a 1:1 ratio in the UK? I have tried the usual suspects rapid, RS etc but I would rearly like an encapsulated toroid if possible and all I can find are the metal framed variety (C cores?) I don't want to use one of these as I can only get them from RS who are...

Hello I am designing a capacitance multiplier for use in a valve rectified supply (5U4G full wave) as using such devices as PI filters with 10h chokes in seems both silly and prohibitively expensive! anyway having trouble finding 400V rated Darlington transistors I decided to use a FET. It all...

What should I do with the 74HC4046's VCO if I'm only using the IC for its charge pump phase comparator? *ignore me I just found the inhibit input (unusual naming)

Hello if someone has any spare time could they check the attached schematic for a PCM2707 configured as a USB>I2S converter. The converter should be 100mA bus powered, the DOUT is connected to the DIN which should (according to the internet) allow me to verify functionality by using the pin...

I am looking for a VCXO that operates at 2.8224MHz or a multiple of that frequency. So far I have only found this very expensive one: VCXO

My I2S clock is going to have 2nS jitter I think this is unacceptably high so I will use a pll to generate a clock with less short term jitter. Doing some rough calculations for 16bit accuracy in the time domain I require a jitter of <5pS?!? this seems smaller than is possible, I will go through...

I was thinking about a DAC with inbuilt headphone amp and would like to totatly isolate it from the computers power supply. As I understand it I2S is uni directional so I could use opto isolators on it? however the wikipedia article says that the word clock will be 64* the sample rate giving a...

Hello I have designed a follower to operate from a single supply for the driving of headphones. It has a JFET input stage for high input impedance (aprox 1Gohm without the divider) and bipolar output stage for low output impedance (aprox 4.7ohm - 0.01175ohm). The matched JFET current source...

hello I am unable to get the folowing cirucit to function corectly.. I think it should have a difirential gain of 2 but I have made a design error I think. Can anyone help out? Image not loading direct link: ImageShack - Hosting :: scematicow8.png output: I presume the problem is how...

Although I don't change things my setup sounds very different at different times of the day to me. At the moment it sounds like the most amazing setup ever and I could listen all night. Sometimes however I find myself dreaming of upgrades because all the music sounds so lifeless that I can't get...

Hello I need ot produce a prototype pcb. I think two at the most unless anyone has a great desire to build an 8x7 animated LED display. I have looked around and all the PCB prototyping companies are charging... well well above my means I think at most I can budget £25 for this project. I have...

I have every AC/DC album but in pretty dreadfull quality (128Kbs MP3) and would like to get some second hand CD's ripped to improve the quality somewhat. Are the remasters "safe"? or are they the usual compresed clippy crap?

has anyone used one of these in an amplifier project? do they live up to expectations?

I haven't seen many head fi users with these headphones so I would like to share my impresions. My pair were £7 aprox $15.50 which makes them one of the cheapest IEM's. Fit: Easy to get a good seal with default tips came with larger and smaller tips. Not secure fit enough for exersise...

I admit I just used some SR-60's as speakers... they didn't distort even at volumes that would lead to almost instant ear death. Also the Bass was much louder than it is from other headphones when removed from the ears. Grado should bring out some speakers! there headphones are halfway there.

Just won a second hand sony ESP2 portable Cd player as mp3 players that would meet my requirments were too expensive and I have pleanty of CD's. I now need some headphones with good isolation to go with it. Going for as low budget as posible without ear rape. Found these are they good...

Any portable player that can play: MP3, FLAC, WAV, WMV and can sort music by folder not tag?

Hello are there any scematics around for low power class D amplifiers? all the amps I see are 400w sub amps etc. Also does anyone know of mosfets with lower than 40pF gate capacitance?

Hello are there any soundcards on the market that output I2S?